WorldWideScience

Sample records for global calcium cycle

  1. Global water cycle

    Robertson, Franklin; Goodman, Steven J.; Christy, John R.; Fitzjarrald, Daniel E.; Chou, Shi-Hung; Crosson, William; Wang, Shouping; Ramirez, Jorge

    1993-01-01

    This research is the MSFC component of a joint MSFC/Pennsylvania State University Eos Interdisciplinary Investigation on the global water cycle extension across the earth sciences. The primary long-term objective of this investigation is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates change on both global and regional scales. Significant accomplishments in the past year are presented and include the following: (1) water vapor variability; (2) multi-phase water analysis; (3) global modeling; and (4) optimal precipitation and stream flow analysis and hydrologic processes.

  2. The global carbon cycle

    Maier-Reimer, E.

    1991-01-01

    Basic concepts of the global carbon cycle on earth are described; by careful analyses of isotopic ratios, emission history and oceanic ventilation rates are derived, which provide crucial tests for constraining and calibrating models. Effects of deforestation, fertilizing, fossil fuel burning, soil erosion, etc. are quantified and compared, and the oceanic carbon process is evaluated. Oceanic and terrestrial biosphere modifications are discussed and a carbon cycle model is proposed

  3. HCl removal using cycled carbide slag from calcium looping cycles

    Xie, Xin; Li, Yingjie; Wang, Wenjing; Shi, Lei

    2014-01-01

    Highlights: • Cycled carbide slag from calcium looping cycles is used to remove HCl. • The optimum temperature for HCl removal of cycled carbide slag is 700 °C. • The presence of CO 2 restrains HCl removal of cycled carbide slag. • CO 2 capture conditions have important effects on HCl removal of cycled carbide slag. • HCl removal capacity of carbide slag drops with cycle number rising from 1 to 50. - Abstract: The carbide slag is an industrial waste from chlor-alkali plants, which can be used to capture CO 2 in the calcium looping cycles, i.e. carbonation/calcination cycles. In this work, the cycled carbide slag from the calcium looping cycles for CO 2 capture was proposed to remove HCl in the flue gas from the biomass-fired and RDFs-fired boilers. The effects of chlorination temperature, HCl concentration, particle size, presence of CO 2 , presence of O 2 , cycle number and CO 2 capture conditions in calcium looping cycles on the HCl removal behavior of the carbide slag experienced carbonation/calcination cycles were investigated in a triple fixed-bed reactor. The chlorination product of the cycled carbide slag from the calcium looping after absorbing HCl is not CaCl 2 but CaClOH. The optimum temperature for HCl removal of the cycled carbide slag from the carbonation/calcination cycles is 700 °C. The chlorination conversion of the cycled carbide slag increases with increasing the HCl concentration. The cycled carbide slag with larger particle size exhibits a lower chlorination conversion. The presence of CO 2 decreases the chlorination conversions of the cycled carbide slag and the presence of O 2 has a trifling impact. The chlorination conversion of the carbide slag experienced 1 carbonation/calcination cycle is higher than that of the uncycled calcined sorbent. As the number of carbonation/calcination cycles increases from 1 to 50, the chlorination conversion of carbide slag drops gradually. The high calcination temperature and high CO 2

  4. Changing global carbon cycle

    Canadell, Pep

    2007-01-01

    Full text: The increase in atmospheric carbon dioxide (C02) is the single largest human perturbation on the earth's radiative balance contributing to climate change. Its rate of change reflects the balance between anthropogenic carbon emissions and the dynamics of a number of terrestrial and ocean processes that remove or emit C02. It is the long term evolution of this balance that will determine to large extent the speed and magnitude of the human induced climate change and the mitigation requirements to stabilise atmospheric C02 concentrations at any given level. In this talk, we show new trends in global carbon sources and sinks, with particularly focus on major shifts occurring since 2000 when the growth rate of atmospheric C02 has reached its highest level on record. The acceleration in the C02 growth results from the combination of several changes in properties of the carbon cycle, including: acceleration of anthropogenic carbon emissions; increased carbon intensity of the global economy, and decreased efficiency of natural carbon sinks. We discuss in more detail some of the possible causes of the reduced efficiency of natural carbon sinks on land and oceans, such as the decreased net sink in the Southern Ocean and on terrestrial mid-latitudes due to world-wide occurrence of drought. All these changes reported here characterise a carbon cycle that is generating stronger than expected climate forcing, and sooner than expected

  5. The Global Nitrogen Cycle

    Galloway, J. N.

    2003-12-01

    Once upon a time nitrogen did not exist. Today it does. In the intervening time the universe was formed, nitrogen was created, the Earth came into existence, and its atmosphere and oceans were formed! In this analysis of the Earth's nitrogen cycle, I start with an overview of these important events relative to nitrogen and then move on to the more traditional analysis of the nitrogen cycle itself and the role of humans in its alteration.The universe is ˜15 Gyr old. Even after its formation, there was still a period when nitrogen did not exist. It took ˜300 thousand years after the big bang for the Universe to cool enough to create atoms; hydrogen and helium formed first. Nitrogen was formed in the stars through the process of nucleosynthesis. When a star's helium mass becomes great enough to reach the necessary pressure and temperature, helium begins to fuse into still heavier elements, including nitrogen.Approximately 10 Gyr elapsed before Earth was formed (˜4.5 Ga (billion years ago)) by the accumulation of pre-assembled materials in a multistage process. Assuming that N2 was the predominate nitrogen species in these materials and given that the temperature of space is -270 °C, N2 was probably a solid when the Earth was formed since its boiling point (b.p.) and melting point (m.p.) are -196 °C and -210 °C, respectively. Towards the end of the accumulation period, temperatures were probably high enough for significant melting of some of the accumulated material. The volcanic gases emitted by the resulting volcanism strongly influenced the surface environment. Nitrogen was converted from a solid to a gas and emitted as N2. Carbon and sulfur were probably emitted as CO and H2S (Holland, 1984). N2 is still the most common nitrogen volcanic gas emitted today at a rate of ˜2 TgN yr-1 (Jaffee, 1992).Once emitted, the gases either remained in the atmosphere or were deposited to the Earth's surface, thus continuing the process of biogeochemical cycling. The rate of

  6. Testing Urey's carbonate-silicate cycle using the calcium isotopic composition of sedimentary carbonates

    Blättler, Clara L.; Higgins, John A.

    2017-12-01

    Carbonate minerals constitute a major component of the sedimentary geological record and an archive of a fraction of the carbon and calcium cycled through the Earth's surface reservoirs for over three billion years. For calcium, carbonate minerals constitute the ultimate sink for almost all calcium liberated during continental and submarine weathering of silicate minerals. This study presents >500 stable isotope ratios of calcium in Precambrian carbonate sediments, both limestones and dolomites, in an attempt to characterize the isotope mass balance of the sedimentary carbonate reservoir through time. The mean of the dataset is indistinguishable from estimates of the calcium isotope ratio of bulk silicate Earth, consistent with the Urey cycle being the dominant mechanism exchanging calcium among surface reservoirs. The variability in bulk sediment calcium isotope ratios within each geological unit does not reflect changes in the global calcium cycle, but rather highlights the importance of local mineralogical and/or diagenetic effects in the carbonate record. This dataset demonstrates the potential for calcium isotope ratios to help assess these local effects, such as the former presence of aragonite, even in rocks with a history of neomorphism and recrystallization. Additionally, 29 calcium isotope measurements are presented from ODP (Ocean Drilling Program) Site 801 that contribute to the characterization of altered oceanic crust as an additional sink for calcium, and whose distinct isotopic signature places a limit on the importance of this subduction flux over Earth history.

  7. Probabilistic encoding of stimulus strength in astrocyte global calcium signals.

    Croft, Wayne; Reusch, Katharina; Tilunaite, Agne; Russell, Noah A; Thul, Rüdiger; Bellamy, Tomas C

    2016-04-01

    Astrocyte calcium signals can range in size from subcellular microdomains to waves that spread through the whole cell (and into connected cells). The differential roles of such local or global calcium signaling are under intense investigation, but the mechanisms by which local signals evolve into global signals in astrocytes are not well understood, nor are the computational rules by which physiological stimuli are transduced into a global signal. To investigate these questions, we transiently applied receptor agonists linked to calcium signaling to primary cultures of cerebellar astrocytes. Astrocytes repetitively tested with the same stimulus responded with global signals intermittently, indicating that each stimulus had a defined probability for triggering a response. The response probability varied between agonists, increased with agonist concentration, and could be positively and negatively modulated by crosstalk with other signaling pathways. To better understand the processes determining the evolution of a global signal, we recorded subcellular calcium "puffs" throughout the whole cell during stimulation. The key requirement for puffs to trigger a global calcium wave following receptor activation appeared to be the synchronous release of calcium from three or more sites, rather than an increasing calcium load accumulating in the cytosol due to increased puff size, amplitude, or frequency. These results suggest that the concentration of transient stimuli will be encoded into a probability of generating a global calcium response, determined by the likelihood of synchronous release from multiple subcellular sites. © 2015 Wiley Periodicals, Inc.

