WorldWideScience

Sample records for activity-dependent vmat-mediated depletion

  1. Activity Dependent Regulation of Inhibitory Circuitry

    Sharma, Nikhil

    2015-01-01

    Inhibition controls information flow through a neural circuit by modulating synaptic integration, restricting action potentials, and coordinating the activity of ensembles of neurons. These functions are mediated by a diverse array of inhibitory neuron subtypes that synapse on defined domains of a postsynaptic neuron. Activity-dependent transcription controls inhibitory synapse number and function, but how this transcription program affects the inhibitory inputs that form on di...

  2. Depleted uranium

    Full text: The Director General of the International Atomic Energy Agency (IAEA), Mohamed ElBaradei, issued today the following statement: The IAEA has been involved in United Nations efforts relating to the impact of the use of depleted uranium (DU) ammunition in Kosovo. It has supported the United Nations Environment Programme (UNEP) in the assessment which it is making, at the request of the Secretary-General, of that impact. In this connection, in November 2000, Agency experts participated in a UNEP-led fact-finding mission in Kosovo. DU is only slightly radioactive, being about 40% as radioactive as natural uranium. Chemically and physically, DU behaves in the same way as natural uranium. The chemical toxicity is normally the dominant factor for human health. However, it is necessary to carefully assess the impact of DU in the special circumstances in which it was used, e.g. to determine whether it was inhaled or ingested or whether fragments came into close contact with individuals. It is therefore essential, before an authoritative conclusion can be reached, that a detailed survey of the territory in which DU was used and of the people who came in contact with the depleted uranium in any form be carried out. In the meantime it would be prudent, as recommended by the leader of the November UNEP mission, to adopt precautionary measures. Depending on the results of the survey further measures may be necessary. The Agency, within its statutory responsibilities and on the basis of internationally accepted radiation safety standards, will continue to co-operate with other organizations, in particular WHO and UNEP, with a view to carrying out a comprehensive assessment. Co-operation by and additional information from NATO will be prerequisites. The experience gained from such an assessment could be useful for similar studies that may be carried out elsewhere in the Balkans or in the Gulf. (author)

  3. DEPLETED URANIUM TECHNICAL WORK

    The Depleted Uranium Technical Work is designed to convey available information and knowledge about depleted uranium to EPA Remedial Project Managers, On-Scene Coordinators, contractors, and other Agency managers involved with the remediation of sites contaminated with this mater...

  4. MPTP-meditated hippocampal dopamine deprivation modulates synaptic transmission and activity-dependent synaptic plasticity

    Parkinson's disease (PD)-like symptoms including learning deficits are inducible by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Therefore, it is possible that MPTP may disturb hippocampal memory processing by modulation of dopamine (DA)- and activity-dependent synaptic plasticity. We demonstrate here that intraperitoneal (i.p.) MPTP injection reduces the number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) within 7 days. Subsequently, the TH expression level in SN and hippocampus and the amount of DA and its metabolite DOPAC in striatum and hippocampus decrease. DA depletion does not alter basal synaptic transmission and changes pair-pulse facilitation (PPF) of field excitatory postsynaptic potentials (fEPSPs) only at the 30 ms inter-pulse interval. In addition, the induction of long-term potentiation (LTP) is impaired whereas the duration of long-term depression (LTD) becomes prolonged. Since both LTP and LTD depend critically on activation of NMDA and DA receptors, we also tested the effect of DA depletion on NMDA receptor-mediated synaptic transmission. Seven days after MPTP injection, the NMDA receptor-mediated fEPSPs are decreased by about 23%. Blocking the NMDA receptor-mediated fEPSP does not mimic the MPTP-LTP. Only co-application of D1/D5 and NMDA receptor antagonists during tetanization resembled the time course of fEPSP potentiation as observed 7 days after i.p. MPTP injection. Together, our data demonstrate that MPTP-induced degeneration of DA neurons and the subsequent hippocampal DA depletion alter NMDA receptor-mediated synaptic transmission and activity-dependent synaptic plasticity. - Highlights: → I.p. MPTP-injection mediates death of dopaminergic neurons. → I.p. MPTP-injection depletes DA and DOPAC in striatum and hippocampus. → I.p. MPTP-injection does not alter basal synaptic transmission. → Reduction of LTP and enhancement of LTD after i.p. MPTP-injection. → Attenuation of NMDA-receptors mediated

  5. Depleted Uranium Management

    The paper considers radiological and toxic impact of the depleted uranium on the human health. Radiological influence of depleted uranium is less for 60 % than natural uranium due to the decreasing of short-lived isotopes uranium-234 and uranium-235 after enrichment. The formation of radioactive aerosols and their impact on the human are mentioned. Use of the depleted uranium weapons has also a chemical effect on intake due to possible carcinogenic influence on kidney. Uranium-236 in the substance of the depleted uranium is determined. The fact of beta-radiation formation in the uranium-238 decay is regarded. This effect practically is the same for both depleted and natural uranium. Importance of toxicity of depleted uranium, as the heavier chemical substance, has a considerable contribution to the population health. The paper analyzes risks regarding the use of the depleted uranium weapons. There is international opposition against using weapons with depleted uranium. Resolution on effects of the use of armaments and ammunitions containing depleted uranium was five times supported by the United Nations (USA, United Kingdom, France and Israel did not support). The decision for banning of depleted uranium weapons was supported by the European Parliament

  6. Activity-dependent plasticity of hippocampal place maps.

    Schoenenberger, Philipp; O'Neill, Joseph; Csicsvari, Jozsef

    2016-01-01

    Hippocampal neurons encode a cognitive map of space. These maps are thought to be updated during learning and in response to changes in the environment through activity-dependent synaptic plasticity. Here we examine how changes in activity influence spatial coding in rats using halorhodopsin-mediated, spatially selective optogenetic silencing. Halorhoposin stimulation leads to light-induced suppression in many place cells and interneurons; some place cells increase their firing through disinhibition, whereas some show no effect. We find that place fields of the unaffected subpopulation remain stable. On the other hand, place fields of suppressed place cells were unstable, showing remapping across sessions before and after optogenetic inhibition. Disinhibited place cells had stable maps but sustained an elevated firing rate. These findings suggest that place representation in the hippocampus is constantly governed by activity-dependent processes, and that disinhibition may provide a mechanism for rate remapping. PMID:27282121

  7. Activity-dependent modulation of neural circuit synaptic connectivity

    Tessier, Charles R.; Kendal Broadie

    2009-01-01

    In many nervous systems, the establishment of neural circuits is known to proceed via a two-stage process; 1) early, activity-independent wiring to produce a rough map characterized by excessive synaptic connections, and 2) subsequent, use-dependent pruning to eliminate inappropriate connections and reinforce maintained synapses. In invertebrates, however, evidence of the activity-dependent phase of synaptic refinement has been elusive, and the dogma has long been that invertebrate circ...

  8. Activity-dependent modulation of neural circuit synaptic connectivity

    Charles R Tessier

    2009-07-01

    Full Text Available In many nervous systems, the establishment of neural circuits is known to proceed via a two-stage process; 1 early, activity-independent wiring to produce a rough map characterized by excessive synaptic connections, and 2 subsequent, use-dependent pruning to eliminate inappropriate connections and reinforce maintained synapses. In invertebrates, however, evidence of the activity-dependent phase of synaptic refinement has been elusive, and the dogma has long been that invertebrate circuits are “hard-wired” in a purely activity-independent manner. This conclusion has been challenged recently through the use of new transgenic tools employed in the powerful Drosophila system, which have allowed unprecedented temporal control and single neuron imaging resolution. These recent studies reveal that activity-dependent mechanisms are indeed required to refine circuit maps in Drosophila during precise, restricted windows of late-phase development. Such mechanisms of circuit refinement may be key to understanding a number of human neurological diseases, including developmental disorders such as Fragile X syndrome (FXS and autism, which are hypothesized to result from defects in synaptic connectivity and activity-dependent circuit function. This review focuses on our current understanding of activity-dependent synaptic connectivity in Drosophila, primarily through analyzing the role of the fragile X mental retardation protein (FMRP in the Drosophila FXS disease model. The particular emphasis of this review is on the expanding array of new genetically-encoded tools that are allowing cellular events and molecular players to be dissected with ever greater precision and detail.

  9. Activity-dependent neuronal signalling and autism spectrum disorder

    Ebert, Daniel H.; Greenberg, Michael E.

    2013-01-01

    Neuronal activity induces the post-translational modification of synaptic molecules, promotes localized protein synthesis within dendrites and activates gene transcription, thereby regulating synaptic function and allowing neuronal circuits to respond dynamically to experience. Evidence indicates that many of the genes that are mutated in autism spectrum disorders are crucial components of the activity-dependent signalling networks that regulate synapse development and plasticity. Dysregulati...

  10. Depleted uranium in Japan

    In Japan, depleted uranium ammunition is regarded as nuclear weapons and meets with fierce opposition. The fact that US Marines mistakenly fired bullets containing depleted uranium on an island off Okinawa during training exercises in December 1995 and January 1996, also contributes. The overall situation in this area in Japan is outlined. (P.A.)

  11. Management of depleted uranium

    Large stocks of depleted uranium have arisen as a result of enrichment operations, especially in the United States and the Russian Federation. Countries with depleted uranium stocks are interested in assessing strategies for the use and management of depleted uranium. The choice of strategy depends on several factors, including government and business policy, alternative uses available, the economic value of the material, regulatory aspects and disposal options, and international market developments in the nuclear fuel cycle. This report presents the results of a depleted uranium study conducted by an expert group organised jointly by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It contains information on current inventories of depleted uranium, potential future arisings, long term management alternatives, peaceful use options and country programmes. In addition, it explores ideas for international collaboration and identifies key issues for governments and policy makers to consider. (authors)

  12. Water Depletion Threatens Agriculture

    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.

  13. A memristor SPICE model accounting for synaptic activity dependence.

    Qingjiang Li

    Full Text Available In this work, we propose a new memristor SPICE model that accounts for the typical synaptic characteristics that have been previously demonstrated with practical memristive devices. We show that this model could account for both volatile and non-volatile memristance changes under distinct stimuli. We then demonstrate that our model is capable of supporting typical STDP with simple non-overlapping digital pulse pairs. Finally, we investigate the capability of our model to simulate the activity dependence dynamics of synaptic modification and present simulated results that are in excellent agreement with biological results.

  14. Uses of depleted uranium

    The depleted uranium is that in which percentage of uranium-235 fission executable is less than 0.2% or 0.3%. It is usually caused by the process of reprocessing the nuclear fuel burning, and also mixed with some other radioactive elements such as uranium 236, 238 and plutonium 239. The good features of the depleted uranium are its high density, low price and easily mined. So, the specifications for depleted uranium make it one of the best materials in case you need to have objects small in size, but quite heavy regarding its size. Uses of deplet ed uranium were relatively increased in domestic industrial uses as well as some uses in nuclear industry in the last few years. So it has increased uses in many areas of military and peaceful means such as: in balancing the giant air crafts, ships and missiles and in the manufacture of some types of concrete with severe hardness. (author)

  15. Activity-dependent neuronal model on complex networks.

    de Arcangelis, Lucilla; Herrmann, Hans J

    2012-01-01

    Neuronal avalanches are a novel mode of activity in neuronal networks, experimentally found in vitro and in vivo, and exhibit a robust critical behavior: these avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems. We present a recent model inspired in self-organized criticality, which consists of an electrical network with threshold firing, refractory period, and activity-dependent synaptic plasticity. The model reproduces the critical behavior of the distribution of avalanche sizes and durations measured experimentally. Moreover, the power spectra of the electrical signal reproduce very robustly the power law behavior found in human electroencephalogram (EEG) spectra. We implement this model on a variety of complex networks, i.e., regular, small-world, and scale-free and verify the robustness of the critical behavior. PMID:22470347

  16. Activity-dependent neural plasticity from bench to bedside.

    Ganguly, Karunesh; Poo, Mu-Ming

    2013-10-30

    Much progress has been made in understanding how behavioral experience and neural activity can modify the structure and function of neural circuits during development and in the adult brain. Studies of physiological and molecular mechanisms underlying activity-dependent plasticity in animal models have suggested potential therapeutic approaches for a wide range of brain disorders in humans. Physiological and electrical stimulations as well as plasticity-modifying molecular agents may facilitate functional recovery by selectively enhancing existing neural circuits or promoting the formation of new functional circuits. Here, we review the advances in basic studies of neural plasticity mechanisms in developing and adult nervous systems and current clinical treatments that harness neural plasticity, and we offer perspectives on future development of plasticity-based therapy. PMID:24183023

  17. Antarctic ozone depletion

    Antarctic ozone depletion is most severe during the southern hemisphere spring, when the local reduction in the column amount may be as much as 50 percent. The extent to which this ozone poor air contributes to the observed global ozone loss is a matter of debate, but there is some evidence that fragments of the 'ozone hole' can reach lower latitudes following its breakup in summer. Satellite data show the seasonal evolution of the ozone hole. A new dimension has been added to Antarctic ozone depletion with the advent of large volcanic eruptions such as that from Mount Pinatubo in 1991. (author). 5 refs., 1 fig

  18. Solar activity dependence of nightside aurora in winter conditions

    Zhou, Su; Luan, Xiaoli; Dou, Xiankang

    2016-02-01

    The dependence of the nightside (21:00-03:00 MLT; magnetic local time) auroral energy flux on solar activity was quantitatively studied for winter/dark and geomagnetically quiet conditions. Using data combined from Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager and Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations, we separated the effects of geomagnetic activity from those of solar flux on the nightside auroral precipitation. The results showed that the nightside auroral power was reduced by ~42% in solar maximum (F10.7 = 200 sfu; solar flux unit 1 sfu = 10-22 W m-2 Hz-1) with respect to that under solar minimum (F10.7 = 70 sfu) for the Kp = 1 condition, and this change rate became less (~21%) for the Kp = 3 condition. In addition, the solar cycle dependence of nightside auroral power was similar with that from both the premidnight (21:00-23:00 MLT) and postmidnight (01:00-03:00 MLT) sectors. These results indicated that as the ionospheric ionization increases with the enhanced auroral and geomagnetic activities, the solar activity dependences of nightside auroral power become weaker, at least under geomagnetically quiet conditions.

  19. Shaping inhibition: activity dependent structural plasticity of GABAergic synapses

    Pablo Mendez

    2014-10-01

    Full Text Available Inhibitory transmission through the neurotransmitter Ɣ-aminobutyric acid (GABA shapes network activity in the mammalian cerebral cortex by filtering synaptic incoming information and dictating the activity of principal cells. The incredibly diverse population of cortical neurons that use GABA as neurotransmitter shows an equally diverse range of mechanisms that regulate changes in the strength of GABAergic synaptic transmission and allow them to dynamically follow and command the activity of neuronal ensembles. Similarly to glutamatergic synaptic transmission, activity-dependent functional changes in inhibitory neurotransmission are accompanied by alterations in GABAergic synapse structure that range from morphological reorganization of postsynaptic density to de novo formation and elimination of inhibitory contacts. Here we review several aspects of structural plasticity of inhibitory synapses, including its induction by different forms of neuronal activity, behavioral and sensory experience and the molecular mechanisms and signaling pathways involved. We discuss the functional consequences of GABAergic synapse structural plasticity for information processing and memory formation in view of the heterogenous nature of the structural plasticity phenomena affecting inhibitory synapses impinging on somatic and dendritic compartments of cortical and hippocampal neurons.

  20. Willpower depletion and framing effects

    de Haan, Thomas; van Veldhuizen, Roel

    2013-01-01

    We investigate whether depleting people's cognitive resources (or willpower) affects the degree to which they are susceptible to framing effects. Recent research in social psychology and economics has suggested that willpower is a resource that can be temporarily depleted and that a depleted level of willpower is associated with self-control problems in a variety of contexts. In this study, we extend the willpower depletion paradigm to framing effects and argue that willpower depletion should...

  1. Intrinsic Depletion or Not

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

    in between he polymer cushion and bulk water the layer was attributed to water of reduced density and was called "depletion layer".  Impurities or preparative artefacts were excluded as its origin. Later on, the formation of nanobubbles from this vapour-like water phase was initiated by tipping the......  The presence of a depletion layer of water along extended hydrophobic interfaces, and a possibly related formation of nanobubbles, is an ongoing discussion. The phenomenon was initially reported when we, years ago, chose thick films (~300-400Å) of polystyrene as cushions between a crystalline...... carrier and biomimetic membranes deposited thereupon and exposed to bulk water. While monitoring the sequential build-up of the sandwiched composite structure by continuous neutron reflectivity experiments the formation of an unexpected additional layer was detected (1). Located at the polystyrene surface...

  2. Depletion of intense fields

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

    2016-01-01

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

  3. Ozone depletion by hydrofluorocarbons

    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.

  4. Capital expenditure and depletion

    In the future, the increase in oil demand will be covered for the most part by non conventional oils, but conventional sources will continue to represent a preponderant share of the world oil supply. Their depletion represents a complex challenge involving technological, economic and political factors. At the same time, there is reason for concern about the decrease in exploration budgets at the major oil companies. (author)

  5. Ozone-depleting Substances (ODS)

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

  6. Cellular mechanisms regulating activity-dependent release of native brain-derived neurotrophic factor from hippocampal neurons.

    Balkowiec, Agnieszka; Katz, David M

    2002-12-01

    Brain-derived neurotrophic factor (BDNF) plays a critical role in activity-dependent modifications of neuronal connectivity and synaptic strength, including establishment of hippocampal long-term potentiation (LTP). To shed light on mechanisms underlying BDNF-dependent synaptic plasticity, the present study was undertaken to characterize release of native BDNF from newborn rat hippocampal neurons in response to physiologically relevant patterns of electrical field stimulation in culture, including tonic stimulation at 5 Hz, bursting stimulation at 25 and 100 Hz, and theta-burst stimulation (TBS). Release was measured using the ELISA in situ technique, developed in our laboratory to quantify secretion of native BDNF without the need to first overexpress the protein to nonphysiological levels. Each stimulation protocol resulted in a significant increase in BDNF release that was tetrodotoxin sensitive and occurred in the absence of glutamate receptor activation. However, 100 Hz tetanus and TBS, stimulus patterns that are most effective in inducing hippocampal LTP, were significantly more effective in releasing native BDNF than lower-frequency stimulation. For all stimulation protocols tested, removal of extracellular calcium, or blockade of N-type calcium channels, prevented BDNF release. Similarly, depletion of intracellular calcium stores with thapsigargin and treatment with dantrolene, an inhibitor of calcium release from caffeine-ryanodine-sensitive stores, markedly inhibited activity-dependent BDNF release. Our results indicate that BDNF release can encode temporal features of hippocampal neuronal activity. The dual requirement for calcium influx through N-type calcium channels and calcium mobilization from intracellular stores strongly implicates a role for calcium-induced calcium release in activity-dependent BDNF secretion. PMID:12451139

  7. Depleted uranium management alternatives

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process

  8. Stratospheric ozone depletion

    The amount of stratospheric ozone and the reduction of the ozone layer vary according to seasons and latitudes. At present total and vertical ozone is monitored over all Austria. The mean monthly ozone levels between 1994 and 2000 are presented. Data on stratospheric ozone and UV-B radiation are published daily on the home page http: www.lebesministerium.at. The use of ozone depleting substances such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) is provided. Besides, the national measures taken to reduce their use. Figs. 2, Tables 2. (nevyjel)

  9. Depleted uranium: Metabolic disruptor?

    The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolizing vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions. (authors)

  10. Riddle of depleted uranium

    Depleted Uranium (DU) is the waste product of uranium enrichment from the manufacturing of fuel rods for nuclear reactors in nuclear power plants and nuclear power ships. DU may also results from the reprocessing of spent nuclear reactor fuel. Potentially DU has both chemical and radiological toxicity with two important targets organs being the kidney and the lungs. DU is made into a metal and, due to its availability, low price, high specific weight, density and melting point as well as its pyrophoricity; it has a wide range of civilian and military applications. Due to the use of DU over the recent years, there appeared in some press on health hazards that are alleged to be due to DU. In these paper properties, applications, potential environmental and health effects of DU are briefly reviewed

  11. The Toxicity of Depleted Uranium

    Wayne Briner

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  12. Depleted zinc: Properties, application, production

    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.

  13. Depletable resources and the economy.

    Heijman, W.J.M.

    1991-01-01

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

  14. The Toxicity of Depleted Uranium

    Wayne Briner

    2010-01-01

    Full Text Available Depleted uranium (DU is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

  15. Stratospheric ozone depletion.

    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

  16. Testing fully depleted CCD

    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.

  17. Impaired activity-dependent neural circuit assembly and refinement in autism spectrum disorder genetic models

    Caleb Andrew Doll; Kendal eBroadie

    2014-01-01

    Early-use activity during circuit-specific critical periods refines brain circuitry by the coupled processes of eliminating inappropriate synapses and strengthening maintained synapses. We theorize these activity-dependent developmental processes are specifically impaired in autism spectrum disorders (ASDs). ASD genetic models in both mouse and Drosophila have pioneered our insights into normal activity-dependent neural circuit assembly and consolidation, and how these developmental mechanism...

  18. Depletable resources and the economy.

    Heijman, W. J. M.

    1991-01-01

    The subject of this thesis is the depletion of scarce resources. The main question to be answered is how to avoid future resource crises. After dealing with the complex relation between nature and economics, three important concepts in relation with resource depletion are discussed: steady state, time preference and efficiency.For the steady state, three variants are distinguished; the stationary state, the physical steady state and the state of steady growth. It is concluded that the so-call...

  19. Activity-dependent brain-derived neurotrophic factor expression regulates cortistatin-interneurons and sleep behavior

    Martinowich Keri

    2011-03-01

    Full Text Available Abstract Background Sleep homeostasis is characterized by a positive correlation between sleep length and intensity with the duration of the prior waking period. A causal role for brain-derived neurotrophic factor (BDNF in sleep homeostasis has been suggested, but the underlying mechanisms remain unclear. Cortistatin, a neuropeptide expressed primarily in a subset of cortical GABAergic interneurons, is another molecule implicated in sleep homeostasis. Results We confirmed that sleep deprivation leads to an increase in cortical cortistatin mRNA expression. Disruption of activity-dependent BDNF expression in a genetically modified mouse line impairs both baseline levels of cortistatin mRNA as well as its levels following sleep deprivation. Disruption of activity-dependent BDNF also leads to a decrease in sleep time during the active (dark phase. Conclusion Our studies suggest that regulation of cortistatin-expressing interneurons by activity-dependent BDNF expression may contribute to regulation of sleep behavior.

  20. Definition of a Bidirectional Activity-Dependent Pathway Involving BDNF and Narp

    Abigail Mariga

    2015-12-01

    Full Text Available One of the cardinal features of neural development and adult plasticity is the contribution of activity-dependent signaling pathways. However, the interrelationships between different activity-dependent genes are not well understood. The immediate early gene neuronal-activity-regulated pentraxin (NPTX2 or Narp encodes a protein that has been associated with excitatory synaptogenesis, AMPA receptor aggregation, and the onset of critical periods. Here, we show that Narp is a direct transcriptional target of brain-derived neurotrophic factor (BDNF, another highly regulated activity-dependent gene involved in synaptic plasticity. Unexpectedly, Narp is bidirectionally regulated by BDNF. Acute BDNF withdrawal results in downregulation of Narp, whereas transcription of Narp is greatly enhanced by BDNF. Furthermore, our results show that BDNF directly regulates Narp to mediate glutamatergic transmission and mossy fiber plasticity. Hence, Narp serves as a significant epistatic target of BDNF to regulate synaptic plasticity during periods of dynamic activity.

  1. Nonlinear lower hybrid wave depletion

    Two numerical ray tracing codes with focusing are used to compute lower hybrid daughter wave amplification by quasi-mode parametric decay. The first code, LHPUMP provides a numerical pump model on a grid. This model is used by a second code, LHFQM which computes daughter wave amplification inside the pump extent and follows the rays until their energy is absorbed by the plasma. An analytic model is then used to estimate pump depletion based on the numerical results. Results for PLT indicate strong pump depletion at the plasma edge at high density operation for the 800 Mhz wave frequency, but weak depletion for the 2.45 Ghz experiment. This is proposed to be the mechanism responsible for the high density limit for current drive as well as for the difficulty to heat ions

  2. Impaired activity-dependent neural circuit assembly and refinement in autism spectrum disorder genetic models

    Caleb Andrew Doll

    2014-02-01

    Full Text Available Early-use activity during circuit-specific critical periods refines brain circuitry by the coupled processes of eliminating inappropriate synapses and strengthening maintained synapses. We theorize these activity-dependent developmental processes are specifically impaired in autism spectrum disorders (ASDs. ASD genetic models in both mouse and Drosophila have pioneered our insights into normal activity-dependent neural circuit assembly and consolidation, and how these developmental mechanisms go awry in specific genetic conditions. The monogenic Fragile X syndrome (FXS, a common cause of heritable ASD and intellectual disability, has been particularly well linked to defects in activity-dependent critical period processes. The Fragile X Mental Retardation Protein (FMRP is positively activity-regulated in expression and function, in turn regulates excitability and activity in a negative feedback loop, and appears to be required for the activity-dependent remodeling of synaptic connectivity during early-use critical periods. The Drosophila FXS model has been shown to functionally conserve the roles of human FMRP in synaptogenesis, and has been centrally important in generating our current mechanistic understanding of the FXS disease state. Recent advances in Drosophila optogenetics, transgenic calcium reporters, highly-targeted transgenic drivers for individually-identified neurons, and a vastly improved connectome of the brain are now being combined to provide unparalleled opportunities to both manipulate and monitor activity-dependent processes during critical period brain development in defined neural circuits. The field is now poised to exploit this new Drosophila transgenic toolbox for the systematic dissection of activity-dependent mechanisms in normal versus ASD brain development, particularly utilizing the well-established Drosophila FXS disease model.

  3. DOPAMINE DEPLETION SLOWS RETINAL TRANSMISSION

    In male hooded rats, depletion of norepinephrine and dopamine by a-methyl-paratyrosine (AMT) significantly increased the latencies of early peaks in flash-evoked potentials recorded from the visual cortex, lateral geniculate nucleus, and optic tract. These effects were not produc...

  4. DREAM controls the on/off switch of specific activity-dependent transcription pathways.

    Mellström, Britt; Sahún, Ignasi; Ruiz-Nuño, Ana; Murtra, Patricia; Gomez-Villafuertes, Rosa; Savignac, Magali; Oliveros, Juan C; Gonzalez, Paz; Kastanauskaite, Asta; Knafo, Shira; Zhuo, Min; Higuera-Matas, Alejandro; Errington, Michael L; Maldonado, Rafael; DeFelipe, Javier; Jefferys, John G R; Bliss, Tim V P; Dierssen, Mara; Naranjo, Jose R

    2014-03-01

    Changes in nuclear Ca(2+) homeostasis activate specific gene expression programs and are central to the acquisition and storage of information in the brain. DREAM (downstream regulatory element antagonist modulator), also known as calsenilin/KChIP-3 (K(+) channel interacting protein 3), is a Ca(2+)-binding protein that binds DNA and represses transcription in a Ca(2+)-dependent manner. To study the function of DREAM in the brain, we used transgenic mice expressing a Ca(2+)-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Using genome-wide analysis, we show that DREAM regulates the expression of specific activity-dependent transcription factors in the hippocampus, including Npas4, Nr4a1, Mef2c, JunB, and c-Fos. Furthermore, DREAM regulates its own expression, establishing an autoinhibitory feedback loop to terminate activity-dependent transcription. Ablation of DREAM does not modify activity-dependent transcription because of gene compensation by the other KChIP family members. The expression of daDREAM in the forebrain resulted in a complex phenotype characterized by loss of recurrent inhibition and enhanced long-term potentiation (LTP) in the dentate gyrus and impaired learning and memory. Our results indicate that DREAM is a major master switch transcription factor that regulates the on/off status of specific activity-dependent gene expression programs that control synaptic plasticity, learning, and memory. PMID:24366545

  5. Civil use of depleted uranium

    In this paper the civilian exploitation of depleted uranium is briefly reviewed. Different scenarios relevant to its use are discussed in terms of radiation exposure for workers and the general public. The case of the aircraft accident which occurred in Amsterdam in 1992 involving a fire, is discussed in terms of the radiological exposure to bystanders. All information given has been obtained on the basis of an extensive literature search and are not based on measurements performed at the Institute for Transuranium Elements

  6. Ozone Depletion from Nearby Supernovae

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

    2003-01-01

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

  7. Ozone Depletion from Nearby Supernovae

    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.

  8. Activity-dependent targeting of TRPV1 with a pore-permeating capsaicin analog

    Hui LI; Wang, Shu; Chuang, Alexander Y.; Cohen, Bruce E.; Chuang, Huai-hu

    2011-01-01

    The capsaicin receptor TRPV1 is the principal transduction channel for nociception. Excessive TRPV1 activation causes pathological pain. Ideal pain mangement requires selective inhibition of hyperactive pain-sensing neurons, but sparing normal nociception. We sought to determine whether it is possible to use activity-dependent TRPV1 agonists to identify nerves with excessive TRPV1 activity, as well as exploit the TRPV1 pore to deliver charged anesthetics for neuronal silencing. We synthesized...

  9. The activity-dependent transcription factor NPAS4 regulates domain-specific inhibition

    Bloodgood, Brenda L.; Sharma, Nikhil; Browne, Heidi Adlman; Trepman, Alissa Z.; Greenberg, Michael E.

    2013-01-01

    A heterogeneous population of inhibitory neurons controls the flow of information through a neural circuit1–3. Inhibitory synapses that form on pyramidal neuron dendrites modulate the summation of excitatory synaptic potentials4–6 and prevent the generation of dendritic calcium spikes7,8. Precisely timed somatic inhibition limits both the number of action potentials and the time window during which firing can occur8,9. The activity-dependent transcription factor NPAS4 regulates inhibitory syn...

  10. Robustness and Enhancement of Neural Synchronization by Activity-Dependent Coupling

    Zhigulin, Valentin P.; Mikhail I. Rabinovich; Huerta, Ramon; Abarbanel, Henry D. I.

    2002-01-01

    We study the synchronization of two model neurons coupled through a synapse having an activity-dependent strength. Our synapse follows the rules of Spike-Timing Dependent Plasticity (STDP). We show that this plasticity of the coupling between neurons produces enlarged frequency locking zones and results in synchronization that is more rapid and much more robust against noise than classical synchronization arising from connections with constant strength. We also present a simple discrete map m...

  11. The Development and Activity-Dependent Expression of Aggrecan in the Cat Visual Cortex

    Kind, P. C.; Sengpiel, F.; Beaver, C. J.; Crocker-Buque, A.; Kelly, G. M.; R. T. Matthews; Mitchell, D E

    2012-01-01

    The Cat-301 monoclonal antibody identifies aggrecan, a chondroitin sulfate proteoglycan in the cat visual cortex and dorsal lateral geniculate nucleus (dLGN). During development, aggrecan expression increases in the dLGN with a time course that matches the decline in plasticity. Moreover, examination of tissue from selectively visually deprived cats shows that expression is activity dependent, suggesting a role for aggrecan in the termination of the sensitive period. Here, we demonstrate for ...

  12. Robustness and Enhancement of Neural Synchronization by Activity-Dependent Coupling

    Zhigulin, V P; Huerta, R; Abarbanel, Henry D I; Zhigulin, Valentin P.; Rabinovich, Mikhail I.; Huerta, Ramon; Abarbanel, Henry D I

    2003-01-01

    We study the synchronization of two model neurons coupled through a synapse having an activity-dependent strength. Our synapse follows the rules of Spike-Timing Dependent Plasticity (STDP). We show that this plasticity of the coupling between neurons produces enlarged frequency locking zones and results in synchronization that is more rapid and much more robust against noise than classical synchronization arising from connections with constant strength. We also present a simple discrete map model that demonstrates the generality of the phenomenon.

  13. Expression of activity-dependent neuroprotective protein in the brain of adult rats

    Gennet, N.; Herden, C.; Bubb, V J; Quinn, J P; Kipar, A.

    2008-01-01

    Activity-dependent neuroprotective protein (ADNP) is a VIP-regulated gene, which is essential for brain development. A synthetic peptide (NAP) derived from the ADNP sequence is highly neuroprotective, therefore it has been hypothesised that ADNP has a similar role. ADNP contains classical transcription factor motifs and nuclear localisation domains, but it has also been reported to be secreted and to co-localise with microtubules, indicating that ADNP may have multiple...

  14. Issues in Stratospheric Ozone Depletion.

    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

  15. The Case of Ozone Depletion

    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.

  16. Uranium, depleted uranium, biological effects

    Physicists, chemists and biologists at the CEA are developing scientific programs on the properties and uses of ionizing radiation. Since the CEA was created in 1945, a great deal of research has been carried out on the properties of natural, enriched and depleted uranium in cooperation with university laboratories and CNRS. There is a great deal of available data about uranium; thousands of analyses have been published in international reviews over more than 40 years. This presentation on uranium is a very brief summary of all these studies. (author)

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

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

    2014-01-01

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

  18. Biomedical consequences of ozone depletion

    Coohill, Thomas P.

    1994-07-01

    It is widely agreed that a portion of the earth's protective stratospheric ozone layer is being depleted. The major effect of this ozone loss will be an increase in the amount of ultraviolet radiation (UV reaching the biosphere. This increase will be completely contained within the UVB (290nm - 320nm). It is imperative that assessments be made of the effects of this additional UVB on living organisms. This requires a detailed knowledge of the UVB photobiology of these life forms. One analytical technique to aid in the approximations is the construction of UV action spectra for such important biological end-points as human skin cancer, cataracts, immune suppression; plant photosynthesis and crop yields; and aquatic organism responses to UVB, especially the phytoplankton. Combining these action spectra with the known solar spectrum (and estimates for various ozone depletion scenarios) can give rise to a series of effectiveness spectra for these parameters. This manuscript gives a first approximation, rough estimate, for the effectiveness spectra for some of these bioresponses, and a series of crude temporary values for how a 10% ozone loss would affect the above end-points. These are not intended to masquerade as final answers, but rather, to serve as beginning attempts for a process which should be continually refined. It is hoped that these estimates will be of some limited use to agencies, such as government and industry, that have to plan now for changes in human activities that might alter future atmospheric chemistry in a beneficial manner.

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

    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.

  20. Early survival factor deprivation in the olfactory epithelium enhances activity-dependent survival

    Adrien eFrançois

    2013-12-01

    Full Text Available The neuronal olfactory epithelium undergoes permanent renewal because of environmental aggression. This renewal is partly regulated by factors modulating the level of neuronal apoptosis. Among them, we had previously characterized endothelin as neuroprotective. In this study, we explored the effect of cell survival factor deprivation in the olfactory epithelium by intranasal delivery of endothelin receptors antagonists to rat pups. This treatment induced an overall increase of apoptosis in the olfactory epithelium. The responses to odorants recorded by electroolfactogram were decreased in treated animal, a result consistent with a loss of olfactory sensory neurons (OSNs. However, the treated animal performed better in an olfactory orientation test based on maternal odor compared to non-treated littermates. This improved performance could be due to activity-dependent neuronal survival of OSNs in the context of increased apoptosis level. In order to demonstrate it, we odorized pups with octanal, a known ligand for the rI7 olfactory receptor (Olr226. We quantified the number of OSN expressing rI7 by RT-qPCR and whole mount in situ hybridization. While this number was reduced by the survival factor removal treatment, this reduction was abolished by the presence of its ligand. This improved survival was optimal for low concentration of odorant and was specific for rI7-expressing OSNs. Meanwhile, the number of rI7-expressing OSNs was not affected by the odorization in non-treated littermates; showing that the activity-dependant survival of OSNs did not affect the OSN population during the 10 days of odorization in control conditions. Overall, our study shows that when apoptosis is promoted in the olfactory mucosa, the activity-dependent neuronal plasticity allows faster tuning of the olfactory sensory neuron population towards detection of environmental odorants.

  1. Depleted Argon from Underground Sources

    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.

  2. Depleted uranium disposal options evaluation

    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

  3. Depleted uranium. Nuclear related problems

    Depleted uranium (DU) has found a military application in Golf War, in Bosnia and in Yugoslavia (Kosovo). In military sense it was very efficient. But the fact that some parts of that ammunition are manufactured from depleted uranium, low level radioactive waste, implies other aspects of this application like radiological, ecological, jurist, ethical and psychological. The subject of this paper is just physical aspect. There are several problems concerning this aspect: production of DU, total amount of DU in the world, 235U/238U relation, radioactivity of DU, measurements, and presence of other radionuclides like plutonium. DU is by product of nuclear technology and represents low-level nuclear waste. Therefore it should be stored. Total amount of DU in the world is about one million tons with an annual increase of 30 000 t. The content of 235U in DU can vary in the range 0.16-0.3%. The total radioactivity of DU is a consequence of 7 radionuclides and amounts 39.42 Bq/mg. This include alpha, beta and gamma radioactivity. Because of characteristics of this radioactivity it is difficult to prospect the terrain except at the site of action. During the impact of DU rods four types of DU particles could be produced: whole penetrators, penetrator parts, big aerosols (>10 μm) and small aerosols (<10 μm). Most of these particles fall locally, although some of them could be find several tens of kilometers away. All these problems have been discussed in this paper. (author)

  4. SRP scientific meeting: depleted uranium

    The meeting was organised by the SRP to review current research and discuss the use, dispersion into the environment and radiological impact of depleted uranium (DU) by the UK and US in recent military conflicts. In addition to other presentations, there were two short presentations by T Cabianca and P Danesi of the IAEA concerning investigations into the DU legacy in Kuwait and the IAEA contribution to environmental contamination assessments of DU in Kosovo. In Kuwait the on-going study is limited to an assessment of the potential radiological consequences of DU residues in three types of site: open desert where DU was fired, farmland where DU was fired and DU storage facilities. The Kuwaiti government has also requested the IAEA to formulate a structured approach to deal with remediating such sites and disposing of the resulting material. In Kosovo the study investigated sand and soil samples from areas where DU had been fired. DU particulates were found in sizes up to 40 μm, but generally much smaller, typically about 5 μm, with 5% less than 1.5 μm in size. These particles were found to contain 90% DU and 1% Ti. Plutonium was also detected, but this was attributed to the 1960s bomb testing programme. This was an informative, well attended meeting that stimulated varied debate between delegates. It revealed that there is still much to learn concerning the effects of depleted uranium in the human body and highlighted the limitations of conventional dose estimates made using ICRP models. A balance must be struck between the operational requirements of the armed forces and acceptable levels of environmental contamination arising from any conflict they are involved in. Most importantly, as a scientific consensus is developed, a clear and consistent approach to providing key information to the public should be adopted, to build confidence in the radiation protection profession

  5. Clodronate treatment significantly depletes macrophages in chickens

    Kameka, Amber M.; Haddadi, Siamak; Jamaldeen, Fathima Jesreen; Moinul, Prima; He, Xiao T.; Nawazdeen, Fathima Hafsa P.; Bonfield, Stephan; Sharif, Shayan; van Rooijen, Nico; Abdul-Careem, Mohamed Faizal

    2014-01-01

    Macrophages function as phagocytes and antigen-presenting cells in the body. As has been demonstrated in mammals, administration of clodronate [dichloromethylene bisphosphonate (Cl2MBP)] encapsulated liposomes results in depletion of macrophages. Although this compound has been used in chickens, its effectiveness in depleting macrophages has yet to be fully determined. Here, we show that a single administration of clodronate liposomes to chickens results in a significant depletion of macropha...

  6. Repulsive depletion interactions in colloid polymer mixtures

    Rudhardt, Daniel; Bechinger, Clemens; Leiderer, Paul

    1999-01-01

    Depletion forces in colloidal systems are known to be entirely attractive, as long as the background of macromolecules is small enough that an ideal gas approach is valid. At higher densities, however, structural correlation effects of the macromolecules which lead to additional repulsive parts in the depletion interaction, have to be taken into account. We have measured the depletion interaction between a single polystyrene sphere and a wall in the presence of non-ionic polymer coils. Althou...

  7. Assessment of the depletion capability in MPACT

    The objective of the paper is to develop and demonstrate the depletion capability with pin resolved transport using the MPACT code. The first section of the paper provides a description of the depletion methodology and the algorithm used to solve the depletion equations in MPACT. A separate depletion library for MPACT is used based on the ORIGEN-S library to provide the basic decay constants and fission yields, as well as the 3-group cross-sections which are used for the isotopes not contained in the MPACT multi-group library. The cross sections for the depletion transmutation matrix were collapsed using the transport flux solution in MPACT based on either the 47 group HELIOS library based on ENDF-VI or a 56 group ORNL library based on ENDF-VII. The second section of this paper then describes the numerical verification of the depletion algorithm using two sets of benchmarks. The first is the JAERI LWR lattice benchmark which had participants from most of the lattice depletion codes currently used in the international nuclear community and the second benchmark is based on data from spent fuel of the Takahama-3 reactor. The results show that MPACT is generally in good agreement with the results of the other benchmark participants as well as the experimental data. Finally, a full core 2D model of CASL AMA benchmark was depleted based on the central plane of the Watts Bar reactor core which demonstrates the whole core depletion capability of MPACT. (author)

  8. Activity-dependent regulation of calcium and ribosomes in the chick cochlear nucleus.

    Call, C L; Hyson, R L

    2016-03-01

    Cochlea removal results in the death of 20-30% of neurons in the chick cochlear nucleus, nucleus magnocellularis (NM). Two potentially cytotoxic events, a dramatic rise in intracellular calcium concentration ([Ca(2+)]i) and a decline in the integrity of ribosomes are observed within 1h of deafferentation. Glutamatergic input from the auditory nerve has been shown to preserve NM neuron health by activating metabotropic glutamate receptors (mGluRs), maintaining both normal [Ca(2+)]i and ribosomal integrity. One interpretation of these results is that a common mGluR-activated signaling cascade is required for the maintenance of both [Ca(2+)]i and ribosomal integrity. This could happen if both responses are influenced directly by a common messenger, or if the loss of mGluR activation causes changes in one component that secondarily causes changes in the other. The present studies tested this common-mediator hypothesis in slice preparations by examining activity-dependent regulation of [Ca(2+)]i and ribosomes in the same tissue after selectively blocking group I mGluRs (1-Aminoindan-1,5-dicarboxylic acid (AIDA)) or group II mGluRs (LY 341495) during unilateral auditory nerve stimulation. Changes in [Ca(2+)]i of NM neurons were measured using fura-2 ratiometric calcium imaging and the tissue was subsequently processed for Y10B immunoreactivity (Y10B-ir), an antibody that recognizes a ribosomal epitope. The group I mGluR antagonist blocked the activity-dependent regulation of both [Ca(2+)]i and Y10B-ir, but the group II antagonist blocked only the activity-dependent regulation of Y10B-ir. That is, even when group II receptors were blocked, stimulation continued to maintain low [Ca(2+)]i, but it did not maintain Y10B-ir. These results suggest a dissociation in how calcium and ribosomes are regulated in NM neurons and that ribosomes can be regulated through a mechanism that is independent of calcium regulation. PMID:26739326

  9. Beneficial Uses of Depleted Uranium

    Naturally occurring uranium contains 0.71 wt% 235U. In order for the uranium to be useful in most fission reactors, it must be enriched the concentration of the fissile isotope 235U must be increased. Depleted uranium (DU) is a co-product of the processing of natural uranium to produce enriched uranium, and DU has a 235U 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 (UF6) 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

  10. Ozone depletion potentials of halocarbons

    The concept of ozone depletion potential (ODP) is widely used in the evaluation of numerous halocarbons and of their replacements for effects on ozone, but the methods, model assumptions and conditions of ODP calculation have not been analyzed adequately. In this paper, a model study of effects on ozone after the instantaneous releases of various amounts of CH3CCl3 and of CHF2Cl(HCFC-22) in the several conditions of the background atmosphere are presented, aimed to understand the main connections of ODP values with the methods of their calculations. To facilitate the ODP computation in numerous versions for long after the releases, the above rather short-lived gases have been used. The variation of released gas global mass from 1 Mt to 1 Gt leads to ODP value increase atmosphere. The same variations are analyzed for the CFC-free atmosphere of 1960s conditions for the anthropogenically loaded atmosphere in the 21st century according to the known IPCC- A scenario (business as usual). Recommendations of proper ways of ODP calculations are proposed for practically important cases

  11. Plutonium in depleted uranium penetrators

    Depleted Uranium (DU) penetrators used in the recent Balkan conflicts have been found to be contaminated with trace amounts of transuranic materials such as plutonium. This contamination is usually a consequence of DU fabrication being carried out in facilities also using uranium recycled from spent military and civilian nuclear reactor fuel. Specific activities of 239+240 Plutonium generally in the range 1 to 12 Bq/kg have been found to be present in DU penetrators recovered from the attack sites of the 1999 NATO bombardment of Kosovo. A DU penetrator recovered from a May 1999 attack site at Bratoselce in southern Serbia and analysed by University College Dublin was found to contain 43.7 +/- 1.9 Bq/kg of 239+240 Plutonium. This analysis is described. An account is also given of the general population radiation dose implications arising from both the DU itself and from the presence of plutonium in the penetrators. According to current dosimetric models, in all scenarios considered likely ,the dose from the plutonium is estimated to be much smaller than that due to the uranium isotopes present in the penetrators. (author)

  12. The Chemistry and Toxicology of Depleted Uranium

    Sidney A. Katz

    2014-03-01

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

  13. Depletion sensitivity predicts unhealthy snack purchases

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

    2016-01-01

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

  14. Depletion sensitivity predicts unhealthy snack purchases

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

    2016-01-01

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

  15. Tritium transport vessel using depleted uranium

    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.

  16. Oil depletion and terms of trade

    Irimia-Vladu, Marina; Thompson, Henry

    2007-01-01

    A model of the international oil market model with optimal depletion and offer curves suggests importers face a backward bending offer curve. An oil tariff would then raise oil imports and lower the price of oil including the tariff. Simulations of price and extraction paths for the coming century provide insight into the future of oil depletion and terms of trade.

  17. Deuterium - depleted water. Achievements and perspectives

    Deuterium - depleted water represents water that has an isotopic content lower than 145 ppm D/(D+H) which is the natural isotopic content of water. The research conducted at ICSI Ramnicu Valcea, regarding deuterium - depleted water were completed by the following patents: - technique and installation for deuterium - depleted water production; - distilled water with low deuterium content; - technique and installation for the production of distilled water with low deuterium content; - mineralized water with low deuterium content and technique to produce it. The gold and silver medals won at international salons for inventions confirmed the novelty of these inventions. Knowing that deuterium content of water has a big influence on living organisms, beginning with 1996, the ICSI Ramnicu Valcea, deuterium - depleted water producer, co-operated with Romanian specialized institutes for biological effects' evaluation of deuterium - depleted water. The role of natural deuterium in living organisms was examined by using deuterium - depleted water instead of natural water. These investigations led to the following conclusions: 1. deuterium - depleted water caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the deuterium - depleted water persists after the removal of the vascular endothelium; -2. animals treated with deuterium - depleted water showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defence mechanism; 3, deuterium - depleted water stimulates immune defence reactions, represented by the opsonic, bactericidal and phagocyte capacity of the immune system, together with increase in the numbers of polymorphonuclear neutrophils; 4. investigations regarding artificial

  18. Specification for the VERA Depletion Benchmark Suite

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

    2015-12-17

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

  19. Developmental and activity-dependent plasticity of filiform hair receptors in the locust

    HaraldWolf

    2013-08-01

    Full Text Available A group of wind sensitive filiform hair receptors on the locust thorax and head makes contact onto a pair of identified interneuron, A4I1. The hair receptors’ central nervous projections exhibit pronounced structural dynamics during nymphal development, for example, by gradually eliminating their ipsilateral dendritic field while maintaining the contralateral one. These changes are dependent not only on hormones controlling development but on neuronal activity as well. The hair-to-interneuron system has remarkably high gain (close to 1 and makes contact to flight steering muscles. During stationary flight in front of a wind tunnel, interneuron A4I1 is active in the wing beat rhythm, and in addition it responds strongly to stimulation of sensory hairs in its receptive field. A role of the hair-to-interneuron in flight steering is thus suggested. This system appears suitable for further study of developmental and activity-dependent plasticity in a sensorimotor context with known connectivity patterns.

  20. Long lasting protein synthesis- and activity-dependent spine shrinkage and elimination after synaptic depression.

    Yazmín Ramiro-Cortés

    Full Text Available Neuronal circuits modify their response to synaptic inputs in an experience-dependent fashion. Increases in synaptic weights are accompanied by structural modifications, and activity dependent, long lasting growth of dendritic spines requires new protein synthesis. When multiple spines are potentiated within a dendritic domain, they show dynamic structural plasticity changes, indicating that spines can undergo bidirectional physical modifications. However, it is unclear whether protein synthesis dependent synaptic depression leads to long lasting structural changes. Here, we investigate the structural correlates of protein synthesis dependent long-term depression (LTD mediated by metabotropic glutamate receptors (mGluRs through two-photon imaging of dendritic spines on hippocampal pyramidal neurons. We find that induction of mGluR-LTD leads to robust and long lasting spine shrinkage and elimination that lasts for up to 24 hours. These effects depend on signaling through group I mGluRs, require protein synthesis, and activity. These data reveal a mechanism for long lasting remodeling of synaptic inputs, and offer potential insights into mental retardation.

  1. The Molecular Physiology of Activity-Dependent Bulk Endocytosis of Synaptic Vesicles

    Clayton, Emma L.; Cousin, Michael A.

    2010-01-01

    Central nerve terminals release neurotransmitter in response to a wide variety of stimuli. Since maintenance of neurotransmitter release is dependent on the continual supply of synaptic vesicles (SVs), nerve terminals possess an array of endocytosis modes to retrieve and recycle SV membrane and proteins. During mild stimulation conditions single SV retrieval modes such as clathrin-mediated endocytosis (CME) predominate. However during increased neuronal activity additional SV retrieval capacity is required, which is provided by activity-dependent bulk endocytosis (ADBE). ADBE is the dominant SV retrieval mechanism during elevated neuronal activity. It is a high capacity SV retrieval mode that is immediately triggered during such stimulation conditions. This review will summarise the current knowledge regarding the molecular mechanism of ADBE, including molecules required for its triggering and subsequent steps, including SV budding from bulk endosomes. The molecular relationship between ADBE and the SV reserve pool will also be discussed. It is becoming clear that an understanding of the molecular physiology of ADBE will be of critical importance in attempts to modulate both normal and abnormal synaptic function during intense neuronal activity. PMID:19765184

  2. Activity-dependent synaptic plasticity modulates the critical phase of brain development.

    Chaudhury, Sraboni; Sharma, Vikram; Kumar, Vivek; Nag, Tapas C; Wadhwa, Shashi

    2016-04-01

    Plasticity or neuronal plasticity is a unique and adaptive feature of nervous system which allows neurons to reorganize their interactions in response to an intrinsic or extrinsic stimulation and shapes the formation and maintenance of a functional neuronal circuit. Synaptic plasticity is the most important form of neural plasticity and plays critical role during the development allowing the formation of precise neural connectivity via the process of pruning. In the sensory systems-auditory and visual, this process is heavily dependent on the external cues perceived during the development. Environmental enrichment paradigms in an activity-dependent manner result in early maturation of the synapses and more efficient trans-synaptic signaling or communication flow. This has been extensively observed in the avian auditory system. On the other hand, stimuli results in negative effect can cause alterations in the synaptic connectivity and strength resulting in various developmental brain disorders including autism, fragile X syndrome and rett syndrome. In this review we discuss the role of different forms of activity (spontaneous or environmental) during the development of the nervous system in modifying synaptic plasticity necessary for shaping the adult brain. Also, we try to explore various factors (molecular, genetic and epigenetic) involved in altering the synaptic plasticity in positive and negative way. PMID:26515724

  3. Cell Biological Mechanisms of Activity-Dependent Synapse to Nucleus Translocation of CRTC1 in Neurons

    Toh Hean eCh'ng

    2015-09-01

    Full Text Available Previous studies have revealed a critical role for CREB-regulated transcriptional coactivator (CRTC1 in regulating neuronal gene expression during learning and memory. CRTC1 localizes to synapses but undergoes activity-dependent nuclear translocation to regulate the transcription of CREB target genes. Here we investigate the long-distance retrograde transport of CRTC1 in hippocampal neurons. We show that local elevations in calcium, triggered by activation of synaptic glutamate receptors and L-type voltage-gated calcium channels, initiate active, dynein-mediated retrograde transport of CRTC1 along microtubules. We identify a nuclear localization signal within CRTC1, and characterize three conserved serine residues whose dephosphorylation is required for nuclear import. Domain analysis reveals that the amino-terminal third of CRTC1 contains all of the signals required for regulated nucleocytoplasmic trafficking. We fuse this region to Dendra2 to generate a reporter construct and perform live-cell imaging coupled with local uncaging of glutamate and photoconversion to characterize the dynamics of stimulus-induced retrograde transport and nuclear accumulation.

  4. Activity-dependent BDNF release via endocytic pathways is regulated by synaptotagmin-6 and complexin.

    Wong, Yu-Hui; Lee, Chia-Ming; Xie, Wenjun; Cui, Bianxiao; Poo, Mu-ming

    2015-08-11

    Brain-derived neurotrophic factor (BDNF) is known to modulate synapse development and plasticity, but the source of synaptic BDNF and molecular mechanisms regulating BDNF release remain unclear. Using exogenous BDNF tagged with quantum dots (BDNF-QDs), we found that endocytosed BDNF-QDs were preferentially localized to postsynaptic sites in the dendrite of cultured hippocampal neurons. Repetitive neuronal spiking induced the release of BDNF-QDs at these sites, and this process required activation of glutamate receptors. Down-regulating complexin 1/2 (Cpx1/2) expression eliminated activity-induced BDNF-QD secretion, although the overall activity-independent secretion was elevated. Among eight synaptotagmin (Syt) isoforms examined, down-regulation of only Syt6 impaired activity-induced BDNF-QD secretion. In contrast, activity-induced release of endogenously synthesized BDNF did not depend on Syt6. Thus, neuronal activity could trigger the release of endosomal BDNF from postsynaptic dendrites in a Cpx- and Syt6-dependent manner, and endosomes containing BDNF may serve as a source of BDNF for activity-dependent synaptic modulation. PMID:26216953

  5. Expression of activity-dependent neuroprotective protein in the brain of adult rats.

    Gennet, N; Herden, C; Bubb, V J; Quinn, J P; Kipar, A

    2008-03-01

    Activity-dependent neuroprotective protein (ADNP) is a VIP-regulated gene, which is essential for brain development. A synthetic peptide (NAP) derived from the ADNP sequence is highly neuroprotective, therefore it has been hypothesised that ADNP has a similar role. ADNP contains classical transcription factor motifs and nuclear localisation domains, but it has also been reported to be secreted and to co-localise with microtubules, indicating that ADNP may have multiple functions. We investigated the pattern of ADNP expression by immunohistology in normal rat brain, in order to generate a framework for future studies examining changes in ADNP expression in response to noxious stimuli or in models of disease. We found widespread ADNP-like immunoreactivity in neurons throughout the rat brain, with the highest expression in the cerebellum, and strong expression in the thalamus, mesencephalon, pons and medulla oblongata. ADNP-like immunoreactivity was mainly observed in the cytoplasm of neurons, and fibre tracts were often strongly positive as well. In addition, positive neuronal nuclei were occasionally observed. ADNP-like immunoreactivity was lost in degenerating "dark" neurons, whereas it appeared to locate to the nucleus in some of the morphologically unaltered adjacent cells. Occasional astrocyte and microglial cells were also positive. We suggest that the widespread expression of ADNP may correlate with the wide-ranging protective effects of NAP, and that the cytoplasmic and axonal localisation of ADNP-like immunoreactivity suggests additional, non-transcriptional functions of ADNP. PMID:18072088

  6. Activity-dependent synaptic plasticity of a chalcogenide electronic synapse for neuromorphic systems.

    Li, Yi; Zhong, Yingpeng; Zhang, Jinjian; Xu, Lei; Wang, Qing; Sun, Huajun; Tong, Hao; Cheng, Xiaoming; Miao, Xiangshui

    2014-01-01

    Nanoscale inorganic electronic synapses or synaptic devices, which are capable of emulating the functions of biological synapses of brain neuronal systems, are regarded as the basic building blocks for beyond-Von Neumann computing architecture, combining information storage and processing. Here, we demonstrate a Ag/AgInSbTe/Ag structure for chalcogenide memristor-based electronic synapses. The memristive characteristics with reproducible gradual resistance tuning are utilised to mimic the activity-dependent synaptic plasticity that serves as the basis of memory and learning. Bidirectional long-term Hebbian plasticity modulation is implemented by the coactivity of pre- and postsynaptic spikes, and the sign and degree are affected by assorted factors including the temporal difference, spike rate and voltage. Moreover, synaptic saturation is observed to be an adjustment of Hebbian rules to stabilise the growth of synaptic weights. Our results may contribute to the development of highly functional plastic electronic synapses and the further construction of next-generation parallel neuromorphic computing architecture. PMID:24809396

  7. Possible ozone depletions following nuclear explosions

    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.-

  8. Real depletion in nodal diffusion codes

    The fuel depletion is described by more than one hundred fuel isotopes in the advanced lattice codes like HELIOS, but only a few fuel isotopes are accounted for even in the advanced steady-state diffusion codes. The general assumption that the number densities of the majority of the fuel isotopes depend only on the fuel burnup is seriously in error if high burnup is considered. The real depletion conditions in the reactor core differ from the asymptotic ones at the stage of lattice depletion calculations. This study reveals which fuel isotopes should be explicitly accounted for in the diffusion codes in order to predict adequately the real depletion effects in the core. A somewhat strange conclusion is that if the real number densities of the main fissionable isotopes are not explicitly accounted for in the diffusion code, then Sm-149 should not be accounted for either, because the net error in k-inf is smaller (Authors)

  9. Fully Depleted Charge-Coupled Devices

    We have developed fully depleted, back-illuminated CCDs that build upon earlier research and development efforts directed towards technology development of silicon-strip detectors used in high-energy-physics experiments. The CCDs are fabricated on the same type of high-resistivity, float-zone-refined silicon that is used for strip detectors. The use of high-resistivity substrates allows for thick depletion regions, on the order of 200-300 um, with corresponding high detection efficiency for near-infrared and soft x-ray photons. We compare the fully depleted CCD to the p-i-n diode upon which it is based, and describe the use of fully depleted CCDs in astronomical and x-ray imaging applications

  10. Polar stratospheric clouds and ozone depletion

    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.

  11. Depleted UF6 programmatic environmental impact statement

    The US Department of Energy has developed a program for long-term management and use of depleted uranium hexafluoride, a product of the uranium enrichment process. As part of this effort, DOE is preparing a Programmatic Environmental Impact Statement (PEIS) for the depleted UF6 management program. This report duplicates the information available at the web site (http://www.ead.anl.gov/web/newduf6) set up as a repository for the PEIS. Options for the web site include: reviewing recent additions or changes to the web site; learning more about depleted UF6 and the PEIS; browsing the PEIS and related documents, or submitting official comments on the PEIS; downloading all or part of the PEIS documents; and adding or deleting one's name from the depleted UF6 mailing list

  12. Ecological considerations of natural and depleted uranium

    Depleted 238U is a major by-product of the nuclear fuel cycle for which increasing use is being made in counterweights, radiation shielding, and ordnance applications. This paper (1) summarizes the pertinent literature on natural and depleted uranium in the environment, (2) integrates results of a series of ecological studies conducted at Los Alamos Scientific Laboratory (LASL) in New Mexico where 70,000 kg of depleted and natural uranium has been expended to the environment over the past 34 years, and (3) synthesizes the information into an assessment of the ecological consequences of natural and depleted uranium released to the environment by various means. Results of studies of soil, plant, and animal communities exposed to this radiation and chemical environment over a third of a century provide a means of evaluating the behavior and effects of uranium in many contexts

  13. Depleted Uranium and Its Effects on Humans

    Zdeněk Hon

    2015-04-01

    Full Text Available The article summarizes contemporary scientific knowledge of depleted uranium effects on human health due to its use in military conflicts. The discussion covers cases of minimal risk due to external irradiation resulting from the storage and handling of depleted uranium ammunition and, in contrast, important toxicological and radio-toxicological risks of late effects resulting from the inhalation and ingestion of dust particles produced by the burning of the core of the anti-tank ammunition.

  14. Depleted Uranium and Its Effects on Humans

    Zdeněk Hon; Jan Österreicher; Leoš Navrátil

    2015-01-01

    The article summarizes contemporary scientific knowledge of depleted uranium effects on human health due to its use in military conflicts. The discussion covers cases of minimal risk due to external irradiation resulting from the storage and handling of depleted uranium ammunition and, in contrast, important toxicological and radio-toxicological risks of late effects resulting from the inhalation and ingestion of dust particles produced by the burning of the core of the anti-tank ammunition.

  15. Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics

    Barkhouse, D. Aaron R.

    2011-05-26

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

  16. Activity-dependent neuroprotective protein (ADNP) exhibits striking sexual dichotomy impacting on autistic and Alzheimer's pathologies.

    Malishkevich, A; Amram, N; Hacohen-Kleiman, G; Magen, I; Giladi, E; Gozes, I

    2015-01-01

    Activity-dependent neuroprotective protein (ADNP) is a most frequent autism spectrum disorder (ASD)-associated gene and the only protein significantly decreasing in the serum of Alzheimer's disease (AD) patients. Is ADNP associated with ASD being more prevalent in boys and AD more prevalent in women? Our results revealed sex-related learning/memory differences in mice, reflecting hippocampal expression changes in ADNP and ADNP-controlled AD/ASD risk genes. Hippocampal ADNP transcript content was doubled in male vs female mice, with females showing equal expression to ADNP haploinsufficient (ADNP(+/)(-)) males and no significant genotype-associated reduction. Increased male ADNP expression was replicated in human postmortem hippocampal samples. The hippocampal transcript for apolipoprotein E (the major risk gene for AD) was doubled in female mice compared with males, and further doubled in the ADNP(+/-) females, contrasting a decrease in ADNP(+/-) males. Previously, overexpression of the eukaryotic translation initiation factor 4E (eIF4E) led to ASD-like phenotype in mice. Here, we identified binding sites on ADNP for eIF4E and co-immunoprecipitation. Furthermore, hippocampal eIF4E expression was specifically increased in young ADNP(+/-) male mice. Behaviorally, ADNP(+/-) male mice exhibited deficiencies in object recognition and social memory compared with ADNP(+/+) mice, while ADNP(+/-) females were partially spared. Contrasting males, which preferred novel over familiar mice, ADNP(+/+) females showed no preference to novel mice and ADNP(+/-) females did not prefer mice over object. ADNP expression, positioned as a master regulator of key ASD and AD risk genes, introduces a novel concept of hippocampal gene-regulated sexual dimorphism and an ADNP(+/-) animal model for translational psychiatry. PMID:25646590

  17. Cellular mechanisms of activity-dependent BDNF expression in primary sensory neurons.

    Vermehren-Schmaedick, A; Khanjian, R A; Balkowiec, A

    2015-12-01

    Brain-derived neurotrophic factor (BDNF) is abundantly expressed by both developing and adult rat visceral sensory neurons from the nodose ganglion (NG) in vivo and in vitro. We have previously shown that BDNF is released from neonatal NG neurons by activity and regulates dendritic development in their postsynaptic targets in the brainstem. The current study was carried out to examine the cellular and molecular mechanisms of activity-dependent BDNF expression in neonatal rat NG neurons, using our established in vitro model of neuronal activation by electrical field stimulation with patterns that mimic neuronal activity in vivo. We show that BDNF mRNA (transcript 4) increases over threefold in response to a 4-h tonic or bursting pattern delivered at the frequency of 6 Hz, which corresponds to the normal heart rate of a newborn rat. No significant increase in BDNF expression was observed following stimulation at 1 Hz. The latter effect suggests a frequency-dependent mechanism of regulated BDNF expression. In addition to BDNF transcript 4, which is known to be regulated by activity, transcript 1 also showed significant upregulation. The increases in BDNF mRNA were followed by BDNF protein upregulation of a similar magnitude after 24h of stimulation at 6 Hz. Electrical stimulation-evoked BDNF expression was inhibited by pretreating neurons with the blocker of voltage-gated sodium channels tetrodotoxin and by removing extracellular calcium. Moreover, our data show that repetitive stimulation-evoked BDNF expression requires calcium influx through N-, but not L-type, channels. Together, our study reveals novel mechanisms through which electrical activity stimulates de novo synthesis of BDNF in sensory neurons, and points to the role of N-type calcium channels in regulating BDNF expression in sensory neurons in response to repetitive stimulation. PMID:26459016

  18. Radiative characteristics of depleted uranium bomb and it is protection

    Based on the developing process of depleted uranium bombs described in the first part, the radiative characteristics and mechanism of depleted uranium bombs are analyzed emphatically. The deeper discussion on protection of depleted uranium bombs is proceeded

  19. Essential role of presynaptic NMDA receptors in activity-dependent BDNF secretion and corticostriatal LTP.

    Park, Hyungju; Popescu, Andrei; Poo, Mu-ming

    2014-12-01

    Activation of N-methyl-D-aspartate subtype of glutamate receptors (NMDARs) in postsynaptic dendrites is required for long-term potentiation (LTP) of many excitatory synapses, but the role of presynaptic axonal NMDARs in synaptic plasticity remains to be clarified. Here we report that axonal NMDARs play an essential role in LTP induction at mouse corticostriatal synapses by triggering activity-induced presynaptic secretion of brain-derived neurotrophic factor (BDNF). Genetic depletion of either BDNF or the NMDAR subunit GluN1 specifically in cortical axons abolished corticostriatal LTP in response to theta burst stimulation (TBS). Furthermore, functional axonal NMDARs were required for TBS-triggered prolonged axonal Ca(2+) elevation and BDNF secretion, supporting the notion that activation of axonal NMDARs induces BDNF secretion via enhancing Ca(2+) signals in the presynaptic nerve terminals. These results demonstrate that presynaptic NMDARs are equally important as postsynaptic NMDARs in LTP induction of corticostriatal synapses due to their role in mediating activity-induced presynaptic BDNF secretion. PMID:25467984

  20. EPRI depletion benchmark calculations using PARAGON

    Highlights: • PARAGON depletion calculations are benchmarked against the EPRI reactivity decrement experiments. • Benchmarks cover a wide range of enrichments, burnups, cooling times, and burnable absorbers, and different depletion and storage conditions. • Results from PARAGON-SCALE scheme are more conservative relative to the benchmark data. • ENDF/B-VII based data reduces the excess conservatism and brings the predictions closer to benchmark reactivity decrement values. - Abstract: In order to conservatively apply burnup credit in spent fuel pool criticality analyses, code validation for both fresh and used fuel is required. Fresh fuel validation is typically done by modeling experiments from the “International Handbook.” A depletion validation can determine a bias and bias uncertainty for the worth of the isotopes not found in the fresh fuel critical experiments. Westinghouse’s burnup credit methodology uses PARAGON™ (Westinghouse 2-D lattice physics code) and its 70-group cross-section library, which have been benchmarked, qualified, and licensed both as a standalone transport code and as a nuclear data source for core design simulations. A bias and bias uncertainty for the worth of depletion isotopes, however, are not available for PARAGON. Instead, the 5% decrement approach for depletion uncertainty is used, as set forth in the Kopp memo. Recently, EPRI developed a set of benchmarks based on a large set of power distribution measurements to ascertain reactivity biases. The depletion reactivity has been used to create 11 benchmark cases for 10, 20, 30, 40, 50, and 60 GWd/MTU and 3 cooling times 100 h, 5 years, and 15 years. These benchmark cases are analyzed with PARAGON and the SCALE package and sensitivity studies are performed using different cross-section libraries based on ENDF/B-VI.3 and ENDF/B-VII data to assess that the 5% decrement approach is conservative for determining depletion uncertainty

  1. Geomagnetic and solar activity dependence of ionospheric upflowing O+: FAST observations

    Zhao, K.; Jiang, Y.; Chen, K. W.; Huang, L. F.

    2016-09-01

    This paper investigates the dependence of the occurrence frequency of ionospheric upflowing oxygen (O+) ions on the sunspot cycle and geomagnetic activity. We examine the upflows response to the geomagnetic disturbances as well as the influence of the ion energy factor in controlling the magnitude of the occurrence frequency and the net energy flux. We discuss the spatial distribution of the upflow occurrence frequency and construct a regression model as a function of the magnetic latitude. The results show an overall enhancement of the upflow occurrence frequency during magnetically disturbed periods and indicate that the high-occurrence area spreads out from the source regions during magnetically quiet periods. The high-occurrence areas are located at 70° magnetic latitude (mLat) in the dayside auroral oval zone and between 76-80° mLat in the dayside polar cusp region. In the nightside auroral oval zone, these areas are near 60° mLat, penetrating further equatorward to 55° mLat during magnetically disturbed periods. High energy (≥1 keV) upflowing ions are common in the nightside auroral oval zone while low energy (<1 keV) upflowing ions are found escaping from the high latitude dayside cusp region. A Gaussian function is shown to be a good fit to the occurrence frequency over the magnetic latitude. For high energy upflowing O+ ions, the occurrence frequency exhibits a single peak located at about 60° mLat in the nightside auroral oval zone while for low energy upflowing O+ ions, it exhibits two peaks, one near 60° mLat in the auroral oval zone and the other near 78° mLat in the cusp region. We study the solar activity dependence by analyzing the relationship between the upflow occurrence frequency and the sunspot number (RZ). The statistical result shows that the frequency decreases with declining solar activity level, from ˜30 % at solar maximum to ˜5 % at solar minimum. In addition, the correlation coefficient between the occurrence frequency and RZ

  2. Activity-dependent increases in local oxygen consumption correlate with postsynaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Engelund;

    2011-01-01

    metabolism via mitochondrial signaling, but whether this also occurs in the intact brain is unknown. Here we applied a pharmacological approach to dissect the effects of ionic currents and cytosolic Ca(2+) rises of neuronal origin on activity-dependent rises in CMRO(2). We used two-photon microscopy and...

  3. Activity-dependent increases in local oxygen consumption correlate with postsynaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Engelund;

    2011-01-01

    Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO(2)) and cerebral blood flow (CBF). Activity-dependent rises in CMRO(2) fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca(2+) stimulate oxidative...

  4. Activity-dependent increases in local oxygen consumption correlate with post-synaptic currents in the mouse cerebellum in vivo

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Joan;

    2011-01-01

    Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow. Activity-dependent rises in CMRO2 fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca2+ stimulate oxidative metabolism via...

  5. Depletion sensitivity predicts unhealthy snack purchases.

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

    2016-01-01

    The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose weight on snack purchase behavior were explored. Participants included in the study were instructed to report every snack they bought over the course of one week. The dependent variables were the number of healthy and unhealthy snacks purchased. The results of the present study demonstrate that depletion sensitivity predicts the amount of unhealthy (but not healthy) snacks bought. The more sensitive people are to depletion, the more unhealthy snacks they buy. Moreover, there was some tentative evidence that this relation is more pronounced for people with a weak as opposed to a strong goal to lose weight, suggesting that a strong goal to lose weight may function as a motivational buffer against self-control failures. All in all, these findings provide evidence for the external validity of depletion sensitivity and the relevance of this construct in the domain of eating behavior. PMID:26321417

  6. The New MCNP6 Depletion Capability

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

    2012-06-19

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

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

    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. PMID:27241617

  8. Depletion of the nuclear Fermi sea

    Rios, A; Dickhoff, W H

    2009-01-01

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

  9. Molten-Salt Depleted-Uranium Reactor

    Dong, Bao-Guo; Gu, Ji-Yuan

    2015-01-01

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

  10. Depleted uranium and the Gulf War syndrome

    Some military personnel involved in the 1991Gulf War have complained of continuing stress-like symptoms for which no obvious cause has been found. These symptoms have at times been attributed to the use of depleted uranium (DU) in shell casings which are believed to have caused toxic effects. Depleted uranium is natural uranium which is depleted in the rarer U-235 isotope. It is a heavy metal and in common with other heavy metals is chemically toxic. It is also slightly radioactive and could give rise to a radiological hazard if dispersed in finely divided form so that it was inhaled. In response to concerns, the possible effects of DU have been extensively studied along with other possible contributors to Gulf War sickness. This article looks at the results of some of the research that has been done on DU. (author)

  11. Ozone depletion and chlorine loading potentials

    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.

  12. Depleted uranium speciation in the Bratoselce soil

    During the air strikes in 1999, about thirteen hundred projectiles with depleted uranium were fired into the Bratoselce, South Serbia. A study providing insight into physical chemical behaviour of depleted uranium originated from dissolved 'material' of projectile penetrators in the contaminated soil have been conducted. Samples were treated according to Tarriers modified procedure of five-step sequential extraction. Suitable choice of solvents for sequential extraction simulated the real conditions in the environment. Fractions are further analysed by alpha spectrometry and atomic absorption spectrometry methods to determine the uranium isotopes and trace or major elements. The results indicated potential substrates for depleted uranium compounds in the investigated environment, with specific soil composition that is essential for prediction of its mobility and bioavailability in certain conditions. (author)

  13. Department of Energy depleted uranium recycle

    With its strategic supply of depleted uranium, the Department of Energy is studying reuse of the material in nuclear radiation shields, military hardware, and commercial applications. the study is expected to warrant a more detailed uranium recycle plan which would include consideration of a demonstration program and a program implementation decision. Such a program, if implemented, would become the largest nuclear material recycle program in the history of the Department of Energy. The bulk of the current inventory of depleted uranium is stored in 14-ton cylinders in the form of solid uranium hexafluoride (UF6). The radioactive 235U content has been reduced to a concentration of 0.2% to 0.4%. Present estimates indicate there are about 55,000 UF6-filled cylinders in inventory and planned operations will provide another 2,500 cylinders of depleted uranium each year. The United States government, under the auspices of the Department of Energy, considers the depleted uranium a highly-refined strategic resource of significant value. A possible utilization of a large portion of the depleted uranium inventory is as radiation shielding for spent reactor fuels and high-level radioactive waste. To this end, the Department of Energy study to-date has included a preliminary technical review to ascertain DOE chemical forms useful for commercial products. The presentation summarized the information including preliminary cost estimates. The status of commercial uranium processing is discussed. With a shrinking market, the number of chemical conversion and fabrication plants is reduced; however, the commercial capability does exist for chemical conversion of the UF6 to the metal form and for the fabrication of uranium radiation shields and other uranium products. Department of Energy facilities no longer possess a capability for depleted uranium chemical conversion

  14. Gammaspectrometric determination of depleted uranium in soil

    Full text: Three years of monitoring the content of natural radionuclides as well as radionuclides of artificial origin in all samples in the south part of the Republic of Serbia and Montenegro indicated that there was widespread, low-level contamination by depleted uranium at this region. High activity of depleted uranium was found in the soil samples taken at the points where the penetrators were found. We used high resolution gamma spectrometry measurements, because of their simplicity and accuracy. Aims of the control were to asses the increase of radioactivity above the natural levels in the immediate and near vicinity of the bomb craters, to asses the corresponding effect of changed natural radioactivity on the health of the population living in these places and finding unexploded depleted uranium bullets. The collected soil samples were cleaned of plants and stones, dried at 105 deg. C - 110 deg. C till constant weight for 24-48 h. After this, the samples were ground, sieved, and measure in cylindrical geometry. Gamma activity was determined by gamma spectrometry measurements using HP Ge detector (ORTEC), with relative efficiency of 25% and energy resolution of 1.85 keV (1332.5 keV 60Co). The analyser system conducts a peak search, energy assignment, quantification and nuclide identification in acquired spectra. Time of measurement varied from 60000 s to 250000 s. Depleted uranium was found in the soil samples from Vranje region and cape Arza (Montenegro). There are four fenced areas in Vranje region (Pljackovica, Bratoselce, Borovac and Reljan) and one in the Montenegro (cape Arza) where we have found depleted uranium penetrators. The 238U and 235U specific activities and their isotopic composition correspond to depleted uranium (238U/235U ratio from 35 to 77). (author)

  15. The Chemistry and Toxicology of Depleted Uranium

    Katz, Sidney A.

    2014-01-01

    Natural uranium is comprised of three radioactive isotopes: 238U, 235U, and 234U. Depleted uranium (DU) is a byproduct of the processes for the enrichment of the naturally occurring 235U isotope. The world wide stock pile contains some 1½ million tons of depleted uranium. Some of it has been used to dilute weapons grade uranium (~90% 235U) down to reactor grade uranium (~5% 235U), and some of it has been used for heavy tank armor and for the fabrication of armor-piercing bullets and missiles....

  16. Toxicological issues after depleted uranium weapons attacked

    Depleted Uranium (DU) is a byproduct of the uranium enrichment for producing nuclear reactor or nuclear weapon. DU is used in the military as an armor-piercing projectile due to its hardness, strength, and density. A lot of DU weapons were fired in the Gulf War, and bring about critical environmental and internal contamination. Therefore, DU becomes suddenly a hot issue. Some toxicological problems after DU weapons attacked have been reviewed, which include features of internal DU contamination. Hazard of wound contamination and inhalation with insoluble uranium, and other urgent toxicological issues. The healthy effects of implanted with depleted uranium pellets were illustrated in particular

  17. Application of backtracking algorithm to depletion calculations

    Based on the theory of linear chain method for analytical depletion calculations, the burn-up matrix is decoupled by the divide and conquer strategy and the linear chain with Markov characteristic is formed. The density, activity and decay heat of every nuclide in the chain can be calculated by analytical solutions. Every possible reaction path of the nuclide must be considered during the linear chain establishment process. To confirm the calculation precision and efficiency, the algorithm which can cover all the reaction paths of the nuclide and search the paths automatically according to to problem description and precision restrictions should be sought. Through analysis and comparison of several kinds of searching algorithms, the backtracking algorithm was selected to search and calculate the linear chains using Depth First Search (DFS) method. The depletion program can solve the depletion problem adaptively and with high fidelity. The solution space and time complexity of the program were analyzed. The new developed depletion program was coupled with Monte Carlo program MCMG-II to calculate the benchmark burn-up problem of the first core of China Experimental Fast Reactor (CEFR). The initial verification and validation of the program was performed by the calculation. (author)

  18. Global Warming: Lessons from Ozone Depletion

    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…

  19. Application of backtracking algorithm to depletion calculations

    Based on the theory of linear chain method for analytical depletion calculations, the burnup matrix is decoupled by the divide and conquer strategy and the linear chain with Markov characteristic is formed. The density, activity and decay heat of every nuclide in the chain then can be calculated by analytical solutions. Every possible reaction path of the nuclide must be considered during the linear chain establishment process. To confirm the calculation precision and efficiency, the algorithm which can cover all the reaction paths and search the paths automatically according to the problem description and precision restrictions should be found. Through analysis and comparison of several kinds of searching algorithms, the backtracking algorithm was selected to establish and calculate the linear chains in searching process using depth first search (DFS) method, forming an algorithm which can solve the depletion problem adaptively and with high fidelity. The complexity of the solution space and time was analyzed by taking into account depletion process and the characteristics of the backtracking algorithm. The newly developed depletion program was coupled with Monte Carlo program MCMG-Ⅱ to calculate the benchmark burnup problem of the first core of China Experimental Fast Reactor (CEFR) and the preliminary verification and validation of the program were performed. (authors)

  20. CPG2 Recruits Endophilin B2 to the Cytoskeleton for Activity-Dependent Endocytosis of Synaptic Glutamate Receptors.

    Loebrich, Sven; Benoit, Marc Robert; Konopka, Jaclyn Aleksandra; Cottrell, Jeffrey Richard; Gibson, Joanne; Nedivi, Elly

    2016-02-01

    Internalization of glutamate receptors at the postsynaptic membrane via clathrin-mediated endocytosis (CME) is a key mechanism for regulating synaptic strength. A role for the F-actin cytoskeleton in CME is well established, and recently, PKA-dependent association of candidate plasticity gene 2 (CPG2) with the spine-cytoskeleton has been shown to mediate synaptic glutamate receptor internalization. Yet, how the endocytic machinery is physically coupled to the actin cytoskeleton to facilitate glutamate receptor internalization has not been demonstrated. Moreover, there has been no distinction of endocytic-machinery components that are specific to activity-dependent versus constitutive glutamate receptor internalization. Here, we show that CPG2, through a direct physical interaction, recruits endophilin B2 (EndoB2) to F-actin, thus anchoring the endocytic machinery to the spine cytoskeleton and facilitating glutamate receptor internalization. Regulation of CPG2 binding to the actin cytoskeleton by protein kinase A directly impacts recruitment of EndoB2 and clathrin. Specific disruption of EndoB2 or the CPG2-EndoB2 interaction impairs activity-dependent, but not constitutive, internalization of both NMDA- and AMPA-type glutamate receptors. These results demonstrate that, through direct interactions with F-actin and EndoB2, CPG2 physically bridges the spine cytoskeleton and the endocytic machinery, and this tripartite association is critical specifically for activity-dependent CME of synaptic glutamate receptors. PMID:26776730

  1. A worldwide view of groundwater depletion

    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

  2. Health and environmental impact of depleted uranium

    Depleted Uranium (DU) is 'nuclear waste' produced from the enrichment process and is mostly made up of 238U and is depleted in the fissionable isotope 235U compared to natural uranium (NU). Depleted uranium has about 60% of the radioactivity of natural uranium. Depleted uranium and natural uranium are identical in terms of the chemical toxicity. Uranium's high density gives depleted uranium shells increased range and penetrative power. This density, combined with uranium's pyrophoric nature, results in a high-energy kinetic weapon that can punch and burn through armour plating. Striking a hard target, depleted uranium munitions create extremely high temperatures. The uranium immediately burns and vaporizes into an aerosol, which is easily diffused in the environment. People can inhale the micro-particles of uranium oxide in an aerosol and absorb them mainly from lung. Depleted uranium has both aspects of radiological toxicity and chemical toxicity. The possible synergistic effect of both kinds of toxicities is also pointed out. Animal and cellular studies have been reported the carcinogenic, neurotoxic, immuno-toxic and some other effects of depleted uranium including the damage on reproductive system and foetus. In addition, the health effects of micro/ nano-particles, similar in size of depleted uranium aerosols produced by uranium weapons, have been reported. Aerosolized DU dust can easily spread over the battlefield spreading over civilian areas, sometimes even crossing international borders. Therefore, not only the military personnel but also the civilians can be exposed. The contamination continues after the cessation of hostilities. Taking these aspects into account, DU weapon is illegal under international humanitarian laws and is considered as one of the inhumane weapons of 'indiscriminate destruction'. The international society is now discussing the prohibition of DU weapons based on 'precautionary principle'. The 1991 Gulf War is reportedly the first

  3. Elemental depletions in the Magellanic Clouds and the evolution of depletions with metallicity

    Tchernyshyov, Kirill; Seale, Jonathan; Fox, Andrew; Friedman, Scott D; Dwek, Eli; Galliano, Frédéric; Sembach, Kenneth

    2015-01-01

    We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC, together -- the MCs) as measured by UV absorption spectroscopy. We have measured P II and Fe II along 85 sightlines toward the MCs using archival FUSE observations. For 16 of those sightlines, we have measured Si II, Cr II, and Zn II from new HST COS observations. We have combined these measurements with H I and H$_2$ column densities and reference stellar abundances from the literature to derive gas-phase abundances, depletions, and gas-to-dust ratios (GDRs). 80 of our 84 P measurements and 13 of our 16 Zn measurements are depleted by more than 0.1 decades, suggesting that P and Zn abundances are not accurate metallicity indicators at and above the metallicity of the SMC. The maximum P and Zn depletions are the same in the MW, LMC, and SMC. Si, Cr, and Fe are systematically less depleted in the SMC than in the MW or LMC. The minimum Si depletion in the SMC is consistent with zero. Our depletion-derive...

  4. Copenhagen delegates advance phaseout of ozone depleters

    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

  5. Depleted uranium hexafluoride: Waste or resource?

    Schwertz, N.; Zoller, J.; Rosen, R.; Patton, S. [Lawrence Livermore National Lab., CA (United States); Bradley, C. [USDOE Office of Nuclear Energy, Science, Technology, Washington, DC (United States); Murray, A. [SAIC (United States)

    1995-07-01

    the US Department of Energy is evaluating technologies for the storage, disposal, or re-use of depleted uranium hexafluoride (UF{sub 6}). This paper discusses the following options, and provides a technology assessment for each one: (1) conversion to UO{sub 2} for use as mixed oxide duel, (2) conversion to UO{sub 2} to make DUCRETE for a multi-purpose storage container, (3) conversion to depleted uranium metal for use as shielding, (4) conversion to uranium carbide for use as high-temperature gas-cooled reactor (HTGR) fuel. In addition, conversion to U{sub 3}O{sub 8} as an option for long-term storage is discussed.

  6. Reactor fuel depletion benchmark of TINDER

    Highlights: • A reactor burnup benchmark of TINDER, coupling MCNP6 to CINDER2008, was performed. • TINDER is a poor candidate for fuel depletion calculations using its current libraries. • Data library modification is necessary if fuel depletion is desired from TINDER. - Abstract: Accurate burnup calculations are key to proper nuclear reactor design, fuel cycle modeling, and disposal estimations. The TINDER code, originally designed for activation analyses, has been modified to handle full burnup calculations, including the widely used predictor–corrector feature. In order to properly characterize the performance of TINDER for this application, a benchmark calculation was performed. Although the results followed the trends of past benchmarked codes for a UO2 PWR fuel sample from the Takahama-3 reactor, there were obvious deficiencies in the final result, likely in the nuclear data library that was used. Isotopic comparisons versus experiment and past code benchmarks are given, as well as hypothesized areas of deficiency and future work

  7. Improvements in EBR-2 core depletion calculations

    The need for accurate core depletion calculations in Experimental Breeder Reactor No. 2 (EBR-2) is discussed. Because of the unique physics characteristics of EBR-2, it is difficult to obtain accurate and computationally efficient multigroup flux predictions. This paper describes the effect of various conventional and higher order schemes for group constant generation and for flux computations; results indicate that higher-order methods are required, particularly in the outer regions (i.e. the radial blanket). A methodology based on Nodal Equivalence Theory (N.E.T.) is developed which allows retention of the accuracy of a higher order solution with the computational efficiency of a few group nodal diffusion solution. The application of this methodology to three-dimensional EBR-2 flux predictions is demonstrated; this improved methodology allows accurate core depletion calculations at reasonable cost. 13 refs., 4 figs., 3 tabs

  8. The depletion of the stratospheric ozone layer

    The protection of the Earth's ozone layer is of the highest importance to mankind. The dangers of its destruction are by now well known. The depletion of that layer has reached record levels. The Antarctic ozone hole covered this year a record area. The ozone layer is predicted to begin recovery in the next one or two decades and should be restored to pre-1980 levels by 2050. This is the achievement of the regime established by the 1985 Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. The regime established by these two agreements has been revised, and made more effective in London (1990), Copenhagen (1992), Vienna (1995), and Beijing (1999)

  9. The ultimate disposition of depleted uranium

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

    1991-12-31

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

  10. Educational software on the ozone layer Depletion

    Psomiadis, Ploutarchos; Chalkidis, Anthimos; Saridaki, Anna; Tampakis, Constantine (Konstantinos); Skordoulis, Constantine

    2007-01-01

    This paper describes the design and the formative evaluation of educational software concerning the ‘Depletion of the Ozone Layer’ designed for the students of the Faculty of Primary Education (pre-service teachers) of the National and Kapodistrian University of Athens. The selection of the topic was based on: i) environmental criteria (importance of the phenomenon, complexity of the phenomenon), ii) societal criteria (local interest, human activities effects), iii) pedagogical cr...

  11. Effects of Streambed Conductance on Stream Depletion

    Greg Lackey; Roseanna M. Neupauer; John Pitlick

    2015-01-01

    Stream depletion, which is the reduction in flow rate of a stream or river due to the extraction of groundwater in a hydraulically connected stream-aquifer system, is often estimated using numerical models. The accuracy of these models depends on the appropriate parameterization of aquifer and streambed hydraulic properties. Streambed conductance is a parameter that relates the head difference between the stream and aquifer to flow across the stream channel. It is a function of streambed hydr...

  12. Molten-Salt Depleted-Uranium Reactor

    Dong, Bao-Guo; Dong, Pei; Gu, Ji-Yuan

    2015-01-01

    The supercritical, reactor core melting and nuclear fuel leaking accidents have troubled fission reactors for decades, and greatly limit their extensive applications. Now these troubles are still open. Here we first show a possible perfect reactor, Molten-Salt Depleted-Uranium Reactor which is no above accident trouble. We found this reactor could be realized in practical applications in terms of all of the scientific principle, principle of operation, technology, and engineering. Our results...

  13. Ecological and corrosion behavior of depleted uranium

    Stojanović Mirjana D.; Lačnjevac Časlav M.; Mihajlović Marija L.; Petrović Marija V.; Šoštarić Tanja D.; Petrović Jelena T.; Lopičić Zorica R.

    2015-01-01

    Environmental pollution with radionuclides, particularly uranium and its decay products is a serious global problem. The current scientific studies estimated that the contamination originating from TENORM, caused by nuclear and non-nuclear technologies, has significantly increased natural level of radioactivity in the last thirty years. During the last decades all the more were talking about the "new pollutant" - depleted uranium (DU), which has been used i...

  14. Depleted uranium during the Kosovo war

    Using the depleted uranium (DU) in the war and civil aims is considered. There are characterized the head parts of projectiles (drifts) from DU, used during Balkan wars, are described. The uranium isotope activity and exposure dose rates from β, γ and photon radiation of the drifts are investigated. The content of uranium and plutonium isotopes in the soil samples are measured. It is concluded that DU cannot exercise the acute influence on the health of military man and civil population

  15. The ultimate disposition of depleted uranium

    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.

  16. Depletion modeling of liquid dominated geothermal reservoirs

    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.

  17. Ecological and corrosion behavior of depleted uranium

    Stojanović Mirjana D.

    2015-01-01

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

  18. Optical assessment of phytoplankton nutrient depletion

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

    1990-01-01

    The ratio of light absorption at 480 and 665 nm by 90% acetone extracts of marine phytoplankton pigments has been examined as a potential indicator of phytoplankton nutritional status in both laboratory and field studies. The laboratory studies demonstrated a clear relationship between nutritional......-replete and nutrient-depleted cells. The field data suggest that the absorption ratio may be a useful indicator of nutritional status of natural phytoplankton populations, and can be used to augment the interpretation of other data....