  8. Global biogeochemical cycle of vanadium.

    Schlesinger, William H; Klein, Emily M; Vengosh, Avner

    2017-12-26

    Synthesizing published data, we provide a quantitative summary of the global biogeochemical cycle of vanadium (V), including both human-derived and natural fluxes. Through mining of V ores (130 × 10 9 g V/y) and extraction and combustion of fossil fuels (600 × 10 9 g V/y), humans are the predominant force in the geochemical cycle of V at Earth's surface. Human emissions of V to the atmosphere are now likely to exceed background emissions by as much as a factor of 1.7, and, presumably, we have altered the deposition of V from the atmosphere by a similar amount. Excessive V in air and water has potential, but poorly documented, consequences for human health. Much of the atmospheric flux probably derives from emissions from the combustion of fossil fuels, but the magnitude of this flux depends on the type of fuel, with relatively low emissions from coal and higher contributions from heavy crude oils, tar sands bitumen, and petroleum coke. Increasing interest in petroleum derived from unconventional deposits is likely to lead to greater emissions of V to the atmosphere in the near future. Our analysis further suggests that the flux of V in rivers has been incremented by about 15% from human activities. Overall, the budget of dissolved V in the oceans is remarkably well balanced-with about 40 × 10 9 g V/y to 50 × 10 9 g V/y inputs and outputs, and a mean residence time for dissolved V in seawater of about 130,000 y with respect to inputs from rivers.

  9. Cycling in a global world : introduction

    Oldenziel, R.; Albert de la Bruhèze, A.A.

    2012-01-01

    Affiliations GO Issue Journal Volume: 2 Issue: 2 Editorial  Editorial Gijs Mom, Georgine Clarsen and Cotten Seiler Article  Motorists, Non-drivers and Traffic Accidents between the Wars: a Provisional Survey Bill Luckin Special Section on Global CyclingCycling in a Global World: Introduction to

  10. Africa and the global carbon cycle

    Williams, CA

    2007-03-01

    Full Text Available The African continent has a large and growing role in the global carbon cycle, with potentially important climate change implications. However, the sparse observation network in and around the African continent means that Africa is one...

  11. Greening the global phosphorus cycle

    Withers, Paul J.A.; Elser, James J.; Hilton, Julian; Ohtake, Hisao; Schipper, Willem J.; Dijk, Van Kimo C.

    2015-01-01

    The sustainability of global phosphorus (P) use is emerging as a major societal goal to secure future food, energy, and water security for a growing population. Phosphate rock (PR) is a critical raw material whose inefficiency of use is leading to widespread eutrophication and uncertainties about

  12. Calcium oxalate contribution to calcium cycling in forests of contrasting nutrient status

    Dauer, Jenny M.; Perakis, Steven S.

    2014-01-01

    Calcium oxalate (Ca oxalate) is an insoluble biomineral that forms in plants and fungi, and occurs in soils across many types of ecosystems. Assessing how Ca oxalate may shape ecosystem Ca cycling requires information on the distribution of Ca oxalate among plant biomass, detritus, and mineral soil, and how it varies with ecosystem Ca status. We compared two Douglas-fir forests of contrasting ecosystem Ca availability, and found that Ca oxalate was partitioned similarly among plant biomass, detritus and mineral soil major ecosystem compartments at both sites, and total pools of Ca oxalate were greater in the high-Ca forest. However, the proportional importance of Ca oxalate was greater in the low-Ca than high-Ca forest (18% versus 4% of actively cycling ecosystem Ca, respectively). And calcium oxalate in mineral soil, which is of particular interest as a potential long-term Ca reservoir, was a larger portion of total available Ca (exchangeable Ca plus Ca oxalate Ca) in the low-Ca site than the high-Ca site (9% versus 1% of available soil Ca, respectively). Calcium oxalate was the dominant form of Ca returned from plants to soil as leaf litterfall at the high-Ca site, yet calcium oxalate disappeared rapidly from decomposing litter (0.28 yr−1 or faster) at both sites. We conclude that accumulation of Ca oxalate in forest ecosystems appears most closely related to overall Ca supply for live biomass pools, and that the accumulation of Ca oxalate in forest floor and mineral soil is limited by rapid microbial degradation of putatively unavailable Ca oxalate.

  13. Observing the Global Water Cycle from Space

    Hildebrand, P. H.

    2004-01-01

    This paper presents an approach to measuring all major components of the water cycle from space. Key elements of the global water cycle are discussed in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers, and in terms of the global fluxes of water between these reservoirs. Approaches to measuring or otherwise evaluating the global water cycle are presented, and the limitations on known accuracy for many components of the water cycle are discussed, as are the characteristic spatial and temporal scales of the different water cycle components. Using these observational requirements for a global water cycle observing system, an approach to measuring the global water cycle from space is developed. The capabilities of various active and passive microwave instruments are discussed, as is the potential of supporting measurements from other sources. Examples of space observational systems, including TRMM/GPM precipitation measurement, cloud radars, soil moisture, sea surface salinity, temperature and humidity profiling, other measurement approaches and assimilation of the microwave and other data into interpretative computer models are discussed to develop the observational possibilities. The selection of orbits is then addressed, for orbit selection and antenna size/beamwidth considerations determine the sampling characteristics for satellite measurement systems. These considerations dictate a particular set of measurement possibilities, which are then matched to the observational sampling requirements based on the science. The results define a network of satellite instrumentation systems, many in low Earth orbit, a few in geostationary orbit, and all tied together through a sampling network that feeds the observations into a data-assimilative computer model.

  14. Calcium constrains plant control over forest ecosystem nitrogen cycling.

    Groffman, Peter M; Fisk, Melany C

    2011-11-01

    Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

  15. Business Cycle Volatility and Globalization: A Survey

    Claudia M. Buch

    2002-01-01

    The globalization of capital and product markets has many implications for economic welfare. Countries can specialize in the production of goods for which they have comparative advantages, and capital is allocated more efficiently. However, one potentially adverse effect of globalization is the possibility that business cycle volatility might increase. Rapid and badly co-ordinated capital account liberalization has been blamed for enhancing the vulnerability of emerging markets to unstable in...

  16. Global Changes of the Water Cycle Intensity

    Bosilovich, Michael G.; Schubert, Siegfried D.; Walker, Gregory K.

    2003-01-01

    In this study, we evaluate numerical simulations of the twentieth century climate, focusing on the changes in the intensity of the global water cycle. A new diagnostic of atmospheric water vapor cycling rate is developed and employed, that relies on constituent tracers predicted at the model time step. This diagnostic is compared to a simplified traditional calculation of cycling rate, based on monthly averages of precipitation and total water content. The mean sensitivity of both diagnostics to variations in climate forcing is comparable. However, the new diagnostic produces systematically larger values and more variability than the traditional average approach. Climate simulations were performed using SSTs of the early (1902-1921) and late (1979- 1998) twentieth century along with the appropriate C02 forcing. In general, the increase of global precipitation with the increases in SST that occurred between the early and late twentieth century is small. However, an increase of atmospheric temperature leads to a systematic increase in total precipitable water. As a result, the residence time of water in the atmosphere increased, indicating a reduction of the global cycling rate. This result was explored further using a number of 50-year climate simulations from different models forced with observed SST. The anomalies and trends in the cycling rate and hydrologic variables of different GCMs are remarkably similar. The global annual anomalies of precipitation show a significant upward trend related to the upward trend of surface temperature, during the latter half of the twentieth century. While this implies an increase in the hydrologic cycle intensity, a concomitant increase of total precipitable water again leads to a decrease in the calculated global cycling rate. An analysis of the land/sea differences shows that the simulated precipitation over land has a decreasing trend while the oceanic precipitation has an upward trend consistent with previous studies and the

  17. The global marine phosphorus cycle: sensitivity to oceanic circulation

    C. P. Slomp

    2007-01-01

    Full Text Available A new mass balance model for the coupled marine cycles of phosphorus (P and carbon (C is used to examine the relationships between oceanic circulation, primary productivity, and sedimentary burial of reactive P and particulate organic C (POC, on geological time scales. The model explicitly represents the exchanges of water and particulate matter between the continental shelves and the open ocean, and it accounts for the redox-dependent burial of POC and the various forms of reactive P (iron(III-bound P, particulate organic P (POP, authigenic calcium phosphate, and fish debris. Steady state and transient simulations indicate that a slowing down of global ocean circulation decreases primary production in the open ocean, but increases that in the coastal ocean. The latter is due to increased transfer of soluble P from deep ocean water to the shelves, where it fuels primary production and causes increased reactive P burial. While authigenic calcium phosphate accounts for most reactive P burial ocean-wide, enhanced preservation of fish debris may become an important reactive P sink in deep-sea sediments during periods of ocean anoxia. Slower ocean circulation globally increases POC burial, because of enhanced POC preservation under anoxia in deep-sea depositional environments and higher primary productivity along the continental margins. In accordance with geological evidence, the model predicts increased accumulation of reactive P on the continental shelves during and following periods of ocean anoxia.