  19. Barium depletion in hollow cathode emitters

    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

  20. Understanding the haling power depletion (HPD) method

    The Pennsylvania State Univ. (PSU) is using the university version of the Studsvik Scandpower Code System (CMS) for research and education purposes. Preparations have been made to incorporate the CMS into the PSU Nuclear Engineering graduate class 'Nuclear Fuel Management' course. The information presented in this paper was developed during the preparation of the material for the course. The Haling Power Depletion (HPD) was presented in the course for the first time. The HPD method has been criticized as not valid by many in the field even though it has been successfully applied at PSU for the past 20 years. It was noticed that the radial power distribution (RPD) for low leakage cores during depletion remained similar to that of the HPD during most of the cycle. Thus, the Haling Power Depletion (HPD) may be used conveniently mainly for low leakage cores. Studies were then made to better understand the HPD and the results are presented in this paper. Many different core configurations can be computed quickly with the HPD without using Burnable Poisons (BP) to produce several excellent low leakage core configurations that are viable for power production. Once the HPD core configuration is chosen for further analysis, techniques are available for establishing the BP design to prevent violating any of the safety constraints in such HPD calculated cores. In summary, in this paper it has been shown that the HPD method can be used for guiding the design for the low leakage core. (authors)

  1. Barium depletion in hollow cathode emitters

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

    2016-01-14

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

  2. Barium depletion in hollow cathode emitters

    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.

  3. Activity-dependent plasticity of electrical synapses: increasing evidence for its presence and functional roles in the mammalian brain.

    Haas, Julie S; Greenwald, Corey M; Pereda, Alberto E

    2016-01-01

    Gap junctions mediate electrical synaptic transmission between neurons. While the actions of neurotransmitter modulators on the conductance of gap junctions have been extensively documented, increasing evidence indicates they can also be influenced by the ongoing activity of neural networks, in most cases via local interactions with nearby glutamatergic synapses. We review here early evidence for the existence of activity-dependent regulatory mechanisms as well recent examples reported in mammalian brain. The ubiquitous distribution of both neuronal connexins and the molecules involved suggest this phenomenon is widespread and represents a property of electrical transmission in general. PMID:27230776

  4. Depletions at Browns Park National Wildlife Refuge [Draft

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

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

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

    1996-01-01

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

  6. 26 CFR 1.642(e)-1 - Depreciation and depletion.

    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...

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

    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…

  8. Targeted, activity-dependent spinal stimulation produces long-lasting motor recovery in chronic cervical spinal cord injury.

    McPherson, Jacob G; Miller, Robert R; Perlmutter, Steve I

    2015-09-29

    Use-dependent movement therapies can lead to partial recovery of motor function after neurological injury. We attempted to improve recovery by developing a neuroprosthetic intervention that enhances movement therapy by directing spike timing-dependent plasticity in spared motor pathways. Using a recurrent neural-computer interface in rats with a cervical contusion of the spinal cord, we synchronized intraspinal microstimulation below the injury with the arrival of functionally related volitional motor commands signaled by muscle activity in the impaired forelimb. Stimulation was delivered during physical retraining of a forelimb behavior and throughout the day for 3 mo. Rats receiving this targeted, activity-dependent spinal stimulation (TADSS) exhibited markedly enhanced recovery compared with animals receiving targeted but open-loop spinal stimulation and rats receiving physical retraining alone. On a forelimb reach and grasp task, TADSS animals recovered 63% of their preinjury ability, more than two times the performance level achieved by the other therapy groups. Therapeutic gains were maintained for 3 additional wk without stimulation. The results suggest that activity-dependent spinal stimulation can induce neural plasticity that improves behavioral recovery after spinal cord injury. PMID:26371306

  9. The DEG/ENaC cation channel protein UNC-8 drives activity-dependent synapse removal in remodeling GABAergic neurons

    Miller-Fleming, Tyne W; Petersen, Sarah C; Manning, Laura; Matthewman, Cristina; Gornet, Megan; Beers, Allison; Hori, Sayaka; Mitani, Shohei; Bianchi, Laura; Richmond, Janet; Miller, David M

    2016-01-01

    Genetic programming and neural activity drive synaptic remodeling in developing neural circuits, but the molecular components that link these pathways are poorly understood. Here we show that the C. elegans Degenerin/Epithelial Sodium Channel (DEG/ENaC) protein, UNC-8, is transcriptionally controlled to function as a trigger in an activity-dependent mechanism that removes synapses in remodeling GABAergic neurons. UNC-8 cation channel activity promotes disassembly of presynaptic domains in DD type GABA neurons, but not in VD class GABA neurons where unc-8 expression is blocked by the COUP/TF transcription factor, UNC-55. We propose that the depolarizing effect of UNC-8-dependent sodium import elevates intracellular calcium in a positive feedback loop involving the voltage-gated calcium channel UNC-2 and the calcium-activated phosphatase TAX-6/calcineurin to initiate a caspase-dependent mechanism that disassembles the presynaptic apparatus. Thus, UNC-8 serves as a link between genetic and activity-dependent pathways that function together to promote the elimination of GABA synapses in remodeling neurons. DOI: http://dx.doi.org/10.7554/eLife.14599.001 PMID:27403890

  10. Benchmark Specification for HTGR Fuel Element Depletion

    explicitly represent the dynamics of neutron slowing down in a heterogeneous environment with randomised grain distributions, but traditional tracking simulations can be extremely slow, and the large number of grains in a fuel element may often represent an extreme burden on computational resources. A number of approximations or simplifying assumptions have been developed to simplify the computational process and reduce the effort. Multi-group (MG) methods, on the other hand, require special treatment of DH fuels in order to properly capture resonance effects, and generally cannot explicitly represent a random distribution of grains due to the excessive computational burden resulting from the spatial grain distribution. The effect of such approximations may be important and has potential to misrepresent the spectrum within a fuel grain. Depletion methods utilised in lattice calculations typically rely on point depletion methods, based on the isotopic inventory of fuel depleted, assuming a single localised neutron flux. This flux is generally determined using either a CE or MG transport solver. Hence, in application to DH fuels, the primary factor influencing the accuracy of a depletion calculation will be the accuracy of the local flux calculated within the transport solution and the cross-sections. The current lack of well-qualified experimental measurements for spent HGTR fuel elements limits the validation of advanced DH depletion method. Because of this shortage of data, this benchmark has been developed as the first, simplest phase in a planned series of increasingly complex set of code-to-code benchmarks. The intent of this benchmark is to encourage submission of a wide range of computational results for depletion calculations in a set of basic fuel cell models. Comparison of results using independent methods and data should provide insight into potential limitations in various modelling approximations. The benchmark seeks to provide the simplest possible models, in

  11. A modern depleted uranium manufacturing facility

    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

  12. A modern depleted uranium manufacturing facility

    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.

  13. Simulation of polar ozone depletion: An update

    Solomon, Susan; Kinnison, Doug; Bandoro, Justin; Garcia, Rolando

    2015-08-01

    We evaluate polar ozone depletion chemistry using the specified dynamics version of the Whole Atmosphere Community Climate Model for the year 2011. We find that total ozone depletion in both hemispheres is dependent on cold temperatures (below 192 K) and associated heterogeneous chemistry on polar stratospheric cloud particles. Reactions limited to warmer temperatures above 192 K, or on binary liquid aerosols, yield little modeled polar ozone depletion in either hemisphere. An imposed factor of three enhancement in stratospheric sulfate increases ozone loss by up to 20 Dobson unit (DU) in the Antarctic and 15 DU in the Arctic in this model. Such enhanced sulfate loads are similar to those observed following recent relatively small volcanic eruptions since 2005 and imply impacts on the search for polar ozone recovery. Ozone losses are strongly sensitive to temperature, with a test case cooler by 2 K producing as much as 30 DU additional ozone loss in the Antarctic and 40 DU in the Arctic. A new finding of this paper is the use of the temporal behavior and variability of ClONO2 and HCl as indicators of the efficacy of heterogeneous chemistry. Transport of ClONO2 from the southern subpolar regions near 55-65°S to higher latitudes near 65-75°S provides a flux of NOx from more sunlit latitudes to the edge of the vortex and is important for ozone loss in this model. Comparisons between modeled and observed total column and profile ozone perturbations, ClONO2 abundances, and the rate of change of HCl bolster confidence in these conclusions.

  14. Capstone Depleted Uranium Aerosols: Generation and Characterization

    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.

  15. Depleted Uranium Penetrators : Hazards and Safety

    Rao, S S; T. Balakrishna Bhat

    1997-01-01

    The depleted uranium (DU) alloy is a state-of-the-art material for kinetic energy penetrators due to its superior ballistic performance. Several countries use DU penetrators in their main battle tanks. There is no gamma radiation hazard to the crew members from stowage of DO rounds. Open air firing can result in environmental contamination and associated hazards due to airborne particles containing essentially U/sub 3/0/sub 8/ and UO/sub 2/. Inhalation of polluted air only through resp...

  16. Uranium: myths and realities the depleted uranium

    Uranium is an element whose name causes worry. The uranium properties are very unknown for people. However the element plays an important roll in the Earth as responsible of numerous natural phenomena, which are vital for life evolution. An example of the low knowledge about uranium has been the Balkan syndrome. A relation between cancers and the use of depleted uranium in ammunition in the Balkan War has been pretended to be established. From the beginning, this hypothesis could have been discarded as it has been confirmed and stated in recent reports of UNEP Commissions who have studied this matter. (Author)

  17. Scientific assessment of ozone depletion: 1991

    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.

  18. The Time of Shipbuilding Order Depletion

    Reporter Xing Dan

    2012-01-01

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

  19. Microscopic to macroscopic depletion model development for FORMOSA-P

    Microscopic depletion has been gaining popularity with regard to employment in reactor core nodal calculations, mainly attributed to the superiority of microscopic depletion in treating spectral history effects during depletion. Another trend is the employment of loading pattern optimization computer codes in support of reload core design. Use of such optimization codes has significantly reduced design efforts to optimize reload core loading patterns associated with increasingly complicated lattice designs. A microscopic depletion model has been developed for the FORMOSA-P pressurized water reactor (PWR) loading pattern optimization code. This was done for both fidelity improvements and to make FORMOSA-P compatible with microscopic-based nuclear design methods. Needless to say, microscopic depletion requires more computational effort compared with macroscopic depletion. This implies that microscopic depletion may be computationally restrictive if employed during the loading pattern optimization calculation because many loading patterns are examined during the course of an optimization search. Therefore, the microscopic depletion model developed here uses combined models of microscopic and macroscopic depletion. This is done by first performing microscopic depletions for a subset of possible loading patterns from which 'collapsed' macroscopic cross sections are obtained. The collapsed macroscopic cross sections inherently incorporate spectral history effects. Subsequently, the optimization calculations are done using the collapsed macroscopic cross sections. Using this approach allows maintenance of microscopic depletion level accuracy without substantial additional computing resources

  20. Equatorial airglow depletions induced by thermospheric winds

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

    1985-08-01

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

  1. Equatorial airglow depletions induced by thermospheric winds

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

    1985-08-01

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

  2. Imaging neurotransmitter uptake and depletion in astrocytes

    Tan, W. [Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)]|[Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200 (United States); Haydon, P.G. [Department of Zoology and Genetics, Laboratory of Cellular Signaling, Iowa State University, Ames, Iowa 50011 (United States); Yeung, E.S. [Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)

    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}

  3. Bone marrow scintigraphy in hemopoietic depletion states

    Bone marrow scintigraphy was performed in 29 patients with hemopoietic depletion states of various etiology. Two tracers were used for visualization, viz., sup(99m)Tc-sulfur-colloid and 111InCl3;some patients were examined using both indicators. 111InCl3 is bound to transferrin and is adsorbed on the surface of reticulocytes and erythroblasts. A scintillation camera PHO GAMMA SEARLE IV fitted with a moving table and computer CLINCOM were used to obtain whole-body images. The comparison of all scans and marrow puncture smears was done. In patients with aplastic anemia with both hyperplastic or hypoplastic marrow good correlation of bone marrow scans and sternal puncture smears was found. In several cases the scintigraphic examination helped to establish the diagnosis of marrow depletion. A peculiar disadvantage of the imaging method with either sup(99m)Tc-sulfur-colloid or 111InCl3 is that it shows the disorders in erythropoietic and reticuloendothelial cells whereas the defects in myelopoietic cell series and platelet precursors are not provable. According to literature data, great attention is paid to the prognostic value of scintigraphic examination in aplastic anemia. (author)

  4. Molecular beam depletion: a new approach

    Dorado, Manuel

    2014-01-01

    During the last years some interesting experimental results have been reported for experiments in N20, N0 , N0 dimer , H2 , Toluene and BaFCH3 cluster. The main result consists in the observation of molecular beam depletion when the molecules of a pulsed beam interact with a static electric or magnetic field and an oscillating field (RF). In these cases, and as a main difference, instead of using four fields as in the original technique developed by I.I. Rabi and others, only two fields, those which configure the resonant unit, are used. That is, without using the nonhomogeneous magnetic fields. The depletion explanation for I.I. Rabi and others is based in the interaction between the molecular electric or magnetic dipole moment and the non-homogeneous fields. But, obviously, the change in the molecules trajectories observed on these new experiments has to be explained without considering the force provided by the field gradient because it happens without using non-homogeneous fields. In this paper a theoreti...

  5. Halocarbon ozone depletion and global warming potentials

    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).

  6. Convective Polymer Depletion on Pair Particle Interactions

    Fan, Tai-Hsi; Taniguchi, Takashi; Tuinier, Remco

    2011-11-01

    Understanding transport, reaction, aggregation, and viscoelastic properties of colloid-polymer mixture is of great importance in food, biomedical, and pharmaceutical sciences. In non-adsorbing polymer solutions, colloidal particles tend to aggregate due to the depletion-induced osmotic or entropic force. Our early development for the relative mobility of pair particles assumed that polymer reorganization around the particles is much faster than particle's diffusive time, so that the coupling of diffusive and convective effects can be neglected. Here we present a nonequilibrium two-fluid (polymer and solvent) model to resolve the convective depletion effect. The theoretical framework is based on ground state approximation and accounts for the coupling of fluid flow and polymer transport to better describe pair particle interactions. The momentum and polymer transport, chemical potential, and local viscosity and osmotic pressure are simultaneously solved by numerical approximation. This investigation is essential for predicting the demixing kinetics in the pairwise regime for colloid-polymer mixtures. This work is supported by NSF CMMI 0952646.

  7. The down-stream effects of mannan-induced lectin complement pathway activation depend quantitatively on alternative pathway amplification

    Harboe, Morten; Garred, Peter; Karlstrøm, Ellen;

    2009-01-01

    of AP was not observed even at high mannan concentrations since addition of the inhibiting anti-MBL mAb 3F8 completely abolished generation of the terminal C5b-9 complex (TCC). However, selective blockade of AP by anti-factor D inhibited more than 80% of TCC release into the fluid phase after LP...... activation showing that AP amplification is quantitatively responsible for the final effect of initial specific LP activation. TCC generation on the solid phase was distinctly but less inhibited by anti-fD. C2 bypass of the LP pathway could be demonstrated, and AP amplification was also essential during C2...... bypass in LP as shown by complete inhibition of TCC generation in C2-deficient serum by anti-fD and anti-properdin antibodies. In conclusion, the down-stream effect of LP activation depends strongly on AP amplification in normal human serum and in the C2 bypass pathway....

  8. The solar activity dependence of nonmigrating tides in electron density at low and middle latitudes observed by CHAMP and GRACE

    Zhou, Yun-Liang; Wang, Li; Xiong, Chao; Lühr, Hermann; Ma, Shu-Ying

    2016-04-01

    In this paper we use more than a decade of in situ electron density observations from CHAMP and GRACE satellites to investigate the solar activity dependence of nonmigrating tides at both low and middle latitudes. The results indicate that the longitudinal patterns of F region electron density vary with season and latitude, which are exhibiting a wavenumber 4 (WN4) pattern around September equinox at low latitudes and WN1/WN2 patterns during local summer at the southern/northern middle latitudes. These wave patterns in the F region ionosphere can clearly be seen during both solar maximum and minimum years. At low latitudes the absolute amplitudes of DE3 (contributing to the WN4 pattern) are found to be highly related to the solar activity, showing larger amplitudes during solar maximum years. Similarly a solar activity dependence can also be found for the absolute amplitudes of D0, DW2 and DE1 (contributing to the WN1 and WN2 pattern) at middle latitudes. The relative amplitudes (normalized by the zonal mean) of these nonmigrating tides at both low and middle altitudes show little dependence on solar activity. We further found a clear modulation by the quasi-biennial oscillation (QBO) of the relative DE3 amplitudes in both satellite observations, which is consistent with the QBO dependence as reported for the E region temperatures and zonal wind. It also supports the strong coupling of the low-latitude nonmigrating tidal activity between the E and F regions. However, the QBO dependence cannot be found for the relative amplitudes of the nonmigrating tides at middle latitudes, which implies that these tides are generated in situ at F region altitudes.

  9. TURTLE 24.0 diffusion depletion code

    TURTLE is a two-group, two-dimensional (x-y, x-z, r-z) neutron diffusion code featuring a direct treatment of the nonlinear effects of xenon, enthalpy, and Doppler. Fuel depletion is allowed. TURTLE was written for the study of azimuthal xenon oscillations, but the code is useful for general analysis. The input is simple, fuel management is handled directly, and a boron criticality search is allowed. Ten thousand space points are allowed (over 20,000 with diagonal symmetry). TURTLE is written in FORTRAN IV and is tailored for the present CDC-6600. The program is core-contained. Provision is made to save data on tape for future reference. (auth)

  10. Vacancy Formation Enthalpy in Polycrystalline Depleted Uranium

    Lund, K. R.; Lynn, K. G.; Weber, M. H.; Okuniewski, M. A.

    2013-06-01

    Positron Annihilation Spectroscopy was performed as a function of temperature and beam energy on polycrystalline depleted uranium (DU) foil. Samples were run with varying heat profiles all starting at room temperature. While collecting Doppler-Broadening data, the temperature of the sample was cycled several times. The first heat cycle shows an increasing S-parameter near temperatures of 400K to 500K much lower than the first phase transition of 941K indicating increasing vacancies possibly due to oxygen diffusion from the bulk to the surface. Vacancy formation enthalpies were calculated fitting a model to the data to be 1.6± 0.16 eV. Results are compared to previous work [3,4].

  11. Depleted Uranium Penetrators : Hazards and Safety

    S. S. Rao

    1997-01-01

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

  12. Assessment of exposure to depleted uranium

    In most circumstances, measurement of uranium excreted in urine at known times after exposure is potentially the most sensitive method for determining the amount of depleted uranium (DU) incorporated. The problems associated with this approach are that natural uranium is always present in urine because of the ingestion of natural uranium in food and drink, and that the uncertainties in the intakes as assessed from excretion measurements can be quite large, because many assumptions concerning the exposure characteristics (time pattern of exposure, route of intake, chemical form, solubility, biokinetics within the body) must be made. Applying currently available methods and instruments for the measurement of uranium in urine samples, DU incorporations of levels relevant with respect to potential health hazards can be detected reliably, even a long time after exposure. (author)

  13. Arctic Ozone Depletion from UARS MLS Measurements

    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.

  14. Design optimization using depletion perturbation theory

    Analysis of the fuel cycle performance of a reactor requires knowledge of the entire fuel burnup history. The optimal design depends upon the desired performance parameter or combination of parameters to be minimized (or maximized). The emphasis to date has been to use some combination of iterations involving a number of direct calculations, static perturbation theory, binary exchange methods, and empirical relationships. The object of this study is to demonstrate an approach to optimization based upon Depletion Perturbation Theory (DPT). The DPT equations directly couple the nuclide burnup equations and the neutron balance equations. The equations require the calculation of forward and adjoint solutions for the neutron flux and nuclide transmutations. The application is for analysis of a modular HTGR. The reactor has axially dependent fuel loadings in order to achieve an axial power shape that keeps fuel temperatures below a specified maximum

  15. Depleted Reactor Analysis With MCNP-4B

    Monte Carlo neutronics calculations are mostly done for fresh reactor cores. There is today an ongoing activity in the development of Monte Carlo plus burnup code systems made possible by the fast gains in computer processor speeds. In this work we investigate the use of MCNP-4B for the calculation of a depleted core of the Soreq reactor (IRR-1). The number densities as function of burnup were taken from the WIMS-D/4 cell code calculations. This particular code coupling has been implemented before. The Monte Carlo code MCNP-4B calculates the coupled transport of neutrons and photons for complicated geometries. We have done neutronics calculations of the IRR-1 core with the WIMS and CITATION codes in the past Also, we have developed an MCNP model of the IRR-1 standard fuel for a criticality safety calculation of a spent fuel storage pool

  16. Depleted uranium waste assay at AWE

    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)

  17. The MOD depleted uranium program independent review board : closure report

    B. Smith

    2007-01-01

    This closure report was prepared by the MOD’s Depleted Uranium Independent Review Board (IRB; see Appendix A for membership) and summarises the review board’s general observations in respect of MOD’s depleted uranium research programme and the associated independent review process. The report starts by providing an introduction to MOD’s research programme on the health and environmental consequences of depleted uranium (DU), membership of the IRB, the operation of the review...

  18. Control of Single Molecule Fluorescence Dynamics by Stimulated Emission Depletion

    Marsh, R J; Osborne, M A; Bain, A. J.

    2003-01-01

    The feasibility of manipulating the single molecule absorption-emission cycle using picosecond stimulated emission depletion (STED) is investigated using a stochastic computer simulation. In the simulation the molecule is subjected to repeated excitation and depletion events using time delayed pairs of excitation (PUMP) and depletion (DUMP) pulses derived from a high repetition rate pulsed laser system. The model is used to demonstrate that a significant and even substantial reduction in the ...

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

    张鹤鸣; 戴显英; 张义门; 马晓华; 林大松

    2000-01-01

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

  20. Effect of greenhouse gas emissions on stratospheric ozone depletion

    Velders GJM; LLO

    1997-01-01

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

  1. Development of heavy concrete mixed with depleted uranium

    Compressive strength and shielding performance tests of heavy weight concrete mixed with depleted Uranium (Depleted Uranium Concrete) were carried out. The depleted uranium pellets (φ 8 mm, height 9.5 mm) were mixed into cement paste instead of coarse aggregate. Specimens with nominal specific gravity of 3.2 - 5.4 were manufactured. The results of the compression strength test showed that compressive strength of more than 30 MPa was obtained with the specimens having the nominal specific gravity of more than 5 and it was confirmed from the shielding performance tests that Depleted Uranium Concrete has shielding corresponding to its nominal specific gravity. (author)

  2. Research on using depleted uranium as nuclear fuel for HWR

    The purpose of our work is to find a way for application of depleted uranium in CANDU reactor by using MOX nuclear fuel of depleted U and Pu instead of natural uranium. From preliminary evaluation and calculation, it was shown that MOX nuclear fuel consisting of depleted uranium enrichment tailings (0.25% 235U) and plutonium (their ratio 99.5%:0.5%) could replace natural uranium in CANDU reactor to sustain chain reaction. The prospects of application of depleted uranium in nuclear energy field are also discussed

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

    R Roth; P-M König

    2005-06-01

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

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

    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. Activity-Dependent NPAS4 Expression and the Regulation of Gene Programs Underlying Plasticity in the Central Nervous System

    José Fernando Maya-Vetencourt

    2013-01-01

    Full Text Available The capability of the brain to change functionally in response to sensory experience is most active during early stages of development but it decreases later in life when major alterations of neuronal network structures no longer take place in response to experience. This view has been recently challenged by experimental strategies based on the enhancement of environmental stimulation levels, genetic manipulations, and pharmacological treatments, which all have demonstrated that the adult brain retains a degree of plasticity that allows for a rewiring of neuronal circuitries over the entire life course. A hot spot in the field of neuronal plasticity centres on gene programs that underlie plastic phenomena in adulthood. Here, I discuss the role of the recently discovered neuronal-specific and activity-dependent transcription factor NPAS4 as a critical mediator of plasticity in the nervous system. A better understanding of how modifications in the connectivity of neuronal networks occur may shed light on the treatment of pathological conditions such as brain damage or disease in adult life, some of which were once considered untreatable.

  6. Activity-dependent branching ratios in stocks, solar x-ray flux, and the Bak-Tang-Wiesenfeld sandpile model

    Martin, Elliot; Shreim, Amer; Paczuski, Maya

    2010-01-01

    We define an activity-dependent branching ratio that allows comparison of different time series Xt . The branching ratio bx is defined as bx=E[ξx/x] . The random variable ξx is the value of the next signal given that the previous one is equal to x , so ξx={Xt+1∣Xt=x} . If bx>1 , the process is on average supercritical when the signal is equal to x , while if bxefficient market hypothesis.” For stock volumes, solar x-ray flux intensities, and the Bak-Tang-Wiesenfeld (BTW) sandpile model, bx is supercritical for small values of activity and subcritical for the largest ones, indicating a tendency to return to a typical value. For stock volumes this tendency has an approximate power-law behavior. For solar x-ray flux and the BTW model, there is a broad regime of activity where bx≃1 , which we interpret as an indicator of critical behavior. This is true despite different underlying probability distributions for Xt and for ξx . For the BTW model the distribution of ξx is Gaussian, for x sufficiently larger than 1, and its variance grows linearly with x . Hence, the activity in the BTW model obeys a central limit theorem when sampling over past histories. The broad region of activity where bx is close to one disappears once bulk dissipation is introduced in the BTW model—supporting our hypothesis that it is an indicator of criticality.

  7. Two-Photon Correlation Spectroscopy in Single Dendritic Spines Reveals Fast Actin Filament Reorganization during Activity-Dependent Growth.

    Jian-Hua Chen

    Full Text Available Two-photon fluorescence correlation spectroscopy (2P-FCS within single dendritic spines of living hippocampal pyramidal neurons was used to resolve various subpopulations of mobile F-actin during activity-dependent structural changes such as potentiation induced spine head growth. Two major classes of mobile F-actin were discovered: very dynamic and about a hundred times less dynamic F-actin. Spine head enlargement upon application of Tetraethylammonium (TEA, a protocol previously used for the chemical induction of long-term potentiation (cLTP strictly correlated to changes in the dynamics and filament numbers in the different actin filament fractions. Our observations suggest that spine enlargement is governed by a mechanism in which longer filaments are first cut into smaller filaments that cooperate with the second, increasingly dynamic shorter actin filament population to quickly reorganize and expand the actin cytoskeleton within the spine head. This process would allow a fast and efficient spine head enlargement using a major fraction of the actin filament population that was already present before spine head growth.

  8. Brain-derived neurotrophic factor in arterial baroreceptor pathways: implications for activity-dependent plasticity at baroafferent synapses.

    Martin, Jessica L; Jenkins, Victoria K; Hsieh, Hui-ya; Balkowiec, Agnieszka

    2009-01-01

    Functional characteristics of the arterial baroreceptor reflex change throughout ontogenesis, including perinatal adjustments of the reflex gain and adult resetting during hypertension. However, the cellular mechanisms that underlie these functional changes are not completely understood. Here, we provide evidence that brain-derived neurotrophic factor (BDNF), a neurotrophin with a well-established role in activity-dependent neuronal plasticity, is abundantly expressed in vivo by a large subset of developing and adult rat baroreceptor afferents. Immunoreactivity to BDNF is present in the cell bodies of baroafferent neurons in the nodose ganglion, their central projections in the solitary tract, and terminal-like structures in the lower brainstem nucleus tractus solitarius. Using ELISA in situ combined with electrical field stimulation, we show that native BDNF is released from cultured newborn nodose ganglion neurons in response to patterns that mimic the in vivo activity of baroreceptor afferents. In particular, high-frequency bursting patterns of baroreceptor firing, which are known to evoke plastic changes at baroreceptor synapses, are significantly more effective at releasing BDNF than tonic patterns of the same average frequency. Together, our study indicates that BDNF expressed by first-order baroreceptor neurons is a likely mediator of both developmental and post-developmental modifications at first-order synapses in arterial baroreceptor pathways. PMID:19054281

  9. Observed and simulated depletion layers with southward IMF

    N. C. Maynard

    2004-06-01

    Full Text Available We present observations from the Polar satellite that confirm the existence of two types of depletion layers predicted under southward interplanetary magnetic field (IMF conditions in magnetohydrodynamic simulations. The first depletion type occurs along the stagnation line when IMF BX and/or dipole tilt are/is present. Magnetic merging occurred away from the equator (Maynard et al., 2003 and flux pile-ups developed while the field lines drape to the high-latitude merging sites. This high-shear type of depletion is consistent with the depletion layer model suggested by Zwan and Wolf (1976 for low-shear northward IMF conditions. Expected sites for depletion layers are associated with places where IMF tubes of force first impinge upon the magnetopause. The second depletion type develops poleward of the cusp. Under strongly driven conditions, magnetic fields from Region 1 current closure over the lobes (Siscoe et al., 2002c cause the high-latitude magnetopause to bulge outward, creating a shoulder above the cusp. These shoulders present the initial obstacle with which the IMF interacts. Flow is impeded, causing local flux pile-ups and low-shear depletion layers to form poleward of the cusps. Merging at the high-shear dayside magnetopause is consequently delayed. In both low- and high-shear cases, we show that the depletion layer structure is part of a slow mode wave standing in front of the magnetopause. As suggested by Southwood and Kivelson (1995, the depletions are rarefactions on the magnetopause side of slow-mode density compressions. While highly sheared magnetic fields are often used as proxies for ongoing local magnetic merging, depletion layers are prohibited at merging locations. Therefore, the existence of a depletion layer is evidence that the location of merging must be remote relative to the observation.

  10. Decommissioning plan depleted uranium manufacturing facility

    Aerojet Ordnance Tennessee, Inc. (Aerojet) is decommissioning its California depleted uranium (DU) manufacturing facility. Aerojet has conducted manufacturing and research and development activities at the facility since 1977 under a State of California Source Materials License. The decontamination is being performed by a contractor selector for technical competence through competitive bid. Since the facility will be released for uncontrolled use it will be decontaminated to levels as low as reasonably achievable (ALARA). In order to fully apply the principles of ALARA, and ensure the decontamination is in full compliance with appropriate guides, Aerojet has retained Rogers and Associaties Engineering Corporation (RAE) to assist in the decommissioning. RAE has assisted in characterizing the facility and preparing contract bid documents and technical specifications to obtain a qualified decontamination contractor. RAE will monitor the decontamination work effort to assure the contractor's performance complies with the contract specifications and the decontamination plan. The specifications require a thorough cleaning and decontamination of the facility, not just sufficient cleaning to meet the numeric cleanup criteria

  11. Nitrogen chemistry and depletion in starless cores

    Hily-Blant, Pierre; forêts, G Pineau Des; Flower, David

    2010-01-01

    We investigated the chemistry of nitrogen--containing species, principally isotopomers of CN, HCN, and HNC, in a sample of pre-protostellar cores. We used the IRAM 30 m telescope to measure the emission in rotational and hyperfine transitions of CN, HCN, 13CN, H13CN, HN13C, and HC15N, in L 1544, L 183, Oph D, L 1517B, L 310. The observations were made along axial cuts through the dust emission peak, at a number of regularly--spaced offset positions. The observations were reduced and analyzed to obtain the column densities, using the measurements of the less abundant isotopic variants in order to minimize the consequences of finite optical depths in the lines. The observations were compared with the predictions of a free--fall gravitational collapse model, which incorporates a non-equilibrium treatment of the relevant chemistry. We found that CN, HCN, and HNC remain present in the gas phase at densities well above that at which CO depletes on to grains. The CN:HCN and the HNC:HCN abundance ratios are larger th...

  12. Levels of depleted uranium in Kosovo soils

    The United Nations Environment Programme 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.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. (author)

  13. Supercontinuum Stimulated Emission Depletion Fluorescence Lifetime Imaging

    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.

  14. Levels of depleted uranium in Kosovo soils

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

    2001-07-01

    The United Nations Environment Programme 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 {sup 234}U/{sup 238}U and {sup 235}U/{sup 238}U activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of {sup 238}U activity concentrations in soils above 100 Bq.kg{sup -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. (author)

  15. Use, effects and legal standing of depleted uranium munitions

    The paper provides a brief description of depleted uranium and its use in weapons. Several exposure scenarios are described, and examples of the use of DU ammunition in training, testing, and combat are provided. A summary of depleted uranium's health and environmental effects follows, and the paper concludes with a brief analysis of the legal standing of DU munitions under international humanitarian law

  16. Effect of greenhouse gas emissions on stratospheric ozone depletion

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric i

  17. Surface depletion in the vacuum distillation of metals from bismuth

    Surface depletion was investigated in laboratory- and plant-scale distillation units with mixing by natural convection or by mechanical surface agitation. A model was developed for predicting the degree of surface depletion during the distillation of metals from bismuth as a function of temperature, still pot dimensions, and degree of agitation. This paper discusses those findings

  18. Mineralized water depleted in deuterium and production technique

    Mineralized water depleted in deuterium is similar to natural water but has an isotopic content of 30-120 ppm D/(D+H). One can obtain mineralized water depleted in deuterium both in continuous and in discontinuous way by mixing deuterium depleted water with strong mineralized water obtained by vacuum distillation at atmospheric pressure of natural water. The mixture is saturated with oxygen by bubbling dry air into it at ambient temperature. This invention allows obtaining a product depleted in deuterium similar to natural water with biostimulating properties that can be used as developing medium for living organisms or for human use. The invention has the following qualities: allows the production of deuterium depleted water with chemical composition similar to natural water; allows the precise control of deuterium content in the product. (authors)

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

    Lauran van Oers

    2016-03-01

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

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

    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.

  1. Barium depletion study on impregnated cathodes and lifetime prediction

    Roquais, J. M.; Poret, F.; le Doze, R.; Ricaud, J. L.; Monterrin, A.; Steinbrunn, A.

    2003-06-01

    In the thermionic cathodes used in cathode ray-tubes (CRTs), barium is the key element for the electronic emission. In the case of the dispenser cathodes made of a porous tungsten pellet impregnated with Ba, Ca aluminates, the evaporation of Ba determines the cathode lifetime with respect to emission performance in the CRT. The Ba evaporation results in progressive depletion of the impregnating material inside the pellet. In the present work, the Ba depletion with time has been extensively characterized over a large range of cathode temperature. Calculations using the depletion data allowed modeling of the depletion as a function of key parameters. The link between measured depletion and emission in tubes has been established, from which an end-of-life criterion was deduced. Taking modeling into account, predicting accelerated life-tests were performed using high-density maximum emission current (MIK).

  2. Barium depletion study on impregnated cathodes and lifetime prediction

    In the thermionic cathodes used in cathode ray-tubes (CRTs), barium is the key element for the electronic emission. In the case of the dispenser cathodes made of a porous tungsten pellet impregnated with Ba, Ca aluminates, the evaporation of Ba determines the cathode lifetime with respect to emission performance in the CRT. The Ba evaporation results in progressive depletion of the impregnating material inside the pellet. In the present work, the Ba depletion with time has been extensively characterized over a large range of cathode temperature. Calculations using the depletion data allowed modeling of the depletion as a function of key parameters. The link between measured depletion and emission in tubes has been established, from which an end-of-life criterion was deduced. Taking modeling into account, predicting accelerated life-tests were performed using high-density maximum emission current (MIK)

  3. Regulation of new depleted uranium uses

    This report evaluates how the existing U.S. Nuclear Regulatory Commission (NRC) regulatory structure and pending modifications would affect full deployment into radiologically uncontrolled areas of certain new depleted uranium (DU) uses being studied as part of the U.S. Department of Energy's DU uses research and development program. Such new DU uses include as catalysts (for destroying volatile organic compounds in off-gases from industrial processes and for hydrodesulfurization [HDS] of petroleum fuels), semiconductors (for fabricating integrated circuits, solar cells, or thermoelectric devices, especially if such articles are expected to have service in hostile environments), and electrodes (for service in solid oxide fuel cells, in photoelectrochemical cells used to produce hydrogen, and in batteries). The report describes each new DU use and provides a detailed analysis of whether any existing NRC licensing exemption or general license would be available to users of products and devices manufactured to deploy the new use. Although one existing licensing exemption was found to be possibly available for catalysts used for HDS of petroleum fuels and one general license was found to be possibly available for catalysts, semiconductors, and electrodes used in hydrogen production or batteries, existing regulations would require most users of products and devices deploying new DU uses to obtain specific source material licenses from the NRC or an Agreement State. This situation would not be improved by pending regulatory modifications. Thus, deployment of new DU uses may be limited because persons having no previous experience with NRC or Agreement State regulations may be hesitant to incur the costs and inconvenience of regulatory compliance, unless using a DU-containing product or device offers a substantial economic benefit over nonradioactive alternatives. Accordingly, estimating the risk of deploying new DU-containing products and devices in certain

  4. Depletion of ozone layer in the stratosphere

    Ozone is a minor and naturally produced component in the stratosphere which encircles the earth some 15 to 45 Km above its surface. It is not an abundant chemical in the atmosphere but it is highly significant due to its property of shielding the earth from much of the potentially damaging ultraviolet radiation coming from the sun. Should ozone disappear, the earth would become uninhabitable for most forms of life. Due to this property, ozone depletion in the stratosphere is now recognized as a major environmental problem with potentially catastrophic effects. Approximately 90% of ozone is found in the stratosphere where its peak concentrations are about 300 ppb. The altitude of peak concentrations varies from about 25 Km near the equator to approximately 15 Km in the polar region (Botkin and Keller, 1995). Ozone concentration is measured in Dobson Units (D.U.) One D.U. is equivalent to a concentration of 1 ppb of ozone. If brought to normal pressure at sea level, all of the existing atmospheric ozone would form a band of no more than 3 mm thick around the earth. (Kemp. 1994). Concentrations of ozone in the stratosphere have been measured for more than 70 years. Today there is nearly a 30-years record of ozone concentrations available from more than 30 locations around the world. It was found that in the Antarctic zone, the ozone concentrations, taken each year in October, decreased from 300 D.U. in 1970 to 200 D.U. in 1984 and a low of about 90 D.U. in 1993. The records indicate that the ozone concentrations in the stratosphere have been decreasing since mid 1960s. (Botkin and Keller, 1995). The concentration of ozone in Polar Regions is more than that near equator. In fact much of ozone is produced near the equator but moves from equator towards poles with global circulation patterns which are not well understood. (author)

  5. Deuterium depleted water. Present applications and prospects

    The deuterium depleted water, DDW, is distilled, microbiologically pure water with an isotopic concentration D/(D+H) under 145 ppm, the natural water value. At ICSI Rm Valcea a procedure was developed and a patent was recorded for the method and installation for obtaining DDW. The procedure consists in vacuum distillation of natural water on columns equipped with highly performing ordered packing. The system allows obtaining DDW at isotopic concentration within the range 20-120 ppm. Biological studies showed that treatment with this DDW reduced significantly the high rate in L929 linear fibroblast cells and annihilated the tumoral growth in xenotransplant. It was suggested that the deuterium occurring naturally has an essential in converting the signals regulating the cellular cycling. A vast program based on collaborations of ICSI with different specialized research institutes in Romania was initiated and important results already obtained among which one can mention: - DDW determines an increase of vascular reactivity seemingly endotelio-dependent and implying radical species (superoxides, nitric oxides); - immunity defense reaction represented by the opsonic, bactericide and phagocytic capacity are stimulated; - animals pre-treated with DDW present an increased resistance to both sub-lethal and lethal doses of gamma radiations, suggesting a radioprotective property; - study of artificial fecundation in fishes with fecundating solution containing an 1:1 mixture of DDW and distilled water showed the beneficent effects both in embryonal development and growth in alevins; - an increase of metabolism rate in aquatic macrophytes following the dilution of spectral energy of sea water mixed with DDW was observed; - studies on three genotypes of Zea mays showed significant effects on coleoptile growth. At present programs for studying prevention and treatment of tumors and various cancer forms are underway

  6. Barium Depletion in Hollow Cathode Emitters

    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.

  7. Removal of depleted uranium from contaminated soils

    Contamination of soil and water with depleted uranium (DU) has increased public health concerns due to the chemical toxicity of DU at elevated dosages. For this reason, there is great interest in developing methods for DU removal from contaminated sources. Two DU laden soils, taken from U.S. Army sites, were characterized for particle size distribution, total uranium concentration and removable uranium. Soil A was found to be a well graded sand containing a total of 3210 mg/kg DU (3.99 x 104 Bq/kg, where a Becquerel (Bq) is a unit of radiation). About 83% of the DU in the fines fraction (particle diameter 4 Bq/kg)) was associated with the carbonate, iron and manganese oxide and organic matter fractions of the material. Soil B was classified as a sandy silt with total DU of 1560 mg/kg (1.94 x 104 Bq/kg). The DU content in the fines fraction was 5171 mg/kg (6.43 x 104 Bq/kg). Sequential extraction of the Soil B fines fraction indicated that 64% of the DU was present either as soluble U(VI) minerals or as insoluble U(IV). Citric acid, sodium bicarbonate and hydrogen peroxide were used in batch experiments to extract DU from the fines fraction of both soils. Citric acid and sodium bicarbonate were relatively successful for Soil A (50-60% DU removal), but not for Soil B (20-35% DU removal). Hydrogen peroxide was found to significantly increase DU extraction from both soils, attaining removals up to 60-80%

  8. Biological effects of deuterium - depleted water

    Deuterium-depleted water (DDW) is represented by water that has an isotopic content smaller than 145 ppm D/(D + H). DDW production technique consists in the separation of deuterium from water by a continuous distillation process under pressure of about 133.3 mbar. The water used as raw material has a isotopic content of 145 ppm D/(D + H) and can be demineralized water, distillated water or condensed-steam. DDW results as a distillate with an isotopic deuterium content of 15-80 ppm, depending on the level we want to achieve. Beginning with 1996 the Institute of Cryogenics and Isotopic Technologies, DDW producer, co-operated with Romanian specialized institutes for studying the biological effects of DDW. The role of naturally occurring D in living organisms was examined by using DDW instead of natural water. These investigations led to the following conclusions: - DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the DDW persists after the removal of the vascular endothelium; - Animals treated with DDW showed an increase of the resistance both to sublethal and lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defense mechanisms; - DDW stimulates immuno-defense reactions represented by the opsonic, bactericidal and phagocyte capacity of the immune system together with an increase in the number of poly-morphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favorable influence in embryo growth stage and resistance and following growth stages; - It was studied germination, growth and quantitative character variability in plants; one can remark the favorable influence of DDW on biological processes in plants in various ontogenetic stages. (authors)

  9. Deuterium depleted water. Romanian achievements and prospects

    The deuterium depleted water (DDW) is microbiologically pure distilled water with a deuterium content lower than that of natural waters which amounts to 140 - 150 ppm D/(D+H); variations depend on geographical zone and altitude. The procedure of obtaining DDW is based on isotopic separation of natural water by vacuum distillation. Isotope concentration can be chosen within 20 to 120 ppm D/(D+H). The ICSI at Rm. Valcea has patented the procedure and equipment for the production of DDW. According to the document SF-01-2002/INC-DTCI - ICSI Rm. Valcea, the product has a D/(D+H) isotope concentration of 25 ± 5. Studies and research for finding the effects and methods of application in different fields were initiated and developed in collaboration with different institutes in Romania. The following important results obtained so far could be mentioned: - absence of toxicity upon organisms; - activation of vascular reactivity; - enhancement of defence capacity of the organism through non-specific immunity activation; - increase of salmonid reproduction capacity and enhancement of the adaptability of alevins to the environmental conditions; - radioprotective effect to ionizing radiation; - maintaining meat freshness through osmotic shock; - stimulation of growth of aquatic macrophytes; - enhancement of culture plant development in certain ontogenetic stages. Mostly, the results and practical applications of the research were patented and awarded with gold medals at international invention fairs. At present, research-development programmes are undergoing to find active biological features of DDW in fighting cancer, on one hand, and its applicability as food additive of pets or performing animals, on the other hand

  10. Determination of depleted uranium in fish

    Depleted uranium (DU) is a by-product of the uranium enrichment process for nuclear fuel. According to the Commission Decision 2002/657/EC, a confirmatory method for the quantification of DU in freeze-dried fish was developed by isotope ratio dynamic reaction cell inductively coupled plasma-mass spectrometry (IR-DRC-ICP-MS). A preliminary study was performed to determine the following parameters: instrumental detection limit (IDL), isotopic ratio measurement limit (IRML), percentage of DU (PDU) in presence of natural uranium (NU) and limit of quantification (LoQDU). The analyses were carried out by means of IR-DRC-ICP-MS. Ammonia was the reaction gas used for the dynamic reaction cell. In addition, a sector field inductively coupled plasma mass spectrometer (SF-ICP-MS) was employed to calculate the within-laboratory reproducibility. For the confirmatory method the following parameters were determined: (a) trueness; (b) precision; (c) critical concentrations alpha and beta (CCα, CCβ); (d) specificity; (e) stability. Trueness was assessed by using the recovery tests. The recovery and within-laboratory reproducibility were determined by fortifying the blank digested solution of dogfish tissue: six aliquots were fortified at 1, 1.5 and 2 times the LOQDU with 25.0, 37.5 and 50.0 ng L-1 or 4.16, 6.24, 8.32 μg kg-1 with a recovery of -8.2, +9.5 and +9.6%, respectively and a within-laboratory reproducibility (three analytical run) of 15.5, 8.0 and 11.0%, respectively. The results for the decision limit and the detection capability were: CCα = 11.69 ng L-1 and CCβ = 19.8 ng L-1. The digested solutions resulted to be stable during testing time (60 days) and the method can be considered highly specific as well

  11. Impact of ozone depletion on immune function

    Jeevan, A.; Kripke, M.L. (Univ. of Texas, Houston, TX (United States). Dept. of Immunology)

    1993-06-01

    Depletion of stratospheric ozone is expected to lead to an increase in the amount of UV-B radiation present in sunlight. In addition to its well known ability to cause skin cancer, UV-B radiation has been shown to alter the immune system. The immune system is the body's primary defense mechanism against infectious diseases and protects against the development of certain types of cancer. Any impairment of immune function may jeopardize health by increasing susceptibility to infectious diseases, increasing the severity of infections, or delaying recovery for infections. In addition, impaired immune function can increase the incidence of certain cancers, particularly cancers of the skin. Research carried out with laboratory animals over the past 15 years has demonstrated that exposure of the skin to UV-B radiation can suppress certain types of immune responses. These include rejection of UV-induced skin cancers and melanomas, contact allergy reactions to chemicals, delayed-type hypersensitivity responses to microbial and other antigens, and phagocytosis and elimination of certain bacteria from lymphoid tissues. Recent studies with mycobacterial infection of mice demonstrated that exposure to UV-B radiation decreased the delayed hypersensitivity response to mycobacterial antigens and increased the severity of infection. In humans, UV-B radiation has also been shown to impair the contact allergy response. These studies demonstrate that UV radiation can decrease immune responses in humans and laboratory and raise the possibility that increased exposure to UV-B radiation could adversely affect human health by increasing the incidence or severity of certain infectious diseases.