  18. A model for global cycling of tritium

    Killough, G.G.; Kocher, D.C.

    1988-01-01

    Dynamic compartment models are widely used to describe global cycling of radionuclides for purposes of dose estimation. In this paper the authors present a new global tritium model that reproduces environmental time-series data on concentrations in precipitation, ocean surface waters, and surface fresh waters in the northern hemisphere, concentrations of atmospheric tritium in the southern hemisphere, and the latitude dependence of tritium in both hemispheres. Names TRICYCLE (for TRItium CYCLE) the model is based on the global hydrologic cycle and includes hemispheric stratospheric compartments, disaggregation of the troposphere and ocean surface waters into eight latitude zones, consideration of the different concentrations of atmospheric tritium over land and over the ocean, and a diffusive model for transport in the ocean. TRICYCLE reproduces the environmental data if it is assumed that about 50% of the tritium from atmospheric weapons testing was injected directly into the northern stratosphere as HTO. The model's latitudinal disaggregation permits taking into account the distribution of population. For a uniformly distributed release of HTO into the worldwide troposphere, TRICYCLE predicts a collective dose commitment to the world population that exceeds the NCRP model's corresponding prediction by a factor of three

  19. A model for global cycling of tritium

    Killough, G.G.; Kocher, D.C.

    1988-01-01

    Dynamic compartment models are widely used to describe global cycling of radionuclides for purposes of dose estimation. In this paper, we present a new global tritium model that reproduces environmental time-series data on concentrations in precipitation, ocean surface waters, and surface fresh waters in the northern hemisphere, concentrations of atmospheric tritium in the soutehrn hemisphere, and the latitude dependence of tritium in both hemispheres. Named TRICYCLE for Tritium CYCLE, the model is based on the global hydrologic cycle and includes hemisphereic stratospheric compartments, disaggregation of the troposphere and ocean surface waters into eight latitudezones, consideration of the different concentrations of atmospheric tritium over land and over the ocean, and a diffusive model for transport in the ocean. TRICYCLE reproduces the environmental data if we assume that about 50% of the tritium from atmospheric weapons testing was injected directly into the northern stratosphere as HTO. The models latitudinal disaggregation permits taking into account the distribution of population. For a unfiormaly distributed release of HTO into the worldwide troposphere, TRICYCLE predicts a collective dose commitment to the world population that exceeds the corresponding prediction by the NCRP model by about a factor of 3. 11 refs., 5 figs., 1 tab

  20. Africa and the global carbon cycle

    Denning A Scott

    2007-03-01

    Full Text Available Abstract The African continent has a large and growing role in the global carbon cycle, with potentially important climate change implications. However, the sparse observation network in and around the African continent means that Africa is one of the weakest links in our understanding of the global carbon cycle. Here, we combine data from regional and global inventories as well as forward and inverse model analyses to appraise what is known about Africa's continental-scale carbon dynamics. With low fossil emissions and productivity that largely compensates respiration, land conversion is Africa's primary net carbon release, much of it through burning of forests. Savanna fire emissions, though large, represent a short-term source that is offset by ensuing regrowth. While current data suggest a near zero decadal-scale carbon balance, interannual climate fluctuations (especially drought induce sizeable variability in net ecosystem productivity and savanna fire emissions such that Africa is a major source of interannual variability in global atmospheric CO2. Considering the continent's sizeable carbon stocks, their seemingly high vulnerability to anticipated climate and land use change, as well as growing populations and industrialization, Africa's carbon emissions and their interannual variability are likely to undergo substantial increases through the 21st century.

  1. Comparing the Life Cycle Energy Consumption, Global ...

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability

  2. Modern Estimates of Global Water Cycle Fluxes

    Rodell, M.; Beaudoing, H. K.; L'Ecuyer, T. S.; Olson, W. S.

    2014-12-01

    The goal of the first phase of the NASA Energy and Water Cycle Study (NEWS) Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. Here we describe results of the water cycle assessment, including mean annual and monthly fluxes over continents and ocean basins during the first decade of the millennium. To the extent possible, the water flux estimates are based on (1) satellite measurements and (2) data-integrating models. A careful accounting of uncertainty in each flux was applied within a routine that enforced multiple water and energy budget constraints simultaneously in a variational framework, in order to produce objectively-determined, optimized estimates. Simultaneous closure of the water and energy budgets caused the ocean evaporation and precipitation terms to increase by about 10% and 5% relative to the original estimates, mainly because the energy budget required turbulent heat fluxes to be substantially larger in order to balance net radiation. In the majority of cases, the observed annual, surface and atmospheric water budgets over the continents and oceans close with much less than 10% residual. Observed residuals and optimized uncertainty estimates are considerably larger for monthly surface and atmospheric water budget closure, often nearing or exceeding 20% in North America, Eurasia, Australia and neighboring islands, and the Arctic and South Atlantic Oceans. The residuals in South America and Africa tend to be smaller, possibly because cold land processes are a non-issue. Fluxes are poorly observed over the Arctic Ocean, certain seas, Antarctica, and the Australasian and Indonesian Islands, leading to reliance on atmospheric analysis estimates. Other details of the study and future directions will be discussed.

  3. Global Carbon Cycle of the Precambrian Earth

    Wiewióra, Justyna

    The carbon isotopic composition of distinct Archaean geological records provides information about the global carbon cycle and emergence of life on early Earth. We utilized carbon isotopic records of Greenlandic carbonatites, diamonds, graphites, marbles, metacarbonates and ultramafic rocks...... in the surface environment and recycled back into the mantle In the third manuscript we investigate the carbon cycle components, which have maintained the carbon isotope composition of the mantle constant through time. Assuming constant organic ratio of the total carbon burial (f), we show that increased.......1‰) and metacarbonate ( -6.1 ± 0.1‰ to +1.5 ± 0.0‰) rocks from the ~3.8 Ga Isua Supracrustal Belt as resulting from the Rayleigh distillation process, which affected the ultramafic reservoir with initial δ13C between -2‰ and 0‰. Due to its high primary δ13C signature, carbon in the Isuan magnesite was most likely...

  4. 76 FR 41525 - Hewlett Packard Global Parts Supply Chain, Global Product Life Cycles Management Unit Including...

    2011-07-14

    ... Parts Supply Chain, Global Product Life Cycles Management Unit Including Teleworkers Reporting to... workers of Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit...). Since eligible workers of Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles...

  5. Artificial oocyte activation with calcium ionophore for frozen sperm cycles.

    Karabulut, Seda; Aksünger, Özlem; Ata, Can; Sağıroglu, Yusuf; Keskin, İlknur

    2018-04-05

    Fertilization problems are the major problems that may be faced in 30-55% of the patients during an intracytoplasmic sperm injection (ICSI) cycle. A successful oocyte activation depends on factors related to both sperm and oocyte, and one of the important factors that mediates the process is Ca 2+ concentration within the oocyte. Artificial oocyte activation (AOA) is a method used for fertilization problems that commonly involve the usage of Ca 2+ ionophores and is usually used in problems such as total fertilization failure (TFF) and globozoospermia. The aim of the present study was to investigate possible effects of AOA for different groups of patients with fertilization failure. Four groups of patients (previous TFF, low oocyte number, severe sperm quality, and frozen sperm (FS) group) that underwent ICSI with AOA were included in the study. All groups had similar control groups with same indications except TFF, where AOA was not performed. Fertilization rates were significantly higher in the TFF group than those observed in other AOA groups. Fertilization rates and quality of embryos observed in the remaining AOA groups were higher than those of the controls, which were statistically insignificant. Prgenancy rates were higher in all AOA groups compared to the controls, although the differences were significant in FS group only. Quality of embryos and pregnancy rates were lower in the TFF group compared to the remaining AOA groups indicating possible concomitant problems. Fertilization rates, quality of embryos and pregnancy rates seemed to be increased in all indication groups suggesting that not only TFF patients but also a wide variety of patients with different indications may benefit from AOA. ICSI: Intracytoplasmic sperm injection; ARTs: Assisted reproductive techniques; Ca: Calcium; AOA: Artificial oocyte activation; TFF: Total fertilization failures; OAT: Oligoasthenoteratozoospemia; IVF: In vitro fertilization; SOAT: Severe OAT; LON: Low ooctye number

  6. An updated view of global water cycling

    Houser, P. R.; Schlosser, A.; Lehr, J.