  12. Ozone Depletion Potential of CH3Br

    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.

  13. Multi-timescale modeling of activity-dependent metabolic coupling in the neuron-glia-vasculature ensemble.

    Jolivet, Renaud; Coggan, Jay S; Allaman, Igor; Magistretti, Pierre J

    2015-02-01

    Glucose is the main energy substrate in the adult brain under normal conditions. Accumulating evidence, however, indicates that lactate produced in astrocytes (a type of glial cell) can also fuel neuronal activity. The quantitative aspects of this so-called astrocyte-neuron lactate shuttle (ANLS) are still debated. To address this question, we developed a detailed biophysical model of the brain's metabolic interactions. Our model integrates three modeling approaches, the Buxton-Wang model of vascular dynamics, the Hodgkin-Huxley formulation of neuronal membrane excitability and a biophysical model of metabolic pathways. This approach provides a template for large-scale simulations of the neuron-glia-vasculature (NGV) ensemble, and for the first time integrates the respective timescales at which energy metabolism and neuronal excitability occur. The model is constrained by relative neuronal and astrocytic oxygen and glucose utilization, by the concentration of metabolites at rest and by the temporal dynamics of NADH upon activation. These constraints produced four observations. First, a transfer of lactate from astrocytes to neurons emerged in response to activity. Second, constrained by activity-dependent NADH transients, neuronal oxidative metabolism increased first upon activation with a subsequent delayed astrocytic glycolysis increase. Third, the model correctly predicted the dynamics of extracellular lactate and oxygen as observed in vivo in rats. Fourth, the model correctly predicted the temporal dynamics of tissue lactate, of tissue glucose and oxygen consumption, and of the BOLD signal as reported in human studies. These findings not only support the ANLS hypothesis but also provide a quantitative mathematical description of the metabolic activation in neurons and glial cells, as well as of the macroscopic measurements obtained during brain imaging. PMID:25719367

  14. Activity-dependent endogenous taurine release facilitates excitatory neurotransmission in the neocortical marginal zone of neonatal rats

    Taizhe eQian

    2014-02-01

    Full Text Available In the developing cerebral cortex, the marginal zone (MZ, consisting of early-generated neurons such as Cajal-Retzius cells, plays an important role in cell migration and lamination. There is accumulating evidence of widespread excitatory neurotransmission mediated by γ-aminobutyric acid (GABA in the MZ. Cajal-Retzius cells express not only GABAA receptors but also α2/β subunits of glycine receptors, and exhibit glycine receptor-mediated depolarization due to high [Cl−]i. However, the physiological roles of glycine receptors and their endogenous agonists during neurotransmission in the MZ are yet to be elucidated. To address this question, we performed optical imaging from the MZ using the voltage-sensitive dye JPW1114 on tangential neocortical slices of neonatal rats. A single electrical stimulus evoked an action-potential-dependent optical signal that spread radially over the MZ. The amplitude of the signal was not affected by glutamate receptor blockers, but was suppressed by either GABAA or glycine receptor antagonists. Combined application of both antagonists nearly abolished the signal. Inhibition of Na+, K+-2Cl− cotransporter by 20 µM bumetanide reduced the signal, indicating that this transporter contributes to excitation. Analysis of the interstitial fluid obtained by microdialysis from tangential neocortical slices with high-performance liquid chromatography revealed that GABA and taurine, but not glycine or glutamate, were released in the MZ in response to the electrical stimulation. The ambient release of taurine was reduced by the addition of a voltage-sensitive Na+ channel blocker. Immunohistochemistry and immunoelectron microscopy indicated that taurine was stored both in Cajal-Retzius and non-Cajal-Retzius cells in the MZ, but was not localized in presynaptic structures. Our results suggest that activity-dependent non-synaptic release of endogenous taurine facilitates excitatory neurotransmission through activation of

  15. Activity-dependent release of endogenous brain-derived neurotrophic factor from primary sensory neurons detected by ELISA in situ.

    Balkowiec, A; Katz, D M

    2000-10-01

    To define activity-dependent release of endogenous brain-derived neurotrophic factor (BDNF), we developed an in vitro model using primary sensory neurons and a modified ELISA, termed ELISA in situ. Dissociate cultures of nodose-petrosal ganglion cells from newborn rats were grown in wells precoated with anti-BDNF antibody to capture released BDNF, which was subsequently detected using conventional ELISA. Conventional ELISA alone was unable to detect any increase in BDNF concentration above control values following chronic depolarization with 40 mM KCl for 72 hr. However, ELISA in situ demonstrated a highly significant increase in BDNF release, from 65 pg/ml in control to 228 pg/ml in KCl-treated cultures. The efficacy of the in situ assay appears to be related primarily to rapid capture of released BDNF that prevents BDNF binding to the cultured cells. We therefore used this approach to compare BDNF release from cultures exposed for 30 min to either continuous depolarization with elevated KCl or patterned electrical field stimulation (50 biphasic rectangular pulses of 25 msec, at 20 Hz, every 5 sec). Short-term KCl depolarization was completely ineffective at evoking any detectable release of BDNF, whereas patterned electrical stimulation increased extracellular BDNF levels by 20-fold. In addition, the magnitude of BDNF release was dependent on stimulus pattern, with high-frequency bursts being most effective. These data indicate that the optimal stimulus profile for BDNF release resembles that of other neuroactive peptides. Moreover, our findings demonstrate that BDNF release can encode temporal features of presynaptic neuronal activity. PMID:11007900

  16. Multi-timescale Modeling of Activity-Dependent Metabolic Coupling in the Neuron-Glia-Vasculature Ensemble

    Jolivet, Renaud

    2015-02-26

    Glucose is the main energy substrate in the adult brain under normal conditions. Accumulating evidence, however, indicates that lactate produced in astrocytes (a type of glial cell) can also fuel neuronal activity. The quantitative aspects of this so-called astrocyte-neuron lactate shuttle (ANLS) are still debated. To address this question, we developed a detailed biophysical model of the brain’s metabolic interactions. Our model integrates three modeling approaches, the Buxton-Wang model of vascular dynamics, the Hodgkin-Huxley formulation of neuronal membrane excitability and a biophysical model of metabolic pathways. This approach provides a template for large-scale simulations of the neuron-glia-vasculature (NGV) ensemble, and for the first time integrates the respective timescales at which energy metabolism and neuronal excitability occur. The model is constrained by relative neuronal and astrocytic oxygen and glucose utilization, by the concentration of metabolites at rest and by the temporal dynamics of NADH upon activation. These constraints produced four observations. First, a transfer of lactate from astrocytes to neurons emerged in response to activity. Second, constrained by activity-dependent NADH transients, neuronal oxidative metabolism increased first upon activation with a subsequent delayed astrocytic glycolysis increase. Third, the model correctly predicted the dynamics of extracellular lactate and oxygen as observed in vivo in rats. Fourth, the model correctly predicted the temporal dynamics of tissue lactate, of tissue glucose and oxygen consumption, and of the BOLD signal as reported in human studies. These findings not only support the ANLS hypothesis but also provide a quantitative mathematical description of the metabolic activation in neurons and glial cells, as well as of the macroscopic measurements obtained during brain imaging.

  17. Cost estimate report for the long-term management of depleted uranium hexafluoride : storage of depleted uranium metal

    This report contains a cost analysis of the long-term storage of depleted uranium in the form of uranium metal. Three options are considered for storage of the depleted uranium. These options are aboveground buildings, partly underground vaults, and mined cavities. Three cases are presented. In the first case, all the depleted uranium metal that would be produced from the conversion of depleted uranium hexafluoride (UF6) generated by the US Department of Energy (DOE) prior to July 1993 would be stored at the storage facility (100% Case). In the second case, half the depleted uranium metal would be stored at this storage facility (50% Case). In the third case, one-quarter of the depleted uranium metal would be stored at the storage facility (25% Case). The technical basis for the cost analysis presented in this report is principally found in the companion report, ANL/EAD/TM-100, ''Engineering Analysis Report for the Long-Term Management of Depleted Uranium Hexafluoride: Storage of Depleted Uranium Metal'', prepared by Argonne National Laboratory

  18. Deuterium depleted water. Current and potential applications

    Deuterium depleted water (DDW) is distilled, microbiologically pure water with a D/(D+H) isotopic content lower than the value 145 ppm of natural water. It is practically unnoxious, with a toxic potential pT 50 > 0.01 mol/kg c.m. At ICSI a procedure was worked out and patented and a facility was achieved for obtaining DDW. The procedure consists in continuous vacuum distillation of natural water on columns with highly performing ordered packings. DDW of controlled isotopic concentration D/(D+H) within the range 20-120 ppm, of quality similar to distilled water can be currently produced. Many studies were reported in literature evidencing the active biological properties of DDW. DDW lowered significantly the high division rate of the L929 linear fibroblast cell and blocked the tumoral growth in xenotransplants. It was suggested that the naturally occurring deuterium plays a prominent role in converting the signal implied in cellular cycle mechanism. Having in view the high significance of the experiments in this field, ICSI has promoted a programme of collaborations with Romanian institutes of various specialties to evaluate the biological effects of DDW with a D/(D+H) concentration of about 30 ppm. The following results obtained so far obtained should be highlighted: - DDW causes an increase of vascular reactivity both in rings isolated from thorax aorta and in vivo upon arterial pressure. The reactivity increase seems to be endothelium-depended and is achieved with participation of the radical species (superoxides, nitric oxide); - DDW stimulates the immunodefence reaction, as represented by the opsonic, bactericide and phagocytic capacity of the immunity system as well as by the increase of the number of polymorphonucleates; - animals pre-treated with DDW exhibit an increased resistance both to sublethal and lethal γ radiation doses, what suggests a radioprotective effect; - studies on artificial fecundation in fishes with fecundant solutions containing a 1

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

    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.

  20. Observations of TEC Depletions in South and Central America

    Valladares, C. E.; Sheehan, R. E.; Pradipta, R.

    2014-12-01

    TEC values gathered with several networks of GPS receivers, which operated in South and Central America and the Caribbean region between 2010 and 2013, have been used to investigate the characteristics and morphology of TEC depletions that develop at these locations. In South America the TEC depletions are associated with low-latitude plasma bubbles. In Central America and the Caribbean region, we found that TEC depletions that occur during magnetically active conditions (Kp > 5o), persist for very long periods and sometimes remain even during afternoon hours. During quiet magnetic conditions, TEC depletions occur around the June solstice in Central America and during the December solstice in the Southern part of South America. We have also studied possible links between mid-latitude depletions and the formation of plasma bubbles at low latitudes. In addition, TEC measurements from North America have been utilized to determine the poleward extension of the mid-latitude depletions. These depletions do not appear to be related to auroral plasma processes or to storm enhanced densities (SED). We are studying the possibility that their initiation process is associated with the disturbance dynamo or the prompt penetrating electric field that develop during storm conditions.

  1. Development of the point-depletion code DEPTH

    Highlights: ► The DEPTH code has been developed for the large-scale depletion system. ► DEPTH uses the data library which is convenient to couple with MC codes. ► TTA and matrix exponential methods are implemented and compared. ► DEPTH is able to calculate integral quantities based on the matrix inverse. ► Code-to-code comparisons prove the accuracy and efficiency of DEPTH. -- Abstract: The burnup analysis is an important aspect in reactor physics, which is generally done by coupling of transport calculations and point-depletion calculations. DEPTH is a newly-developed point-depletion code of handling large burnup depletion systems and detailed depletion chains. For better coupling with Monte Carlo transport codes, DEPTH uses data libraries based on the combination of ORIGEN-2 and ORIGEN-S and allows users to assign problem-dependent libraries for each depletion step. DEPTH implements various algorithms of treating the stiff depletion systems, including the Transmutation trajectory analysis (TTA), the Chebyshev Rational Approximation Method (CRAM), the Quadrature-based Rational Approximation Method (QRAM) and the Laguerre Polynomial Approximation Method (LPAM). Three different modes are supported by DEPTH to execute the decay, constant flux and constant power calculations. In addition to obtaining the instantaneous quantities of the radioactivity, decay heats and reaction rates, DEPTH is able to calculate the integral quantities by a time-integrated solver. Through calculations compared with ORIGEN-2, the validity of DEPTH in point-depletion calculations is proved. The accuracy and efficiency of depletion algorithms are also discussed. In addition, an actual pin-cell burnup case is calculated to illustrate the DEPTH code performance in coupling with the RMC Monte Carlo code

  2. Solution of depletion chain equations using nonsingular Bateman coefficients

    The exact solution of the depletion chain equations for arbitrary values of depletion constants is obtained. New nonsingular coefficients are introduced, and recurrence formulas that provide an efficient and accurate method of calculation are derived. Generality and simplicity of the method are found to be useful in evaluating depletion chains with one hundred or more nuclides in the chain, such as the s-process chain in studies of nucleosynthesis by neutron capture. The method can also be used to check the validity of approximate solutions

  3. Iron Depletion into Dust Grains in Galactic Planetary Nebulae

    Delgado-Inglada, G

    2010-01-01

    We present preliminary results of an analysis of the iron depletion factor into dust grains for a sample of 20 planetary nebulae (PNe) from the Galactic bulge. We compare these results with the ones we obtained in a prior analysis of 28 Galactic disk PNe and 8 Galactic H II regions. We derive high depletion factors in all the objects, suggesting that more than 80% of their iron atoms are condensed into dust grains. The range of iron depletions in the sample PNe covers about two orders of magnitude, and we explore here if the differences are related to the PN morphology. However, we do not find any significant correlation.

  4. Groundwater depletion in the United States (1900-2008)

    U.S. Geological Survey, Department of the Interior — A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion in...

  5. The Role of Gluon Depletion in J/$\\psi$ Suppression

    Hwa, R C; Pisútová, N

    1997-01-01

    The depletion of gluons as the parton flux traverses a nucleus in a heavy-ion collision can influence the production rate of heavy-quark states. Thus the suppression of $J/\\psi$ can be due to gluon depletion in the initial state in addition to nuclear and hadronic absorption in the final state. A formalism is developed to describe the depletion effect. It is shown that, without constraints from other experimental facts beside the $J/\\psi$ suppression data in $pA$ and $AB$ collisions, it is not possible to determine the relative importance of depletion vs absorption. Possible relevance to the enhanced suppression seen in the $Pb - Pb$ data is mentioned but not studied.

  6. TISSUE DISTRIBUTION AND RESIDUE DEPLETION OF OXYTETRACYCLINE IN THE RABBIT

    Villa, R.; Cagnardi, P; Bacchetta, P.; Sonzogni, O.; Faustini, M.; Carli, S.

    2001-01-01

    Abstract not available. Villa, R.; Cagnardi, P.; Bacchetta, P.; Sonzogni, O.; Faustini, M.; Carli, S. (2001). TISSUE DISTRIBUTION AND RESIDUE DEPLETION OF OXYTETRACYCLINE IN THE RABBIT. http://hdl.handle.net/10251/10016.

  7. Verification of Depleted Uranium in non-Nuclear use

    The present work describes a system for the verification of depleted uranium-being recognized by the International Atomic Energy as a Nuclear which should be accounted for and put under Nuclear Safeguards even if it is used for non-nuclear applications such as in shielding against gamma radiation in Radiotherapy facilities, industrial radiography systems or as counterweights in air craft. Measurement of depleted uranium is performed by employing Non-Destructive Assay techniques, which use a gamma-ray spectrometer system and/or a neutron coincidence counter system. Results show that the used techniques can detect the presence of depleted uranium in the investigated materials. Also, quantitative values of U-235 enrichment and mass content of the assayed material could be obtained with a precision of better than 7%. This work would find important applications for the verification and control of depleted uranium for the purposes of Nuclear Safeguards

  8. Mass measurement of depleted uranium components with coincidence neutron count

    The technique of the mass measurement of depleted uranium components was studied with active and passive coincidence neutron count. A well neutron coincidence counter was used to measure the coincidence neutron counts of the depleted uranium components with various mass. Am-Be source was selected as the external neutron source for induced fission in the active measurement, and a shield was optimized to reduce the accidental coincidence counts. In the active measurement, the maximum relative deviation of the linear fit mass from the nominal mass of the depleted uranium components is 11.71%, compared to 4.05% in the passive measurement. It is proved that because of the weakening of the shape influence, the passive method is more accurate and reliable to measure the mass of depleted uranium components than the active method. (authors)

  9. Prediction Method of Safety Mud Density in Depleted Oilfields

    Yuan Jun-Liang

    2013-04-01

    Full Text Available At present, many oilfields were placed in the middle and late development period and the reservoir pressure depleted usually, resulting in more serious differential pressure sticking and drilling mud leakage both in the reservoir and cap rock. In view of this situation, a systematic prediction method of safety mud density in depleted oilfields was established. The influence of reservoir depletion on stress and strength in reservoir and cap formation were both studied and taken into the prediction of safety mud density. The research showed that the risk of differential pressure sticking and drilling mud leakage in reservoir and cap formation were both increased and they were the main prevention object in depleted oilfields drilling. The research results were used to guide the practice drilling work, the whole progress gone smoothly.

  10. Importance of energetic solar protons in ozone depletion

    CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by ∼ 9% over ∼ 20% of the total area between the South Pole and latitude 70oS. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored. (author)

  11. AFSC/REFM: Pacific cod Localized Depletion Study

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from Localized Depletion study for Pacific cod 2001-2005. Study was conducted using cod pot gear to measure localized abundance of Pacific cod inside and...

  12. Net depletion determination for Hankin Wetland Development Project

    US Fish and Wildlife Service, Department of the Interior — This memorandum contains the analysis and the data used to produce the net depletion that would occur as a result of the Hankin Wetland Development Project.

  13. Nondestructive testing of 105mm depleted uranium penetrators

    The report is an information update concerning the nondestructive testing (NDT) activities at Pacific Northwest Laboratories (PNL) for depleted uranium penetrator (XM774, XM833) quality inspection and evaluation. This report covers NDT activities from August to November, 1979

  14. Use of Depleted Uranium Weapons in Contemporary Military Interventions

    Okafor-Yarwood, Ifesinachi Marybenedette

    2014-01-01

    This research note examines the use of depleted uranium weapons in contemporarymilitary interventions and the hazardous effects of their use. It also demonstratesattempts made by the United States and the United Kingdom to block anyinternational efforts to ban the use of these weapons. Although there is no laboratory evidence, experiential evidence from Iraq indicates that depleted uranium weapons are dangerous to human health and the environment. This research note argues that the United Nat...

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

    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

  16. Depletion models can predict shorebird distribution at different spatial scales.

    Gill, J. A.; Sutherland, W. J.; Norris, K.

    2001-01-01

    Predicting the impact of habitat change on populations requires an understanding of the number of animals that a given area can support. Depletion models enable predictions of the numbers of individuals an area can support from prey density and predator searching efficiency and handling time. Depletion models have been successfully employed to predict patterns of abundance over small spatial scales, but most environmental change occurs over large spatial scales. We test the ability of depleti...

  17. Assessment Of Depleted Uranium Contamination In Selective IRAQI Soils

    The aim of this research was to measure the radiation exposure rates in three selected Locations in southren part of Iraq (two in Nassireya, and one in Amara) resulted from the existence of depleted uranium in soil and metal pieces have been taken from destroyed tank and study mathmatically the concentration of Depleted Uranium by its dispersion from soil surface by winds and rains from 2003 to 2007. The exposure rates were measured using inspector device, while depleted uranium concentration in soil samples and tank's matal pieces were detected with Solid State Nuclear Track Detectors(SSNTDs). The wind and rain effects were considered in the calculation of dispersion effect on depleted uranium concentration in soil, where the wind effect were calculated with respect to the sites nature and soil conditions, and rain effect with respect to dispersive-convective equation for radionuclide in soil. The results obtained for the exposure rates were high near the penetrated surfac, moderate and low in soil and metal pices. The Depleted Uranium concentration in soil and metal pieces have the highest value in Nassireya. The results from dispersion calculation (wind & rain) showed that the depleted uranium concentration in 2008 will be less than the danger level and in allowable contamination range

  18. Yield, utilization, storage and ultimate storage of depleted uranium

    More than 80% of the uranium leaving uranium enrichment plants is depleted to a residual content of about 0,25% U 235. Due to the present ineconomical further depletion to the technically possible residual content of 0,1% U 235, the so-called 'tails' are first of all stored. The quantity of stored depleted uranium in the FRG should be about 100.000 t by the year 2000. It represents a strategic reserve for future energy supply regardless of profitableness. The study analysis the conceivable possible uses for the tails quantity considered. These are, besides further depletion whose profitableness is considered, also the use as breeder material in breeder reactors and the use in the non-nuclear field. The main part of the study deals with the various storage possibilities of the depleted uranium in oxidic or fluoride form. A comparison of costs of alternative storage concepts showed a clear advantage for the storage of UF6 in 48 inch containers already in use. The conceivable accidents in storing are analyzed and measures to reduce the consequences are discussed. Finally, the problems of ultimate storage for the remaining waste after further depletion or use are investigated and the costs arising here are also estimated. (RB)

  19. Engineering analysis report for the long-term management of depleted uranium hexafluoride : storage of depleted uranium metal

    This report contains an engineering analysis of long-term storage of uranium metal in boxes as an option for long-term management of depleted uranium hexafluoride (UF6). Three storage facilities are considered: buildings, vaults, and mined cavities. Three cases are considered: either all, half, or a quarter of the depleted uranium metal that would be produced from the conversion of depleted UF6 is stored at the facility. The analysis of these alternatives is based on a box design used in the Final Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted Uranium Hexafluoride, report DOE/EIS-0269, published in 1999 by the US Department of Energy. This box design does not appear to effectively use space within the box. Hence, an alternative box design that allows for a reduced storage area is addressed in the appendices for long-term storage in buildings

  20. The influence of ego depletion on sprint start performance in athletes without track and field experience

    Englert, Chris; Persaud, Brittany N.; Oudejans, Raôul R. D.; Bertrams, Alex

    2015-01-01

    We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting...

  1. Depletion of nonlinearity in the pressure force driving Navier-Stokes flows : nonlinear depletion in NS flows

    Tran, Chuong Van; Yu, Xinwei

    2015-01-01

    The dynamics of the velocity norms ||u||Lq for q ≥ 3, in Navier-Stokes flows is studied. The pressure term that drives this dynamics has a high degree of nonlinear depletion, which owes its origin to a genuine negative correlation between |u| and |∇|u||, among other things. Under viscous effects, such depletion may give rise to mild growth of ||u||Lq. We explore the possibility of non-singular growth of ||u||Lq.

  2. Genome-Wide Analysis of MEF2 Transcriptional Program Reveals Synaptic Target Genes and Neuronal Activity-Dependent Polyadenylation Site Selection

    Flavell, Steven W; Kim, Tae-Kyung; Gray, Jesse M.; Harmin, David A.; Hemberg, Martin; Hong, Elizabeth J.; Markenscoff-Papadimitriou, Eirene; Bear, Daniel M.; Greenberg, Michael E.

    2008-01-01

    Although many transcription factors are known to control important aspects of neural development, the genome-wide programs that are directly regulated by these factors are not known. We have characterized the genetic program that is activated by MEF2, a key regulator of activity-dependent synapse development. These MEF2 target genes have diverse functions at synapses, revealing a broad role for MEF2 in synapse development. Several of the MEF2 targets are mutated in human neurological disorder...

  3. Genome-wide analysis of MEF2 transcriptional program reveals synaptic target genes and neuronal activity-dependent polyadenylation site selection

    Flavell, Steven W; Kim, Tae-Kyung; Gray, Jesse M.; Harmin, David A.; Hemberg, Martin; Hong, Elizabeth J.; Markenscoff-Papadimitriou, Eirene; Bear, Daniel M.; Greenberg, Michael E.

    2008-01-01

    Although many transcription factors are known to control important aspects of neural development, the genome-wide programs that are directly regulated by these factors are not known. We have characterized the genetic program that is activated by MEF2, a key regulator of activity-dependent synapse development. These MEF2 target genes have diverse functions at synapses, revealing a broad role for MEF2 in synapse development. Several of the MEF2 targets are mutated in human neurological disorder...

  4. The Etv1 transcription factor activity-dependently downregulates a set of genes controlling cell growth and differentiation in maturing cerebellar granule cells.

    Okazawa, Makoto; Abe, Haruka; Nakanishi, Shigetada

    2016-05-13

    In the early postnatal period, cerebellar granule cells exhibit an activity-dependent downregulation of a set of immaturation genes involved in cell growth and migration and are shifted to establishment of a mature network formation. Through the use of a granule cell culture and both pharmacological and RNA interference (siRNA) analyses, the present investigation revealed that the downregulation of these immaturation genes is controlled by strikingly unified signaling mechanisms that operate sequentially through the stimulation of AMPA and NMDA receptors, tetrodotoxin-sensitive Na(+) channels and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). This signaling cascade induces the Etv1 transcription factor, and knockdown of Etv1 by a siRNA technique prevented this activity-dependent downregulation of immaturation genes. Thus, taken into consideration the mechanism that controls the upregulation of maturation genes involved in synaptic formation, these results indicate that Etv1 orchestrates the activity-dependent regulation of both maturation and immaturation genes in developing granule cells and plays a key role in specifying the identity of mature granule cells in the cerebellum. PMID:27059140

  5. Vitamin D depletion aggravates hypertension and target-organ damage

    Andersen, Louise Bjørkholt; Przybyl, Lukasz; Haase, Nadine; von Versen-Höynck, Frauke; Qadri, Fatimunnisa; Jørgensen, Jan Stener; Sorensen, Grith Lykke; Fruekilde, Palle; Poglitsch, Marko; Szijarto, István; Gollasch, Maik; Peters, Joerg; Muller, Dominik N; Christesen, Henrik Thybo; Dechend, Ralf

    2015-01-01

    BACKGROUND: We tested the controversial hypothesis that vitamin D depletion aggravates hypertension and target-organ damage by influencing renin. METHODS AND RESULTS: Four-week-old double-transgenic rats (dTGR) with excess angiotensin (Ang) II production due to overexpression of the human renin (h......REN) and angiotensinogen (hAGT) genes received vitamin D-depleted (n=18) or standard chow (n=15) for 3 weeks. The depleted group had very low serum 25-hydroxyvitamin D levels (mean±SEM; 3.8±0.29 versus 40.6±1.19 nmol/L) and had higher mean systolic BP at week 5 (158±3.5 versus 134.6±3.7 mm Hg, P<0......, hREN, and rRen were increased by vitamin D depletion. Regulatory T cells in the spleen and in the circulation were not affected. Ang metabolites, including Ang II and the counter-regulatory breakdown product Ang 1 to 7, were significantly up-regulated in the vitamin D-depleted groups, while ACE-1...

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

    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.

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

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

    2013-12-01

    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

  8. Effect of Shim Arm Depletion in the NBSR

    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.

  9. Observations of ozone depletion associated with solar proton events

    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.

  10. International aspects of restrictions of ozone-depleting substances

    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.

  11. Depletion induced clustering of red blood cells in microchannels

    Wagner, Christian; Brust, Mathias; Podgorski, Thomas; Coupier, Gwennou

    2012-11-01

    The flow properties of blood are determined by the physical properties of its main constituents, the red blood cells (RBC's). At low shear rates RBC's form aggregates, so called rouleaux. Higher shear rates can break them up and the viscosity of blood shows a shear thinning behavior. The physical origin of the rouleaux formation is not yet fully resolved and there are two competing models available. One predicts that the adhesion is induced by bridging of the plasma (macromolecular) proteins in-between two RBC's. The other is based on the depletion effect and thus predicts the absence of macromolecules in-between the cells of a rouleaux. Recent single cell force measurements by use of an AFM support strongly the depletion model. By varying the concentration of Dextran at different molecular weights we can control the adhesions strength. Measurements at low hematocrit in a microfluidic channel show that the number of size of clusters is determined by the depletion induced adhesion strength.

  12. Plasma depletion layer: Magnetosheath flow structure and forces

    Y. L. Wang

    2004-03-01

    Full Text Available The plasma depletion layer (PDL is a layer on the sunward side of the magnetopause with lower plasma density and higher magnetic field compared to the corresponding upstream magnetosheath values. In a previous study, we have validated the UCLA global (MHD model in studying the formation of the PDL by comparing model results, using spacecraft solar wind observations as the driver, with in situ PDL observations. In this study, we extend our previous work and examine the detailed MHD forces responsible for the PDL formation. We argue that MHD models, instead of gasdynamic models, should be used to study the PDL, because gasdynamic models cannot produce the PDL on the sunward side of the magnetopause. For northward (IMF, flux tube depletion occurs in almost all the subsolar magnetosheath. However, the streamlines closest to the magnetopause and the stagnation line show the greatest depletion. The relative strength of the various MHD forces changes along these streamlines. Forces along a flux tube at different stages of its depletion in the magnetosheath are analyzed. We find that a strong plasma pressure gradient force along the magnetic field at the bow shock and a pressure gradient force along the flux tube within the magnetosheath usually exist pushing plasma away from the equatorial plane to deplete the flux tube. More complex force structures along the flux tube are found close to the magnetopause. This new, more detailed description of flux tube depletion is compared with the results of Zwan and Wolf (1976 and differences are found. Near the magnetopause, the pressure gradient force along the flux tube either drives plasma away from the equatorial plane or pushes plasma toward the equatorial plane. As a result, a slow mode structure is seen along the flux tube which might be responsible for the observed two-layered slow mode structures.

    Key words. Magnetospheric physics (magnetosheath; solar wind-magnetosphere interactions. Space

  13. Monte Carlo solver for UWB1 nuclear fuel depletion code

    Highlights: • A new Monte Carlo solver was developed in order to speed-up depletion calculations. • For LWR model, UWB1 Monte Carlo solver is on average 10 times faster than MCNP6. • The UWB1 code will allow faster calculation analysis of BA parameters in fuel design. - Abstract: Recent nuclear reactor burnable absorber research tries to introduce new materials in the nuclear fuel. As a part of this effort, a fast computational tool is being developed for the advanced nuclear fuel. The first version of the newly developed UWB1 fast nuclear fuel depletion code significantly reduced calculation time by omitting the solution step for the Boltzmann transport equation. However, estimation of neutron multiplication factor during depletion was not sufficiently calculated. Therefore, at least one transport calculation for fuel depletion is necessary. This paper presents a new Monte Carlo solver that is implemented into the UWB1 code. The UWB1 Monte Carlo solver calculates neutron multiplication factor and neutron flux in the fuel for collapsed cross sections. Accuracy of the solver is supported by using current nuclear data stored in the ENDF/B-VII.1 library. Speed of the solver is the product of development focusing on minimization of CPU utilization at the expense of RAM demands. The UWB1 Monte Carlo solver is approximately 14 times faster than the MCNP6 reference code when one transport equation solution within fuel depletion is compared. Another speed-up can be achieved by employing advanced depletion scheme in the coupled transport and burnup equations. The resulting faster code will be used in optimization studies for ideal burnable absorber material selection where many various materials and concentrations will be evaluated

  14. Depletion of energy or depletion of knowledge alternative use of energy resources

    This research paper is about the depletion of Energy resources being a huge problem facing the world at this time. As available energy sources are coming to a shortage and measures are be taken in order to conserve the irreplaceable energy resources that leads to sustainability and fair use of energy sources for future generations. Alternative energy sources are being sought; however no other energy source is able to provide even a fraction of energy as that of fossil fuels. Use of the alternative energy resources like wind corridors (Sindh and Baluchistan), fair use of Hydro energy (past monsoon flooding can produce enough energy that may available for next century). Uranium Resources which are enough for centuries energy production in Pakistan (Dhok Pathan Formation) lying in Siwalick series from Pliocene to Pleistocene. Among all of these, my focus is about energy from mineral fuels like Uranium from Sandstone hosted deposits in Pakistan (Siwalik Series in Pakistan). A number of uranium bearing mineralized horizons are present in the upper part of the Dhok Pathan Formation. These horizons have secondary uranium mineral carnotite and other ores. Uranium mineralization is widely distributed throughout the Siwaliks The purpose of this paper was to introduce the use of alternative energy sources in Pakistan which are present in enough amounts by nature. Pakistan is blessed with wealth of natural resources. Unfortunately, Pakistan is totally depending on non renewable energy resource. There are three main types of fossil fuels: coal, oil and natural gas. After food, fossil fuel is humanity's most important source of energy. Pakistan is among the most gas dependent economies of the world. Use of fossil fuel for energy will not only increase the demand of more fossils but it has also extreme effects on climate as well as direct and indirect effects to humans. These entire remedial thinking can only be possible if you try to use alternative energy resources rather than

  15. Depletion of the ozone layer and its biological consequences

    The high concentration of ozone in the stratosphere serves as a protective shield against the harmful ultraviolet radiation from the sun. The increase in human activities is the main cause of the depletion of this ozone layer. The continued depletion of ozone layer will result in an increased exposure ultraviolet radiation which will have serve biological consequences. In this paper a detailed review of ozone, its production and decomposition alongwith its main depletors chlorofluoro-carbons is presented. The ozone data for Quetta Valley for the period 1960-90 is analysed. The biological consequences of increased ultraviolet radiation due to reduction in ozone layer are also discussed. (author)

  16. Enhanced J/$\\psi$ suppression due to gluon depletion

    Hwa, R C; Pisútová, N

    1998-01-01

    The nonlinear effect of gluon depletion in the collision of large nuclei can be large. It is due to multiple scatterings among comoving partons initiated by primary scattering of partons in the colliding nuclei. The effect can give rise to substantial suppression of $J/\\psi$ production in very large nuclei, even if the linear depletion effect is insignificant for the collisions of nuclei of smaller sizes. This mechanism offers a natural explanation of the enhanced suppression in the Pb-Pb data recently observed by NA50.

  17. Characterization of a Depleted Monolithic Active Pixel Sensor (DMAPS) prototype

    New monolithic pixel detectors integrating CMOS electronics and sensor on the same silicon substrate are currently explored for particle tracking in future HEP experiments, most notably at the LHC . The innovative concept of Depleted Monolithic Active Pixel Sensors (DMAPS) is based on high resistive silicon bulk material enabling full substrate depletion and the application of an electrical drift field for fast charge collection, while retaining full CMOS capability for the electronics. The technology (150 nm) used offers quadruple wells and allows to implement the pixel electronics with independently isolated N- and PMOS transistors. Results of initial studies on the charge collection and sensor performance are presented

  18. Towards a complete propagation uncertainties in depletion calculations

    Martinez, J.S. [Universidad Politecnica de Madrid (Spain). Dept. of Nuclear Engineering; Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Garching (Germany); Zwermann, W.; Gallner, L.; Puente-Espel, Federico; Velkov, K.; Hannstein, V. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Garching (Germany); Cabellos, O. [Universidad Politecnica de Madrid (Spain). Dept. of Nuclear Engineering

    2013-07-01

    Propagation of nuclear data uncertainties to calculated values is interesting for design purposes and libraries evaluation. XSUSA, developed at GRS, propagates cross section uncertainties to nuclear calculations. In depletion simulations, fission yields and decay data are also involved and are a possible source of uncertainty that should be taken into account. We have developed tools to generate varied fission yields and decay libraries and to propagate uncertainties through depletion in order to complete the XSUSA uncertainty assessment capabilities. A generic test to probe the methodology is defined and discussed. (orig.)

  19. Characterization of a Depleted Monolithic Active Pixel Sensor (DMAPS) prototype

    Obermann, T.; Havranek, M.; Hemperek, T.; Hügging, F.; Kishishita, T.; Krüger, H.; Marinas, C.; Wermes, N.

    2015-03-01

    New monolithic pixel detectors integrating CMOS electronics and sensor on the same silicon substrate are currently explored for particle tracking in future HEP experiments, most notably at the LHC . The innovative concept of Depleted Monolithic Active Pixel Sensors (DMAPS) is based on high resistive silicon bulk material enabling full substrate depletion and the application of an electrical drift field for fast charge collection, while retaining full CMOS capability for the electronics. The technology (150 nm) used offers quadruple wells and allows to implement the pixel electronics with independently isolated N- and PMOS transistors. Results of initial studies on the charge collection and sensor performance are presented.

  20. Simulating distinguish enriched uranium from depleted uranium by activation method

    Detecting uranium material is an important work in arms control Active detection is an efficient method for uranium material. The paper focuses on the feasibility that can distinguish the enriched uranium and the depleted uranium by MCNP program. It can distinguish the enriched uranium and the depleted uranium by the curve of relationship between fission rate of uranium material and thickness of moderator.Advantages of 252Cf and 14 MeV neutron sources are discussed in detecting uranium material through calculation. The results show that 252Cf neutron source is better than 14 MeV one. Delayed neutrons are more easily detected than delayed gamma ray at measurement aspect. (authors)

  1. Long-term management and use of depleted uranium

    The products resulting from the process of enrichment of natural uranium, or reprocessed uranium, are enriched uranium products as the light fraction and depleted uranium (uranium tails) as the heavy fraction. If the source material is natural uranium, the mass ratios of uranium products and uranium tails can be derived relatively easily from the required enrichment level of the uranium product (product assay (% of U-235)) and the selected depletion level of the uranium tails (tails assay (% of U-235)). The paper discusses among other aspects the dependence of the tails mass on the required enrichment level of the relevant uranium product, for various tails assays. (orig./CB)

  2. Depleted uranium determination at the Novi Sad low level facility

    Natural uranium determination in environmental samples at the low-level gamma-spectroscopy laboratory of the Faculty of Science in Novi Sad has more than 20 years long tradition. When the issue of depleted uranium emerged the experimental advantages of the measuring equipment (GMX type of HPGe detector with enhanced efficiency below 100 keV, and iron low level shielding) where fully exploited. A detection technique selective for depleted uranium was developed. The details of this method together with the results for about 100 samples (soil, plants, water, food) are presented, and discussed. (author)

  3. UV radiation below an Arctic vortex with severe ozone depletion

    B. M. Knudsen

    2005-01-01

    Full Text Available The erythemally weighted (UV irradiance below the severely depleted Arctic vortices in spring 1996 and 1997 were substantially elevated. On average the UV increased 36 and 33% relative to the 1979-1981 mean assuming clear skies from day 80-100 in 1996 and 1997, respectively. On clear sky days large regions of the Arctic experienced maximum UV increases exceeding 70 and 50% on single days in 1996 and 1997, respectively. A minor fraction of these increases are not anthropogenic and have a dynamical origin as seen by comparison to 1982, when hardly any ozone depletion is expected.

  4. Impact and mitigation of stratospheric ozone depletion by chemical rockets

    The American Institute of Aeronautics and Astronautics (AIAA) conducted a workshop in conjunction with the 1991 AIAA Joint Propulsion Conference in Sacramento, California, to assess the impact of chemical rocket propulsion on the environment. The workshop included recognized experts from the fields of atmospheric physics and chemistry, solid rocket propulsion, liquid rocket propulsion, government, and environmental agencies, and representatives from several responsible environmental organizations. The conclusion from this workshop relative to stratospheric ozone depletion was that neither solid nor liquid rocket launchers have a significant impact on stratospheric ozone depletion, and that there is no real significant difference between the two

  5. Ozone depletion over the polar caps caused by solar protons

    Energetic solar protons are a natural source of ozone depletion due to nitric oxides they produce in the earth's atmosphere. In March 1989, following a period of intense solar activity, the TOMS instrument aboard the Nimbus 7 satellite recorded very similar ozone losses over both polar caps for areas extending from 90 degrees to 70 degrees. Ozone depletions of 7.4 x 109 kg for the south polar cap and 8.0 x 109 kg for the north polar cap indicate the degree of symmetry over the polar caps. 11 refs., 6 figs

  6. The manufacturing of depleted uranium biological shield components

    The unique combination of the physical and mechanical properties of uranium made it possible to manufacture biological shield components of transport package container (TPC) for transportation nuclear power plant irradiated fuel and radionuclides of radiation diagnostic instruments. Protective properties are substantially dependent on the nature radionuclide composition of uranium, that why I recommended depleted uranium after radiation chemical processing. Depleted uranium biological shield (DUBS) has improved specific mass-size characteristics compared to a shield made of lead, steel or tungsten. Technological achievements in uranium casting and machining made it possible to manufacture DUBS components of TPC up to 3 tons of mass and up to 2 metres of the maximum size. (authors)

  7. NUMERICAL SIMULATION FOR FORMED PROJECTILE OF DEPLETED URANIUM ALLOY

    宋顺成; 高平; 才鸿年

    2003-01-01

    The numerical simulation for forming projectile of depleted uranium alloy with the SPH ( Smooth Particle Hydrodynamic ) algorithm was presented. In the computations the artificial pressures of detonation were used, i. e. , the spatial distribution and time distribution were given artificially. To describe the deformed behaviors of the depleted uranium alloy under high pressure and high strain rate, the Johnson-Cook model of materials was introduced. From the numerical simulation the formed projectile velocity,projectile geometry and the minimum of the height of detonation are obtained.

  8. Role of nucleonic Fermi surface depletion in neutron star cooling

    Dong, J M; Zhang, H F; Zuo, W

    2015-01-01

    The Fermi surface depletion of beta-stable nuclear matter is calculated to study its effects on several physical properties which determine the neutron star 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 neutron stars are significantly slowed

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

    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.

  10. Depleting methyl bromide residues in soil by reaction with bases

    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...

  11. DIRECT MEASUREMENT OF WEAK DEPLETION FORCE BETWEEN TWO SURFACES*

    Xiang-jun Gong; Xiao-chen Xing; Xiao-ling Wei; To Ngai

    2011-01-01

    In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive “depletion force” if the size of the polymer molecule is larger than the interparticle separation. This is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space,which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. This depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBT and beyond. We present here our results for applying total internal reflection microscopy (TIRM) to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles (ca. 150 nm) exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using TIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo-sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBT-scale depletion attraction as function of solution pH.

  12. Optimal reload and depletion method for pressurized water reactors

    A new method has been developed to automatically reload and deplete a PWR so that both the enriched inventory requirements during the reactor cycle and the cost of reloading the core are minimized. This is achieved through four stepwise optimization calculations: 1) determination of the minimum fuel requirement for an equivalent three-region core model, 2) optimal selection and allocation of fuel requirement for an equivalent three-region core model, 2) optimal selection and allocation of fuel assemblies for each of the three regions to minimize the cost of the fresh reload fuel, 3) optimal placement of fuel assemblies to conserve regionwise optimal conditions and 4) optimal control through poison management to deplete individual fuel assemblies to maximize EOC k/sub eff/. Optimizing the fuel cost of reloading and depleting a PWR reactor cycle requires solutions to two separate optimization calculations. One of these minimizes the enriched fuel inventory in the core by optimizing the EOC k/sub eff/. The other minimizes the cost of the fresh reload cost. Both of these optimization calculations have now been combined to provide a new method for performing an automatic optimal reload of PWR's. The new method differs from previous methods in that the optimization process performs all tasks required to reload and deplete a PWR

  13. B-cell depletion in the treatment of lupus nephritis.

    Gregersen, Jon W; Jayne, David R W

    2012-09-01

    Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that is clinically heterogeneous and affects multiple organs. Lupus nephritis is the most frequent severe manifestation of SLE. Conventional immunosuppressive therapy has increased the life expectancy of patients diagnosed with lupus nephritis, but only 70-80% of patients respond to this treatment and its adverse effects are considerable. B cells are central to the pathogenesis of SLE and are, therefore, an attractive therapeutic target. B-cell depletion has been used successfully to treat other autoimmune diseases, such as rheumatoid arthritis and antineutrophil cytoplasmic antibody-associated vasculitis, and many case reports and small nonrandomized trials of B-cell-depleting agents in patients with lupus nephritis have reported positive results. By contrast, two large placebo-controlled trials designed to investigate the efficacy of the B-cell-depleting agents rituximab and ocrelizumab as a treatment for lupus nephritis, failed to meet their primary efficacy end points (LUNAR and BELONG, respectively). This Review discusses the current evidence on the use of B-cell depletion in the treatment of lupus nephritis, which is derived from case studies and clinical trials including a total of over 800 patients. PMID:22801948

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

    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.

  15. Efficiency-Inducing Taxation for a Monopolistically Supplied Depletable Resource

    Bergstrom, Ted; Cross, John; Porter, Dick

    1981-01-01

    We show that for a depletable resource, if the competitive time path of prices is known, and if the profit function is concave, then there is an easily described time path of taxes and/or subsidies that would induce a monopolist to follow an efficient time path of extraction.

  16. Phosphorus resources, their depletion and conservation, a review

    L. Reijnders

    2014-01-01

    Yearly, about 22 × 1012 g phosphorus (P) from mined fossil phosphate resources are added to the world economy. The size of remaining fossil phosphate resources is uncertain but practically finite. Thus, fossil P resources may become depleted by ongoing mining. Despite calls for resource conservation

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

    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

  18. Monte Carlo simulation in UWB1 depletion code

    UWB1 depletion code is being developed as a fast computational tool for the study of burnable absorbers in the University of West Bohemia in Pilsen, Czech Republic. In order to achieve higher precision, the newly developed code was extended by adding a Monte Carlo solver. Research of fuel depletion aims at development and introduction of advanced types of burnable absorbers in nuclear fuel. Burnable absorbers (BA) allow the compensation of the initial reactivity excess of nuclear fuel and result in an increase of fuel cycles lengths with higher enriched fuels. The paper describes the depletion calculations of VVER nuclear fuel doped with rare earth oxides as burnable absorber based on performed depletion calculations, rare earth oxides are divided into two equally numerous groups, suitable burnable absorbers and poisoning absorbers. According to residual poisoning and BA reactivity worth, rare earth oxides marked as suitable burnable absorbers are Nd, Sm, Eu, Gd, Dy, Ho and Er, while poisoning absorbers include Sc, La, Lu, Y, Ce, Pr and Tb. The presentation slides have been added to the article

  19. Apoptosis and T cell depletion during feline infectious peritonitis

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

    1996-01-01

    Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activa

  20. Specific depletion of mature T lymphocytes from human bone marrow

    Geisler, C; Møller, J; Plesner, T;

    1989-01-01

    An effective method for specific depletion of mature T lymphocytes from human bone marrow mononuclear cells (BMMC) with preservation of prethymic T cells and natural killer (NK) cells is presented. The BMMC were incubated with F101.01, a monoclonal antibody recognizing an epitope of the T...

  1. Engineering analysis for disposal of depleted uranium tetrafluoride (UF4)

    This report presents and evaluates options for disposing of depleted uranium in the chemical form of uranium tetrafluoride (UF4). Two depleted uranium inventories are considered. One results from the original U.S. Department of Energy (DOE) inventory of 560,000 metric tons (te) of depleted uranium hexafluoride (UF6); the other inventory is the original DOE inventory augmented by 145,000 te of depleted UF6 from the United States Enrichment Corporation. Preconceptual designs are included for three disposal options: disposal in a vault, disposal in an engineered trench, and disposal in a deep mine cavity. The disposal container is taken to be either a 30-gallon drum or a 55-gallon drum. Descriptions of the facilities associated with the three disposal options are provided. Staffing estimates for the construction and operation of the facilities are also provided. Wastes and emissions from the facilities during construction, operation, and maintenance have been estimated. Parametric studies have also been performed on the basis of 25% and 50% of the original inventory

  2. C18O Depletion in Starless Cores in Taurus

    Ford, Amanda Brady

    2011-01-01

    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 insuff...

  3. Ozone depletion and skin cancer incidence: an integrated modelling approach

    Slaper H; den Elzen MGJ; de Woerd HJ; de Greef J

    1992-01-01

    A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. The incidence of skin cancer is expected to increase due to ozone depletion. An integrated source-risk model is developed and applied to evaluate the increased

  4. A method to estimate groundwater depletion from confining layers

    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.

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

    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...

  6. Development of depletion perturbation theory for a reactor nodal code

    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

  7. Depleted uranium weapons and international law: A precautionary approach

    A. McDonald; J.K. Kleffner; B. Toebes

    2008-01-01

    This books provides an in-depth analysis of the international legal aspects of the use of depleted uranium (DU) ammunition and armour. The military use of DU has been surrounded by considerable controversy, mainly as regards the health and environmental risks that such use entails. The debate about

  8. Seasonal oxygen depletion in the North Sea, a review.

    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. PMID:26234616

  9. 5.0. Depletion, activation, and spent fuel source terms

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

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

    G. Mulder

    2014-10-01

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

  11. Compared studies of natural and artificial deuterium depleted water

    The biological influence of the deuterium on animals was studied insensitively in the last years. When animal cell cultures were analyzed it turned out an inhibition of the development, due to the reduced deuterium concentration. In the in vivo experiments a decreasing of the number of tumoral cells was pointed out when performing the depleted water treatment. It is obvious that the presence of deuterium in water is necessary for the development, especially for the tumoral cell proliferation. The aim of this work was to establish influence of the natural and artificial deuterium depleted water on the vegetal organisms development. For this purpose, the developmental stages of Lactuca sativa L. growth were followed. The experimental data were compared with the data obtained with distilled water. The birch, wine sap and some fruit juices are considered 'natural depleted' water sources because their deuterium content is smaller in comparison to natural water (D2=150 ppm). The effect of artificial deuterium depleted water (29 ppm D2) was analyzed in comparison to three types of wine saps, which also have a reduced deuterium concentration (125-130 ppm D2). If the deuterium depleted water was used, the germination percent and the root and shoot length were higher compared to control in the first stages. In wine sap it had a negative effect on germination and development. After three days the plants were transferred to soil and their development was followed. The foliage area was larger for all of the experimental variants compared to control. The differences were without significance when deuterium depleted water was tested but they were high and very significant in case of wine sap. The experiment pointed out a stimulative effect of the artificial deuterium depleted water. In case of wine sap the effect was negative when the contact was direct, but the growth was stimulated after the stress cessation. The first ontogenetic stages were represented by direct action on

  12. MCOR - Monte Carlo depletion code for reference LWR calculations

    Research highlights: → Introduction of a reference Monte Carlo based depletion code with extended capabilities. → Verification and validation results for MCOR. → Utilization of MCOR for benchmarking deterministic lattice physics (spectral) codes. - Abstract: The MCOR (MCnp-kORigen) code system is a Monte Carlo based depletion system for reference fuel assembly and core calculations. The MCOR code is designed as an interfacing code that provides depletion capability to the LANL Monte Carlo code by coupling two codes: MCNP5 with the AREVA NP depletion code, KORIGEN. The physical quality of both codes is unchanged. The MCOR code system has been maintained and continuously enhanced since it was initially developed and validated. The verification of the coupling was made by evaluating the MCOR code against similar sophisticated code systems like MONTEBURNS, OCTOPUS and TRIPOLI-PEPIN. After its validation, the MCOR code has been further improved with important features. The MCOR code presents several valuable capabilities such as: (a) a predictor-corrector depletion algorithm, (b) utilization of KORIGEN as the depletion module, (c) individual depletion calculation of each burnup zone (no burnup zone grouping is required, which is particularly important for the modeling of gadolinium rings), and (d) on-line burnup cross-section generation by the Monte Carlo calculation for 88 isotopes and usage of the KORIGEN libraries for PWR and BWR typical spectra for the remaining isotopes. Besides the just mentioned capabilities, the MCOR code newest enhancements focus on the possibility of executing the MCNP5 calculation in sequential or parallel mode, a user-friendly automatic re-start capability, a modification of the burnup step size evaluation, and a post-processor and test-matrix, just to name the most important. The article describes the capabilities of the MCOR code system; from its design and development to its latest improvements and further ameliorations

  13. Ozone depletion, related UVB changes and increased skin cancer incidence

    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

  14. MCOR - Monte Carlo depletion code for reference LWR calculations

    Puente Espel, Federico, E-mail: fup104@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Tippayakul, Chanatip, E-mail: cut110@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Ivanov, Kostadin, E-mail: kni1@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Misu, Stefan, E-mail: Stefan.Misu@areva.com [AREVA, AREVA NP GmbH, Erlangen (Germany)

    2011-04-15

    Research highlights: > Introduction of a reference Monte Carlo based depletion code with extended capabilities. > Verification and validation results for MCOR. > Utilization of MCOR for benchmarking deterministic lattice physics (spectral) codes. - Abstract: The MCOR (MCnp-kORigen) code system is a Monte Carlo based depletion system for reference fuel assembly and core calculations. The MCOR code is designed as an interfacing code that provides depletion capability to the LANL Monte Carlo code by coupling two codes: MCNP5 with the AREVA NP depletion code, KORIGEN. The physical quality of both codes is unchanged. The MCOR code system has been maintained and continuously enhanced since it was initially developed and validated. The verification of the coupling was made by evaluating the MCOR code against similar sophisticated code systems like MONTEBURNS, OCTOPUS and TRIPOLI-PEPIN. After its validation, the MCOR code has been further improved with important features. The MCOR code presents several valuable capabilities such as: (a) a predictor-corrector depletion algorithm, (b) utilization of KORIGEN as the depletion module, (c) individual depletion calculation of each burnup zone (no burnup zone grouping is required, which is particularly important for the modeling of gadolinium rings), and (d) on-line burnup cross-section generation by the Monte Carlo calculation for 88 isotopes and usage of the KORIGEN libraries for PWR and BWR typical spectra for the remaining isotopes. Besides the just mentioned capabilities, the MCOR code newest enhancements focus on the possibility of executing the MCNP5 calculation in sequential or parallel mode, a user-friendly automatic re-start capability, a modification of the burnup step size evaluation, and a post-processor and test-matrix, just to name the most important. The article describes the capabilities of the MCOR code system; from its design and development to its latest improvements and further ameliorations. Additionally

  15. Global Storm-Time Depletion of the Outer Electron Belt

    Ukhorskiy, A. Y.; Sitnov, M. I.; Millan, R. M.; Kress, B. T.; Fennell, J. F.

    2014-12-01

    The outer radiation belt consists of relativistic (≳0.5 MeV) electrons trapped on closed trajectories around Earth where its magnetic field is nearly dipolar. During increased geomagnetic activity electron intensities in the belt can vary by orders of magnitude at different spatial and temporal scale. The main phase of geomagnetic storms often produces deep depletions of electron intensities over broad regions of the outer belt. Previous studies identified three possible processes that can contribute to the depletions: fully adiabatic inflation of electron drift orbits caused the ring current growth, electron loss into the atmosphere due to pitch-angle scattering by plasma waves (e.g., EMIC and whistler waves), and electron escape through the magnetopause boundary. In this paper we investigate the relative importance of the magnetopause losses to the rapid depletion of the outer belt observed at the Van Allen Probes spacecraft during the main phase of March 17, 2013 storm. The intensities of > 1 MeV electrons were depleted by more that an order of magnitude over the entire radial extent of the belt in less than 6 hours after the sudden storm commencement. For the analysis we used three-dimensional test-particle simulations of global evolution of the outer belt in the Tsyganenko-Sitnov (TS07D) magnetic field model with the inductive electric field. The comparison of the simulation results with electron measurements from the MagEIS experiment shows that the magnetopause losses in the model accounts for most of the observed depletion. The individual electron motion the process is non-adiabatic; the third invariant is violated by global variations of the inner magnetospheric fields caused by the magnetopause compressions and the buildup of ring current, while the second invariant is violated at drift orbit bifurcations. The analysis shows that the observed deep depletion of radiation belt intensities is enabled by the change in the global configuration of magnetic

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

    Quapp, W.J.; Lessing, P.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Cooley, C.R. [Department of Technology, Germantown, MD (United States)

    1997-02-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability problem in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. DOE is evaluating several options for the disposition of this UF{sub 6}, including continued storage, disposal, and recycle into a product. Based on studies conducted to date, the most feasible recycle option for the depleted uranium is shielding in low-level waste, spent nuclear fuel, or vitrified high-level waste containers. Estimates for the cost of disposal, using existing technologies, range between $3.8 and $11.3 billion depending on factors such as the disposal site and the applicability of the Resource Conservation and Recovery Act (RCRA). Advanced technologies can reduce these costs, but UF{sub 6} disposal still represents large future costs. This paper describes an application for depleted uranium in which depleted uranium hexafluoride is converted into an oxide and then into a heavy aggregate. The heavy uranium aggregate is combined with conventional concrete materials to form an ultra high density concrete, DUCRETE, weighing more than 400 lb/ft{sup 3}. DUCRETE can be used as shielding in spent nuclear fuel/high-level waste casks at a cost comparable to the lower of the disposal cost estimates. Consequently, the case can be made that DUCRETE shielded casks are an alternative to disposal. In this case, a beneficial long term solution is attained for much less than the combined cost of independently providing shielded casks and disposing of the depleted uranium. Furthermore, if disposal is avoided, the political problems associated with selection of a disposal location are also avoided. Other studies have also shown cost benefits for low level waste shielded disposal containers.

  17. Improved radiochemical assay analyses using TRITON depletion sequences in SCALE

    With the release of TRITON in SCALE 5.0, Oak Ridge National Laboratory has made available a rigorous two-dimensional (2D) depletion sequence based on the arbitrary-geometry 2D discrete ordinates transport solver NEWT. TRITON has recently been further enhanced by the addition of depletion sequences that use KENO V.a and KENO-VI for three-dimensional (3D) transport solutions. The Monte Carlo-based depletion sequences add stochastic uncertainty issues to the solution, but also provide a means to perform direct 3D depletion that can capture the effect of leakage near the ends of fuel assemblies. Additionally, improved resonance processing capabilities are available to TRITON using CENTRM. CENTRM provides lattice-weighted cross sections using a continuous energy solution that directly treats the resonance overlap effects that become more important in high-burnup fuel. And beginning with the release of SCALE 5.1 in the summer of 2006, point data and fine-structure multigroup libraries derived from ENDF/B-VI evaluations will be available. The combination of rigorous 2D and 3D capabilities with improved cross section processing capabilities and data will provide a powerful and accurate means for the characterization of spent fuel, making it possible to analyze a broad range of assembly designs and assay data. This in turn will reduce biases and uncertainties associated with the preduction of spent fuel isotopic compositions. This paper describes advanced capabilities of the TRITON sequence for depletion calculations and the results of analyses performed to date for radiochemical assay data. (author)

  18. Depletion of compounds from thin oil films in seawater

    When oil is spilled on water, the oil compounds distribute between droplets and water-soluble phases in the water column. Some small organic acids, phenols, BTEX, and aromatic compounds will dissolve completely, but larger polycyclic aromatic hydrocarbons (PAH) and alkanes will remain in the droplet fraction. The biodegradation of droplets occurs at the oil-water interface. A method for immobilizing the oil films onto hydrophobic surfaces was developed in order to obtain a stable oil surface during the biodegradation period. A test system was also established to determine the depletion of oil compounds from the oil phase, including both abiotic and biotic processes. Three North Sea oils were used in the study. Two were paraffinic oils rich in n-alkanes and aromatic compounds, and one was asphalthenic which was richer in branched alkanes and PAH. The biodegradation period was 2 months at 13 degrees C. Samples from the water and thin film on the fabric was analyzed for carbon 10 and carbon 36 by gas chromatography-flame ionization detection. Semi-volatile organic compounds were analyzed using gas chromatography-mass spectrometry. Results indicated that the depletion process for alkanes was completely caused by biodegradation, while aromatic compounds were depleted by abiotic dissolution as well as by biodegradation. The system has potential for determining oil depletion processes under controlled surface-to-volume conditions, such as thin oil films and dispersed oil droplets. In addition, the system can be used to determine the depletion process in flow-through systems. 13 refs., 3 tabs., 9 figs

  19. The health hazards of depleted uranium munitions. Part 1

    Depleted uranium is a toxic and weakly radioactive metal used for a variety of purposes. Perhaps its most controversial use is in battlefield munitions, where it can be widely dispersed in the form of fine particles and shrapnel that may enter the bodies of combatants and others through inhalation, ingestion or wounding. It is a matter of legitimate public concern whether the use of this material in this way could create unacceptable health hazards or damage to the environment. The objective of our study has been to provide the best scientific understanding of the ways in which the material may be distributed, how it may be taken up by humans, and the potential implications for health. For politicians, any hazards to health have to be balanced against the military advantages that the use of these munitions confers. We have not tried to reach a judgment on these political issues, but we believe that a better scientific understanding of the extent of the hazards will make it easier for these wider questions to be addressed in a more objective way. This report is the first of two, and addresses the likely levels of exposure to depleted uranium, the resulting radiological risks, and the lessons to be learned from epidemiological studies. Our second report will address toxicological risks and environmental issues. So far, we conclude that risks from radiation are low for most soldiers on the battlefield, and for civilians who later return to the area. However, there are uncertainties about the maximal levels of exposure to depleted uranium on the battlefield, and there may be circumstances in which a few soldiers are exposed to levels of depleted uranium that result in a significant risk to health. Further studies are needed to determine the levels of exposure to depleted uranium that might occur on the battlefield and to judge whether such higher risks are likely to occur in practice

  20. Oceanic bromoform emissions weighted by their ozone depletion potential

    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

  1. Iron depletion enhances the effect of sorafenib in hepatocarcinoma.

    Urano, Shinichi; Ohara, Toshiaki; Noma, Kazuhiro; Katsube, Ryoichi; Ninomiya, Takayuki; Tomono, Yasuko; Tazawa, Hiroshi; Kagawa, Shunsuke; Shirakawa, Yasuhiro; Kimura, Fumiaki; Nouso, Kazuhiro; Matsukawa, Akihiro; Yamamoto, Kazuhide; Fujiwara, Toshiyoshi

    2016-06-01

    ABSTACT Human hepatocellular carcinoma (HCC) is known to have a poor prognosis. Sorafenib, a molecular targeted drug, is most commonly used for HCC treatment. However, its effect on HCC is limited in clinical use and therefore new strategies regarding sorafenib treatment are required. Iron overload is known to be associated with progression of chronic hepatitis and increased risk of HCC. We previously reported that iron depletion inhibited cancer cell proliferation and conversely induced angiogenesis. Indeed iron depletion therapy including iron chelator needs to be combined with anti-angiogenic drug for its anti-cancer effect. Since sorafenib has an anti-angiogenic effect by its inhibitory targeting VEGFR, we hypothesized that sorafenib could complement the anti-cancer effect of iron depletion. We retrospectively analyzed the relationship between the efficacy of sorafenib and serum iron-related markers in clinical HCC patients. In clinical cases, overall survival was prolonged in total iron binding capacity (TIBC) high- and ferritin low-patients. This result suggested that the low iron-pooled patients, who could have a potential of more angiogenic properties in/around HCC tumors, could be adequate for sorafenib treatment. We determined the effect of sorafenib (Nexavar®) and/or deferasirox (EXJADE®) on cancer cell viability, and on cell signaling of human hepatocarcinoma HepG2 and HLE cells. Both iron depletion by deferasirox and sorafenib revealed insufficient cytotoxic effect by each monotherapy, however, on the basis of increased angiogenesis by iron depletion, the addition of deferasirox enhanced anti-proliferative effect of sorafenib. Deferasirox was confirmed to increase vascular endothelial growth factor (VEGF) secretion into cellular supernatants by ELISA analysis. In in vivo study sorafenib combined with deferasirox also enhanced sorafenib-induced apoptosis. These results suggested that sorafenib combined with deferasirox could be a novel combination

  2. Ovarian ageing, follicle depletion, and cancer: a hypothesis for the aetiology of epithelial ovarian cancer involving follicle depletion

    Smith, Elizabeth R.; Xu, Xiang-Xi

    2008-01-01

    The association between ovarian cancer risk and reproductive factors has been well established, and two main theories, incessant ovulation and gonadotropin stimulation, have been proposed to explain the mechanism. Recent studies using animal models of ovarian tumorigenesis, and analysis of ovarian tissues from prophylactic oophorectomies, suggest that depletion of ovarian follicles might underlie the epidemiological findings linking reproductive history and ovarian cancer risk.

  3. Evaluating groundwater depletion as computed by a global water model

    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

  4. Depletion modeling of integral burnable absorbers containing enriched boron

    Depletion modeling of fuel assembly with different integral fuel burnable absorber loadings containing enriched boron has been performed by WIMSD transport code. Equivalent boron concentration that represents depletion of the integral fuel burnable absorbers containing enriched boron has been calculated using modified PSU/LEOPARD code. The calculated equivalent boron concentrations have been introduced into FUMACS computer code package master files, upgrading the code package with new global calculation feature for core modeling with different integral fuel burnable absorber loadings containing enriched boron. This new feature of FUMACS/FEEC2001 code package has been verified and validated on 12-month and 18-month operating cycle core loading patterns of NPP Krsko.(author)

  5. Dietary phosphorus depletion in sheep: Longterm effects on bone structure

    Experiments were performed on 6 sheep from 8 months old to study effects of dietary phosphorus depletion on bone structure. Sheep were given a semisynthetic diet of chopped straw and pellets for 38 weeks. Mean daily P in the diet was 0.97 g and 3 sheep were given additional NaH2PO4.H2O, increasing daily P supply to 4.5 g (controls). Bone density was estimated photometrically within the laterodistal metaphysis of the foreleg and standardized by a copper step wedge. Metacarpal cortical thickness was also measured. Cortical thickness and bone density started to decrease about 4 weeks after start of P depletion. The trabecular structure of the distal radius was coarser and less dense with reduced cross-linking between trabeculae

  6. Visualization of stratospheric ozone depletion and the polar vortex

    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.

  7. Cytotoxicity and glutathione depletion studies using CHOK cells

    Radiosensitization characteristics of newly synthesized isoindole-4, 7-diones have been established in the authors' laboratories. Cytotoxicity studies of isoindole-4, 7-diones on chinese hamster ovary cell (CHOK) have been carried out. The effects that different concentrations of isoindole-4, 7-diones have on cell growth as a function of time after treatment on both systems (oxic and hypoxic) have been determined. Most of isoindole-4, 7-diones used in these studies show more cytotoxic effect under hypoxic conditions. Gluthathione depletion was also measured in both systems. Most of the quinones studied deplete the concentration of glutathione in the CHOK cells. The results will be compared with similar studies carried out with the well known radiosensitizers misonidazole. It is hoped that the isoindole-r, 7-diones are a new family of chemical radiosensitizers

  8. High pressure elasticity and thermal properties of depleted uranium

    Jacobsen, M. K.; Velisavljevic, N.

    2016-04-01

    Studies of the phase diagram of uranium have revealed a wealth of high pressure and temperature phases. Under ambient conditions the crystal structure is well defined up to 100 gigapascals (GPa), but very little information on thermal conduction or elasticity is available over this same range. This work has applied ultrasonic interferometry to determine the elasticity, mechanical, and thermal properties of depleted uranium to 4.5 GPa. Results show general strengthening with applied load, including an overall increase in acoustic thermal conductivity. Further implications are discussed within. This work presents the first high pressure studies of the elasticity and thermal properties of depleted uranium metal and the first real-world application of a previously developed containment system for making such measurements.

  9. Is depleted uranium a threat to health and the environment?

    This issue has come to the fore in recent years now that Norwegian military personnel have been sent to regions of the world where ammunition made of depleted uranium has been used. A number of surveys have been conducted in the Balkans, so far indicating no health hazards to people present in these areas. However, the latest international surveys show that contamination may be long-lasting. Tonje Sekse represented the Norwegian Radiation Protection Authority at the United Nations Environment Programme's (UNEP) inspection tour to Serbia and Montenegro in the autumn of 2001. The report, entitled ''Depleted uranium in Serbia and Montenegro - Post-Conflict Environmental Assessment in the Federal Republic of Yugoslavia'' was published by UNEP in March 2002.(author)

  10. Characteristics of depleted uranium for the storage of hydrogen isotopes

    The characteristics for the hydrogen storage was investigated using depleted uranium that was the waste of nuclear fuel manufacturing. Activation process was conducted to heat the experimental vessel to 450 .deg. C under vacuum and the reaction temperature was room temperature. The absorption reaction between hydrogen and depleted uranium was very fast with rapid increasing of temperature and reached to the saturated state within 10 minutes. The ratio of hydrogen to uranium was 2.95 and the amounts of absorbed hydrogen were 3.5 liter after one hour of reaction. The experimental results of reproducibility showed the similar tendencies after third reaction. The reaction of hydrogen and deuterium showed similar tendencies and the initial reaction rate of deuterium was slower than that of hydrogen. The desorption of absorbed hydrogen started around 250 .deg. C. It was confirmed that the almost absorbed hydrogen was desorbed by heating to 450 .deg. C

  11. Detecting Grain-Boundary Chromium Depletion in Inconel 600

    Airey, G. P.; Vaia, A. R.; Pessall, N.; Aspden, R. G.

    1981-11-01

    Techniques to evaluate grain-boundary chromium depletion in Inconel Alloy 600 were investigated. Procedures studied were a modified Huey test, reactivation polarization, magnetic permeability measurements, and eddy current measurements. Results from these tests were correlated with susceptibility to stress-assisted intergranular cracking in polythionic acid. Thermally treated Inconel Alloy 600 steam generator tubing was the principal source of material evaluated, but experimental heats of Ni-Cr-Fe alloys with 8-18 wt.% Cr were prepared to determine the critical chromium level below which stress-assisted intergranular cracking occurs; this critical chromium content was found to be between 9.8 and 11.7 wt.%. All four techniques were considered suitable to evaluate grain-boundary chromium depletion; the modified Huey test and reactivation polarization technique showed a greater sensitivity than the magnetic permeability and eddy current measurements.

  12. Lower hybrid wave phenomena associated with density depletions

    Seyler, C. E.

    1994-01-01

    A fluid description of lower hybrid, whistler and magnetosonic waves is applied to study wave phenomena near the lower hybrid resonance associated with plasma density depletions. The goal is to understand the nature of lower hybrid cavitons and spikelets often associated with transverse ion acceleration events in the auroral ionosphere. Three-dimensional simulations show the ponderomotive force leads to the formation of a density cavity (caviton) in which lower hybrid wave energy is concentrated (spikelet) resulting in a three-dimensional collapse of the configuration. Plasma density depletions of the order of a few percent are shown to greatly modify the homogeneous linear properties of lower hybrid waves and account for many of the observed features of lower hybrid spikelets.

  13. Ozone depletion in the stratosphere: extent, causes and consequences

    According to present knowledge the causes of depleting the stratospheric ozone layer are exclusively anthropogenic. CFC's and (to smaller extent) halons enter the chain mechanisms of photochemical ozone loss with the result that its steady state concentration is reduced. Ozone depletion in the stratosphere has a number of consequences for the chemistry and the dynamics of the stratosphere. More severe, however, is its potential consequence to humans, animals and plants due to an increase in UV-B intensity near the surface. Current model studies predict, that the observed ozone change in mid-latitudes of the northern hemisphere should have resulted in a change of the UV-B-dose by as much as +7%/decade. (orig./DG)

  14. Effect of temperature coupling on ozone depletion prediction

    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.

  15. PP005. Vitamin D depletion aggravates hypertension in transgenic rats

    Bjørkholt Andersen, Louise; Herse, Florian; Christesen, Henrik Thybo;

    2013-01-01

    overexpressing the human renin and angiotensinogen genes, group 1 (n=18) received vitamin D depleted chow; group 2 (n=15) standard chow and intraperitoneal paricalcitol at 800ng/kg thrice weekly; and group 3 (n=15) standard chow and vehicle injections. Blood pressure (tail cuff) and 24-h albuminuria were......INTRODUCTION: Vitamin D may ameliorate hypertension and kidney disease through genomic and extra-genomic pathways. OBJECTIVE: To investigate the impact of vitamin D in a transgenic rat model of angiotensin II-mediated hypertensive organ failure. METHODS: In 4-week-old age-matched rats...... determined once weekly. After three weeks, animals were sacrificed. Heart tissue was examined for atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) by RT-PCR. RESULTS: The vitamin D depleted group had higher blood pressure at week 1 (mean difference 23.4mmHg, 95% CI 9.1-37.7) and tended to...

  16. Processing of depleted uranium for sub-atomic particle detectors

    About 1000 metric tons of Depleted Uranium (DU) is being used in three advanced detectors at CERN (UA-1), Fermilab (DZero), and DESY (Zeus). Nearly all of the approximately 25,000 precision DU Sheet metal components assembled into these detectors have been produced at Manufacturing Sciences Corporation (MSC) of Oak Ridge, Tennessee. This paper describes the manufacturing procedures used to make these components and offers suggestions to help reduce cost of future detectors

  17. Macrophage Depletion in Hypertensive Rats Accelerates Development of Cardiomyopathy

    Zandbergen, H.R.; Sharma, U.C.; S. Gupta; Verjans, J.W.H.; Borne, van den, J.J.G.C.; S Pokharel; Brakel, T.; Duijvestijn, A; Rooijen, van, J.; Maessen, J.G.; Reutelingsperger, C.P.M.; Pinto, Y.; Narula, J.; Hofstra, L

    2009-01-01

    Inflammation contributes to the process of ventricular remodeling after acute myocardial injury. To investigate the role of macrophages in the chronic process of cardiac remodeling, they were selectively depleted by intravenous administration of liposomal clodronate in heart failure-prone hypertensive Ren-2 rats from the age of 7 until 13 weeks. plain liposomes were used for comparison. Liposomal clodronate treatment reduced the number of blood monocytes and decreased the number of macrophage...

  18. Helpful Self-Control: Autonomy Support, Vitality, and Depletion

    Muraven, Mark; Gagné, Marylène; Rosman, Heather

    2008-01-01

    Why someone exerts self-control may influence how depleting a task is. Feeling compelled to exert self-control require more self-control strength than exerting self-control for more autonomous reasons. Across three experiments, individuals whose autonomy was supported while exerting self-control performed better on a subsequent test of self-control as compared to individuals who had more pressure placed upon them while exerting self-control. The differences in self-control performance were no...

  19. Identification of biological microparticles using ultrafast depletion spectroscopy

    Courvoisier, François; Bonacina, Luigi; Boutou, Véronique; Guyon, Laurent; Bonnet, Christophe; Thuillier, Benoit; Extermann, Jérôme; Roth, Matthias; Rabitz, Herschel; Wolf, Jean-Pierre

    2008-01-01

    We show how an ultrafast pump–pump excitation induces strong fluorescence depletion in biological samples, such as bacteria-containing droplets, in contrast with fluorescent interferents, such as polycyclic aromatic compounds, despite similar spectroscopic properties. Application to the optical remote discrimination of biotic versus non-biotic particles is proposed. Further improvement is required to allow the discrimination of one pathogenic among other non-pathogenic micro-organisms. This i...

  20. Fundamental differences between Arctic and Antarctic ozone depletion

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J.; Min, Flora

    2014-01-01

    Fundamental differences in observed ozone depletion between the Arctic and the Antarctic are shown, clarifying distinctions between both average and extreme ozone decreases in the two hemispheres. Balloon-borne and satellite measurements in the heart of the ozone layer near 18−24 km altitude show that extreme ozone decreases often observed in the Antarctic ozone hole region have not yet been measured in the Arctic in any year, including the unusually cold Arctic spring of 2011. The data provi...

  1. Residue depletion of colistin in swine after intramuscular administration

    S. S. Tang; Gong, L. J.; J.K. He; Jin, X; X.L. Xiao

    2009-01-01

    A newly formulated colistin sulphate solution was prepared in a previous study as a potential agent for intramuscular injection and its effectiveness, toxicity and pharmacokinetics were investigated. In order to provide more information to establish scientific guidance for safe use of this preparation, its residue depletion in swine tissues following intramuscular administration was investigated in this experiment. Fifty healthy cross-bred piglets (13.3 ± 0.9 kg) were used in this study. Five...

  2. Gamma-ray line intensities for depleted uranium

    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

  3. Application of depletion perturbation theory to fuel cycle burnup analysis

    Over the past several years static perturbation theory methods have been increasingly used for reactor analysis in lieu of more detailed and costly direct computations. Recently, perturbation methods incorporating time dependence have also received attention, and several authors have demonstrated their applicability to fuel burnup analysis. The objective of the work described here is to demonstrate that a time-dependent perturbation method can be easily and accurately applied to realistic depletion problems

  4. Consistent Cosmic Microwave Background Spectra from Quantum Depletion

    Casadio, Roberto; Kuhnel, Florian; Orlandi, Alessio

    2015-01-01

    Following a new quantum cosmological model proposed by Dvali and Gomez, we quantitatively investigate possible modifications to the Hubble parameter and following corrections to the cosmic microwave background spectrum. In this model, scalar and tensor perturbations are generated by the quantum depletion of the background inflaton and graviton condensate respectively. We show how the inflaton mass affects the power spectra and the tensor-to-scalar ratio. Masses approaching the Planck scale wo...

  5. Radiation survey and decontamination of cape Arza from depleted uranium

    Vukotić Perko

    2003-01-01

    Full Text Available In the action of NATO A-10 airplanes in 1999, the cape Arza, Serbia and Montenegro was contaminated by depleted uranium. The clean-up operations were undertaken at the site, and 242 uranium projectiles and their 49 larger fragments were removed from the cape. That is about 85% of the total number of projectiles by which Arza was contaminated. Here are described details of the applied procedures and results of the soil radioactivity measurements after decontamination.

  6. Uranium and the use of depleted uranium in weaponry

    In this brief report the author shows that the use of shells involving a load of depleted uranium might lead to lasting hazards to civil population and environment. These hazards come from the part of the shell that has been dispersed as contaminating radioactive dusts. The author describes some features of radioactivity and highlights the role of Uranium-238 as a provider of energy to the planet. (A.C.)

  7. Population Exposure to Depleted Uranium in the Han Pijesak Region

    Zora S. Žunić; Rodoljub Simović; Zoran Ćurguz; Olivera Čuknić; Jerzy Mietelski; Predrag Ujić; Igor Čeliković; Predrag Kolarž; Branko Predojević

    2011-01-01

    In September 1995 the Han Pijesak area of Republic of Srpska was heavily attacked by Depleted Uranium (DU) ammunition. In this area, from 2003 to 2004, during one year, the components of natural ionizing radiation sources like radon, thoron, and gamma radiation were measured. In addition, during the same period, the samples of soil, moss, and lichen were collected in order to identify the content of technologically enhanced natural radionuclides in them and particularly their isotopic ratios,...

  8. Uranio impoverito: perch'e? (Depleted uranium: why?)

    D'Abramo, G

    2003-01-01

    In this paper we develop a simple model of the penetration process of a long rod through an uniform target. Applying the momentum and energy conservation laws, we derive an analytical relation which shows how the penetration depth depends upon the density of the rod, given a fixed kinetic energy. This work was sparked off by the necessity of the author of understanding the reasons of the effectiveness of high density penetrators (e.g. depleted uranium penetrators) as anti-tank weapons.

  9. Depleted uranium report from the Health Council of the Netherlands

    The Health Council of the Netherlands, which is an independent scientific advisory body established in 1902 to advise the government and Parliament on the current level of knowledge with respect to public health issues', has recently published an overview report on depleted uranium. The title of the report is Health risks of exposure to depleted uranium' and it is freely available in both English and the original Dutch language. A brief summary of the report that was published on 16 May 2001 is presented here. The use of ammunition containing depleted uranium (DU) in Kosovo and elsewhere in the Balkans has provoked disquiet in Europe. In the Netherlands, concern over the release of this material had already been aroused previously following the crash of the El-Al airliner in the Bijlmermeer district of Amsterdam in 1992. It was against this background that the President of the Health Council decided to set up a Committee charged with the task of reviewing the health risks of exposure to DU and the preventive measures required for individuals present in areas where DU has been released into the environment. After reviewing the properties of uranium in general and depleted uranium in particular, and presenting data on the occurrence of the element in the environment and biological tissues, the committee assessed the chemical and radiological health effect of uranium and uranium compounds. The Health Council Committee concludes that radioactive contamination of the lungs is the principal health risk to be considered in connection with exposure to slightly soluble uranium compounds in the atmosphere. For soluble compounds, the chemical toxic effect in the kidneys is the primary consideration. The toxicological effects are to some extent concordant with those of other heavy metals. For relevant exposure scenarios the Committee does not anticipate that exposure to DU will result in a demonstrable increased risk of diseases and symptoms among exposed individuals as a

  10. Mitochondrial Toxicity of Depleted Uranium: Protection by Beta-Glucan

    Shaki, Fatemeh; Pourahmad, Jalal

    2013-01-01

    Considerable evidence suggests that mitochondrial dysfunction contributes to the toxicity of uranyl acetate (UA), a soluble salt of depleted uranium (DU). We examined the ability of the two antioxidants, beta-glucan and butylated hydroxyl toluene (BHT), to prevent UA-induced mitochondrial dysfunction using rat-isolated kidney mitochondria. Beta-glucan (150 nM) and BHT (20 nM) attenuated UA-induced mitochondrial reactive oxygen species (ROS) formation, lipid peroxidation and glutathione oxidat...

  11. Uranio impoverito: perch\\'e? (Depleted uranium: why?)

    D'Abramo, Germano

    2003-01-01

    In this paper we develop a simple model of the penetration process of a long rod through an uniform target. Applying the momentum and energy conservation laws, we derive an analytical relation which shows how the penetration depth depends upon the density of the rod, given a fixed kinetic energy. This work was sparked off by the necessity of understanding the effectiveness of high density penetrators (e.g. depleted uranium penetrators) as anti-tank weapons.

  12. Military use of depleted uranium: assessment of prolonged population exposure

    Giannardi, C.; Dominici, D.

    2001-01-01

    This work is an exposure assessment for a population living in an area contaminated by use of depleted uranium (DU) weapons. RESRAD 5.91 code is used to evaluate the average effective dose delivered from 1, 10, 20 cm depths of contaminated soil, in a residential farmer scenario. Critical pathway and group are identified in soil inhalation or ingestion and children playing with the soil, respectively. From available information on DU released on targeted sites, both critical and average exposu...

  13. Radiation survey and decontamination of cape Arza from depleted uranium

    Vukotić Perko; Anđelić Tomislav; Zekić Ranko; Kovačević Milojko S.; Vasić Vladimir; Savić Slobodan

    2003-01-01

    In the action of NATO A-10 airplanes in 1999, the cape Arza, Serbia and Montenegro was contaminated by depleted uranium. The clean-up operations were undertaken at the site, and 242 uranium projectiles and their 49 larger fragments were removed from the cape. That is about 85% of the total number of projectiles by which Arza was contaminated. Here are described details of the applied procedures and results of the soil radioactivity measurements after decontamination.

  14. Depleted uranium exposure and health effects in Gulf War veterans

    Squibb, Katherine S.; McDiarmid, Melissa A.

    2006-01-01

    Health effects stemming from depleted uranium (DU) exposure in a cohort of Gulf War veterans who were in or on US Army vehicles hit by friendly fire involving DU munitions are being carefully monitored through the Baltimore Veterans Affairs (VA) DU Follow-Up Program initiated in 1993. DU exposure in this cohort has been directly measured using inductively coupled plasma-mass spectrometer (ICP-MS) isotopic analysis for DU in urine specimens. Soldiers with embedded DU fragments continue to excr...

  15. The health effects of depleted uranium munitions: a summary

    Spratt, B.; Stoneham, A. M.

    2002-01-01

    There has been a substantial amount of public discussion on the health effects of the use of depleted uranium (DU) munitions. In response to this concern the Royal Society set up an independent, expert working group to investigate the health effects of DU munitions. The Royal Society has now produced two reports, and this summary covering the key conclusions and recommendations from both reports. The part I report considered the increased risks of radiation-induced cancer from exposures to DU...

  16. Verification of the COCAGNE core code using cluster depletion calculations

    EDF/R and D is developing a new calculation scheme based on the transport- Simplified Pn (SPn) approach. The lattice code used is the deterministic code APOLLO2, developed at CEA with the support of EDF and AREVA-NP. The core code is the code COCAGNE, developed at EDF R and D. The latter can take advantage of a microscopic depletion solver which improves the treatment of spectral history effects. This solver can resort to a specific correction based on the use of the Pu239 concentration as a spectral indicator. In order to evaluate the improvements brought by this Pu239 correction model, one uses (3x3 assemblies) cluster depletion calculations as test-cases. UOX and UOX/MOX clusters are both considered. As a reference, APOLLO2 depletion calculations of these clusters, using a critical boron (CB) search scheme at each calculation step, are performed. This choice of methodology (using CB search instead of a fixed average CB) enables to highlight historical spectral effects related to the boron concentration. This methodology is also more consistent with the depletion calculation of real cores. Pin by pin COCAGNE calculations are performed and compared with the APOLLO2 results. The analysis of the results obtained shows that the boron concentration computed by COCAGNE gets more consistent with APOLLO2 when the Pu239 corrector is used, especially for UOX/MOX clusters. As for pin power distribution, the use of the Pu239 model also enables to reduce slightly the gap between APOLLO2 and COCAGNE. This work will be extended to clusters with gadolinium-poisoned fuel assemblies and reflector regions. (author)

  17. MEASURING Be DEPLETION IN COOL STARS WITH EXOPLANETS

    Mena, Elisa Delgado; Israelian, Garik; Hernández, Jonay I. González; Santos, Nuno C.; Rebolo, Rafael

    2011-01-01

    We present new UVES spectra of a sample of 14 mostly cool unevolved stars with planetary companions with the aim of studying possible differences in Be abundance with respect to stars without detected planets. We determine Be abundances for these stars that show an increase in Be depletion as we move to lower temperatures. We carry out a differential analysis of spectra of analog stars with and without planets to establish a possible difference in Be content. While for hot stars no measurable...

  18. Response: Depletion and degradation are not the same

    This article responses to the Case against Environmental Taxes for Sustainable Forestry. The author points out that in the previous article the implications of continuity of ownership and associate responsibilities are obscured by not clearly distinguishing timber-related depletion costs from nontimber environmental costs. Because the environmental effects of tropical logging are externalities, some type of public policy is neccessary to ensure that private actions coincide with socially optimal behavior. Environmental taxes may not be the only policy action available though

  19. Huntington's disease: effect of cysteamine, a somatostatin-depleting agent.

    Shults, C; Steardo, L; Barone, P; Mohr, E; Juncos, J; Serrati, C; Fedio, P; Tamminga, C A; Chase, T N

    1986-08-01

    Somatostatin levels in the basal ganglia are elevated in Huntington's disease. A controlled therapeutic trial of the somatostatin-depleting agent, cysteamine, was therefore conducted in five patients, including one with the rigid-akinetic form. Maximum tolerated dosage for 2 weeks produced no consistent change in extrapyramidal or dementia scores. Somatostatin concentrations were not significantly altered in plasma or CSF. Growth hormone levels, on the other hand, more than doubled, suggesting a functionally significant decrease in central somatostatin levels. PMID:2874527

  20. EZH2 depletion blocks the proliferation of colon cancer cells.

    Bettina Fussbroich

    Full Text Available The Enhancer of Zeste 2 (EZH2 protein has been reported to stimulate cell growth in some cancers and is therefore considered to represent an interesting new target for therapeutic intervention. Here, we investigated a possible role of EZH2 for the growth control of colon cancer cells. RNA interference (RNAi-mediated intracellular EZH2 depletion led to cell cycle arrest of colon carcinoma cells at the G1/S transition. This was associated with a reduction of cell numbers upon transient transfection of synthetic EZH2-targeting siRNAs and with inhibition of their colony formation capacity upon stable expression of vector-borne siRNAs. We furthermore tested whether EZH2 may repress the growth-inhibitory p27 gene, as reported for pancreatic cancer. However, expression analyses of colon cancer cell lines and colon cancer biopsies did not reveal a consistent correlation between EZH2 and p27 levels. Moreover, EZH2 depletion did not re-induce p27 expression in colon cancer cells, indicating that p27 repression by EZH2 may be cell- or tissue-specific. Whole genome transcriptome analyses identified cellular genes affected by EZH2 depletion in colon cancer cell lines. They included several cancer-associated genes linked to cellular proliferation or invasion, such as Dag1, MageD1, SDC1, Timp2, and Tob1. In conclusion, our results demonstrate that EZH2 depletion blocks the growth of colon cancer cells. These findings might provide benefits for the treatment of colon cancer.

  1. Bromine measurements in ozone depleted air over the Arctic Ocean

    J. A. Neuman

    2010-07-01

    Full Text Available In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL. Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS study. Fast (1 s and sensitive (detection limits at the low pptv level measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br2. Subsequent laboratory studies showed that HOBr rapidly converts to Br2 on the Teflon instrument inlets. This detected Br2 is identified as active bromine and represents a lower limit of the sum HOBr + Br2. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere.

  2. Safety evaluation for packaging (onsite) depleted uranium waste boxes

    This safety evaluation for packaging (SEP) allows the one-time shipment of ten metal boxes and one wooden box containing depleted uranium material from the Fast Flux Test Facility to the burial grounds in the 200 West Area for disposal. This SEP provides the analyses and operational controls necessary to demonstrate that the shipment will be safe for the onsite worker and the public

  3. A search for relativistic electron induced stratospheric ozone depletion

    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.

  4. Evaluating ozone depletion from very short-lived halocarbons

    Olsen, Seth C.; Hannegan, Bryan J; Zhu, Xin; Prather, Michael J.

    2000-01-01

    A new approach is needed for calculating the ozone depletion potential (ODP) of short-lived gases with mean lifetimes less than 100 days. Clearly, the ozone loss from such gases depends strongly on the location and season of emissions. It is proposed that delivery to the tropical tropopause is a surrogate for the amount of halogen entering the stratosphere. Thus 3-D global models, with accurate simulation of tropospheric chemistry and transport, can calculate the ODP specific to tropical sour...

  5. Motif depletion in bacteriophages infecting hosts with CRISPR systems

    Kupczok, Anne; Bollback, Jonathan P

    2014-01-01

    Background CRISPR is a microbial immune system likely to be involved in host-parasite coevolution. It functions using target sequences encoded by the bacterial genome, which interfere with invading nucleic acids using a homology-dependent system. The system also requires protospacer associated motifs (PAMs), short motifs close to the target sequence that are required for interference in CRISPR types I and II. Here, we investigate whether PAMs are depleted in phage genomes due to selection pre...

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

    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 re...

  7. Ozone depletion and skin cancer incidence: an integrated modelling approach

    Slaper H; den Elzen MGJ; de Woerd HJ; Greef J de

    1992-01-01

    A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. The incidence of skin cancer is expected to increase due to ozone depletion. An integrated source-risk model is developed and applied to evaluate the increased skin cancer incidence related to various CFC emission scenarios. The source-risk model is an independent submodule within the framework of IMAGE, an integrated source-effect-model for climate change...

  8. The relationship between skin cancers, solar radiation and ozone depletion.

    Moan, J.; Dahlback, A.

    1992-01-01

    During the period 1957-1984 the annual age-adjusted incidence rate of cutaneous malignant melanoma (CMM) increased by 350% for men and 440% for women in Norway. The annual exposure to carcinogenic sunlight in Norway, calculated by use of measured ozone levels, showed no increasing trend during the same period. Thus, ozone depletion is not a cause of the increasing trend of the incidence rates of skin cancers. The incidence rates of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) ...