    2009-04-01

    Unprecedented new observation capacities combined with revolutions in modeling, we are poised to make huge advances in water cycle assessment, understanding, and prediction. To realize this goal, we must develop a discipline of prediction and verification through the integration of water and energy cycle observations and models, and to verify model predictions against observed phenomena to ensure that research delivers reliable improvements in prediction skill. Accomplishing these goals will require, in part, an accurate accounting of the key reservoirs and fluxes associated with the global water and energy cycle, including their spatial and temporal variability, through integration of all necessary observations and research tools. A brief history of the lineage of the conventional water balance and a summary accounting of all major parameters of the water balance using highly respected secondary sources will be presented. Principally, recently published peer reviewed papers reporting results of original work involving direct measurements and new data generated by high-tech devices (e.g. satellite / airborne instruments, supercomputers, geophysical tools) will be employed. This work lends credence to the conventional water balance ideas, but also reveals anachronistic scientific concepts/models, questionable underlying data, longstanding oversights and outright errors in the water balance.

  7. Global ablation of the mitochondrial calcium uniporter increases glycolysis in cortical neurons subjected to energetic stressors.

    Nichols, Matthew; Elustondo, Pia A; Warford, Jordan; Thirumaran, Aruloli; Pavlov, Evgeny V; Robertson, George S

    2017-08-01

    The effects of global mitochondrial calcium (Ca 2+ ) uniporter (MCU) deficiency on hypoxic-ischemic (HI) brain injury, neuronal Ca 2+ handling, bioenergetics and hypoxic preconditioning (HPC) were examined. Forebrain mitochondria isolated from global MCU nulls displayed markedly reduced Ca 2+ uptake and Ca 2+ -induced opening of the membrane permeability transition pore. Despite evidence that these effects should be neuroprotective, global MCU nulls and wild-type (WT) mice suffered comparable HI brain damage. Energetic stress enhanced glycolysis and depressed Complex I activity in global MCU null, relative to WT, cortical neurons. HI reduced forebrain NADH levels more in global MCU nulls than WT mice suggesting that increased glycolytic consumption of NADH suppressed Complex I activity. Compared to WT neurons, pyruvate dehydrogenase (PDH) was hyper-phosphorylated in MCU nulls at several sites that lower the supply of substrates for the tricarboxylic acid cycle. Elevation of cytosolic Ca 2+ with glutamate or ionomycin decreased PDH phosphorylation in MCU null neurons suggesting the use of alternative mitochondrial Ca 2+ transport. Under basal conditions, global MCU nulls showed similar increases of Ca 2+ handling genes in the hippocampus as WT mice subjected to HPC. We propose that long-term adaptations, common to HPC, in global MCU nulls compromise resistance to HI brain injury and disrupt HPC.

  8. Global dietary calcium intake among adults: a systematic review

    Purpose: Low calcium intake may adversely affect bone health in adults. Recognizing the presence of low calcium intake is necessary to develop national strategies to optimize intake. To highlight regions where calcium intake should be improved, we systematically searched for the most representative ...

  9. Atmospheric carbon dioxide and the global carbon cycle

    Trabalka, J R [ed.

    1985-12-01

    This state-of-the-art volume presents discussions on the global cycle of carbon, the dynamic balance among global atmospheric CO2 sources and sinks. Separate abstracts have been prepared for the individual papers. (ACR)

  10. Tree species effects on calcium cycling: The role of calcium uptake in deep soils

    Dijkstra, F.A.; Smits, M.M.

    2002-01-01

    Soil acidity and calcium (Ca) availability in the surface soil differ substantially beneath sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) trees in a mixed forest in northwestern Connecticut. We determined the effect of pumping of Ca from deep soil (rooting zone below 20-cm

  11. 76 FR 34271 - Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit, Including...

    2011-06-13

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,671] Hewlett Packard, Global Parts Supply Chain, Global Product Life Cycles Management Unit, Including Teleworkers Reporting to... Supply Chain, Global Product Life Cycles Management Unit, including teleworkers reporting to Houston...

  12. Closed Cycle Solar Refrigeration with the Calcium Chloride System ...

    A closed cycle solid absorption intermittent refrigerator, using CaC12 absorbent and NH3 refrigerant, was constructed and tested to obtain the instantaneous and cumulative available overall COP. The combined collector/absorber/generator unit had double glazing of 1.14 m2 exposed areas. The system was fitted with a ...

  13. Global water cycle: geochemistry and environment

    Berner, Elizabeth Kay; Berner, Robert A

    1987-01-01

    .... The book provides an integrated approach to global geochemistry and environmental problems and introduces the reader to some fundamental concepts of geology, oceanography, meteorology, environmental...

  14. Globalization of the nuclear fuel cycle

    Rougeau, J.P. [Cogema, Corporate Strategy and International Development, Velizy (France)

    1996-07-01

    The article deals with the increased scale and sophistication of the markets in the nuclear fuel cycle, with the increased vulnerability to outside pressures, and with changes in the decision process.

  15. Calcium

    ... You can get decent amounts of calcium from baked beans, navy beans, white beans, and others. Canned fish. You're in luck if you like sardines and canned salmon with bones. Almond milk. Working Calcium Into Your ...

  16. GEWEX: The Global Energy and Water Cycle Experiment

    Chahine, M.; Vane, D.

    1994-01-01

    GEWEX is one of the world's largest global change research programs. Its purpose is to observe and understand the hydrological cycle and energy fluxes in the atmosphere, at land surfaces and in the upper oceans.

  17. How Does Globalization Affect the Synchronization of Business Cycles?

    Ayhan Kose; Eswar S Prasad; Marco Terrones

    2003-01-01

    This paper examines the impact of rising trade and financial integration on international business cycle comovement among a large group of industrial and developing countries. The results provide at best limited support for the conventional wisdom that globalization has increased the degree of synchronization of business cycles. The evidence that trade and financial integration enhance global spillovers of macroeconomic fluctuations is mostly limited to industrial countries. One striking resu...

  18. Watch: Current knowledge of the terrestrial Global Water Cycle"

    Harding, R.; Best, M.; Hagemann, S.; Kabat, P.; Tallaksen, L.M.; Warnaars, T.; Wiberg, D.; Weedon, G.P.; Lanen, van H.A.J.; Ludwig, F.; Haddeland, I.

    2011-01-01

    Water-related impacts are among the most important consequences of increasing greenhouse gas concentrations. Changes in the global water cycle will also impact the carbon and nutrient cycles and vegetation patterns. There is already some evidence of increasing severity of floods and droughts and

  19. Global life cycle releases of engineered nanomaterials

    Keller, Arturo A.; McFerran, Suzanne; Lazareva, Anastasiya; Suh, Sangwon

    2013-01-01

    Engineered nanomaterials (ENMs) are now becoming a significant fraction of the material flows in the global economy. We are already reaping the benefits of improved energy efficiency, material use reduction, and better performance in many existing and new applications that have been enabled by these technological advances. As ENMs pervade the global economy, however, it becomes important to understand their environmental implications. As a first step, we combined ENM market information and material flow modeling to produce the first global assessment of the likely ENM emissions to the environment and landfills. The top ten most produced ENMs by mass were analyzed in a dozen major applications. Emissions during the manufacturing, use, and disposal stages were estimated, including intermediate steps through wastewater treatment plants and waste incineration plants. In 2010, silica, titania, alumina, and iron and zinc oxides dominate the ENM market in terms of mass flow through the global economy, used mostly in coatings/paints/pigments, electronics and optics, cosmetics, energy and environmental applications, and as catalysts. We estimate that 63–91 % of over 260,000–309,000 metric tons of global ENM production in 2010 ended up in landfills, with the balance released into soils (8–28 %), water bodies (0.4–7 %), and atmosphere (0.1–1.5 %). While there are considerable uncertainties in the estimates, the framework for estimating emissions can be easily improved as better data become available. The material flow estimates can be used to quantify emissions at the local level, as inputs for fate and transport models to estimate concentrations in different environmental compartments.

  20. The carbon cycle and global warming

    Anon.

    1991-01-01

    Five land-use-based approaches can be used to slow the buildup of CO 2 in the atmosphere: slowing or stopping the loss of existing forests, thus preserving current carbon reservoirs; adding to the planet's vegetative cover through reforestation or other means, thus enlarging living terrestrial carbon reservoirs; increasing the carbon stored in nonliving carbon reservoirs such as agricultural soils; increasing the carbon stored in artificial reservoirs, including timber products; and substituting sustainable biomass energy sources for fossil fuel consumption, thus reducing energy-related carbon emissions. These approaches are all based on the same basic premise: adding to the planet's net carbon stores in vegetative cover or soil, or preventing any net loss, will help moderate global warming by keeping atmospheric CO 2 levels lower than they would otherwise be. Because biotic policy options appear capable of contributing significantly to the mitigation of global warming while also furthering many other public policy objectives, their role deserves careful consideration on a country-by-country basis

  1. GLOBALIZATION VERSUS SEGREGATION - BUSINESS CYCLES SYNCHRONIZATION IN EUROPE

    Sebastian Florian Enea

    2012-12-01

    Full Text Available Globalization and business cycles are equally elusive economic phenomena; hence they represent a continuous research possibility and a source of possible inquiries due to their complex nature. The aim of the paper is to explain the synchronization of business cycles using the relationship between the growth rate of the GDP and FDI, considered as percentage of the GDP. The results show that there is no unique European business cycle, but two cores between which countries migrate and stress out the importance of the FDI channel in business cycle transmission. The future research directions will employ fuzzy cluster techniques, used on a larger sample.

  2. Agricultural trade and the global phosphorus cycle

    Schipanski, M.; Bennett, E.; Riskin, S.; Porder, S.

    2012-12-01

    Trends of increasing agricultural trade, increased concentration of livestock production systems, and increased human consumption of livestock products influence the distribution of nutrients across the global landscape. Phosphorus (P) represents a unique management challenge as we are rapidly depleting mineable reserves of this essential and non-renewable resource. At the same time, its overuse can lead to pollution of aquatic ecosystems. We analyzed the relative contributions of food crop, feed crop, and livestock product trade to P flows through agricultural soils for twelve countries from 1961 to 2007. We then used case studies of P fertilizer use in the world's three major soybean export regions: Iowa (USA), Mato Grosso (Brazil), and Buenos Aires (Argentina) to examine the influence of historical P management and soil types on agriculture's environmental consequences. Due to the intensification of agricultural production, average soil surface P balances more than tripled from 6 to 21 kg P per ha between 1961 and 2007 for the twelve study countries. Consequently, countries that are primarily agricultural exporters carried increased risks for water pollution or, for Argentina, reduced soil fertility due to soil P mining to support exports. In 2007, nations imported food and feed from regions with higher apparent P fertilizer use efficiencies than if those crops were produced domestically. However, this was largely because imports were sourced from regions depleting soil P resources to support export crop production. In addition, the pattern of regional specialization and intensification of production systems also reduced the potential to recycle P resources, with greater implications for livestock production than crop production. In a globalizing world, it will be increasingly important to integrate biophysical constraints of our natural resources and environmental impacts of agricultural systems into trade policy and agreements and to develop mechanisms that

  3. Has globalization increased the synchronicity of international business cycles?

    Berge, Travis

    2012-01-01

    The past 30 years have been witness to an inexorable change in the degree to which economies are connected internationally. At the same time, the 2007-2008 recession was the first ‘global recession’ in decades. This article explores how international trade and cross-border holdings financial assets impact the synchronization of business cycles internationally. The paper begins by producing chronologies of business cycle turning points for a group of 32 major economies covering 40 years of his...

  4. Climate Change and Expected Impacts on the Global Water Cycle

    Rind, David; Hansen, James E. (Technical Monitor)

    2002-01-01

    How the elements of the global hydrologic cycle may respond to climate change is reviewed, first from a discussion of the physical sensitivity of these elements to changes in temperature, and then from a comparison of observations of hydrologic changes over the past 100 million years. Observations of current changes in the hydrologic cycle are then compared with projected future changes given the prospect of global warming. It is shown that some of the projections come close to matching the estimated hydrologic changes that occurred long ago when the earth was very warm.

  5. The role of urbanization in the global carbon cycle

    Galina eChurkina

    2016-01-01

    Full Text Available Urban areas account for more than 70% of CO2 emissions from burning fossil fuels. Urban expansion in tropics is responsible for 5% of the annual emissions from land use change. Here I show that the effect of urbanization on the global carbon cycle extends beyond these emissions. I quantify the contribution of urbanization to the major carbon fluxes and pools globally and identify gaps crucial for predicting the evolution of the carbon cycle in the future. Urban residents currently control ~22 (12-40 % of the land carbon uptake (112 PgC/yr and ~24 (15-39 % of the carbon emissions (117 PgC/yr from land globally. Urbanization resulted in the creation of new carbon pools on land such as buildings (~6.7 PgC and landfills (~30 PgC. Together these pools store 1.6 (±0.3 % of the total vegetation and soil carbon pools globally. The creation and maintenance of these new pools has been associated with high emissions of CO2, which are currently better understood than the processes associated with the dynamics of these pools and accompanying uptake of carbon. Predictions of the future trajectories of the global carbon cycle will require a much better understanding of how urban development affects the carbon cycle over the long term.

  6. Weak ionization of the global ionosphere in solar cycle 24

    Y. Q. Hao

    2014-07-01

    Full Text Available Following prolonged and extremely quiet solar activity from 2008 to 2009, the 24th solar cycle started slowly. It has been almost 5 years since then. The measurement of ionospheric critical frequency (foF2 shows the fact that solar activity has been significantly lower in the first half of cycle 24, compared to the average levels of cycles 19 to 23; the data of global average total electron content (TEC confirm that the global ionosphere around the cycle 24 peak is much more weakly ionized, in contrast to cycle 23. The weak ionization has been more notable since the year 2012, when both the ionosphere and solar activity were expected to be approaching their maximum level. The undersupply of solar extreme ultraviolet (EUV irradiance somewhat continues after the 2008–2009 minimum, and is considered to be the main cause of the weak ionization. It further implies that the thermosphere and ionosphere in the first solar cycle of this millennium would probably differ from what we have learned from the previous cycles of the space age.

  7. Compression and rupture cycles as tools for compressibility characterization application to apatitic calcium phosphates

    Pontier, C. [S.P.C.T.S., Faculte des Sciences, Limoges (France); G.E.F., Faculte de Pharmacie, Limoges (France); Viana, M.; Chulia, D. [G.E.F., Faculte de Pharmacie, Limoges (France); Champion, E.; Bernache-Assollant, D. [S.P.C.T.S., Faculte des Sciences, Limoges (France)

    2002-07-01

    Measurement of the cycles of compression and rupture helps to understand the phenomena occurring during compaction. Different parameters are deduced from the cycles, such as the packing of the material and energies used during compression. The ratio between the energy of rupture and the energy of compaction defines the efficacy of compaction of the materials. This technique is applied to ceramic materials using apatitic calcium phosphates with a Ca/P molar ratio of 1.5 (apatitic tricalcium phosphate and {beta}-tricalcium phosphate) and 1.667 (stoichiometric hydroxyapatite). The methodology uses a uniaxial instrumented press to plot the cycles of compaction and rupture. The results point out the good compaction and cohesion properties of apatitic tricalcium phosphate, compared to the other apatitic materials. (orig.)

  8. Methods for global sensitivity analysis in life cycle assessment

    Groen, Evelyne A.; Bokkers, Eddy; Heijungs, Reinout; Boer, de Imke J.M.

    2017-01-01

    Purpose: Input parameters required to quantify environmental impact in life cycle assessment (LCA) can be uncertain due to e.g. temporal variability or unknowns about the true value of emission factors. Uncertainty of environmental impact can be analysed by means of a global sensitivity analysis to

  9. Modeling of the Global Water Cycle - Analytical Models

    Yongqiang Liu; Roni Avissar

    2005-01-01

    Both numerical and analytical models of coupled atmosphere and its underlying ground components (land, ocean, ice) are useful tools for modeling the global and regional water cycle. Unlike complex three-dimensional climate models, which need very large computing resources and involve a large number of complicated interactions often difficult to interpret, analytical...