  9. Seasonal Storage of Hydrogen in a Depleted Natural Gas Reservoir

    Mignard, Dimitri; Wilkinson, Mark; Amid, Adrian

    2016-01-01

    Hydrogen storage in a depleted gas reservoir or in an aquifer offers the potential for the seasonal storage of inherently variable renewable energy, by the electrolysis of water during periods of excess energy production. Here we investigate whether such storage is technically feasible. We compared the respective capacities and deliverabilities of hydrogen to established natural gas in a seasonal storage facility, on the basis of an estimated total volumetric capacity of 48MMm3, delivery pres...

  10. Satellite-based estimates of groundwater depletion in India

    Rodell, M.; Velicogna, I; Famiglietti, JS

    2009-01-01

    Groundwater is a primary source of fresh water in many parts of the world. Some regions are becoming overly dependent on it, consuming groundwater faster than it is naturally replenished and causing water tables to decline unremittingly. Indirect evidence suggests that this is the case in northwest India, but there has been no regional assessment of the rate of groundwater depletion. Here we use terrestrial water storage-change observations from the NASA Gravity Recovery and Climate Experimen...

  11. The Lithium Depletion Boundary as a Clock and Thermometer

    Jeffries, R. D.; T. Naylor

    2000-01-01

    We take a critical look at the lithium depletion boundary (LDB) technique that has recently been used to derive the ages of open clusters. We identify the sources of experimental and systematic error and show that the probable errors are larger by approximately a factor two than presently claimed in the literature. We then use the Pleiades LDB age and photometry in combination with evolutionary models to define empirical colour-T_eff relations that can be applied to younger clusters. We find ...

  12. Effects of deuterium depleted water on reproduction of Rainbow fish

    The paper refers to an isotopic composition used to prepare fecundating solutions for artificial reproduction of fish. The solution is constituted as a mixture of deuterium depleted water and natural water (whose isotopic concentration is of 85-90 ppm D/(D+H)) in which we can add activating and energizing substances. This fecundating solution ensures an improved fecundating level of fish roe, increase life index in the next growth up stages and increase fish resistance at special medium conditions. (authors)

  13. Inhomogeneous depletion of oxygen ions in metal oxide nanoparticles

    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.

  14. Alignment of gold nanorods by angular photothermal depletion

    Taylor, Adam B.; Chow, Timothy T. Y.; Chon, James W. M., E-mail: jchon@swin.edu.au [Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, P.O. Box 218, Hawthorn, 3122 VIC (Australia)

    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.

  15. Accounting for Depletion of Oil and Gas Resources in Malaysia

    Othman, Jamal, E-mail: jortman@ukm.my; Jafari, Yaghoob, E-mail: yaghoob.jafari@gmail.com [Universiti Kebangsaan Malaysia, Faculty of Economics and Management (Malaysia)

    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.

  16. Accounting for Depletion of Oil and Gas Resources in Malaysia

    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.

  17. Radioprotective and Immunostimulating Effects of Deuterium-Depleted Water

    Full text: Mice fed during 15 days with Deuterium-Depleted Water (30 ppm deuterium) had a statistically significant increased survival compared with control groups fed with normal distilled water (150 ppm deuterium) after 8.5 Gy irradiation (61% survival in test group towards 25% in control group). Hematological picture showed maintaining of the normal WBC, RBC and platelet count in test groups. Immunological parameters (serum opsonic and bactericidal capacity, bactericidal capacity of the peritoneal macrophages) showed a marked increase in test groups compared to a severe decrease in the control groups. Auxiliary tests using chemical radiomimetics (hydrochloric embihine) and immunosupressors (cyclophosphamide) showed a strong protective effect of deuterium-depleted water against the decrease of the leukocyte counts and other immunologic parameters. In conditions of experimental inflammation with subcutaneous-implanted pellets, deuterium-depleted water feeding statistically significant increased inflammatory response, obviated by increased percentages of PMN and lymphocytes in the peripheral blood and increased phagocytic capacity of the peripheral blood PMN. Experimental infections with K. pneumoniae 506 and S. pneumoniae 558 in mice irradiated or treated with cyclophosphamide showed increased non-specific immunity parameters. All results show a marked intensification of the immune defenses and increased proliferation of the peripheral blood cells, probably accounting for the radioprotective effects. (author)

  18. Alteration of bleomycin cytotoxicity by glutathione depletion or elevation

    In part, some of the cytotoxicity of bleomycin may be lessened or enhanced by modulation of glutathione (GSH) concentrations. Enhancement of bleomycin cytotoxicity was observed when GSH levels were low and protection was observed when GSH levels were elevated. Since H2O2 is one of the reactive species produced by bleomycin catalyzed oxygen activation, the authors studied the effects of H2O2 exposure after GSH depletion. H2O2, like bleomycin, shows enhanced cytotoxicity in GSH depleted cells. It has been proposed that bleomycin cytotoxicity requires reducing equivalents from non-protein bound thiols (such as GSH) to activate the bleomycin-metal complex, which in turn reacts with oxygen to generate free radicals and peroxides. The data suggest that either GSH is not required to cycle reducing equivalents to the oxidized bleomycin-metal complex, or the low levels of depleted GSH attained (less than 5% of control) were still sufficient to effect reduction. Further, the data shows that GSH in fact provides a means of protection and detoxification from the cytotoxic effects of bleomycin

  19. MEASURING Be DEPLETION IN COOL STARS WITH EXOPLANETS

    We present new UVES spectra of a sample of 14 mostly cool unevolved stars with planetary companions with the aim of studying possible differences in Be abundance with respect to stars without detected planets. We determine Be abundances for these stars that show an increase in Be depletion as we move to lower temperatures. We carry out a differential analysis of spectra of analog stars with and without planets to establish a possible difference in Be content. While for hot stars no measurable difference is found in Be, for the only cool (Teff∼ 5000 K) planet-host star with several analogs in the sample we find enhanced Be depletion by 0.25 dex. This is a first indication that the extra-depletion of Li in solar-type stars with planets may also happen for Be, but shifted toward lower temperatures (Teff < 5500 K) due to the depth of the convective envelopes. The processes that take place in the formation of planetary systems may affect the mixing of material inside their host stars and hence the abundances of light elements.

  20. CO depletion --- An evolutionary tracer for molecular clouds

    Liu, Tie; Zhang, Huawei

    2013-01-01

    Planck cold clumps are among the most promising objects to investigate the initial conditions of the evolution of molecular clouds. In this work, by combing the dust emission data from the survey of Planck satellite with the molecular data of $^{12}$CO/$^{13}$CO (1-0) lines from observations with the Purple Mountain Observatory (PMO) 14 m telescope, we investigate the CO abundance, CO depletion and CO-to-H$_{2}$ conversion factor of 674 clumps in the early cold cores (ECC) sample. The median and mean values of the CO abundance are 6.2$\\times10^{-5}$ and 9.1$\\times10^{-5}$, respectively. The mean and median of CO depletion factor are 2.8 and 1.4, respectively. The median value of $X_{CO-to-H_{2}}$ for the whole sample is $3.3\\times10^{20}$ cm$^{-2}$K$^{-1}$km$^{-1}$ s. The CO abundance, CO depletion factor and CO-to-H$_{2}$ conversion factor seems to be strongly correlated to other physical parameters (e.g. dust temperature, dust emissivity spectra index and column density). CO gas severely freeze out in colde...

  1. Rhizosphere effect of different aquatic plants on phosphorus depletion

    Zhenyu WANG; Shengfang WEN; Baoshan XING; Dongmei GAO; Fengmin LI

    2008-01-01

    A series of pot experiments with Alternanthera philoxeroides, Typha latifolia, Sagittaria sagittifolia and Phragmites communis were conducted to assess the phos-phorus depletion effect in the rhizosphere. The ratio of root to shoot, root morphology, phosphorus uptake efficiency and phosphorus utilization efficiency were analyzed. An obvious variation in phosphorus concentrations between the rhizosphere soil and non-rhizosphere soil was observed. The water-soluble P contents in the rhizosphere soil of A. philoxeroides, T. latifolia, S. sagittifolia and P. communis were reduced by 81%, 42%, 18% and 16%, respectively, compared with that in the non-rhizosphere soil. A. philox-eroides had the highest phosphorus uptake efficiency (1.32 mg/m), while T. latifolia achieved the effective phos-phorus depletion by the strong rooting system and the high phosphorus uptake efficiency (0.52 mg/m). T. latifolia not only used phosphorus to produce biomass economically, but also adjusted carbon allocation to the roots to explore the soil for more available phosphorus. A. philoxeroides and T. latifolia were more effective in depleting phosphorus in the rhizosphere than S. sagittifolia and P. communis.

  2. Valence bands offset between depleted semiconductors measured by photoelectron spectroscopy

    A modified method to measure the valence bands offset by photoelectron spectroscopy (PES) between low doped and depleted semiconductors have been used. The surface photovoltage (SPV) and the charging effects modify the PES spectra of depleted semiconductors. The valence bands offset at the heterojunction of depleted ZnSe film and doped GaAs substrate have been measured. These samples were prepared by the laser ablation technique. The shift of PES spectra of ZnSe by about 6 eV has been observed due to the charging and SPV effects. The charging and SPV effects on PES spectra, have been reduced to negligible values in the presence of excess plasma (due to absorption from a secondary white light source) density of the order of 1018 cm-3. The effect of the charging and SPV is very small on the value of the valence bands offset measured in the presence of the excess plasma. This method to measure the valence bands offset is useful for samples prepared in ex situ conditions and with film thickness of the order of 100 nm

  3. Ionospheric heating, upwelling, and depletions in auroral current systems

    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.

  4. [Biomedical and economic consequences of stratosphere ozone depletion].

    Strzhizhovskiĭ, A D

    1998-01-01

    Information on possible human health-changes associated with stratosphere ozone depletion and amplification factor (% increase of the stick rate by 1% decrease of ozone) values for acute (erythema, keratitis, cataract, immunosuppression) and chronic (skin cancer, cataract) effects of natural UV-radiation was analysed. Amplification factor (AF) values for acute UV-effects increase with degree of ozone depletion. For degrees less than 12.5% they are independent of latitude and equal to 1.9 for erythema, 1.3-1.5 for keratitis, 1.7-2.3 for cataract and 0.9-1.1 for immunosuppression. AF values for incidence of non-melanoma skin cancer are independent of age, higher in males than females, and higher for squamous cell carcinoma, than for basal cell carcinoma. Their optimal estimations for whites equal to 2.7 for basal cell and 4.6 for squamous cell carcinoma. AF values for incidence of cutaneous malignant melanoma range between 1 and 2, for melanoma mortality--between 0.3 and 2. AF values for incidence of cataract range between 0.3 and 1.2 with optimal estimations between 0.6 and 0.8. Prognosis of non-melanoma skin cancer and cataract incidences, melanoma mortality and economic loss for different scenarios of stratosphere ozone depletion are presented. PMID:9633627

  5. Measurement of camera image sensor depletion thickness with cosmic rays

    Vandenbroucke, J; Bravo, S; Jensen, K; Karn, P; Meehan, M; Peacock, J; Plewa, M; Ruggles, T; Santander, M; Schultz, D; Simons, A L; Tosi, D

    2015-01-01

    Camera image sensors can be used to detect ionizing radiation in addition to optical photons. In particular, cosmic-ray muons are detected as long, straight tracks passing through multiple pixels. The distribution of track lengths can be related to the thickness of the active (depleted) region of the camera image sensor through the known angular distribution of muons at sea level. We use a sample of cosmic-ray muon tracks recorded by the Distributed Electronic Cosmic-ray Observatory to measure the thickness of the depletion region of the camera image sensor in a commercial smart phone, the HTC Wildfire S. The track length distribution prefers a cosmic-ray muon angular distribution over an isotropic distribution. Allowing either distribution, we measure the depletion thickness to be between 13.9~$\\mu$m and 27.7~$\\mu$m. The same method can be applied to additional models of image sensor. Once measured, the thickness can be used to convert track length to incident polar angle on a per-event basis. Combined with ...

  6. Russian roulette. [Problem of USSR production offsetting depletion

    1979-10-15

    The world's largest producer of crude oil is the Soviet Union, lifting about 11.6 million barrels per day (bpd). Next is Saudi Arabia at about 9.5 million bpd, followed by the US at 8.5 million bpd. What if the Soviet Union should, like the US before it, cross over from a net exporter to net importer of oil. Since 1977 the US Central Intelligence Agency has been warning of just such a crossover. For just about as long, analysts within the US oil industry have been dismissing the CIA's warnings as unduly alarmist. This year's numbers - reported by the Soviets themselves - tend to confirm the CIA's case. The heart of the problem is the Soviet Union's enormous production rate, 11.6 million bpd and headed for 12 million to 13 million. Producing these oceanic amounts depletes reservoirs fast. As old ones decline, they must be offset with new finds. The current five-year plan calls for a depletion offset of 7.8 million bpd. They must bring in new production not much less than the US' total annual production just to stay even. Think of it as two Irans. A depletion offset that big and growing, the CIA believes, will become unachievable.

  7. DEPLETION POTENTIAL OF COLLOIDS:A DIRECT SIMULATION STUDY

    LI; Wei-hua(

    2001-01-01

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

  8. Decontamination of Cape Arza (Montenegro) from depleted Uranium

    On May 30, 1999, NATO A-10 aircrafts attacked Cape Arza, a very attractive touring area on peninsula Lustica, at the entrance of Boka Kotorska Bay, in Montenegro. They fired anti-armour rounds with penetrators made of depleted uranium. Such an armour-penetrating round has a length of 173 mm and a diameter of 30 mm. The bullet has an aluminium case (jacket) and inside it a conical DU penetrator. The length of the penetrator itself is 95 mm, and the diameter of its base is 16 mm. The penetrator weight is 292 g. According to the data reported by NATO (NATO, 2001), the total number of rounds fired against Cape Arza was 480. As to the data on combat mix of the A-10 aircraft gun, 300 (UNEP, 2001) or 400 (UNEP, 2001; FAS) of these rounds where with DU penetrators, and the rest with a classical charge. This means that Cape Arza was contaminated with 90 or 120 kg of DU, or with a radioactivity of (3.5 - 4.7) · 109 Bq. Depleted uranium is a waste product of the process of uranium enrichment in 235U isotope, for use in nuclear reactors or in nuclear weapons. The isotopic composition of depleted uranium is (Harley et al., 1999): (99.7 - 99.8) % of 238U, (0.2 - 0.3) % of 235U, 0.001 % of 234U, and only traces of 234Th, 234Pa and 231Th. If traces of the isotopes 236U, 239Pu and 240Pu are also present, as it is the case with DU from Cape Arza (UNEP, 2002), the depleted uranium is obtained by reprocessing of spent nuclear reactor fuel. The activity concentration of depleted uranium is 39.42 · 106 Bq/kg. Most of it comes from 238U and its decay products 234Th and 234Pa which are in radioactive equilibrium (12.27 · 106 Bq/kg per each of them), and the less part from 235U and 231Th (0.16 · 106 Bq/kg per each) (UNEP, 1999), while the activity concentration of 236U, 239Pu and 240Pu is below 100 Bq/kg (UNEP, 2001)

  9. 77 FR 53236 - Proposed International Isotopes Fluorine Extraction Process and Depleted Uranium Deconversion...

    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, New Mexico. On December 30, 2009, International Isotopes Fluorine Products, Inc. (IIFP), a...

  10. The functionalized amino acid (S-Lacosamide subverts CRMP2-mediated tubulin polymerization to prevent constitutive and activity-dependent increase in neurite outgrowth

    Sarah M Wilson

    2014-07-01

    Full Text Available Activity-dependent neurite outgrowth is a highly complex, regulated process with important implications for neuronal circuit remodeling in development as well as in seizure-induced sprouting in epilepsy. Recent work has linked outgrowth to collapsin response mediator protein 2 (CRMP2, an intracellular phosphoprotein originally identified as axon guidance and growth cone collapse protein. The neurite outgrowth promoting function of CRMP2 is regulated by its phosphorylation state. In this study, depolarization (potassium chloride-driven activity increased the level of active CRMP2 by decreasing its phosphorylation by GSK3β via a reduction in priming by Cdk5. To determine the contribution of CRMP2 in activity-driven neurite outgrowth, we screened a limited set of compounds for their ability to reduce neurite outgrowth but not modify voltage-gated sodium channel (VGSC biophysical properties. This led to the identification of (S-lacosamide ((S-LCM, a stereoisomer of the clinically used antiepileptic drug (R-LCM (Vimpat®, as a novel tool for preferentially targeting CRMP2-mediated neurite outgrowth. Whereas (S-LCM was ineffective in targeting VGSCs, the presumptive pharmacological targets of (R-LCM, (S-LCM was more efficient than (R-LCM in subverting neurite outgrowth. Biomolecular interaction analyses revealed that (S-LCM bound to wildtype CRMP2 with low micromolar affinity, similar to (R-LCM. Through the use of this novel tool, the activity-dependent increase in neurite outgrowth observed following depolarization was characterized to be reliant on CRMP2 function. Knockdown of CRMP2 by siRNA in cortical neurons resulted in reduced CRMP2-dependent neurite outgrowth; incubation with (S-LCM phenocopied this effect. Other CRMP2-mediated processes were unaffected. (S-LCM subverted neurite outgrowth not by affecting the canonical CRMP2-tubulin association but rather by impairing the ability of CRMP2 to promote tubulin polymerization, events that are

  11. Fighting self-control failure: overcoming ego depletion by increasing self-awareness

    Alberts, Hugo J. E. M.; Martijn, Carolien; de Vries, Nanne K

    2010-01-01

    International audience According to the limited strength model (Muraven, Tice, & Baumeister, 1998), exerting self-control causes ego depletion: a depletion of cognitive resources resulting in poorer performance on later self-control tasks. Previous studies have demonstrated a positive effect of self-awareness on self-control performance. The present study examined whether the occurrence of ego depletion can be circumvented by increasing self-awareness. Initially depleted participants who r...

  12. The consequences and hazards of depleted uranium weapons used by US army since gulf war

    Military equipment and development of depleted uranium weapon in USA, the depleted uranium weapon used in gulf war by USA army, personnel irradiation in the gulf war, and the protection in the gulf war are introduced. The radioactivity, radioactive characteristics, chemical toxicity and hazard of the depleted uranium are also introduced

  13. Selection of a management strategy for depleted uranium hexafluoride

    A consequence of the uranium enrichment process used in the United States (US) is the accumulation of a significant amount of depleted uranium hexafluoride (UF6). Currently, approximately 560,000 metric tons of the material are stored at three different sites. The US Department of Energy (DOE) has recently initiated a program to consider alternative strategies for the cost-effective and environmentally safe long-term management of this inventory of depleted UF6. The program involves a technology and engineering assessment of proposed management options (use/reuse, conversion, storage, or disposal) and an analysis of the potential environmental impacts and life-cycle costs of alternative management strategies. The information obtained from the studies will be used by the DOE to select a preferred long-term management strategy. The selection and implementation of a management strategy will involve consideration of a number of important issues such as environmental, health, and safety effects; the balancing of risks versus costs in a context of reduced government spending; socioeconomic implications, including effects on the domestic and international uranium industry; the technical status of proposed uses or technologies; and public involvement in the decision making process. Because of its provisions for considering a wide range of relevant issues and involving the public, this program has become a model for future DOE materials disposition programs. This paper presents an overview of the Depleted Uranium Hexafluoride Management Program. Technical findings of the program to date are presented, and major issues involved in selecting and implementing a management strategy are discussed

  14. Depleted-Heterojunction Colloidal Quantum Dot Solar Cells

    Pattantyus-Abraham, Andras G.

    2010-06-22

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processability with quantum size-effect tunability to match absorption with the solar spectrum. Rapid recent advances in CQD photovoltaics have led to impressive 3.6% AM1.5 solar power conversion efficiencies. Two distinct device architectures and operating mechanisms have been advanced. The first-the Schottky device-was optimized and explained in terms of a depletion region driving electron-hole pair separation on the semiconductor side of a junction between an opaque low-work-function metal and a p-type CQD film. The second-the excitonic device-employed a CQD layer atop a transparent conductive oxide (TCO) and was explained in terms of diffusive exciton transport via energy transfer followed by exciton separation at the type-II heterointerface between the CQD film and the TCO. Here we fabricate CQD photovoltaic devices on TCOs and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation, and that they also exploit the large bandgap of the TCO to improve rectification and block undesired hole extraction. The resultant depletedheterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS CQDs, enabling broadband harvesting of the solar spectrum. We report the highest opencircuit voltages observed in solid-state CQD solar cells to date, as well as fill factors approaching 60%, through the combination of efficient hole blocking (heterojunction) and very small minority carrier density (depletion) in the large-bandgap moiety. © 2010 American Chemical Society.

  15. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization.

    Jorgelina Buschiazzo

    Full Text Available Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1 a decrease of the fertilization rate and index; and (2 a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.

  16. Inhibition of lytic infection of pseudorabies virus by arginine depletion

    Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzing the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression

  17. L-Tryptophan depletion bioreactor, a possible cancer therapy

    Rolf Bambauer

    2015-04-01

    Full Text Available The cancer therapeutic strategies knownto date are not adequate for all cancer patients. Most of them are followed by a high rate of side effects and complications. The L-tryptophan depletion bioreactor is described as a possible new method of cancer therapy. L-tryptophan is an essential amino acid which has been recognized as an important cancer nutrient and its removal can lead to destruction of the tumour. Normal human cells or tumor cells cannot synthesize L-tryptophan and therefore tumor resistance is unlikely to develop. L-tryptophan is also a constituent for different bio-molecules such as Serotonin, Melatonin, and is needed for other synthesis processes in the cell growth. L-tryptophan degrading enzymes with 3 iso-enzymes called tryptophan side chain oxydase (TSO I, II, III were isolated. The 3 iso-enzymes can be differentiated by tryptic digestion. They have different molecular weights with different effectivenesses. All the TSO enzymes have heme that can catalyze essentially similar reactions involving L-tryptophan as a substrate. The most effective TSO is the type TSO III. A column which contained TSO as a bioreactor was integrated in a plasmapheresis unit and tested it in different animals. In sheep and rabbits L-tryptophan depletion in plasma was shown at 95% and 100% rates respectively by a single pass through the bioreactor. The results in immune supprimized rats with tumors were impressive, too. In 20 different tumor cell lines there were different efficacies. Brest cancer and medulloblastoma showed the greatest efficacy of L-tryptophan degrading. The gene technology of TSO production from Pseudomonas is associated with formation of endotoxins. This disadvantage can be prevented by different washing procedures or by using fungal sources for the TSO production. TSO III is developed to treat cancer diseases successfully, and has low side effects. A combination of L-tryptophan depletion with all available cancer therapies is

  18. Transient T cell depletion causes regression of melanoma metastases

    Lear Sheron C

    2008-03-01

    Full Text Available Abstract Background Cognate immunity against neoplastic cells depends on a balance between effector T cells and regulatory T (Treg cells. Treg cells prevent immune attack against normal and neoplastic cells by directly suppressing the activation of effector CD4+ and CD8+ T cells. We postulated that a recombinant interleukin 2/diphtheria toxin conjugate (DAB/IL2; Denileukin Diftitox; Ontak may serve as a useful strategy to deplete Treg cells and break tolerance against neoplastic tumors in humans. Methods We administered DAB/IL2 (12 μg/kg; four daily doses; 21 day cycles to 16 patients with metastatic melanoma and measured the effects on the peripheral blood concentration of several T cell subsets and on tumor burden. Results We found that DAB/IL2 caused a transient depletion of Treg cells as well as total CD4+ and CD8+ T cells (de novo appearance of melanoma antigen-specific CD8+ T cells in several patients as determined by flow cytometry using tetrameric MART-1, tyrosinase and gp100 peptide/MHC conjugates. Sixteen patients received at least one cycle of DAB/IL2 and five of these patients experienced regressions of melanoma metastases as measured by CT and/or PET imaging. One patient experienced a near complete response with the regression of several hepatic and pulmonary metastases coupled to the de novo appearance of MART-1-specific CD8+ T cells. A single metastatic tumor remained in this patient and, after surgical resection, immunohistochemical analysis revealed MART1+ melanoma cells surrounded by CD8+ T cells. Conclusion Taken together, these data indicate that transient depletion of T cells in cancer patients may disrupt the homeostatic control of cognate immunity and allow for the expansion of effector T cells with specificity against neoplastic cells. Several T cell depleting agents are clinically available and this study provides strong rationale for an examination of their efficacy in cancer patients. Trial registration NCT00299689

  19. Depleted uranium storage and disposal trade study: Summary report

    The objectives of this study were to: identify the most desirable forms for conversion of depleted uranium hexafluoride (DUF6) for extended storage, identify the most desirable forms for conversion of DUF6 for disposal, evaluate the comparative costs for extended storage or disposal of the various forms, review benefits of the proposed plasma conversion process, estimate simplified life-cycle costs (LCCs) for five scenarios that entail either disposal or beneficial reuse, and determine whether an overall optimal form for conversion of DUF6 can be selected given current uncertainty about the endpoints (specific disposal site/technology or reuse options)

  20. Consistent Cosmic Microwave Background Spectra from Quantum Depletion

    Casadio, Roberto; Orlandi, Alessio

    2015-01-01

    Following a new quantum cosmological model proposed by Dvali and Gomez, we quantitatively investigate possible modifications to the Hubble parameter and following corrections to the cosmic microwave background spectrum. In this model, scalar and tensor perturbations are generated by the quantum depletion of the background inflaton and graviton condensate respectively. We show how the inflaton mass affects the power spectra and the tensor-to-scalar ratio. Masses approaching the Planck scale would lead to strong deviations, while standard spectra are recovered for an inflaton mass much smaller than the Planck mass.

  1. Consistent cosmic microwave background spectra from quantum depletion

    Casadio, Roberto; Kühnel, Florian; Orlandi, Alessio

    2015-09-01

    Following a new quantum cosmological model proposed by Dvali and Gomez, we quantitatively investigate possible modifications to the Hubble parameter and following corrections to the cosmic microwave background spectrum. In this model, scalar and tensor perturbations are generated by the quantum depletion of the background inflaton and graviton condensate respectively. We show how the inflaton mass affects the power spectra and the tensor-to-scalar ratio. Masses approaching the Planck scale would lead to strong deviations, while standard spectra are recovered for an inflaton mass much smaller than the Planck mass.

  2. Effect of acrolein and glutathione depleting agents on thioredoxin

    Acrolein is a widespread environmental pollutant that reacts rapidly with nucleophiles, especially cellular thiols. In addition to glutathione (GSH), thioredoxin (Trx) and thioredoxin reductase (TR) contain thiol groups and may react with electrophiles. In the present study, A549 cells treated with 5-25 μM acrolein for 30 min lost cellular Trx activity in a dose-dependent fashion. Over 90% of Trx activity was lost at concentrations of 25 μM or greater. In contrast, Trx protein content, as assessed by western blotting, was not altered immediately after the 30 min acrolein treatment. Both Trx activity and protein levels increased 4 h after the acrolein treatment. However, Trx activity remained below control levels at 24 h. A similar dose-response relationship was seen with TR in A549 cells exposed to acrolein. There was, however, a rapid recovery of TR activity such that it attained normal levels by 4 h after doses ≤75 μM acrolein. Diethyl maleate (DEM), a common but not highly specific, agent used to deplete GSH, also inactivated Trx. A 2 h exposure of A549 cells to 1 mM DEM depleted cellular GSH by ∼50% and diminished Trx activity by over 67%. Lower DEM doses (0.125 mM and 0.25 mM) for 1 h had no significant effect on GSH but significantly decreased Trx activity 12 and 23%, respectively. Similar to immediately after acrolein exposure, DEM did not affect Trx protein levels. A Trx-1-GFP fusion protein was transfected into A549 cells. While the fusion protein was expressed, the Trx component was inactive by the insulin reducing assay. In summary, Trx and TR are inactivated by acrolein. In addition, the GSH depleting agent DEM inactivates Trx somewhat more effectively than it depletes GSH. The Trx-1-GFP fusion protein, while readily expressed, appears to have little or no activity, perhaps because the small size of Trx-1 (12 kDa) is affected by the larger GFP

  3. Acid gelation of colloidal calcium phosphate-depleted preheated milk

    Famelart, Marie-Hélène; Gauvin, Géraldine; Paquet, Denis; Brulé, Gérard

    2009-01-01

    Abstract – This study aimed at understanding the role of colloidal calcium phosphate (CCP) in acid gelation of milk. Milks were depleted in Calcium (Ca) by dialysis against milk permeate containing a cation-exchange resin. Dialysed milks were then heated (90 °C-10 min) and acidgelled at 42 °C with a yoghurt culture. Minerals, total and soluble protein contents, pH and optical density were measured in unheated and heated dialysed milk, together with diameters and ζ-potentials of particles. Dia...

  4. Depleted-Uranium Weapons: the Whys and Wherefores

    Gsponer, Andre

    2003-01-01

    The only military application in which depleted-uranium (DU) alloys out-perform present-day tungsten alloys is long-rod penetration into a main battle-tank's armor. However, this advantage is only on the order of 10%, and it disappears when the comparison is made in terms of actual lethality of complete anti-tank systems instead of laboratory-type steel penetration capability. Therefore, new micro- and nano-engineered tungsten alloys may soon out-perform DU alloys, enabling the production of ...

  5. Upscaling of gas relative permeability during pressure depletion

    Grepstad, Kristian

    2011-01-01

    Pressure depletion of an oil reservoir will result in release of dissolved gas when the bubble point of the oil is reached in the reservoir. This liberated gas will segregate upwards in the reservoir with low mobility until a vertical flow barrier is met by the gas. Liberated gas will accumulate below this barrier and create thin "layers" with high gas saturation, where the mobility of gas becomes high. These thin layers with high mobility will result in a relatively quick production of the l...

  6. Serotonin 2A Receptors, Citalopram and Tryptophan-Depletion

    Macoveanu, Julian; Hornboll, Bettina; Elliott, Rebecca;

    2013-01-01

    neural correlates of inhibition using intravenous citalopram and acute tryptophan depletion during functional magnetic resonance imaging. We adapted the NoGo paradigm to isolate effects on inhibition per se as opposed to other aspects of the NoGo paradigm. Successful NoGo inhibition was associated with...... greater activation of the right IFG compared to control trials with alternative responses, indicating that the IFG is activated with inhibition in NoGo trials rather than other aspects of invoked cognitive control. Activation of the left IFG during NoGo trials was greater with citalopram than acute...

  7. Interstellar abundance and depletion studies along Galactic sightlines

    Haris, U.; Murthy, Jayant; Sofia, Ulysses

    2016-07-01

    The Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) has enhanced our understanding many aspects of interstellar medium of our galaxy. The wavelength coverage of FUSE and HST is of great astrophysical importance. We use FUSE and HST data for interstellar abundances studies of some important atomic species, such as sulphur and silicon. We report the newly derived column densities by measuring the equivalent widths of several ultraviolet absorption lines. Comparisons of observed depletions and grain properties with existing dust models will be discussed.

  8. Relativistic nuclear physics: symmetry and the correlation depletion principle

    The author's view on the role of symmetry in fundamental physics is presented. The concept of the 'symmetry of solutions' is analyzed. It is stressed that it is impossible to deduce the basic laws of relativistic nuclear physics from the QCD Lagrangians without recourse to additional hypotheses about the symmetry of solutions (Green functions). The test of these hypotheses is the major prospect of the study of hadron and nuclear collisions. Special importance is given to the Correlation Depletions Principle that makes it possible to construct mathematical models of relativistic nuclear physics, and analyze, by using simple terms, topologically complicated events of nucleus-nucleus collisions. 15 refs., 4 figs

  9. Microstructure of depleted uranium under uniaxial strain conditions

    Zurek, A.K.; Embury, J.D.; Kelly, A.; Thissell, W.R.; Gustavsen, R.L.; Vorthman, J.E.; Hixson, R.H.

    1997-09-01

    Uranium samples of two different purities were used for spall strength measurements. Samples of depleted uranium were taken from very high purity material (38 ppM carbon) and from material containing 280 ppM C. Experimental conditions were chosen to effectively arrest the microstructural damage at two places in the development to full spall separation. Samples were soft recovered and characterized with respect to the microstructure and the form of damage. This allowed determination of the dependence of spall mechanisms on stress level, stress state, and sample purity. This information is used in developing a model to predict the mode of fracture.

  10. Human Health Effects of Ozone Depletion From Stratospheric Aircraft

    Wey, Chowen (Technical Monitor)

    2001-01-01

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

  11. Depleted uranium storage and disposal trade study: Summary report

    Hightower, J.R.; Trabalka, J.R.

    2000-02-01

    The objectives of this study were to: identify the most desirable forms for conversion of depleted uranium hexafluoride (DUF6) for extended storage, identify the most desirable forms for conversion of DUF6 for disposal, evaluate the comparative costs for extended storage or disposal of the various forms, review benefits of the proposed plasma conversion process, estimate simplified life-cycle costs (LCCs) for five scenarios that entail either disposal or beneficial reuse, and determine whether an overall optimal form for conversion of DUF6 can be selected given current uncertainty about the endpoints (specific disposal site/technology or reuse options).

  12. Depleting the curriculum: teaching digital platforms and curricular impoverishment

    Fino, Carlos Manuel Nogueira

    2013-01-01

    The paper aims at showing how curricular complexity tends to be depleted by the use of digital platforms based on the SCORM (Sharable Content Object Reference Model) standard, which was created with the main purpose of recycling content as it is supposed to be independent both from the context of learning and the supporting technology also deemed to be neutral, all surrounded by a rhetoric of innovation and “pedagogical” innovation. The starting point of the discussion is García Perez’s mo...

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

    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

  14. The Influence of Chronic Ego Depletion on Goal Adherence: An Experience Sampling Study.

    Ligang Wang

    Full Text Available Although ego depletion effects have been widely observed in experiments in which participants perform consecutive self-control tasks, the process of ego depletion remains poorly understood. Using the strength model of self-control, we hypothesized that chronic ego depletion adversely affects goal adherence and that mental effort and motivation are involved in the process of ego depletion. In this study, 203 students reported their daily performance, mental effort, and motivation with respect to goal directed behavior across a 3-week time period. People with high levels of chronic ego depletion were less successful in goal adherence than those with less chronic ego depletion. Although daily effort devoted to goal adherence increased with chronic ego depletion, motivation to adhere to goals was not affected. Participants with high levels of chronic ego depletion showed a stronger positive association between mental effort and performance, but chronic ego depletion did not play a regulatory role in the effect of motivation on performance. Chronic ego depletion increased the likelihood of behavior regulation failure, suggesting that it is difficult for people in an ego-depletion state to adhere to goals. We integrate our results with the findings of previous studies and discuss possible theoretical implications.

  15. Chromium depletion from stainless steels during vacuum annealing

    The behaviour of chromium during selective evaporation by high temperature vacuum annealing has been investigated by means of energy dispersive X-ray analysis and by neutron activation analysis. It was established that the rate of chromium loss from austenitic stainless steels 316 and 321 is controlled by chromium inter-diffusion rather than tracer diffusion in the alloy. Two important parameters in selective removal of chromium from alloy steels are the variation in the chromium surface concentration with time and the depletion profile in the alloy. The present work gives support for the model in which loss of chromium is dependent on its diffusivity in the alloy and on an interface transfer coefficient. The results showed that the surface concentration of chromium decreased with increasing vacuum annealing time. The chromium depletion profile in the metal was in accord with the previous derived model, apart from an anomalous near surface region. Here the higher resolution of a neutron activation technique indicated a region within approximately 2 microns of the surface where the chromium concentration decreased more steeply than expected. (author)

  16. Effects of Macrophage Depletion on Sleep in Mice.

    Ames, Conner; Boland, Erin; Szentirmai, Éva

    2016-01-01

    The reciprocal interaction between the immune system and sleep regulation has been widely acknowledged but the cellular mechanisms that underpin this interaction are not completely understood. In the present study, we investigated the role of macrophages in sleep loss- and cold exposure-induced sleep and body temperature responses. Macrophage apoptosis was induced in mice by systemic injection of clodronate-containing liposomes (CCL). We report that CCL treatment induced an immediate and transient increase in non-rapid-eye movement sleep (NREMS) and fever accompanied by decrease in rapid-eye movement sleep, motor activity and NREMS delta power. Chronically macrophage-depleted mice had attenuated NREMS rebound after sleep deprivation compared to normal mice. Cold-induced increase in wakefulness and decrease in NREMS, rapid-eye movement sleep and body temperature were significantly enhanced in macrophage-depleted mice indicating increased cold sensitivity. These findings provide further evidence for the reciprocal interaction among the immune system, sleep and metabolism, and identify macrophages as one of the key cellular elements in this interplay. PMID:27442442

  17. Satellite surveillance of evaporative depletion across the Indus Basin

    Bastiaanssen, Wim G. M.; Ahmad, Mobin-Ud-Din; Chemin, Yann

    2002-12-01

    The irrigated Indus Basin in Pakistan has insufficient water resources to supply all its stakeholders. Information on evaporative depletion across the Basin is an important requirement if the water resources are to be managed efficiently. This paper presents the Surface Energy Balance Algorithm for Land (SEBAL) method used to compute actual evapotranspiration for large areas based on public domain National Oceanic and Atmospheric Administration (NOAA) satellite data. Computational procedures for retrieving actual evapotranspiration from satellites have been developed over the last 20 years. The current work is among the first applications used to estimate actual evapotranspiration on an annual scale across a vast river basin system with a minimum of ground data. Only sunshine duration and wind speed are required as input data for the remote sensing flux algorithm. The results were validated in the Indus Basin by comparing results from a field-scale transient moisture flow model, in situ Bowen ratio measurements, and residual water balance analyses for an area of 3 million ha. The accuracy of assessing time-integrated actual annual evapotranspiration varied from 0% to 10% on a field scale to 5% at the regional level. Spatiotemporal information on actual evapotranspiration helps to evaluate water distribution and water use between large irrigation project areas. Wide variations in evaporative depletion between project areas and crop types were found. Satellite-based measurements can provide such information and avoid the need to rely on field databases.

  18. Depletion GPT-free sensitivity analysis for reactor eigenvalue problems

    This manuscript introduces a novel approach to solving depletion perturbation theory problems without the need to set up or solve the generalized perturbation theory (GPT) equations. The approach, hereinafter denoted generalized perturbation theory free (GPT-Free), constructs a reduced order model (ROM) using methods based in perturbation theory and computes response sensitivity profiles in a manner that is independent of the number or type of responses, allowing for an efficient computation of sensitivities when many responses are required. Moreover, the reduction error from using the ROM is quantified in the GPT-Free approach by means of a Wilks' order statistics error metric denoted the K-metric. Traditional GPT has been recognized as the most computationally efficient approach for performing sensitivity analyses of models with many input parameters, e.g. when forward sensitivity analyses are computationally intractable. However, most neutronics codes that can solve the fundamental (homogenous) adjoint eigenvalue problem do not have GPT capabilities unless envisioned during code development. The GPT-Free approach addresses this limitation by requiring only the ability to compute the fundamental adjoint. This manuscript demonstrates the GPT-Free approach for depletion reactor calculations performed in SCALE6 using the 7x7 UAM assembly model. A ROM is developed for the assembly over a time horizon of 990 days. The approach both calculates the reduction error over the lifetime of the simulation using the K-metric and benchmarks the obtained sensitivities using sample calculations. (authors)

  19. Tyrosine depletion lowers in vivo DOPA synthesis in ventral hippocampus.

    Bongiovanni, Rodolfo; Kyser, Abby N; Jaskiw, George E

    2012-12-01

    In vivo dopamine synthesis in the medial prefrontal cortex of the rat is sensitive to the availability of tyrosine. Whether other limbic cortical dopamine terminal regions are similarly tyrosine-dependent is not known. In this study we examined the effects of tyrosine depletion on dopamine synthesis and catecholamine levels in the ventral hippocampus. A tyrosine- and phenylalanine-free neutral amino acid mixture was used to lower brain tyrosine levels in rats undergoing in vivo microdialysis. In one group, NSD-1015 was included in perfusate to permit measurement of DOPA levels. In a second group, NSD-1015 was not included in perfusate so that catecholamine levels could be assayed. Tyrosine depletion significantly lowered DOPA levels in the NSD-1015 treated group and lowered DOPAC but not dopamine or noradrenaline levels in the group not exposed to NSD-1015. We conclude that while catecholamine synthesis in the ventral hippocampus declines when tyrosine availability is lowered, under basal conditions, compensatory mechanisms are able to maintain stable extracellular catecholamine levels. PMID:23022716

  20. Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements

    Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols. Establishing a calibration curve between beta activity measurements and uranium mass measurements is straightforward if the uranium isotopes are in equilibrium with their immediate short-lived, beta-emitting progeny. For DU samples collected during the Capstone study, it was determined that the equilibrium between the uranium isotopes and their immediate short lived, beta-emitting progeny had been disrupted when penetrators had perforated target vehicles. Adjustments were made to account for the disrupted equilibrium and for wall losses in the aerosol samplers. Correction factors for the disrupted equilibrium ranged from 0.16 to 1, and the wall loss correction factors ranged from 1 to 1.92

  1. Adult mitochondrial DNA depletion syndrome with mild manifestations

    Josef Finsterer

    2013-06-01

    Full Text Available Mitochondrial DNA depletion syndrome (MDS is usually a severe disorder of infancy or childhood, due to a reduced copy number of mtDNA molecules. MDS with only mild, non-specific clinical manifestations and onset in adulthood has not been reported. A 47-year-old Caucasian female with short stature and a history of migraine, endometriosis, Crohn’s disease, C-cell carcinoma of the thyroid gland, and a family history positive for mitochondrial disorder (2 sisters, aunt, niece, developed day-time sleepiness, exercise intolerance, and myalgias in the lower-limb muscles since age 46y. She slept 9-10 hours during the night and 2 hours after lunch daily. Clinical exam revealed sore neck muscles, bilateral ptosis, and reduced Achilles tendon reflexes exclusively. Blood tests revealed hyperlipidemia exclusively. Nerve conduction studies, needle electromyography, and cerebral and spinal magnetic resonance imaging were non-informative. Muscle biopsy revealed detached lobulated fibers with subsarcolemmal accentuation of the NADH and SDH staining. Real-time polymerase chain reaction revealed depletion of the mtDNA down to 9% of normal. MDS may be associated with a mild phenotype in adults and may not significantly progress during the first year after onset. In an adult with hypersomnia, severe tiredness, exercise intolerance, and a family history positive for mitochondrial disorder, a MDS should be considered.

  2. VERA Core Simulator Methodology for PWR Cycle Depletion

    Kochunas, Brendan [University of Michigan; Collins, Benjamin S [ORNL; Jabaay, Daniel [University of Michigan; Kim, Kang Seog [ORNL; Graham, Aaron [University of Michigan; Stimpson, Shane [University of Michigan; Wieselquist, William A [ORNL; Clarno, Kevin T [ORNL; Palmtag, Scott [Core Physics, Inc.; Downar, Thomas [University of Michigan; Gehin, Jess C [ORNL

    2015-01-01

    This paper describes the methodology developed and implemented in MPACT for performing high-fidelity pressurized water reactor (PWR) multi-cycle core physics calculations. MPACT is being developed primarily for application within the Consortium for the Advanced Simulation of Light Water Reactors (CASL) as one of the main components of the VERA Core Simulator, the others being COBRA-TF and ORIGEN. The methods summarized in this paper include a methodology for performing resonance self-shielding and computing macroscopic cross sections, 2-D/1-D transport, nuclide depletion, thermal-hydraulic feedback, and other supporting methods. These methods represent a minimal set needed to simulate high-fidelity models of a realistic nuclear reactor. Results demonstrating this are presented from the simulation of a realistic model of the first cycle of Watts Bar Unit 1. The simulation, which approximates the cycle operation, is observed to be within 50 ppm boron (ppmB) reactivity for all simulated points in the cycle and approximately 15 ppmB for a consistent statepoint. The verification and validation of the PWR cycle depletion capability in MPACT is the focus of two companion papers.

  3. Use of 60 ppm deuterium depleted water in companionship animals

    There are presented the results of studies on the effects of deuterium depleted water in companionship animals. Based on these results, a new product was realized, 'Aqua Forte' that is a deuterium depleted potable water (60 ppm deuterium) with beneficial effects in animal's health maintaining. Aqua forte has prophylactic properties (in preventing diseases related to immune system) and therapeutic properties, as adjuvant in various therapeutic programs. The mechanism of action takes place at the cellular metabolism level by replacing the constitutional and free water of 150 ppm deuterium, this resulting in the stimulation of the immune cellular system and also of resistance at the onset of some pathological states. The non-specific stimulation implies performing both the humoral mediated immune reactions and of those cellularly mediated. Aqua forte is recommended in: - the feeding of the young weaned animals, the action being of growth stimulation, and increasing of the resistance against some diseases specific to the age; - as an adjuvant in some chronic diseases (hepatitis, pancreatitis, dermatological diseases, osteoarthropaties, hepato-renal syndrome, renal insufficiency, after surgical interventions, in antitumoral therapy); - in the feeding of the old animals for the quality of life improvement. (authors)

  4. International regime formation: Ozone depletion and global climate change

    Two theoretical perspectives, neorealism and neoliberal institutionalism, dominate in international relations. An assessment is made of whether these perspectives provide compelling explanations of why a regime with specific targets and timetables was formed for ozone depletion, while a regime with such specificity was not formed for global climate change. In so doing, the assumptions underlying neorealism and neoliberal institutionalism are examined. A preliminary assessment is offered of the policymaking and institutional bargaining process. Patterns of interstate behavior are evolving toward broader forms of cooperation, at least with regard to global environmental issues, although this process is both slow and cautious. State coalitions on specific issues are not yet powerful enough to create a strong community of states in which states are willing to devolve power to international institutions. It is shown that regime analysis is a useful analytic framework, but it should not be mistaken for theory. Regime analysis provides an organizational framework offering a set of questions regarding the principles and norms that govern cooperation and conflict in an issue area, and whether forces independent of states exist which affect the scope of state behavior. An examination of both neorealism and neoliberal institutionalism, embodied by four approaches to regime formation, demonstrates that neither has sufficient scope to account for contextual dynamics in either the ozone depletion or global climate change regime formation processes. 261 refs

  5. PAU, a fully depleted mosaic imager with narrow band filters

    Bauer, A.; Casas, R.; Castander, F. J.; Serrano, S.