  10. Advances in Global Water Cycle Science Made Possible by Global Precipitation Mission (GPM)

    Smith, Eric A.; Starr, David OC. (Technical Monitor)

    2001-01-01

    Within this decade the internationally sponsored Global Precipitation Mission (GPM) will take an important step in creating a global precipitation observing system from space. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams from very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and on to blends of the former datastreams with other less-high caliber PMW-based and IR-based rain retrievals. Within the context of NASA's role in global water cycle science and its own Global Water & Energy Cycle (GWEC) program, GPM is the centerpiece mission for improving our understanding of the global water cycle from a space-based measurement perspective. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in global temperature. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination, This paper presents an overview of the Global Precipitation Mission and how its datasets can be used in a set of quantitative tests within the framework of the oceanic and continental water budget equations to determine comprehensively whether substantive rate changes do accompany perturbations in global temperatures and how such rate changes manifest themselves in both water storage and water flux transport processes.

  11. Satellite Global and Hemispheric Lower Tropospheric Temperature Annual Temperature Cycle

    Michael A. Brunke

    2010-11-01

    Full Text Available Previous analyses of the Earth’s annual cycle and its trends have utilized surface temperature data sets. Here we introduce a new analysis of the global and hemispheric annual cycle using a satellite remote sensing derived data set during the period 1979–2009, as determined from the lower tropospheric (LT channel of the MSU satellite. While the surface annual cycle is tied directly to the heating and cooling of the land areas, the tropospheric annual cycle involves additionally the gain or loss of heat between the surface and atmosphere. The peak in the global tropospheric temperature in the 30 year period occurs on 10 July and the minimum on 9 February in response to the larger land mass in the Northern Hemisphere. The actual dates of the hemispheric maxima and minima are a complex function of many variables which can change from year to year thereby altering these dates.Here we examine the time of occurrence of the global and hemispheric maxima and minima lower tropospheric temperatures, the values of the annual maxima and minima, and the slopes and significance of the changes in these metrics.  The statistically significant trends are all relatively small. The values of the global annual maximum and minimum showed a small, but significant trend. Northern and Southern Hemisphere maxima and minima show a slight trend toward occurring later in the year. Most recent analyses of trends in the global annual cycle using observed surface data have indicated a trend toward earlier maxima and minima.

  12. Advances in Understanding Global Water Cycle with Advent of Global Precipitation Measurement (GPM) Mission

    Smith, Eric A.; Starr, David (Technical Monitor)

    2002-01-01

    Within this decade the internationally organized Global Precipitation Measurement (GPM) Mission will take an important step in creating a global precipitation observing system from space. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams beginning with very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and then on to blends of the former datastreams with additional lower-caliber PMW-based and IR-based rain retrievals. Within the context of the now emerging global water & energy cycle (GWEC) programs of a number of research agencies throughout the world, GPM serves as a centerpiece space mission for improving our understanding of the global water cycle from a global measurement perspective. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in climate, e.g., climate warming. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination. This paper presents an overview of the GPM Mission and how its observations can be used within the framework of the oceanic and continental water budget equations to determine whether a given perturbation in precipitation is indicative of an actual rate change in the global water cycle, consistent with required responses in water storage and/or water flux transport processes, or whether it is the natural variability of a fixed rate cycle.

  13. INTRODUCTION: Anticipated changes in the global atmospheric water cycle

    Allan, Richard P.; Liepert, Beate G.

    2010-06-01

    The atmospheric branch of the water cycle, although containing just a tiny fraction of the Earth's total water reserves, presents a crucial interface between the physical climate (such as large-scale rainfall patterns) and the ecosystems upon which human societies ultimately depend. Because of the central importance of water in the Earth system, the question of how the water cycle is changing, and how it may alter in future as a result of anthropogenic changes, present one of the greatest challenges of this century. The recent Intergovernmental Panel on Climate Change report on Climate Change and Water (Bates et al 2008) highlighted the increasingly strong evidence of change in the global water cycle and associated environmental consequences. It is of critical importance to climate prediction and adaptation strategies that key processes in the atmospheric water cycle are precisely understood and determined, from evaporation at the surface of the ocean, transport by the atmosphere, condensation as cloud and eventual precipitation, and run-off through rivers following interaction with the land surface, sub-surface, ice, snow and vegetation. The purpose of this special focus issue of Environmental Research Letters on anticipated changes in the global atmospheric water cycle is to consolidate the recent substantial advances in understanding past, present and future changes in the global water cycle through evidence built upon theoretical understanding, backed up by observations and borne out by climate model simulations. Thermodynamic rises in water vapour provide a central constraint, as discussed in a guest editorial by Bengtsson (2010). Theoretical implications of the Clausius-Clapeyron equation are presented by O'Gorman and Muller (2010) and with reference to a simple model (Sherwood 2010) while observed humidity changes confirm these anticipated responses at the land and ocean surface (Willett et al 2008). Rises in low-level moisture are thought to fuel an

  14. Modeling of the global carbon cycle - isotopic data requirements

    Ciais, P.

    1994-01-01

    Isotopes are powerful tools to constrain carbon cycle models. For example, the combinations of the CO 2 and the 13 C budget allows to calculate the net-carbon fluxes between atmosphere, ocean, and biosphere. Observations of natural and bomb-produced radiocarbon allow to estimate gross carbon exchange fluxes between different reservoirs and to deduce time scales of carbon overturning in important reservoirs. 18 O in CO 2 is potentially a tool to make the deconvolution of C fluxes within the land biosphere (assimilation vs respirations). The scope of this article is to identify gaps in our present knowledge about isotopes in the light of their use as constraint for the global carbon cycle. In the following we will present a list of some future data requirements for carbon cycle models. (authors)

  15. Separating decadal global water cycle variability from sea level rise.

    Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

    2017-04-20

    Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

  16. Soil organic matter dynamics and the global carbon cycle

    Post, W.M.; Emanuel, W.R.; King, A.W.

    1992-01-01

    The large size and potentially long residence time of the soil organic matter pool make it an important component of the global carbon cycle. Net terrestrial primary production of about 60 Pg C·yr -1 is, over a several-year period of time, balanced by an equivalent flux of litter production and subsequent decomposition of detritus and soil organic matter. We will review many of the major factors that influence soil organic matter dynamics that need to be explicitly considered in development of global estimates of carbon turnover in the world's soils. We will also discuss current decomposition models that are general enough to be used to develop a representation of global soil organic matter dynamics

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

    Zaehle, S

    2013-07-05

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

  18. Biogenic sulfur compounds and the global sulfur cycle

    Aneja, V.P.; Aneja, A.P.; Adams, D.F.

    1982-01-01

    Field measurements of biogenic sulfur compounds shows a great variation in concentrations and emission rates for H 2 S, DMS, CS 2 and COS. Measurements by the chamber method and estimates from micrometeorological sampling are employed to determine the earth-atmosphere flux of these gases. Much of the variation can be attributed to differences of climate and surface conditions, with marshes being a large source of biogenic sulfur (mean contribution 4 x 10 to the 6th ton/year maximum contribution 142 x 10 to the 6th ton/year). Considering that the estimated biogenic contribution needed to balance the global sulfur cycle ranges from 40- 230 x 10 to the 6th tons/year, the mean values are not sufficient to balance this cycle. Further experimental investigations are suggested in order to characterize the biogenic processes adequately

  19. Investigation of duty cycle effect on corrosion properties of electrodeposited calcium phosphate coatings

    Azem, Funda Ak, E-mail: funda.ak@deu.edu.tr [Dokuz Eylul University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Buca, 35390 Izmir (Turkey); Delice, Tulay Koc, E-mail: tulaykocdelice@gmail.com [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Buca, 35390 Izmir (Turkey); Ungan, Guler, E-mail: gulerungan@hotmail.com [Es Group, Izmir (Turkey); Cakir, Ahmet, E-mail: ahmet.cakir@deu.edu.tr [Dokuz Eylul University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Buca, 35390 Izmir (Turkey)

    2016-11-01

    The bioceramic calcium phosphate (CaP) is frequently used for improving bone fixation in titanium medical implants and thus increasing lifetime of the implant. It is known that the application of CaP coatings on metallic implant devices offers the possibility of combining the strength of the metals and the bioactivity of the ceramic materials. Many different techniques are available for producing CaP coatings. Electrochemical deposition method is widely used because of its ease of operation parameters, low temperature requirement, reproducibility and suitability for coating complex structures. This technique allows obtaining CaP coatings which promote bone in growth during the first healing period leading to permanent fixation. Electrochemical pulse technique is an alternative to calcium phosphate deposition techniques usually employed to cover orthopedic or dental titanium implant surfaces. Additionally, pulse electrodeposition technique can produce more uniform and denser CaP coatings on metallic implants. In this study, CaP based coatings were produced by electrochemical pulse technique on Ti6Al4V substrates. The resulting CaP deposits were investigated by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Corrosion properties of the CaP coatings were also investigated. The results showed that various duty cycle ranges have remarkably effect on morphology, crystallinity and corrosion properties of the produced CaP coatings. - Highlights: • Electrodeposited CaP based coating were produced by pulse deposition technique. • The pulsed electrodeposited coatings produced under 30% and 50% duty cycles were exhibited better corrosion resistance. • Produced coatings consist of irregular flake-like structure and compact network with fine needles.