    2014-03-01

    The PAU Survey studies the existence and properties of dark energy from the observations of redshift space distortions and weak lensing magnification from galaxy cross-correlations as main cosmological probes. The PAU Team is building an instrument, PAUCam, equipped with fully depleted CCD detectors, designed to be mounted at the prime focus of the 4.2 m diameter William Herschel Telescope (WHT) in La Palma. Simulations indicate that PAUCam at the WHT will be able to image about 2 square degrees per night in 40 narrow-band filters plus six wide-band filters to an AB magnitude depth of i ~ 22.5, providing low-resolution (R ~ 50) photometric spectra for around 30,000 galaxies, 5,000 stars and 1,000 quasars per square degree. Accurate photometric calibration of the PAU data is vital to achieve the survey science goals. This calibration is challenging due to the large and unusual filter set. We outline the data management pipelines being developed for the survey, both for nightly data reduction and co-addition of multiple epochs, with emphasis on the photometric calibration strategies. We also describe the main tests and results in the characterization of our Hamamatsu fully depleted detectors.

  6. Depleted uranium instead of lead in munitions: the lesser evil

    Uranium has many similarities to lead in its exposure mechanisms, metabolism and target organs. However, lead is more toxic, which is reflected in the threshold limit values. The main potential hazard associated with depleted uranium is inhalation of the aerosols created when a projectile hits an armoured target. A person can be exposed to lead in similar ways. Accidental dangerous exposures can result from contact with both substances. Encountering uranium fragments is of minor significance because of the low penetration depth of alpha particles emitted by uranium: they are unable to penetrate even the superficial keratin layer of human skin. An additional cancer risk attributable to the uranium exposure might be significant only in case of prolonged contact of the contaminant with susceptible tissues. Lead intoxication can be observed in the wounded, in workers manufacturing munitions etc; moreover, lead has been documented to have a negative impact on the intellectual function of children at very low blood concentrations. It is concluded on the basis of the literature overview that replacement of lead by depleted uranium in munitions would be environmentally beneficial or largely insignificant because both lead and uranium are present in the environment. (opinion)

  7. Depleted uranium instead of lead in munitions: the lesser evil.

    Jargin, Sergei V

    2014-03-01

    Uranium has many similarities to lead in its exposure mechanisms, metabolism and target organs. However, lead is more toxic, which is reflected in the threshold limit values. The main potential hazard associated with depleted uranium is inhalation of the aerosols created when a projectile hits an armoured target. A person can be exposed to lead in similar ways. Accidental dangerous exposures can result from contact with both substances. Encountering uranium fragments is of minor significance because of the low penetration depth of alpha particles emitted by uranium: they are unable to penetrate even the superficial keratin layer of human skin. An additional cancer risk attributable to the uranium exposure might be significant only in case of prolonged contact of the contaminant with susceptible tissues. Lead intoxication can be observed in the wounded, in workers manufacturing munitions etc; moreover, lead has been documented to have a negative impact on the intellectual function of children at very low blood concentrations. It is concluded on the basis of the literature overview that replacement of lead by depleted uranium in munitions would be environmentally beneficial or largely insignificant because both lead and uranium are present in the environment. PMID:24594921

  8. Cystamine induces AIF-mediated apoptosis through glutathione depletion.

    Cho, Sung-Yup; Lee, Jin-Haeng; Ju, Mi-kyeong; Jeong, Eui Man; Kim, Hyo-Jun; Lim, Jisun; Lee, Seungun; Cho, Nam-Hyuk; Park, Hyun Ho; Choi, Kihang; Jeon, Ju-Hong; Kim, In-Gyu

    2015-03-01

    Cystamine and its reduced form cysteamine showed protective effects in various models of neurodegenerative disease, including Huntington's disease and Parkinson's disease. Other lines of evidence demonstrated the cytotoxic effect of cysteamine on duodenal mucosa leading to ulcer development. However, the mechanism for cystamine cytotoxicity remains poorly understood. Here, we report a new pathway in which cystamine induces apoptosis by targeting apoptosis-inducing factor (AIF). By screening of various cell lines, we observed that cystamine and cysteamine induce cell death in a cell type-specific manner. Comparison between cystamine-sensitive and cystamine-resistant cell lines revealed that cystamine cytotoxicity is not associated with unfolded protein response, reactive oxygen species generation and transglutaminase or caspase activity; rather, it is associated with the ability of cystamine to trigger AIF nuclear translocation. In cystamine-sensitive cells, cystamine suppresses the levels of intracellular glutathione by inhibiting γ-glutamylcysteine synthetase expression that triggers AIF translocation. Conversely, glutathione supplementation completely prevents cystamine-induced AIF translocation and apoptosis. In rats, cysteamine administration induces glutathione depletion and AIF translocation leading to apoptosis of duodenal epithelium. These results indicate that AIF translocation through glutathione depletion is the molecular mechanism of cystamine toxicity, and provide important implications for cystamine in the neurodegenerative disease therapeutics as well as in the regulation of AIF-mediated cell death. PMID:25549939

  9. Residue depletion of colistin in swine after intramuscular administration

    S.S. Tang

    2009-05-01

    Full Text Available A newly formulated colistin sulphate solution was prepared in a previous study as a potential agent for intramuscular injection and its effectiveness, toxicity and pharmacokinetics were investigated. In order to provide more information to establish scientific guidance for safe use of this preparation, its residue depletion in swine tissues following intramuscular administration was investigated in this experiment. Fifty healthy cross-bred piglets (13.3 ± 0.9 kg were used in this study. Five animals were kept as untreated controls and the other 45 animals were intramuscularly injected with the colistin preparation at a dose of 2.5 mg / kg of body weight. From the treated piglets, 5 animals were randomly selected and sacrificed at different withdrawal times. Liver, kidney and muscle tissues were sampled to examine the colistin residue levels by microbiological assay. The results showed that the colistin residue in liver and muscle decreased quickly and could not be detected at 1 day after the final dosing. However, the residue depletion in the kidneys was much slower than that in other tissues and even a small quantity of drug could be detected at 14 days after withdrawal. Using the method recommended by the Committee for Veterinary Medical Products (CVMP, a withdrawal time of 10 days was established for the safe use of the newly formulated colistin sulphate solution.

  10. Martian meteorite Tissint records unique petrogenesis among the depleted shergottites

    Basu Sarbadhikari, A.; Babu, E. V. S. S. K.; Vijaya Kumar, T.; Chennaoui Aoudjehane, H.

    2016-09-01

    Tissint, a new unaltered piece of Martian volcanic materials, is the most silica-poor and Mg-Fe-rich igneous rock among the "depleted" olivine-phyric shergottites. Fe-Mg zoning of olivine suggests equilibrium growth (control the Ca-buffer in the residual melt suppressing the plagioclase crystallization, which also caused a profound effect on the Al-content in the late-crystallized pyroxenes. Mineral chemical stability, phase-assemblage saturation, and pressure-temperature path of evolution indicates that the parent magma entered the solidus and left the liquidus field at a depth of 40-80 km in the upper mantle. Petrogenesis of Tissint appears to be similar to LAR 06319, an enriched olivine-phyric shergottite, during the early to intermediate stage of crystallization. A severe shock-induced deformation resulted in remelting (10-15 vol%), recrystallization (most Fe-rich phases), and exhumation of Tissint in a time scale of 1-8 yr. Tissint possesses some distinct characteristics, e.g., impact-induced melting and deformation, forming phosphorus-rich recrystallization rims of olivine, and shock-induced melt domains without relative enrichment of LREEs compared to the bulk; and shared characteristics, e.g., modal composition and magmatic evolution with the enriched basaltic shergottites, evidently reflecting unique mantle source in comparison to the clan of the depleted members.

  11. SUZ12 Depletion Suppresses the Proliferation of Gastric Cancer Cells

    Yingjun Cui

    2013-05-01

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

  12. The Antarctic ozone depletion caused by Erebus volcano gas emissions

    Zuev, V. V.; Zueva, N. E.; Savelieva, E. S.; Gerasimov, V. V.

    2015-12-01

    Heterogeneous chemical reactions releasing photochemically active molecular chlorine play a key role in Antarctic stratospheric ozone destruction, resulting in the Antarctic ozone hole. Hydrogen chloride (HCl) is one of the principal components in these reactions on the surfaces of polar stratospheric clouds (PSCs). PSCs form during polar nights at extremely low temperatures (lower than -78 °C) mainly on sulfuric acid (H2SO4) aerosols, acting as condensation nuclei and formed from sulfur dioxide (SO2). However, the cause of HCl and H2SO4 high concentrations in the Antarctic stratosphere, leading to considerable springtime ozone depletion, is still not clear. Based on the NCEP/NCAR reanalysis data over the last 35 years and by using the NOAA HYSPLIT trajectory model, we show that Erebus volcano gas emissions (including HCl and SO2) can reach the Antarctic stratosphere via high-latitude cyclones with the annual average probability Pbarann. of at least ∼0.235 (23.5%). Depending on Erebus activity, this corresponds to additional annual stratospheric HCl mass of 1.0-14.3 kilotons (kt) and SO2 mass of 1.4-19.7 kt. Thus, Erebus volcano is the natural and powerful source of additional stratospheric HCl and SO2, and hence, the cause of the Antarctic ozone depletion, together with man-made chlorofluorocarbons.

  13. Using molybdenum depleted in 95Mo in UMo fuel

    In recent years significant interest was gained in UMo fuel to be used in Material Test Reactors. This interest was induced by the fact that UMo fuel is mechanically stable, even at high uranium concentrations and high U-burnup. These properties are required in order to use Low Enriched Uranium (LEU) and still be able to achieve high flux and burnup values and, thus, to facilitate the conversion from High Enriched Uranium (HEU) to LEU. Neutronics computations have shown that, although the Mo concentration in UMo fuel is not very high (about 5 - 10w%), the neutron absorption cross sections of natural Mo are sufficiently high to have a considerable negative impact on the reactivity of this UMo fuel. In the present research the neutron absorption cross sections of natural Mo are discussed and the option to reduce the cross section of molybdenum by depleting the Mo in 95Mo is described. Finally the economic consequences of using Mo depleted in 95Mo are briefly discussed

  14. Deep Mixing and Metallicity: Carbon Depletion in Globular Cluster Giants

    Martell, Sarah L; Briley, Michael M

    2008-01-01

    We present the results of an observational study of the efficiency of deep mixing in globular cluster red giants as a function of stellar metallicity. We determine [C/Fe] abundances based on low-resolution spectra taken with the Kast spectrograph on the 3m Shane telescope at Lick Observatory. Spectra centered on the 4300 Angstrom CH absorption band were taken for 42 bright red giants in 11 Galactic globular clusters ranging in metallicity from M92 ([Fe/H]=-2.29) to NGC 6712 ([Fe/H]=-1.01). Carbon abundances were derived by comparing values of the CH bandstrength index S2(CH) measured from the data with values measured from a large grid of SSG synthetic spectra. Present-day abundances are combined with theoretical calculations of the time since the onset of mixing, which is also a function of stellar metallicity, to calculate the carbon depletion rate across our metallicity range. We find that the carbon depletion rate is twice as high at a metallicity of [Fe/H]=-2.3 than at [Fe/H]=-1.3, which is a result qual...

  15. Sensitivity analysis for actinide production and depletion in fast reactors

    In sensitivity analysis of the actinide production and depletion in fast reactors, a mathematical method of calculating sensitivity coefficients is improved and simplified by combining the time-dependent generalized perturbation technique with the eigenvalue method. Numerical calculations show that the eigenvalue method is well applicable in solving the nuclide chain equation and its adjoint equation and the cylic chains in the decay scheme of the actinides can be interpreted by means of complex eigenvalues. The sensitivity coefficients of actinide production and depletion in a 1000 MWe fast reactor are strongly dependent on the type of Pu fuel used, i.e. Pu fuel from BWR or Pu fuel from the blanket of FBR. The sensitivity coefficients due to variations of capture cross sections, σsub(n,2n) of 238U, lambda sub(β) of 241Pu and lambda sub(α) of 242Cm are especially large. Sensitivity analyses for the 1000 MWe fast reactors show that higher priorily should be given to decay constants of 241Pu and 242Cm, capture cross sections of 237Np, 241Am, 243Am and 242Pu, and fission cross sections of 237Np, 242Pu, 241Am and sup(242m)Am. (author)

  16. Experimental depletion of different renal interstitial cell populations

    To define different populations of renal interstitial cells and investigate some aspects of their function, we studied the kidneys of normal rats and rats with hereditary diabetes insipidus (DI, Brattleboro) after experimental manipulations expected to alter the number of interstitial cells. DI rats showed an almost complete loss of interstitial cells in their renal papillae after treatment with a high dose of vasopressin. In spite of the lack of interstitial cells, the animals concentrated their urine to the same extent as vasopressin-treated normal rats, indicating that the renomedullary interstitial cells do not have an important function in concentrating the urine. The interstitial cells returned nearly to normal within 1 week off vasopressin treatment, suggesting a rapid turnover rate of these cells. To further distinguish different populations of interstitial cells, we studied the distribution of class II MHC antigen expression in the kidneys of normal and bone-marrow depleted Wistar rats. Normal rats had abundant class II antigen-positive interstitial cells in the renal cortex and outer medulla, but not in the inner medulla (papilla). Six days after 1000 rad whole body irradiation, the stainable cells were almost completely lost, but electron microscopic morphometry showed a virtually unchanged volume density of interstitial cells in the cortex and outer medulla, as well as the inner medulla. Thus, irradiation abolished the expression of the class II antigen but caused no significant depletion of interstitial cells

  17. Ozone-depleting-substance control and phase-out plan

    Title VI of the Federal Clean Air Act Amendments of 1990 requires regulation of the use and disposal of ozone-depleting substances (ODSs) (e.g., Halon, Freon). Several important federal regulations have been promulgated that affect the use of such substances at the Hanford Site. On April 23, 1993, Executive Order (EO) 12843, Procurement Requirements and Policies for Federal Agencies for Ozone-Depleting Substances (EPA 1993) was issued for Federal facilities to conform to the new US Environmental Protection Agency (EPA) regulations implementing the Clean Air Act of 1963 (CAA), Section 613, as amended. To implement the requirements of Title VI the US Department of Energy, Richland Operations Office (RL), issued a directive to the Hanford Site contractors on May 25, 1994 (Wisness 1994). The directive assigns Westinghouse Hanford Company (WHC) the lead in coordinating the development of a sitewide comprehensive implementation plan to be drafted by July 29, 1994 and completed by September 30, 1994. The implementation plan will address several areas where immediate compliance action is required. It will identify all current uses of ODSs and inventories, document the remaining useful life of equipment that contains ODS chemicals, provide a phase-out schedule, and provide a strategy that will be implemented consistently by all the Hanford Site contractors. This plan also addresses the critical and required elements of Federal regulations, the EO, and US Department of Energy (DOE) guidance. This plan is intended to establish a sitewide management system to address the clean air requirements

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

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

    2005-05-01

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

  19. Extracellular Microreactor for the Depletion of Phenylalanine Toward Phenylketonuria Treatment

    Rigau, Leticia Hosta; Durán, María José York; Kang, Tse Siang; Staedler, Brigitte

    2015-01-01

    Phenylketonuria (PKU) is a genetic enzyme defect affecting 1:10 000-20 000 newborn children every year. The amino acid phenylalanine (Phe) is not depleted but accumulates in tissues of several organs, which leads to severe medical conditions. A promising concept to restore the metabolism of the a...... extracellular multicompartment microreactor is reported using the relevant enzymes and settings toward the treatment of the medical condition PKU.......Phenylketonuria (PKU) is a genetic enzyme defect affecting 1:10 000-20 000 newborn children every year. The amino acid phenylalanine (Phe) is not depleted but accumulates in tissues of several organs, which leads to severe medical conditions. A promising concept to restore the metabolism of the...... affected patients will be to orally administer the defective enzyme which will remove Phe in the intestine. Herein, capsosomes, a multicompartment carrier consisting of thousands of liposomes embedded within a polymeric carrier, are employed as encapsulation platform for this purpose. It is shown that the...

  20. Reconciling Groundwater Storage Depletion Due to Pumping with Sustainability

    Annukka Lipponen

    2010-11-01

    Full Text Available Groundwater pumping causes depletion of groundwater storage. The rate of depletion incurred by any new well is gradually decreasing and eventually becomes zero in the long run, after induced recharge and reduction of natural discharge of groundwater combined (capture have become large enough to balance the pumping rate completely. If aquifer-wide aggregated pumping rates are comparatively large, then such a new dynamic equilibrium may not be reached and groundwater storage may become exhausted. Decisions to pump groundwater are motivated by people’s need for domestic water and by expected benefits of using water for a variety of activities. But how much finally is abstracted from an aquifer (or is considered to be an optimal aggregate abstraction rate depends on a wide range of other factors as well. Among these, the constraint imposed by the groundwater balance (preventing aquifer exhaustion has received ample attention in the professional literature. However, other constraints or considerations related to changes in groundwater level due to pumping are observed as well and in many cases they even may dominate the decisions on pumping. This paper reviews such constraints or considerations, examines how they are or may be incorporated in the decision-making process, and evaluates to what extent the resulting pumping rates and patterns create conditions that comply with principles of sustainability.

  1. Plasma Depletion and Mirror Waves Ahead of Interplanetary Mass Ejections

    Liu, Y; Belcher, J W; Kasper, J C; Skoug, R M

    2006-01-01

    We find that the sheath regions between fast interplanetary mass ejections (ICMEs) and their preceding shocks are often characterized by plasma depletion and mirror wave structures, analogous to planetary magnetosheaths. A case study of these signatures in the sheath of a magnetic cloud (MC) shows that a plasma depletion layer (PDL) coincides with magnetic field draping around the MC. In the same event, we observe an enhanced thermal anisotropy and plasma beta as well as anti-correlated density and magnetic fluctuations which are signatures of mirror mode waves. We perform a superposed epoch analysis of ACE and Wind plasma and magnetic field data from different classes of ICMEs to illuminate the general properties of these regions. For MCs preceded by shocks, the sheaths have a PDL with an average duration of 6 hours (corresponding to a spatial span of about 0.07 AU), a proton temperature anisotropy ${T_{\\perp p}\\over T_{\\parallel p}} \\simeq$ 1.2 - 1.3 and are marginally unstable to the mirror instability. Pl...

  2. Evaluation of acute tryptophan depletion and sham depletion with a gelatin-based collagen peptide protein mixture

    Stenbæk, D S; Einarsdottir, H S; Goregliad-Fjaellingsdal, T;

    2016-01-01

    Acute Tryptophan Depletion (ATD) is a dietary method used to modulate central 5-HT to study the effects of temporarily reduced 5-HT synthesis. The aim of this study is to evaluate a novel method of ATD using a gelatin-based collagen peptide (CP) mixture. We administered CP-Trp or CP+Trp mixtures ...... effects of CP-Trp compared to CP+Trp were observed. The transient increase in plasma Trp after CP+Trp may impair comparison to the CP-Trp and we therefore recommend in future studies to use a smaller dose of Trp supplement to the CP mixture....

  3. HP1 recruits activity-dependent neuroprotective protein to H3K9me3 marked pericentromeric heterochromatin for silencing of major satellite repeats.

    Kerstin Mosch

    Full Text Available H3 lysine 9 trimethylation (H3K9me3 is a histone posttranslational modification (PTM that has emerged as hallmark of pericentromeric heterochromatin. This constitutive chromatin domain is composed of repetitive DNA elements, whose transcription is differentially regulated. Mammalian cells contain three HP1 proteins, HP1α, HP1β and HP1γ These have been shown to bind to H3K9me3 and are thought to mediate the effects of this histone PTM. However, the mechanisms of HP1 chromatin regulation and the exact functional role at pericentromeric heterochromatin are still unclear. Here, we identify activity-dependent neuroprotective protein (ADNP as an H3K9me3 associated factor. We show that ADNP does not bind H3K9me3 directly, but that interaction is mediated by all three HP1 isoforms in vitro. However, in cells ADNP localization to areas of pericentromeric heterochromatin is only dependent on HP1α and HP1β. Besides a PGVLL sequence patch we uncovered an ARKS motif within the ADNP homeodomain involved in HP1 dependent H3K9me3 association and localization to pericentromeric heterochromatin. While knockdown of ADNP had no effect on HP1 distribution and heterochromatic histone and DNA modifications, we found ADNP silencing major satellite repeats. Our results identify a novel factor in the translation of H3K9me3 at pericentromeric heterochromatin that regulates transcription.

  4. Endosome-mediated endocytic mechanism replenishes the majority of synaptic vesicles at mature CNS synapses in an activity-dependent manner.

    Park, Joohyun; Cho, Oh Yeon; Kim, Jung Ah; Chang, Sunghoe

    2016-01-01

    Whether synaptic vesicles (SVs) are recovered via endosome-mediated pathways is a matter of debate; however, recent evidence suggests that clathrin-independent bulk endocytosis (CIE) via endosomes is functional and preferentially replenishes SV pools during strong stimulation. Here, using brefeldin-A (BFA) to block CIE, we found that CIE retrieved a minority of SVs at developing CNS synapses during strong stimulation, but its contribution increased up to 61% at mature CNS synapses. Contrary to previous views, BFA not only blocked SV formation from the endosome but also blocked the endosome formation at the plasma membrane. Adaptor protein 1 and 3 (AP-1/3) have key roles in SV reformation from endosomes during CIE, and AP-1 also affects bulk endosome formation from the plasma membrane. Finally, temporary blocking of chronic or acute neuronal activity with tetrodotoxin in mature neurons redirected most SV retrieval to endosome-independent pathways. These results show that during high neuronal activity, CIE becomes the major endocytic pathway at mature CNS synapses. Moreover, mature neurons use clathrin-mediated endocytosis and the CIE pathway to different extents depending on their previous activity; this may result in activity-dependent alterations of the SV composition which ultimately influence transmitter release and contribute to synaptic plasticity. PMID:27534442

  5. The combined depletion of monoamines alters the effectiveness of subthalamic deep brain stimulation.

    Faggiani, Emilie; Delaville, Claire; Benazzouz, Abdelhamid

    2015-10-01

    Non-motor symptoms of Parkinson's disease are under-studied and therefore not well treated. Here, we investigated the role of combined depletions of dopamine, norepinephrine and/or serotonin in the manifestation of motor and non-motor deficits in the rat. Then, we studied the impact of these depletions on the efficacy of deep brain stimulation of the subthalamic nucleus (STN-DBS). We performed selective depletions of dopamine, norepinephrine and serotonin, and the behavioral effects of different combined depletions were investigated using the open field, the elevated plus maze and the forced swim test. Bilateral dopamine depletion alone induced locomotor deficits associated with anxiety and mild "depressive-like" behaviors. Although additional depletions of norepinephrine and/or serotonin did not potentiate locomotor and anxiety disorders, combined depletions of the three monoamines dramatically exacerbated "depressive-like" behavior. STN-DBS markedly reversed locomotor deficits and anxiety behavior in animals with bilateral dopamine depletion alone. However, these improvements were reduced or lost by the additional depletion of norepinephrine and/or serotonin, indicating that the depletion of these monoamines may interfere with the antiparkinsonian efficacy of STN-DBS. Furthermore, our results showed that acute STN-DBS improved "depressive-like" disorder in animals with bilateral depletion of dopamine and also in animals with combined depletions of the three monoamines, which induced severe immobility in the forced swim test. Our data highlight the key role of monoamine depletions in the pathophysiology of anxiety and depressive-like disorders and provide the first evidence of their negative consequences on the efficacy of STN-DBS upon the motor and anxiety disorders in the context of Parkinson's disease. PMID:26206409

  6. Military use of depleted uranium assessment of prolonged population exposure

    Giannardi, C

    2001-01-01

    This work is an exposure assessment for a population living in an area contaminated by use of depleted uranium (DU) weapons. RESRAD 5.91 code is used to evaluate the average effective dose delivered from 1, 10, 20 cm depths of contaminated soil, in a residential farmer scenario. Critical pathway and group are identified in soil inhalation or ingestion and children playing with the soil, respectively. From available information on DU released on targeted sites, both critical and average exposure can leave to toxicological hazards; annual dose limit for population can be exceeded on short-term period (years) for soil inhalation. As a consequence, in targeted sites cleaning up must be planned on the basis of measured concentration, when available, while special cautions have to be adopted altogether to reduce unaware exposures, taking into account the amount of the avertable dose.

  7. Properties of drift waves in a filamentary density depletion

    This analytical and numerical study explores the properties of electrostatic, drift-wave eigenmodes trapped within a magnetic field-aligned depletion in plasma density and temperature whose transverse dimension is on the order of the electron skin depth. The dependence of the complex eigenfrequencies on key parameters is investigated for collisionless and collisional plasma. The collisional description is based on the Lorentz model of electron pitch-angle scattering. The separate roles of the gradients in density and temperature are illustrated for the collisional and collisionless regimes. The predictions are compared to experimental observations [J. E. Maggs and G. J. Morales, Geophys. Res. Lett. 23, 633 (1996); Phys. Plasmas 4, 290 (1997)] of a controlled striation in the laboratory. copyright 1997 American Institute of Physics

  8. Active volume studies with depleted and enriched BEGe detectors

    Sturm, Katharina von [Eberhard Karls Universitaet Tuebingen (Germany); Universita degli Studi di Padova, Padua (Italy); Collaboration: GERDA-Collaboration

    2013-07-01

    The Gerda experiment is currently taking data for the search of the 0νββ decay in {sup 76}Ge. In 2013, 30 newly manufactured Broad Energy Germanium (BEGe) diodes will be deployed which will double the active mass within Gerda. These detectors were fabricated from high-purity germanium enriched in {sup 76}Ge and tested in the HADES underground laboratory, owned by SCK.CEN, in Mol, Belgium. As the BEGes are source and detector at the same time, one crucial parameter is their active volume which directly enters into the evaluation of the half-life. This talk illustrates the dead layer and active volume determination of prototype detectors from depleted germanium as well as the newly produced detectors from enriched material, using gamma spectroscopy methods and comparing experimental results to Monte-Carlo simulations. Recent measurements and their results are presented, and systematic effects are discussed.

  9. Mitochondria, cellular stress resistance, somatic cell depletion and lifespan.

    Robb, Ellen L; Page, Melissa M; Stuart, Jeffrey A

    2009-03-01

    The causes of aging and determinants of maximum lifespan in animal species are multifaceted and complex. However, a wealth of experimental data suggests that mitochondria are involved both in the aging process and in regulating lifespan. Here we outline a somatic cell depletion (SCD) model to account for correlations between: (1) mitochondrial reactive oxygen species and lifespan; (2) mitochondrial antioxidant enzymes and lifespan; (3) mitochondrial DNA mutation and lifespan and (4) cellular stress resistance and lifespan. We examine the available data from within the framework of the SCD model, in which mitochondrial dysfunction leading to cell death and gradual loss of essential somatic cells eventually contributes to the decline in physiological performance that limits lifespan. This model is useful in explaining many of the mitochondrial manipulations that alter maximum lifespan in a variety of animal species; however, there are a number of caveats and critical experiments outstanding, and these are outlined in this review. PMID:20021396

  10. Self-regulatory failure: a resource-depletion approach.

    Vohs, K D; Heatherton, T F

    2000-05-01

    Three studies were conducted to test the behavioral consequences of effortful self-regulation. Individuals with chronic inhibitions about eating were exposed to situations varying in level of self-regulatory demand. Subsequently, participants' ability to self-regulate was measured. Two studies manipulated self-regulatory demand by exposing participants to good-tasting snack foods, whereas a third study required participants to control their emotional expressions. As hypothesized, exerting self-control during the first task led to decrements in self-control on a subsequent task. Moreover, these effects were not due to changes in affective state and occurred only when self-control was required in the first task. These findings are explained in terms of depletion of self-regulatory resources, which impairs successful volitional control. PMID:11273412

  11. Fuel depletion calculation in MTR-LEU NUR reactor

    Zeggar Foudil

    2008-01-01

    Full Text Available In this article, we present the results of a few energy groups calculations for the NUR reactor fuel depletion analysis up to 45 000 MWd/tU taken as the maximum fuel burn up. The WIMSD-4 cell code has been employed as a calculation tool. In this study, we are interested in actinides such as the uranium and plutonium isotopes, as well as fission products Xe-135, Sm-149, Sm-151, Eu-155, and Gd-157. Calculation results regarding the five energy groups are in a good agreement with those obtained with only two energy groups which can, therefore, be used in all subsequent calculations. Calculation results presented in this article can be used as a microscopic data base for estimating the amount of radioactive sources randomly dispersed in the environment. They can also be used to monitor the fuel assemblies inventory at the core level.

  12. Quantification of depletion-induced adhesion of Red Blood Cells

    Steffen, Patrick; Wagner, Christian

    2012-01-01

    Red blood cells (RBC) are known to form aggregates in the forms of rouleaux due to the presence of plasma proteins under physiological conditions. Rouleaux formation can be also induced in vitro by the addition of macromolecules to the RBC solution. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly rely on indirect measurements like flow chamber experiments, but on the single cell level data is lacking. Here we present measurements on the dextran induced aggregation of red blood cells by use of atomic force microscopy based single cell force spectroscopy (SCFS). The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs was determined. The results are in good agreement with a model based on the depletion effect and former experimental studies.

  13. Measurement of Holmium Rydberg series through MOT depletion spectroscopy

    Hostetter, J; Lawler, J E; Saffman, M

    2014-01-01

    We report measurements of the absolute excitation frequencies of $^{165}$Ho $4f^{11}6sns$ and $4f^{11}6snd$ odd-parity Rydberg series. The states are detected through depletion of a magneto-optical trap via a two-photon excitation scheme. Measurements of 162 Rydberg levels in the range $n=40-101$ yield quantum defects well described by the Rydberg-Ritz formula. We observe a strong perturbation in the $ns$ series around $n=51$ due to an unidentified interloper at 48515.47(4) cm$^{-1}$. From the series convergence, we determine the first ionization potential $E_\\mathrm{IP}=48565.939(4)$ cm$^{-1}$, which is three orders of magnitude more accurate than previous work. This work represents the first time such spectroscopy has been done in Holmium and is an important step towards using Ho atoms for collective encoding of a quantum register.

  14. M cell-depletion blocks oral prion disease pathogenesis.

    Donaldson, D S; Kobayashi, A; Ohno, H; Yagita, H; Williams, I R; Mabbott, N A

    2012-03-01

    Many prion diseases are orally acquired. Our data show that after oral exposure, early prion replication upon follicular dendritic cells (FDC) in Peyer's patches is obligatory for the efficient spread of disease to the brain (termed neuroinvasion). For prions to replicate on FDC within Peyer's patches after ingestion of a contaminated meal, they must first cross the gut epithelium. However, the mechanism through which prions are conveyed into Peyer's patches is uncertain. Within the follicle-associated epithelium overlying Peyer's patches are microfold cells (M cells), unique epithelial cells specialized for the transcytosis of particles. We show that following M cell-depletion, early prion accumulation upon FDC in Peyer's patches is blocked. Furthermore, in the absence of M cells at the time of oral exposure, neuroinvasion and disease development are likewise blocked. These data suggest M cells are important sites of prion uptake from the gut lumen into Peyer's patches. PMID:22294048

  15. The depletion of the human resources pool in South Africa

    J. Du Preez

    2002-12-01

    Full Text Available The brain drain has become one of the dominant realities within the South African economy. The official emigration statistics from South African sources inadvertently minimizes the seriousness of the threat, but emigration figures received from foreign countries are indicative of the size of the problem. Emigration, however, is not the only cause for the depletion of the human resource pool. Internal migration, pseudo-emigration and the influx of unskilled workers also negatively effect the composition of the human resource provision in the country. Murder, HIV/AIDS and related diseases severely impact industry and will increasingly contribute to the brain drain. A radical reduction of the skilled work force and a dramatic shift in the composition of the human resource pool towards unskilled labour negatively impact on industry and inhibits South Africa's ability to compete effectively in an increasingly global market.

  16. Groundwater Depletion and Long term Food Security in India

    Fishman, R.; Lall, U.; Modi, V.; Siegfried, T. U.; Narula, K. K.

    2009-12-01

    Unsustainable extraction of groundwater has led water tables to decline in many parts of India - the same parts that tend to produce most of the country’s food. Government policies like procurement and price guarantees for water intensive grains as well as subsidies on energy for pumping, originally intended to ensure national self-sufficiency in grain, are partly responsible for unsustainable groundwater extraction. The resulting groundwater depletion is associated with increasing burdens on state budgets and farmer incomes, and also risks irreversible damages to aquifers as a result of saline intrusion and other forms of pollution, processes that can undermine the prospects of long term food security. We discuss the policies and proposed solutions that might be able to maintain food security in the face of this impending crisis.

  17. The potentiality of depleted water to modify the tomatoes

    The possibility to improve the tomatoes bio-productivity parameters was tested using H2O-d and deuterium depleted water (DDW). There are presented the results obtained by seeds moisten before sowing. The plants vegetation until the first harvest and the fruits production and quality were studied. Making use of DDW has the following advantages: -accessibility, as the practical work is easy and economical; - nonpolluting, making use of the plants own bio-productive resources thus promoting the ecological agriculture. The effects registered during the experiments are: - seeds germination rhythm was faster in DDW conditions; - plants productivity was increased; - the capacity of light energetic convertibility was enhanced in the stress condition; - DDW seems to act as a 'helper' in the critical life cycle periods. (authors)

  18. The health effects of depleted uranium munitions: a summary

    There has been a substantial amount of public discussion on the health effects of the use of depleted uranium (DU) munitions. In response to this concern the Royal Society set up an independent, expert working group to investigate the health effects of DU munitions. The Royal Society has now produced two reports, and this summary covering the key conclusions and recommendations from both reports. The part I report considered the increased risks of radiation-induced cancer from exposures to DU on the battlefield. Part II dealt with the risks from the chemical toxicity of uranium, non-malignant radiation effects from DU intakes, the long-term environmental consequences of the deployment of DU munitions and responses to part I including issues arising at a public meeting to discuss the part I report. (author)

  19. Depleted uranium and radiation - induced lung cancer and leukaemia

    Reports of leukaemias and other cancers among servicemen who took part in the 1991 Gulf war or in the more recent operations in the Balkans are of continuing interest, as is the possibility, however slight, that depleted uranium (DU) is one of the causative factors. This commentary includes the results of a UK epidemiological study on the mortality of Gulf war veterans and , although not containing information on DU exposure, gives data on overall levels of mortality and therefore carries more weight than anecdotal reports. Also included are brief summaries on radiation-induced lung cancer in uranium workers as well as radiation-induced leukaemia in Japanese atomic bomb survivors and patients ankylosing spondylitis treated using x-rays. This commentary concludes with a critique of Iraqi cancer statistics as well as giving information on environmental contamination in Kosovo and the use of DU ammunition. (author)

  20. Depletion of mucosal substance P in acute otitis media

    Cayé-Thomasen, Per; Schmidt, Peter Thelin; Hermansson, Ann; Holst, Jens Juul; Thomsen, Jens

    2004-01-01

    OBJECTIVE: The neuropeptide substance P (SP) is an inducer of neurogenic inflammation and bone resorption in the middle ear. Resorption of the bone tissue structures surrounding the middle ear cavity is a distinct feature of the initial stage of acute otitis media (AOM), which may be due to nerve...... fiber release of SP. MATERIAL AND METHODS: To investigate possible release of SP in the middle ear mucosa during AOM, we used a well-established rat model of AOM caused by Streptococcus pneumoniae. Following tissue extraction on Days 1, 3 and 6 post-inoculation, the mucosal concentration of SP was...... measured using a radioimmunoassay. RESULTS: Compared to sham-inoculated control ears, the concentration of SP was significantly reduced on Day 1 and even further reduced on Day 3, whereas partial replenishment was found on Day 6. CONCLUSION: SP seems to be depleted in the rat middle ear mucosa in the...

  1. Implications of stratospheric ozone depletion upon plant production

    An increase in the amount of UV-B radiation reaching the earth's surface is identified as the major factor of concern to result from stratospheric ozone depletion. UV radiation is believed to have wide ranging effects on plant physiology and biochemistry. In screening studies of > 300 species and cultivars, > 50% have shown sensitivity to UV radiation. The most sensitive plant families appear to be Leguminosae, Cucurbitaceae and Cruciferae. The need for a better understanding of the effects of UV radiation on crop plant physiology and particularly of the repair and protective mechanisms developed by some species is stressed. This paper was presented at a colloquium on Implications of global climate changes on horticultural cropping practices and production in developing countries held at the 86th Annual Meeting of the American Society for Horticultural Science at Tulsa, Oklahoma, on 2 Aug. 1989

  2. Ozone depletion zone and ozone smog. Ozone chemistry fundamentals

    This book elucidates the fundamentals of the ozone theory. The knowledge verified through measurements is compiled, and the gaps in the knowledge of ozone are defined. While the knowledge of ozone appears to be well-established the gaps in the knowledge are responsible for uncertainties. Measurement methods for determination of the atmospheric concentration of ozone are described. Details are given about the basic processes of atmospheric ozone formation and ozone depletion and about the role of CFC. The factors which determine ozone concentrations in the southern hemisphere are described first because South Pole ozone formation processes, in spite of their complexity, are not as complex as North Pole ozone formation processes. The differences between these processes in the two polar regions are described. (orig.)

  3. Depletion of Arctic ozone in the winter 1990

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

    1991-01-01

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

  4. Ozone depletion - Ultraviolet radiation and phytoplankton biology in Antarctic waters

    Smith, R. C.; Prezelin, B. B.; Baker, K. S.; Bidigare, R. R.; Boucher, N. P.; Coley, T.; Karentz, D.; Macintyre, S.; Matlick, H. A.; Menzies, D.

    1992-01-01

    The near-50-percent thinning of the stratospheric ozone layer over the Antarctic, with increased passage of mid-UV radiation to the surface of the Southern Ocean, has prompted concern over possible radiation damage to the near-surface phytoplankton communities that are the bases of Antarctic marine ecosystems. As the ozone layer thinned, a 6-week study of the marginal ice zone of the Bellingshousen Sea in the austral spring of 1990 noted sea-surface and depth-dependent ratios of mid-UV irradiance to total irradiance increased, and mid-UV inhibition of photosynthesis increased. A 6-12 percent reduction in primary production associated with ozone depletion was estimated to have occurred over the course of the present study.

  5. Antarctic springtime ozone depletion computed from temperature observations

    Rosenfield, Joan E.; Schoeberl, Mark R.; Newman, Paul A.

    1988-01-01

    An observationally based, mechanistic dynamical model is used to simulate the decline of total ozone during September and October for the years 1979 through 1986. Vertical velocities derived from observed stratospheric temperature changes and computed radiative heating rates are used to advect an ozone mixing ratio profile during the Antarctic spring period. An early August 1982 Syowa balloonsonde ozone profile is used to initialize the computations. The model reasonably simulates the September and October changes in total ozone, considering the uncertainties in the observed data and the radiative heating. The simulated decline is found to be very sensitive to the choice of initial ozone profile and to small changes in the radiative heating. The results of this study suggest that the dynamical hypothesis of the Antarctic ozone depletion is both quantitatively credible and consistent with the observed temperature changes.

  6. The effect of pump depletion on reversible photodegradation

    Anderson, Benjamin; Kuzyk, Mark G

    2013-01-01

    We model the effect of pump depletion on reversible photodegradation using the extended domain model[Anderson and Kuzyk, arXiv:1309.5176v1, 2013] and the Beer-Lambert law. We find that neglecting pump absorption in the analysis of the linear optical transmittance leads to an underestimate of the degree and rate of photodegradation. The model is used to accurately measure the molecular absorbance cross sections of the three species involved in photodegradation of disperse orange 11 dye in (poly)methyl-methacralate polymer (DO11/PMMA). Finally we find that the processing history of a dye-doped polymer affects reversible photodegradation, with polymerized monomer solutions of DO11 being more photostable than those prepared from solvent evaporated dye-polymer solutions.

  7. The effect of pump depletion on reversible photodegradation

    Anderson, Benjamin; Hung, Sheng-Ting; Kuzyk, Mark G.

    2014-05-01

    We model the effect of pump depletion on reversible photodegradation using the extended domain model [Anderson and Kuzyk, arXiv:1309.5176v1, 2013] and the Beer-Lambert law. We find that neglecting pump absorption in the analysis of the linear optical transmittance leads to an underestimate of the degree and rate of photodegradation. The model is used to accurately measure the molecular absorbance cross sections of the three species involved in photodegradation of disperse orange 11 dye in (poly)methyl-methacralate polymer (DO11/PMMA). Finally we find that the processing history of a dye-doped polymer affects reversible photodegradation, with polymerized monomer solutions of DO11 being more photostable than those prepared from solvent evaporated dye-polymer solutions.

  8. Monitoring bioremediation of weathered diesel NAPL using oxygen depletion profiles

    Semicontinuous logging of oxygen concentrations at multiple depths has been used to evaluate the progress of an in situ bioremediation trial at a site contaminated by weathered diesel nonaqueous-phase liquid (NAPL). The evaluation trial consisted of periodic addition of nutrients and aeration of a 100-m2 trial plot. During the bioremediation trial, aeration was stopped periodically, and decreases in dissolved and gaseous oxygen concentrations were monitored using data loggers attached to in situ oxygen sensors placed at multiple depths above and within a thin NAPL-contaminated zone. Oxygen usage rate coefficients were determined by fitting zero- and first-order rate equations to the oxygen depletion curves. For nutrient-amended sites within the trial plot, estimates of oxygen usage rate coefficients were significantly higher than estimates from unamended sites. These rates also converted to NPL degradation rates, comparable to those achieved in previous studies, despite the high concentrations and weathered state of the NAPL at this test site

  9. Depleted CMOS pixels for LHC proton-proton experiments

    Wermes, N.

    2016-07-01

    While so far monolithic pixel detectors have remained in the realm of comparatively low rate and radiation applications outside LHC, new developments exploiting high resistivity substrates with three or four well CMOS process options allow reasonably large depletion depths and full CMOS circuitry in a monolithic structure. This opens up the possibility to target CMOS pixel detectors also for high radiation pp-experiments at the LHC upgrade, either in a hybrid-type fashion or even fully monolithic. Several pixel matrices have been prototyped with high ohmic substrates, high voltage options, and full CMOS electronics. They were characterized in the lab and in test beams. An overview of the necessary development steps and different approaches as well as prototype results are presented in this paper.

  10. Effects of depleted uranium on decomposition and soil bacterial communities

    A soil microcosm experiment was used to analyze effects of depleted uranium on soil community function. Uranium treatment levels were 0, 50, 500, 5,000, 10,000, and 25,000 ppm. Decomposition was followed through measurement of mass loss of several different plant litter types, as well as through analysis of soil respiration. Litter types tested were lignin, cellulose, and both high-nitrogen and low-nitrogen grass. Functional diversity of soil bacteria was assessed using the BIOLOG system of sole carbon source utilization. There was a significant reduction in litter decomposition at the 25,000 ppm level versus the control for all litter types except the high-nitrogen grass. Changes in functional diversity of the soil bacterial communities were more pronounced. Changes were observed both in terms of the number of carbon sources utilized, as well as in the intensity of utilization

  11. Contribution of Groundwater Depletion to Global Mean Sea Level Rise

    Lambinicio, A.; An, K.; Reager, J. T.; Druffel-Rodriguez, R. E.; Richey, A. S.; Famiglietti, J. S.; Rodell, M.

    2012-12-01

    The contribution of groundwater depletion to Global Mean Sea Level Rise (GMSLR) is an important topic and source of great uncertainty in the GMSLR budget. This research uses gridded GRACE Tellus satellite data to quantify changes in total land water storage, including those of groundwater. Global Land Data Assimilation System land components such as soil moisture, canopy moisture, and snow, are subtracted from the GRACE data to isolate the groundwater component. The resulting trends show that most continents are gaining in groundwater storage, which is consistent with GRACE-based estimates of zero-to-increasing changes in total land water. Results indicate a negative contribution to GMSLR for the GRACE time period, which is in contrast to the positive contribution identified in recent studies.

  12. Nonlinear laser energy depletion in laser-plasma accelerators

    Shadwick, B.A.; Schroeder, C.B.; Esarey, E.

    2009-04-03

    Energy depletion of intense, short-pulse lasers via excitation of plasma waves is investigated numerically and analytically. The evolution of a resonant laser pulse proceeds in two phases. In the first phase, the pulse steepens, compresses, and frequency red-shifts as energy is deposited in the plasma. The second phase of evolution occurs after the pulse reaches a minimum length at which point the pulse rapidly lengthens, losing resonance with the plasma. Expressions for the rate of laser energy loss and rate of laser red-shifting are derived and are found to be in excellent agreement with the direct numerical solution of the laser field evolution coupled to the plasma response. Both processes are shown to have the same characteristic length-scale. In the high intensity limit, for nearly-resonant Gaussian laser pulses, this scale length is shown to be independent of laser intensity.