  20. East Asian Financial Cycles: Asian vs. Global Financial Crises

    Akira Kohsaka; Jun-ichi Shinkai

    2014-01-01

    We examine the role of financial shocks in business cycles in general and in financial crises in particular in East Asia (Indonesia, Korea, Malaysia and Thailand) since the 1990s. Estimating a Financial Conditions Index, we found that financial shocks explain most of business downturns in all the economies in the Asian Financial Crisis (AFC) in 1997-98, but that the effects of financial shocks are diverse across economies in the Global Financial Crisis (GFC) in 2008-09. In the GFC, the financ...

  1. A Seamless Framework for Global Water Cycle Monitoring and Prediction

    Sheffield, J.; Wood, E. F.; Chaney, N.; Fisher, C. K.; Caylor, K. K.

    2013-12-01

    The Global Earth Observation System of Systems (GEOSS) Water Strategy ('From Observations to Decisions') recognizes that 'water is essential for ensuring food and energy security, for facilitating poverty reduction and health security, and for the maintenance of ecosystems and biodiversity', and that water cycle data and observations are critical for improved water management and water security - especially in less developed regions. The GEOSS Water Strategy has articulated a number of goals for improved water management, including flood and drought preparedness, that include: (i) facilitating the use of Earth Observations for water cycle observations; (ii) facilitating the acquisition, processing, and distribution of data products needed for effective management; (iii) providing expertise, information systems, and datasets to the global, regional, and national water communities. There are several challenges that must be met to advance our capability to provide near real-time water cycle monitoring, early warning of hydrological hazards (floods and droughts) and risk assessment under climate change, regionally and globally. Current approaches to monitoring and predicting hydrological hazards are limited in many parts of the world, and especially in developing countries where national capacity is limited and monitoring networks are inadequate. This presentation describes the development of a seamless monitoring and prediction framework at all time scales that allows for consistent assessment of water variability from historic to current conditions, and from seasonal and decadal predictions to climate change projections. At the center of the framework is an experimental, global water cycle monitoring and seasonal forecast system that has evolved out of regional and continental systems for the US and Africa. The system is based on land surface hydrological modeling that is driven by satellite remote sensing precipitation to predict current hydrological conditions

  2. GEWEX - The Global Energy and Water Cycle Experiment

    Chahine, Moustafa T.

    1992-01-01

    GEWEX, which is part of the World Climate Research Program, has as its goal an order-of-magnitude improvement in the ability to model global precipitation and evaporation and furnish an accurate assessment of the sensitivity of atmospheric radiation and clouds. Attention will also be given to the response of the hydrological cycle and water resources to climate change. GEWEX employs a single program to coordinate all aspects of climatology from model development to the deployment and operation of observational systems. GEWEX will operate over the next two decades.

  3. The oceanic cycle and global atmospheric budget of carbonyl sulfide

    Weiss, P.S.

    1994-12-31

    A significant portion of stratospheric air chemistry is influenced by the existence of carbonyl sulfide (COS). This ubiquitous sulfur gas represents a major source of sulfur to the stratosphere where it is converted to sulfuric acid aerosol particles. Stratospheric aerosols are climatically important because they scatter incoming solar radiation back to space and are able to increase the catalytic destruction of ozone through gas phase reactions on particle surfaces. COS is primarily formed at the surface of the earth, in both marine and terrestrial environments, and is strongly linked to natural biological processes. However, many gaps in the understanding of the global COS cycle still exist, which has led to a global atmospheric budget that is out of balance by a factor of two or more, and a lack of understanding of how human activity has affected the cycling of this gas. The goal of this study was to focus on COS in the marine environment by investigating production/destruction mechanisms and recalculating the ocean-atmosphere flux.

  4. Global LC/MS Metabolomics Profiling of Calcium Stressed and Immunosuppressant Drug Treated Saccharomyces cerevisiae

    Stefan Jenkins

    2013-12-01

    Full Text Available Previous studies have shown that calcium stressed Saccharomyces cerevisiae, challenged with immunosuppressant drugs FK506 and Cyclosporin A, responds with comprehensive gene expression changes and attenuation of the generalized calcium stress response. Here, we describe a global metabolomics workflow for investigating the utility of tracking corresponding phenotypic changes. This was achieved by efficiently analyzing relative abundance differences between intracellular metabolite pools from wild-type and calcium stressed cultures, with and without prior immunosuppressant drugs exposure. We used pathway database content from WikiPathways and YeastCyc to facilitate the projection of our metabolomics profiling results onto biological pathways. A key challenge was to increase the coverage of the detected metabolites. This was achieved by applying both reverse phase (RP and aqueous normal phase (ANP chromatographic separations, as well as electrospray ionization (ESI and atmospheric pressure chemical ionization (APCI sources for detection in both ion polarities. Unsupervised principle component analysis (PCA and ANOVA results revealed differentiation between wild-type controls, calcium stressed and immunosuppressant/calcium challenged cells. Untargeted data mining resulted in 247 differentially expressed, annotated metabolites, across at least one pair of conditions. A separate, targeted data mining strategy identified 187 differential, annotated metabolites. All annotated metabolites were subsequently mapped onto curated pathways from YeastCyc and WikiPathways for interactive pathway analysis and visualization. Dozens of pathways showed differential responses to stress conditions based on one or more matches to the list of annotated metabolites or to metabolites that had been identified further by MS/MS. The purine salvage, pantothenate and sulfur amino acid pathways were flagged as being enriched, which is consistent with previously published

  5. Increasing water cycle extremes in California and in relation to ENSO cycle under global warming

    Yoon, Jin-Ho; Wang, S-Y Simon; Gillies, Robert R.; Kravitz, Ben; Hipps, Lawrence; Rasch, Philip J.

    2015-01-01

    Since the winter of 2013–2014, California has experienced its most severe drought in recorded history, causing statewide water stress, severe economic loss and an extraordinary increase in wildfires. Identifying the effects of global warming on regional water cycle extremes, such as the ongoing drought in California, remains a challenge. Here we analyse large-ensemble and multi-model simulations that project the future of water cycle extremes in California as well as to understand those associations that pertain to changing climate oscillations under global warming. Both intense drought and excessive flooding are projected to increase by at least 50% towards the end of the twenty-first century; this projected increase in water cycle extremes is associated with a strengthened relation to El Niño and the Southern Oscillation (ENSO)—in particular, extreme El Niño and La Niña events that modulate California's climate not only through its warm and cold phases but also its precursor patterns. PMID:26487088

  6. Long-term global nuclear energy and fuel cycle strategies

    Krakowski, R.A.

    1997-01-01

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E 3 (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E 3 model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E 3 model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues

  7. Long-term global nuclear energy and fuel cycle strategies

    Krakowski, R.A. [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

    1997-09-24

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E{sup 3} (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E{sup 3} model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E{sup 3} model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues.

  8. Process modelling and techno-economic analysis of natural gas combined cycle integrated with calcium looping

    Erans María

    2016-01-01

    Full Text Available Calcium looping (CaL is promising for large-scale CO2 capture in the power generation and industrial sectors due to the cheap sorbent used and the relatively low energy penalties achieved with this process. Because of the high operating temperatures the heat utilisation is a major advantage of the process, since a significant amount of power can be generated from it. However, this increases its complexity and capital costs. Therefore, not only the energy efficiency performance is important for these cycles, but also the capital costs must be taken into account, i.e. techno-economic analyses are required in order to determine which parameters and configurations are optimal to enhance technology viability in different integration scenarios. In this study the integration scenarios of CaL cycles and natural gas combined cycles (NGCC are explored. The process models of the NGCC and CaL capture plant are developed to explore the most promising scenarios for NGCC-CaL integration with regards to efficiency penalties. Two scenarios are analysed in detail, and show that the system with heat recovery steam generator (HRSG before and after the capture plant exhibited better performance of 49.1% efficiency compared with that of 45.7% when only one HRSG is located after the capture plant. However, the techno-economic analyses showed that the more energy efficient case, with two HRSGs, implies relatively higher cost of electricity (COE, 44.1€/MWh, when compared to that of the reference plant system (33.1€/MWh. The predicted cost of CO2 avoided for the case with two HRSGS is 29.3 €/ton CO2.