  13. Global oil depletion: A review of the evidence

    Within the polarised and contentious debate over future oil supply a growing number of commentators are forecasting a near term peak and subsequent decline in production. But although liquid fuels form the foundation of modern industrial economies, the growing debate on 'peak oil' has relatively little influence on energy and climate policy. With this in mind, the UK Energy Research Centre (UKERC) has conducted an independent, thorough and systematic review of the evidence, with the aim of establishing the current state of knowledge, identifying key uncertainties and improving consensus. The study focuses upon the physical depletion of conventional oil in the period to 2030 and includes an in-depth literature review, analysis of industry databases and a detailed comparison of global supply forecasts. This Communication summarises the main findings of the UKERC study. A key conclusion is that a peak of conventional oil production before 2030 appears likely and there is a significant risk of a peak before 2020.

  14. Military use of depleted uranium: assessment of prolonged population exposure

    This work is an exposure assessment for a population living in an area contaminated by the use of depleted uranium (DU) weapons. RESRAD 5.91 code was used to evaluate the average effective dose at depths of 1, 10, 20 cm of contaminated soil, in a residential farming scenario. Critical pathways and groups are identified in soil inhalation and ingestion; critical group is identified in children playing with the soil. From the available information on DU released at targeted sites, both critical and average exposure can produce toxicological hazards. The annual dose limit for the population can be exceeded within a few years from DU deposition for soil inhalation. As a result, clean up at targeted sites must be planned on the basis of measured concentration, when available, while special measures must be adopted anyway to reduce unaware exposures

  15. Special Issue: Planar Fully-Depleted SOI technology

    Allibert, F.; Hiramoto, T.; Nguyen, B. Y.

    2016-03-01

    We are in the era of mobile computing with smart handheld devices and remote data storage "in the cloud," with devices that are almost always on and driven by needs of high data transmission rate, instant access/connection and long battery life. With all the ambitious requirements for better performance with lower power consumption, the SoC solution must also be cost-effective in order to capture the large, highly-competitive consumer mobile and wearable markets. The Fully-Depleted SOI device/circuit is a unique option that can satisfy all these requirements and has made tremendous progress in development for various applications and adoption by foundries, integrated device manufacturers (IDM), and fabless companies in the last 3 years.

  16. The Lithium Depletion Boundary as a Clock and Thermometer

    Jeffries, R D

    2000-01-01

    We take a critical look at the lithium depletion boundary (LDB) technique that has recently been used to derive the ages of open clusters. We identify the sources of experimental and systematic error and show that the probable errors are larger by approximately a factor two than presently claimed in the literature. We then use the Pleiades LDB age and photometry in combination with evolutionary models to define empirical colour-T_eff relations that can be applied to younger clusters. We find that these relationships DO NOT produce model isochrones that match the younger cluster data. We propose that this is due either to systematic problems in the evolutionary models or an age (gravity) sensitivity in the colour-T_eff relation which is not present in published atmospheric models.

  17. Electrolyte depletion in white-nose syndrome bats

    Cryan, Paul M.; Meteyer, Carol Uphoff; Blehert, David S.; Lorch, Jeffrey M.; Reeder, DeeAnn M.; Turner, Gregory G.; Webb, Julie; Behr, Melissa; Verant, Michelle L.; Russell, Robin E.; Castle, Kevin T.

    2013-01-01

    The emerging wildlife disease white-nose syndrome is causing widespread mortality in hibernating North American bats. White-nose syndrome occurs when the fungus Geomyces destructans infects the living skin of bats during hibernation, but links between infection and mortality are underexplored. We analyzed blood from hibernating bats and compared blood electrolyte levels to wing damage caused by the fungus. Sodium and chloride tended to decrease as wing damage increased in severity. Depletion of these electrolytes suggests that infected bats may become hypotonically dehydrated during winter. Although bats regularly arouse from hibernation to drink during winter, water available in hibernacula may not contain sufficient electrolytes to offset winter losses caused by disease. Damage to bat wings from G. destructans may cause life-threatening electrolyte imbalances.

  18. Depleted uranium: Metabolic disruptor?; Uranium appauvri: perturbateur metabolique?

    Souidi, Maamar; Dublineau, Isabelle; Lestaevel, Philippe [Institut de Radioprotection et de Surete Nucleaire - IRSN, Direction de la radioprotection de l' homme, Laboratoire de radiotoxicologie experimentale, Service de radiobiologie et d' epidemiologie, BP 17, 92262 Fontenay-aux-Roses cedex (France)

    2011-11-15

    The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolizing vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions. (authors)

  19. Deuterium-depleted water. Short history and news

    Deuterium-depleted water represents water that has an isotopic content lower than 144 ppm D/(D+H) which is the natural isotopic content of water. DDW is a non-toxic product. Knowing that deuterium content of water has a significant influence on living organisms, since 1996 NIR-DCIT ICSTI at Rm. Valcea cooperated with Romanian specialized instititutes for biological effects' evaluation of DDW. The investigations lead to the conclusion that DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects. Animals teated with DDW showed an increase of the resistance both to sub lethal and to lethal gamma radiation doses. DDW stimulates immune defense reactions. Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favorable influence in embryo growth stage and resistance in next growth stages. One can remark the favourable influence of DDW on biological process in plants in various ontogenetic stages. (authors)

  20. Quantification of Depletion-Induced Adhesion of Red Blood Cells

    Steffen, P.; Verdier, C.; Wagner, C.

    2013-01-01

    Red blood cells (RBCs) are known to form aggregates in the form of rouleaux due to the presence of plasma proteins under physiological conditions. The formation of rouleaux can also be induced in vitro by the addition of macromolecules to the RBC suspension. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly originate from indirect measurements such as flow chamber experiments, but data is lacking at the single cell level. Here, we present measurements on the dextran-induced aggregation of red blood cells using atomic force microscopy-based single cell force spectroscopy. The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs were determined. The results on adhesion energy are in excellent agreement with a model based on the depletion effect and previous experimental studies. Furthermore, our method allowed to determine the adhesion force, a quantity that is needed in theoretical investigations on blood flow.

  1. Delayed lubricant depletion on liquid-infused randomly rough surfaces

    Kim, Jeong-Hyun; Rothstein, Jonathan P.

    2016-05-01

    In this study, pressure drops on liquid-infused superhydrophobic surfaces were measured through a microchannel. A number of different superhydrophobic surfaces were prepared and tested. These surfaces included several PDMS surfaces containing precisely patterned microposts and microridges as well as a number of PTFE surfaces with random surface roughness created by sanding the PTFE with different sandpapers. Silicone oil was selected as the lubricant fluid and infused into the microstructures of the superhydrophobic surfaces. Several aqueous glycerin solutions with different viscosities were used as working fluids so that the viscosity ratio between the lubricant and the working fluid could be varied. The lubricant layer trapped within the precisely patterned superhydrophobic PDMS surfaces was found to be easily depleted over a short period of time even in limit of low flow rates and capillary numbers. On the other hand, the randomly rough superhydrophobic PTFE surfaces tested were found to maintain the layer of lubricant oil even at moderately high capillary numbers resulting in drag reduction that was found to increase with increasing viscosity ratio. The pressure drops on the liquid-infused PTFE surfaces were measured over time to determine the longevity of the lubricant layer. The pressure drops for the randomly rough PTFE surfaces were found to initially diminish with time before reaching a short-time plateau which is equivalent to maximum drag reduction. This minimum pressure drop was maintained for at least three hours in all cases regardless of feature size. However, as the depletion of the oil from the lubricant layer was initiated, the pressure drop was observed to grow slowly before reaching a second long-time asymptote which was equivalent to a Wenzel state.

  2. Precious Metals in Automotive Technology: An Unsolvable Depletion Problem?

    Ugo Bardi

    2014-04-01

    Full Text Available Since the second half of the 20th century, various devices have been developed in order to reduce the emissions of harmful substances at the exhaust pipe of combustion engines. In the automotive field, the most diffuse and best known device of this kind is the “three way” catalytic converter for engines using the Otto cycle designed to abate the emissions of carbon monoxide, nitrogen oxides and unburnt hydrocarbons. These catalytic converters can function only by means of precious metals (mainly platinum, rhodium and palladium which exist in a limited supply in economically exploitable ores. The recent increase in prices of all mineral commodities is already making these converters significantly expensive and it is not impossible that the progressive depletion of precious metals will make them too expensive for the market of private cars. The present paper examines how this potential scarcity could affect the technology of road transportation worldwide. We argue that the supply of precious metals for automotive converters is not at risk in the short term, but that in the future it will not be possible to continue using this technology as a result of increasing prices generated by progressive depletion. Mitigation methods such as reducing the amounts of precious metals in catalysts, or recycling them can help but cannot be considered as a definitive solution. We argue that precious metal scarcity is a critical factor that may determine the future development of road transportation in the world. As the problem is basically unsolvable in the long run, we must explore new technologies for road transportation and we conclude that it is likely that the clean engine of the future will be electric and powered by batteries.

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

    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.

  4. The back-end question for depleted uranium

    Depleted uranium (DU) is uranium primarily composed of the isotope uranium-238 (U-238). DU is useful because of its very high density. Civilian uses include counterweights in aircraft, radiation shielding in medical radiation therapy and industrial radiography equipment, and containers used to transport radioactive materials. Military uses include defensive armor plating and armor-piercing projectiles. A review of present and future situation of DU inventories in the world points out the back-end of the depleted uranium cycle as a future important question: what are the possible destinations of the relatively large quantities of DU produced by the nuclear industry in the past and in the future? An evaluation of the alternatives for the final destination of DU is carried out: recycle and re-use, now and in the future, is one of the options. Immediate use deals with re-enrichment of part of the tails, while future uses may regard the extraction of more LEU (Low-Enriched Uranium), and the use in the fuel cycle of breeder reactors. In all these cases, the implicit store option requires a disposal option that is recoverable. Innovative civil uses of DU in perspective are described in the paper, such as for Spent Nuclear Fuel (SNF) waste packages. This appears to be a valid alternative to the pure waste disposal option: DU has a unique chemical capability for SNF disposal applications (criticality control and suppressing SNF uranium dioxide matrix dissolution). The 'waste only' option can foresee seawater dilution (four billion tons of U in equilibrium with the ocean seabed), geological disposal (different European/U.S. requirements for heavy metals), and shallow land burial in the US (with chemical and radiological issues). (authors)

  5. Depleted uranium residual radiological risk assessment for Kosovo sites

    During the recent conflict in Yugoslavia, depleted uranium rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of areas in Kosovo with depleted uranium penetrators and dust. Although chemical toxicity is the most significant health risk related to uranium, radiation exposure has been allegedly related to cancers among veterans of the Balkan conflict. Uranium munitions are considered to be a source of radiological contamination of the environment. Based on measurements and estimates from the recent Balkan Task Force UNEP mission in Kosovo, we have estimated effective doses to resident populations using a well-established food-web mathematical model (RESRAD code). The UNEP mission did not find any evidence of widespread contamination in Kosovo. Rather than the actual measurements, we elected to use a desk assessment scenario (Reference Case) proposed by the UNEP group as the source term for computer simulations. Specific applications to two Kosovo sites (Planeja village and Vranovac hill) are described. Results of the simulations suggest that radiation doses from water-independent pathways are negligible (annual doses below 30 μSv). A small radiological risk is expected from contamination of the groundwater in conditions of effective leaching and low distribution coefficient of uranium metal. Under the assumptions of the Reference Case, significant radiological doses (>1 mSv/year) might be achieved after many years from the conflict through water-dependent pathways. Even in this worst-case scenario, DU radiological risk would be far overshadowed by its chemical toxicity

  6. Depletion in Antarctic ozone and associated climatic change

    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 the authors 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 their 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. Further, the stratospheric cooling due to the ozone hole phenomenon is not only restricted to low and middle stratosphere but also extends deep into the upper Antarctic stratosphere, particularly in the beginning of November. In view of this, it is possible that the polar stratospheric warming phenomenon associated with planetary wave events could be significantly disturbed by ozone depletion in the Antarctic atmosphere, leading to appreciable perturbations in the general circulation

  7. Multi-scale entropic depletion phenomena in polymer liquids

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

    2015-06-07

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

  8. Multi-scale entropic depletion phenomena in polymer liquids

    Banerjee, Debapriya; Schweizer, Kenneth S.

    2015-06-01

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

  9. Depleted uranium residual radiological risk assessment for Kosovo sites

    Durante, Marco E-mail: durante@na.infn.it; Pugliese, Mariagabriella

    2003-07-01

    During the recent conflict in Yugoslavia, depleted uranium rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of areas in Kosovo with depleted uranium penetrators and dust. Although chemical toxicity is the most significant health risk related to uranium, radiation exposure has been allegedly related to cancers among veterans of the Balkan conflict. Uranium munitions are considered to be a source of radiological contamination of the environment. Based on measurements and estimates from the recent Balkan Task Force UNEP mission in Kosovo, we have estimated effective doses to resident populations using a well-established food-web mathematical model (RESRAD code). The UNEP mission did not find any evidence of widespread contamination in Kosovo. Rather than the actual measurements, we elected to use a desk assessment scenario (Reference Case) proposed by the UNEP group as the source term for computer simulations. Specific applications to two Kosovo sites (Planeja village and Vranovac hill) are described. Results of the simulations suggest that radiation doses from water-independent pathways are negligible (annual doses below 30 {mu}Sv). A small radiological risk is expected from contamination of the groundwater in conditions of effective leaching and low distribution coefficient of uranium metal. Under the assumptions of the Reference Case, significant radiological doses (>1 mSv/year) might be achieved after many years from the conflict through water-dependent pathways. Even in this worst-case scenario, DU radiological risk would be far overshadowed by its chemical toxicity.

  10. Influence of deuterium-depleted water on living organisms

    Deuterium-depleted water (DDW) production technique consists in the separation of deuterium from water by means of an continuos distillation process under a pressure value of about 133,3 mbar. Water that is used as basic material has an isotopic content of 144 ppm D/(D+H). DDW results as distillate with an isotopic deuterium content of 15-80 ppm, depending on the level we want to achieve. Beginning with 1996 NIR and DCIT Rm. Valcea, which is a DDW producer, co-operated with Romanian specialised institutes for biological effects' evaluation of DDW. These investigations led to the next conclusions: - DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tonus and vascular reactivity produced by the DDW persist after the removal of the vascular endothelium; - Animals treated with DDW showed an increase of the resistance both to sublethal and to lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defence mechanisms; - DDW stimulate immune defence reactions, represented by the opsonic, bactericidal and phagocyte capacity of the immune system, together with increase in the numbers of polymorphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favourable influence in embryo growth stage and resistance in next growth stages; - It was studied germination, growth and quantitative characters' variability at plants; one can remark the favourable influence of DDW on biological process at plants in various ontogenic stages. Further investigations are needed in order to establish the influence of deuterium-depleted water on living organisms. (authors)

  11. Modeling of precipitation and Cr depletion profiles of Inconel 600 during heat treatments and LSM procedure

    A model based on the thermodynamic and kinetic was conducted to simulate the Cr depletion profiles near the grain boundary in Inconel 600 during the heat treatments and laser surface melting (LSM) process using Thermo-Calc and Dictra code. Based on the good agreement of Cr concentration distribution during heat treatments measured by experiments, the microsegregation of Cr induced by cellular microstructure formed during the LSM process was also modeled. The Cr depletion profile was evaluated using the Cr depletion area below the critical Cr concentration for intergranular cracking/intergranular stress corrosion cracking (IGC/IGSCC) susceptibility (8 mass%). Comparing with the result of Streicher test, the Cr depletion area calculated showed good coherence with the IGC/IGSCC susceptibility. The sample after SR + LTS treatment with the largest Cr depletion area showed the worst IGC/IGSCC resistance, while, the sample after LSM process with the smaller Cr depletion area showed the excellent IGC/IGSCC resistance

  12. Past and future contribution of global groundwater depletion to sea-level rise

    Wada, Yoshihide; van Beek, Ludovicus P. H.; Sperna Weiland, Frederiek C.; Chao, Benjamin F.; Wu, Yun-Hao; Bierkens, Marc F. P.

    2012-01-01

    Recent studies suggest the increasing contribution of groundwater depletion to global sea-level rise. Groundwater depletion has more than doubled during the last decades, primarily due to increase in water demand, while the increase in water impoundments behind dams has been tapering off since the 1990s. As a result, the contribution of groundwater depletion to sea-level rise is likely to dominate over those of other terrestrial water sources in the coming decades. Yet, no projections into th...

  13. Optimization of depletion focal spot in STED nanoscopy using amplitude manipulation

    Li, Yanghui; Lai, Lin; Rui, Congshan; Wang, Le

    2016-08-01

    To optimize the performance of stimulated emission depletion (STED) nanoscopy, a high-quality ring-shaped depletion pattern with a "zero"-intensity point at the center is mandatory. Here, we propose a novel strategy to enhance the two-dimensional (2D) resolution of STED nanoscopy by amplitude manipulation. In particular, we employ an annular mask to the depletion beam to enable a compression to the size of effective point spread function (PSF) by at least 20%.

  14. Teratogenicity of depleted uranium aerosols: A review from an epidemiological perspective

    Panikkar Bindu; Brugge Doug; Hindin Rita

    2005-01-01

    Abstract Background Depleted uranium is being used increasingly often as a component of munitions in military conflicts. Military personnel, civilians and the DU munitions producers are being exposed to the DU aerosols that are generated. Methods We reviewed toxicological data on both natural and depleted uranium. We included peer reviewed studies and gray literature on birth malformations due to natural and depleted uranium. Our approach was to assess the "weight of evidence" with respect to...

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

    Thompson, C. R.; P. B. Shepson; Liao, J.; Huey, L.G.; E. C. Apel; Cantrell, C. A.; Flocke, F.; Orlando, J.; Fried, A.; Hall, S. R; R. S. Hornbrook; D. J. Knapp; Mauldin III, R. L; Montzka, D. D.; B. C. Sive

    2014-01-01

    The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there ha...

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

    Thompson, C. R.; P. B. Shepson; Liao, J.; Huey, L.G.; E. C. Apel; Cantrell, C. A.; Flocke, F.; Orlando, J.; Fried, A.; Hall, S. R; R. S. Hornbrook; D. J. Knapp; Mauldin III, R. L; Montzka, D. D.; B. C. Sive

    2015-01-01

    The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs) has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indicatio...

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

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

    2006-01-01

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

  18. Rhodium in-core detector sensitivity depletion, cycles 2-5

    Sensitivity depletion of two rhodium (Rh) self-powered neutron detectors (SPNDs) has been measured since July 1976 at the Oconee 2 pressurized water reactor (PWR). The detectors were positioned inside the reactor core throughout the measurement period. Depletion has been determined as a function of electric charge released by each detector. The goal of the project is the empirical definition of the depletion characteristics over the operating life-time of the Rh detector. Results to date show that the sensitivity depletion rate of the Rh detector in the PWR is highly linear with charge released from the detector

  19. Using the depleted fraction to manage the groundwater table in irrigated areas

    Bos, M. G.; Bastiaanssen, W. G. M.

    2003-01-01

    The depleted fraction, defined as the ratio of ETactual over (P + Vc ), relates parameters of the water balance of an irrigated area with each other in such a way that the (water) manager obtains information on the rate of change of water stored in the area (soil moisture and groundwater). If the depleted fraction equals about 0.6 water storage in the area is stable, while water is stored for lower values of the depleted fraction. If the value of the depleted fraction exceeds 0.6, the volume ...

  20. Observation of radiation-specific damage in human cells exposed to depleted uranium: dicentric frequency and neoplastic transformation as endpoints

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalised human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. DU possesses both a radiological (alpha-particle) and chemical (metal) component. Since DU has a low specific activity in comparison to natural uranium, it is not considered to be a significant radiological hazard. The potential contribution of radiation to DU-induced biological effects is unknown and the involvement of radiation in DU-induced biological effects could have significant implication for current risk estimates for internalised DU exposure. Two approaches were used to address this question. The frequency of dicentrics was measured in HOS cells following DU exposure in vitro. Data demonstrated that DU exposure (50 μM, 24h) induced a significant elevation in dicentric frequency in vitro in contrast to incubation with the heavy metals, nickel and tungsten which did not increase dicentric frequency above background levels. Using the same concentration (50 μM) of three uranyl nitrate compounds that have different uranium isotopic concentrations and therefore, different specific activities, the effect on neoplastic transformation in vitro was examined. HOS cells were exposed to one of three-uranyl nitrate compounds (238U-uranyl nitrate, specific activity 0.33 μCi.g-1: DU-uranyl nitrate, specific activity 0.44 μCi.g-1: and 235U-uranyl nitrate, specific activity 2.2 μCi.g-1) delivered at a concentration of 50 μM for 24 h. Results showed, at equal uranium concentration, there was a specific activity dependent increase in neoplastic transformation frequency. Taken together these data suggest that radiation can play a role in DU-induced biological effects in vitro. (author)

  1. Gadolinium depletion event in a CANDU® moderator - causes and recovery

    Gadolinium nitrate is added to the moderator of CANDU units to maintain the reactor in a guaranteed shutdown state (GSS). In April 2008, after being in stable GSS for over 30 hours, one of Ontario Power Generation's Pickering-B units showed a gradual depletion of the dissolved gadolinium, despite purification being isolated. Further additions of gadolinium stabilized the moderator gadolinium concentration, however, since the root cause of the depletion was not immediately identified, the unit was placed in the drained shutdown state, per established procedures. The cumulative gadolinium depletion amounted to about 3200 grams, the equivalent of about 12 ppm. Analysis showed the presence of oxalate in the moderator water. It is well-known that gadolinium forms a very insoluble oxalate (log Ksp = -29.1). Although sub-micron filtration of water samples did not show the presence of gadolinium particulate, the measured levels of oxalate, 1.2 to 2 ppm, were sufficient to react with 1.4 to 2.4 ppm of gadolinium. The source of oxalate was traced to radiolysis of dissolved CO2 species. This unit had been experiencing chronic low-level ingress of CO2 from the Annulus Gas System. Free oxalate ion is normally susceptible to radiolytic breakdown back to CO2, but Gd3+ provides a stable sink for radiogenic oxalate, 2 Gd3+ + 3 C2O42- → Gd2(C2O4)3. Subsequent testing confirmed that gadolinium oxalate is quite stable with respect to gamma irradiation. Inspections showed well-crystallized gadolinium oxalate deposited on moderator system surfaces. Estimates indicated that about 1200 grams of gadolinium could have deposited on in-core surfaces, including the outside of the calandria tubes. That amount of negative reactivity was a concern, since it would prevent re-start of the unit. OPG, with support from AECL-Chalk River and Kinectrics, embarked on a two-pronged chemistry recovery program aimed at 1) developing solvents for dissolution of the gadolinium oxalate deposits and 2

  2. Pantethine, a somatostatin depleting agent, increases food intake in rats.

    Abucham, J; Bollinger-Gruber, J; Reichlin, S

    1989-07-01

    During the course of studies of the effects of pantethine, a cysteamine precursor known to deplete tissue concentration of immunoreactive somatostatin, we observed that the subject rats continued to eat despite marked distension of the stomach. To determine whether this effect was caused by drug-altered food intake, we have measured food and water intake in pantethine-injected rats in the fed and fasting state. In three separate experiments, rats allowed free access to food until the morning of study showed significant increased food intake accompanied by an increased stomach content (at 4 hr) of both food and water following the IP injection of pantethine. In one experiment, intake at 3 hours was 0.60 g/100 g b.wt. (pantethine dose 0.74 g/kg b.wt.) and 0.64 g/100 g b.wt. (pantethine dose 1.47 g/kg b.wt.) compared with 0.24 g/100 g b.wt. in saline-treated animals (p less than 0.05). In contrast, pantethine, 1.47 g/kg b.wt., when administered to overnight-fasted rats, significantly inhibited food intake (3-hr intake 1.54 +/- 0.16 g/100 g b.wt. in rats injected with pantethine 1.47 g/kg b.wt. as compared with 3.3 +/- 0.21 g/100 g b.wt. in saline-injected controls). The intake-stimulating effect of pantethine in ad lib-fed rats was not demonstrable when the drug was administered shortly before the "lights out"-induced feeding at night. These findings indicate that pantethine, a cysteamine precursor, stimulates food intake in satiated rats, depending upon the stage of circadian rhythm, but is inhibitory to intake in fasted animals. We postulate that the effects are mediated directly or indirectly through the disinhibition of central appetite-regulating somatostatinergic pathways but, since cysteamine also inhibits dopamine-beta-hydroxylase, an effect on depletion of appetite-regulating central catecholamines cannot be excluded. PMID:2587601

  3. The effects of deuterium-depleted water on bacteria

    Due to their adaptability the bacteria are ubiquitous, occurring in a large variety of habitats. Most of them are saprotrophs or parasites. Bacteria are agents causing many diseases in animals and humans. The main purpose of this work was to reveal the deuterium-depleted water bactericidal effect. Nonpathogenic Gram-positive (Bacillus subtilis and Bacillus cereus) and pathogenic Gram-negative (Agrobacterium tumefaciens, Erwinia amylovora and Escherichia coli) bacteria were used. The variant deuterium depleted (DDW) eater was compared with distilled water eater one. The diffusometric method was found the proper way of investigation. The bacteria culture was developed in Petri dishes (diam = 70 mm) at a temperature of 25 deg. C. After 24 h, 48 h and 72 h the clear area was measured. The clear area was one in which the bacteria were killed. The surface was determined by the area of the small disc on the filter paper. The statistical data were determined by variance analysis. The results pointed out a large response to DDW presence. The data were classified in: 1. without response when no clear area occurred; - 2. with response when a clear area of under 5 mm2 occurred; - 3. strong response when the clear area was higher than 10 mm2. The Gram-positive and Gram-negative bacteria behaviours were not in correlation with the DDW bactericidal effect. The Bacillus cereus and Escherichia coli were scored as without response and we presume that they were very tolerant. No clear area was induced by DDW. Bacillus subtilis and Erwinia amylovora showed weak response. After 24 h the killed bacteria were extended on the same area, namely, 2.89 mm2. Even if the DDW effect seems to be small it was significantly in comparison with the control case (sd = 2.78 mm2 > 0.1). After 48 h and 72 h the clear surface remained the same. The Agrobacterium tumefaciens' response was very strong. The bacteria were killed on 22.50 mm2 after 24 h and on 26.95 mm2 after 48 h, being very significantly

  4. Depleted uranium in the food chain at south of Iraq

    Depleted Uranium (D U) is uranium with low content of 2351) produced as a result of uranium enrichment. Du has high density (19.05 g/c m3), which is 2.54 more than Iron, so it's high penetrating power makes it preferable as emanations with high penetration power. It was used in second Gulf ware in 1991 for first time. The radioactivity of soil, plants, fruit, meat, milk and water is measured using gamma ray spectroscopy. Materials and Methods: One hundred samples of soil, plants and tomato fruit were selected from the tomato farms near Basra city south of Iraq and 6 control samples from other farms not contaminated with depleted uranium (Du). Also samples of meats, milk and water were collected in January 2003. Radioactivity of these samples was measured using Gamma-ray spectrograph system with high purity Germanium detector with resolution of 2.2 keV at the energy of 1332.3 keV of Co-60. The system is connected to P C Pentium 111 with PCA program. Results: The measurements show that radiation equilibrium between 234Th and 226R existed with the range between (0.86-1.16) in uncontaminated soil samples. For contaminated soil samples radiation equilibrium between 234Th and Pa-234m existed with the range between (0.928- 0.956). The mathematical equations of Kosovo team were used. Results show that the soils of two farms were contaminated with (D U). The radioactivity of 226R for plants ranging from 5.97 to 7.26 and for tomato fruits samples between 9.16 to 12.4 Bq/kg. Comparing these values with the control radioactivity which range between 6.25 to 7.34 for fruits and 13.3 to 13.9 Bq/kg for plants indicate that these samples were not contaminated with D U. Conclusion: The soil samples of two farms were contaminated with D U but the fruit of these farms was not contaminated with D U may be due to its high molecular weight and not being water soluble. The radioactivity of 226R for different kinds of meat and milk for animal grazing near destroyed tanks contaminated with

  5. STAR FORMATION IN PARTIALLY GAS-DEPLETED SPIRAL GALAXIES

    Broadband B and R and Hα images have been obtained with the 4.1 m SOAR telescope atop Cerro Pachon, Chile, for 29 spiral galaxies in the Pegasus I galaxy cluster and for 18 spirals in non-cluster environments. Pegasus I is a spiral-rich cluster with a low-density intracluster medium and a low galaxy velocity dispersion. When combined with neutral hydrogen (H I) data obtained with the Arecibo 305 m radio telescope, acquired by Levy et al. (2007) and by Springob et al. (2005b), we study the star formation rates in disk galaxies as a function of their H I deficiency. To quantify H I deficiency, we use the usual logarithmic deficiency parameter, DEF. The specific star formation rate (SSFR) is quantified by the logarithmic flux ratio of Hα flux to R-band flux, and thus roughly characterizes the logarithmic SFR per unit stellar mass. We find a clear correlation between the global SFR per unit stellar mass and DEF, such that the SFR is lower in more H I-deficient galaxies. This correlation appears to extend from the most gas-rich to the most gas-poor galaxies. We also find a correlation between the central SFR per unit mass relative to the global values, in the sense that the more H I-deficient galaxies have a higher central SFR per unit mass relative to their global SFR values than do gas-rich galaxies. In fact, approximately half of the H I-depleted galaxies have highly elevated SSFRs in their central regions, indicative of a transient evolutionary state. In addition, we find a correlation between gas depletion and the size of the Hα disk (relative to the R-band disk); H I-poor galaxies have truncated disks. Moreover, aside from the elevated central SSFR in many gas-poor spirals, the SSFR is otherwise lower in the Hα disks of gas-poor galaxies than in gas-rich spirals. Thus, both disk truncation and lowered SSFR levels within the star-forming part of the disks (aside from the enhanced nuclear SSFR) correlate with H I deficiency, and both phenomena are found to

  6. Ozone depletion in the stratosphere. Stratospheric ozone depletion is increasing dramatically. How is such massive ozone loss brought about? What are the consequences?

    The causes of stratospheric ozone depletion are exclusively man-made. Chlorofluorocarbons and, to a smaller extent, halones interfere with the chain mechanisms of photochemical ozone depletion. They thereby lower the concentration of stationary ozone. Contrary to expectations, compensatory effects consisting in enhanced ozone formation in lower layers do not occur. Heterogeneous processes at ice particles during the cold polar night contribute particularly to ozone loss. Reactions at these particles activate chlorine-containing storage compounds in such a way that the light of the rising sun in spring leads to enhanced release of compounds containing radicals which deplete ozone. This phenomenon is well documented for the events during the formation of the ozone hole over the Antarctic, but the winterly north polar region, too, shows similar instances of coupling between meteorological conditioning and chlorine-induced ozone depletion. (orig./EF)

  7. Soluble ICAM-5, a product of activity dependent proteolysis, increases mEPSC frequency and dendritic expression of GluA1.

    Irina Lonskaya

    Full Text Available Matrix metalloproteinases (MMPs are zinc dependent endopeptidases that can be released from neurons in an activity dependent manner to play a role in varied forms of learning and memory. MMP inhibitors impair hippocampal long term potentiation (LTP, spatial memory, and behavioral correlates of drug addiction. Since MMPs are thought to influence LTP through a β1 integrin dependent mechanism, it has been suggested that these enzymes cleave specific substrates to generate integrin binding ligands. In previously published work, we have shown that neuronal activity stimulates rapid MMP dependent shedding of intercellular adhesion molecule-5 (ICAM-5, a synaptic adhesion molecule expressed on dendrites of the telencephalon. We have also shown that the ICAM-5 ectodomain can interact with β1 integrins to stimulate integrin dependent phosphorylation of cofilin, an event that occurs with dendritic spine maturation and LTP. In the current study, we investigate the potential for the ICAM-5 ectodomain to stimulate changes in α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR dependent glutamatergic transmission. Single cell recordings show that the ICAM-5 ectodomain stimulates an increase in the frequency, but not the amplitude, of AMPA mini excitatory post synaptic currents (mEPSCs. With biotinylation and precipitation assays, we also show that the ICAM-5 ectodomain stimulates an increase in membrane levels of GluA1, but not GluA2, AMPAR subunits. In addition, we observe an ICAM-5 associated increase in GluA1 phosphorylation at serine 845. Concomitantly, ICAM-5 affects an increase in GluA1 surface staining along dendrites without affecting an increase in dendritic spine number. Together these data are consistent with the possibility that soluble ICAM-5 increases glutamatergic transmission and that post-synaptic changes, including increased phosphorylation and dendritic insertion of GluA1, could contribute. We suggest that future studies

  8. NF-kB activity-dependent P-selectin involved in ox-LDL-induced foam cell formation in U937 cell

    Wang, Yi, E-mail: wangyi2004a@126.com [Department of Cardiology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080 (China); Wang, Xiang; Sun, Minghui; Zhang, Zhenyu; Cao, Heng; Chen, Xiaoqing [Department of Cardiology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200080 (China)

    2011-08-05

    Highlights: {yields} Ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. {yields} Ox-LDL induced expression of P-selectin through degradation of IkBa and augment of NF-kB activity and protein level during macrophage-derived foam cell formation. {yields} P-selectin and NF-kB may be identified as pivotal regulators of ox-LDL-induced foam cell formation. {yields} Therapy based on the inhibition of P-selectin and NF-kB may complement conventional treatments to prevent atherosclerosis. -- Abstract: Oxidized low-density lipoprotein (ox-LDL) plays a critical role in regulation of atherosclerosis. However, little is known about the role of Nuclear factor kB (NF-kB) activity-dependent P-selectin in ox-LDL-induced foam cell formation during atherosclerosis. In this study, we first investigated ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. Treatment of U937 cells with ox-LDL increased lipid accumulation as well as intracellular cholesterol content. Next, a comparative analysis of gene expression profiling using cDNA microarray and Real-time-PCR indicated that ox-LDL exposure induced, in three treated groups, an extremely marked increase in the mRNA level of P-selectin. Protein levels of P-selectin and its upstream regulators IkBa and NF-kB showed that NF-kB pathway is involved in the ox-LDL-induced foam cell formation. Finally, overexpression of NF-kB significantly accelerated, whereas, inhibition of NF-kB with siRNA remarkably attenuated ox-LDL-induced macrophage-derived foam cell formation. It was concluded that the activity of NF-kB is augmented during macrophage-derived foam cell formation. Activation of NF-kB increased, whereas, inhibition of NF-kB decreased ox-LDL-induced P-selectin expression and lipid accumulation in macrophages, suggesting ox-LDL induced expression of P-selectin through degradation of IkBa and activation of NF-kB in the

  9. NF-kB activity-dependent P-selectin involved in ox-LDL-induced foam cell formation in U937 cell

    Highlights: → Ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. → Ox-LDL induced expression of P-selectin through degradation of IkBa and augment of NF-kB activity and protein level during macrophage-derived foam cell formation. → P-selectin and NF-kB may be identified as pivotal regulators of ox-LDL-induced foam cell formation. → Therapy based on the inhibition of P-selectin and NF-kB may complement conventional treatments to prevent atherosclerosis. -- Abstract: Oxidized low-density lipoprotein (ox-LDL) plays a critical role in regulation of atherosclerosis. However, little is known about the role of Nuclear factor kB (NF-kB) activity-dependent P-selectin in ox-LDL-induced foam cell formation during atherosclerosis. In this study, we first investigated ox-LDL induced foam cell formation in the human U937 promonocytic cell line in a dose- and time-dependent manner. Treatment of U937 cells with ox-LDL increased lipid accumulation as well as intracellular cholesterol content. Next, a comparative analysis of gene expression profiling using cDNA microarray and Real-time-PCR indicated that ox-LDL exposure induced, in three treated groups, an extremely marked increase in the mRNA level of P-selectin. Protein levels of P-selectin and its upstream regulators IkBa and NF-kB showed that NF-kB pathway is involved in the ox-LDL-induced foam cell formation. Finally, overexpression of NF-kB significantly accelerated, whereas, inhibition of NF-kB with siRNA remarkably attenuated ox-LDL-induced macrophage-derived foam cell formation. It was concluded that the activity of NF-kB is augmented during macrophage-derived foam cell formation. Activation of NF-kB increased, whereas, inhibition of NF-kB decreased ox-LDL-induced P-selectin expression and lipid accumulation in macrophages, suggesting ox-LDL induced expression of P-selectin through degradation of IkBa and activation of NF-kB in the regulation of foam

  10. Evaluation of three high abundance protein depletion kits for umbilical cord serum proteomics

    Nie Jing

    2011-05-01

    Full Text Available Abstract Background High abundance protein depletion is a major challenge in the study of serum/plasma proteomics. Prior to this study, most commercially available kits for depletion of highly abundant proteins had only been tested and evaluated in adult serum/plasma, while the depletion efficiency on umbilical cord serum/plasma had not been clarified. Structural differences between some adult and fetal proteins (such as albumin make it likely that depletion approaches for adult and umbilical cord serum/plasma will be variable. Therefore, the primary purposes of the present study are to investigate the efficiencies of several commonly-used commercial kits during high abundance protein depletion from umbilical cord serum and to determine which kit yields the most effective and reproducible results for further proteomics research on umbilical cord serum. Results The immunoaffinity based kits (PROTIA-Sigma and 5185-Agilent displayed higher depletion efficiency than the immobilized dye based kit (PROTBA-Sigma in umbilical cord serum samples. Both the PROTIA-Sigma and 5185-Agilent kit maintained high depletion efficiency when used three consecutive times. Depletion by the PROTIA-Sigma Kit improved 2DE gel quality by reducing smeared bands produced by the presence of high abundance proteins and increasing the intensity of other protein spots. During image analysis using the identical detection parameters, 411 ± 18 spots were detected in crude serum gels, while 757 ± 43 spots were detected in depleted serum gels. Eight spots unique to depleted serum gels were identified by MALDI- TOF/TOF MS, seven of which were low abundance proteins. Conclusions The immunoaffinity based kits exceeded the immobilized dye based kit in high abundance protein depletion of umbilical cord serum samples and dramatically improved 2DE gel quality for detection of trace biomarkers.

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

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

    2014-12-28

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

  12. Comparison of depletion algorithms for large systems of nuclides

    In this work five algorithms for solving the system of decay and transmutation equations with constant reaction rates encountered in burnup calculations were compared. These are Chebyshev rational approximation method (CRAM), which is a new matrix exponential method, the matrix exponential power series with instant decay and a secular equilibrium approximations for short-lived nuclides, which is used in ORIGEN, and three different variants of transmutation trajectory analysis (TTA), which is also known as the linear chains method. The common feature of these methods is their ability to deal with thousands of nuclides and reactions. Consequently, there is no need to simplify the system of equations and all nuclides can be accounted for explicitly. The methods were compared in single depletion steps using decay and cross-section data taken from the default ORIGEN libraries. Very accurate reference solutions were obtained from a high precision TTA algorithm. The results from CRAM and TTA were found to be very accurate. While ORIGEN was not as accurate, it should still be sufficient for most purposes. All TTA variants are much slower than the other two, which are so fast that their running time should be negligible in most, if not all, applications. The combination of speed and accuracy makes CRAM the clear winner of the comparison.

  13. Depletion of [14C]clorsulon in cows' milk

    Radioactive residue levels were determined in milk and plasma of Holstein cows dosed once with an oral suspension of 14C-labeled clorsulon at 7 mg/kg of body weight. Average milk residue levels decreased from 0.54 ppm at 0.9 day postdose to 0.004 ppm at 6.9 days postdose with a half-life of 0.81 day. The drug residue was isolated by a batch adsorption method on an affinity agarose gel of carbonic anhydrase-Sepharose 4B and analyzed by HPCL-reverse isotope dilution assay (RIDA). This novel method greatly simplified the extraction of drug residue from milk and provided pure drug residue isolates. RIDA results of the isolates indicated that the unchanged drug was the major residue component in milk at 0-4 days postdose accounting for 56-99% of the total radioactive residue. Depletion half-life of the parent drug was 0.82 day, in close agreement with that of the total residue in milk. About 0.7% of the dose was recovered in the milk during the 6.9-day period

  14. Elastic expansion of the lithosphere caused by groundwater depletion

    Several centimeters of man-induced elastic expansion of the lithosphere is inferred to have been caused by the depletion and removal from the area of large masses of groundwater in parts of Arizona, California, and Texas. The water was removed principally by evapotranspiration by crops of groundwater pumped from aquifers. Arguments for elastic expansion are based on both theoretical estimates and comparison with the elastic deformations observed at Lake Mead and Lake Kariba, where comparable masses of water were loaded on the earth's surface. In one area, south central Arizona, 6 cm of crustal uplift observed from 198 to 1967 may be related to the removal of 4 4.35 x 1013 kg of groundwater. First, if the observed uplift is assumed to be due to man-induced unloading, a Young's modulus of the lithosphere of approximately 0.68 Mbar is implied, which is comparable to values reported elsewhere. Second, the uplift compares favorably with the depression caused by the formation of Lake Mead, 430 km northwest of the study area, when allowance is made for the different magnitudes, sense, and areas of surface loading

  15. Depleted-Uranium Weapons the Whys and Wherefores

    Gsponer, A

    2003-01-01

    The only military application in which present-day depleted-uranium (DU) alloys out-perform tungsten alloys is long-rod penetration into a main battle-tank's armor. However, this advantage is only on the order of 10% and disappearing when the comparison is made in terms of actual lethality of complete anti-tank systems instead of laboratory-type steel penetration capability. Therefore, new micro- and nano-engineered tungsten alloys may soon out-perform existing DU alloys, enabling the production of tungsten munition which will be better than uranium munition, and whose overall life-cycle cost will be less due to the absence of the problems related to the radioactivity of uranium. The reasons why DU weapons have been introduced and used are analysed from the perspective that their radioactivity must have played an important role in the decision making process. It is found that DU weapons belong to the diffuse category of low-radiological-impact nuclear weapons to which emerging types of low-yield, i.e., fourth...

  16. Hormetic effect induced by depleted uranium in zebrafish embryos.

    Ng, C Y P; Cheng, S H; Yu, K N

    2016-06-01

    The present work studied the hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio) using apoptosis as the biological endpoint. Hormetic effect is characterized by biphasic dose-response relationships showing a low-dose stimulation and a high-dose inhibition. Embryos were dechorionated at 4h post fertilization (hpf), and were then exposed to 10 or 100μg/l depleted uranium (DU) in uranyl acetate solutions from 5 to 6 hpf. For exposures to 10μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20 hpf but were significantly decreased at 24 hpf, which demonstrated the presence of U-induced hormesis. For exposures to 100μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20, 24 and 30 hpf. Hormetic effect was not shown but its occurrence between 30 and 48 hpf could not be ruled out. In conclusion, hormetic effect could be induced in zebrafish embryos in a concentration- and time-dependent manner. PMID:27060238

  17. Linkages between ozone depleting substances, tropospheric oxidation and aerosols

    A. Voulgarakis

    2012-09-01

    Full Text Available Coupling between the stratosphere and the troposphere allows changes in stratospheric ozone abundances to affect tropospheric chemistry. Large-scale effects from such changes on chemically produced tropospheric aerosols have not been systematically examined in past studies. We use a composition-climate model to investigate potential past and future impacts of changes in stratospheric Ozone Depleting Substances (ODS on tropospheric oxidants and sulfate aerosols. In most experiments, we find significant responses in tropospheric photolysis and oxidants, with small but significant effects on methane radiative forcing. The response of sulfate aerosols is sizeable when examining the effect of increasing future nitrous oxide (N2O emissions. We also find that without the regulation of chlorofluorocarbons (CFCs through the Montreal Protocol, sulfate aerosols could have increased by 2050 by a comparable amount to the decreases predicted due to relatively stringent sulfur emissions controls. The historical radiative forcing of CFCs through their indirect effects on methane (−22.6 mW m−2 and sulfate aerosols (−3.0 mW m−2 discussed here is non-negligible when compared to known historical CFC forcing. Our results stress the importance of accounting for stratosphere-troposphere, gas-aerosol and composition-climate interactions when investigating the effects of changing emissions on atmospheric composition and climate.

  18. Measurement of thermal diffusivity of depleted uranium metal microspheres

    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.

  19. Investigation of breached depleted UF{sub 6} cylinders

    DeVan, J.H. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

  20. Depletion of florfenicol and florfenicol amine residues in chicken eggs.

    Filazi, A; Sireli, U T; Yurdakok, B; Aydin, F G; Kucukosmanoglu, A G

    2014-01-01

    1. The aim of this study was to develop a suitable method for the analysis of florfenicol (FF) and its metabolite florfenicol amine (FFA) in chicken eggs and to determine FF and FFA residue depletion in eggs of laying hens. 2. The analytes were extracted from yolk, albumen and whole egg by phosphate buffer and ethyl acetate. Following purification, samples were analysed by high-performance liquid chromatography. 3. Fifty laying hens were divided into 5 groups, and each hen received doses of 20 mg/kg FF: Group 1 (received a single oral dose by gavage); Group 2 (a single intramuscular dose); Group 3 (a single subcutaneous dose); Group 4 (multiple oral doses for 3 d) and Group 5 (multiple oral doses for 5 d). 4. Limits of detection and of quantitation values were 1.94 and 6.45 g/10(9) g (ppb) for FF, respectively, and 0.48 and 1.58 ppb for FFA, respectively. Relative standard deviation values of intra-day and inter-day variation below 11% also confirmed the usefulness of the method for analysing FF and FFA in eggs. 5. From the first day of both oral and parenteral administration, FF and FFA were detected at 0.1% and 0.08% of dosage, respectively, and 57% of the drugs were eliminated from the egg yolk. Elimination time of FF was 8 d in Groups 1, 2 and 3; 9 d in Group 4 and 10 d in Group 5. PMID:24945307