  9. Role of volcanic forcing on future global carbon cycle

    J. F. Tjiputra

    2011-06-01

    Full Text Available Using a fully coupled global climate-carbon cycle model, we assess the potential role of volcanic eruptions on future projection of climate change and its associated carbon cycle feedback. The volcanic-like forcings are applied together with a business-as-usual IPCC-A2 carbon emissions scenario. We show that very large volcanic eruptions similar to Tambora lead to short-term substantial global cooling. However, over a long period, smaller eruptions similar to Pinatubo in amplitude, but set to occur frequently, would have a stronger impact on future climate change. In a scenario where the volcanic external forcings are prescribed with a five-year frequency, the induced cooling immediately lower the global temperature by more than one degree before it returns to the warming trend. Therefore, the climate change is approximately delayed by several decades, and by the end of the 21st century, the warming is still below two degrees when compared to the present day period. Our climate-carbon feedback analysis shows that future volcanic eruptions induce positive feedbacks (i.e., more carbon sink on both the terrestrial and oceanic carbon cycle. The feedback signal on the ocean is consistently smaller than the terrestrial counterpart and the feedback strength is proportionally related to the frequency of the volcanic eruption events. The cooler climate reduces the terrestrial heterotrophic respiration in the northern high latitude and increases net primary production in the tropics, which contributes to more than 45 % increase in accumulated carbon uptake over land. The increased solubility of CO2 gas in seawater associated with cooler SST is offset by a reduced CO2 partial pressure gradient between the ocean and the atmosphere, which results in small changes in net ocean carbon uptake. Similarly, there is nearly no change in the seawater buffer capacity simulated between the different volcanic scenarios. Our study shows that even

  10. eWaterCycle: A global operational hydrological forecasting model

    van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2015-04-01

    Development of an operational hyper-resolution hydrological global model is a central goal of the eWaterCycle project (www.ewatercycle.org). This operational model includes ensemble forecasts (14 days) to predict water related stress around the globe. Assimilation of near-real time satellite data is part of the intended product that will be launched at EGU 2015. The challenges come from several directions. First, there are challenges that are mainly computer science oriented but have direct practical hydrological implications. For example, we aim to make use as much as possible of existing standards and open-source software. For example, different parts of our system are coupled through the Basic Model Interface (BMI) developed in the framework of the Community Surface Dynamics Modeling System (CSDMS). The PCR-GLOBWB model, built by Utrecht University, is the basic hydrological model that is the engine of the eWaterCycle project. Re-engineering of parts of the software was needed for it to run efficiently in a High Performance Computing (HPC) environment, and to be able to interface using BMI, and run on multiple compute nodes in parallel. The final aim is to have a spatial resolution of 1km x 1km, which is currently 10 x 10km. This high resolution is computationally not too demanding but very memory intensive. The memory bottleneck becomes especially apparent for data assimilation, for which we use OpenDA. OpenDa allows for different data assimilation techniques without the need to build these from scratch. We have developed a BMI adaptor for OpenDA, allowing OpenDA to use any BMI compatible model. To circumvent memory shortages which would result from standard applications of the Ensemble Kalman Filter, we have developed a variant that does not need to keep all ensemble members in working memory. At EGU, we will present this variant and how it fits well in HPC environments. An important step in the eWaterCycle project was the coupling between the hydrological and

  11. Comparative study the expression of calcium cycling genes in Bombay duck (Harpadon nehereus and beltfish (Trichiurus lepturus with different swimming activities

    Hui Zhang

    2017-06-01

    Full Text Available The contraction and relaxation events of the muscle is mediated by the coordination of many important calcium cycling proteins of ryanodine receptor (RYR, troponin C (TNNC, parvalbumin (PVALB, sarcoendoplasmic reticulum calcium transport ATPase (SERCA and calsequestrin (CASQ. In higher vertebrates, the expression level of calcium cycling proteins are positively correlated to the muscle contraction/relaxation ability of the cell. In this study, we used RNAseq to explore the expression profile of calcium cycling genes between two marine fish of Bombay duck (Harpadon nehereus and beltfish (Trichiurus lepturus with poor and robust swimming activities, respectively. We have studied the hypothesis whether the expression level of calcium cycling proteins are also positive correlated to swimming ability in fish. We used Illumina sequencing technology (NextSeq500 to sequence, assemble and annotate the muscle transcriptome of Bombay duck for the first time. A total of 47,752,240 cleaned reads (deposited in NCBI SRA database with accession number of SRX1706379 were obtained from RNA sequencing and 26,288 unigenes (with N50 of 486 bp were obtained after de novo assembling with Trinity software. BLASTX against NR, GO, KEGG and eggNOG databases show 100%, 65%, 26%, 94% and 88% annotation rate, respectively. Comparison of the dominantly expressed unigenes in fish muscle shows calcium cycling gene expression in beltfish (SRX1674471 is 1.4- to 51.6-fold higher than Bombay duck. Among five calcium cycling genes, the fold change results are very significant in CASQ (51.6 fold and PVALB (9.1 fold and both of them are responsive for calcium binding to reduce free calcium concentration in the sarcoendoplasmic reticulum and cytoplasm. In conclusion, we confirmed that the high abundant expression rate of calcium cycling genes in robust swimming fish species. The current muscle transcriptome and identified calcium cycling gene data can provide more insights into the

  12. Andreae is New Editor of Global Biogeochemical Cycles

    Andreae, Meinrat O.

    2004-10-01

    As the incoming editor of Global Biogeochemical Cycles, I would like to introduce myself and my ideas for the journal to Eos readers and to current and potential GBC authors. I've had a somewhat ``roaming'' scientific evolution, coming from ``straight'' chemistry through hard-rock geochemistry to chemical oceanography, the field in which I did my Ph.D. I taught marine chemistry at Florida State University for a number of years, and developed an interest in ocean/atmosphere interactions and atmospheric chemistry. In 1987 I took on my present job at the Max Planck Institute for Chemistry, in Mainz, Germany, and, after leaving the seacoast, my interests shifted to interactions between the terrestrial biosphere and atmosphere, including the role of vegetation fires. My present focus is on the role of biogenic aerosols and biomass smoke in regulating cloud properties and influencing climate.

  13. Role of Mineral Deposits in Global Geochemical Cycles

    Kesler, S.; Wilkinson, B.

    2009-12-01

    Mineral deposits represent the most extreme degree of natural concentration for most elements and their formation and destruction are important parts of global geochemical cycles. Quantitative estimates of the role that mineral deposits play in these geochemical cycles has been limited, however, by the lack of information on actual amounts of elements that are concentrated in these deposits, and their rates of formation and destruction at geologic time scales. Recent use of a “tectonic diffusion” model for porphyry copper deposits, the most important source of world copper, in conjunction with estimates of their copper content (Kesler and Wilkinson, 2008), allows an assessment of the role of copper deposits in Earth’s global copper cycles. These results indicate that ~4.5*10^8 Gg of Cu have been concentrated in porphyry copper deposits through Phanerozoic time, that deposits containing ~2.8*10^8 Gg of Cu have been removed by uplift and erosion over the same time period, and that deposits containing ~1.7*10^8 Gg remain in Earth’s crust. If styles of formation and destruction of other copper-bearing mineral deposits are similar, then all crustal deposits contain ~3*10^8 Gg of copper. This constitutes about 0.03% of the copper that resides in crustal rocks and provides a first-ever estimate of the rate at which natural geochemical cycles produce the extreme concentrations that constitute mineral deposits. Another ~8*10^8 Gg of copper have been destroyed during the uplift and erosion of mineral deposits over Phanerozoic time, a flux amounting to an annual contribution of about 1.5 Gg of copper to the near-surface environment. This amount is similar in magnitude to copper released by volcanic outgassing, but only ~2.5% of the 56 Gg of copper estimated to be released annually by weathering of average crustal rocks (Rauch and Graedel, 2007). The amount of copper removed from mineral deposits by mining, 1.1*10^4 Gg/year, is much larger than any natural

  14. TRMM and Its Connection to the Global Water Cycle

    Kummerow, Christian; Hong, Ye

    1999-01-01

    The importance of quantitative knowledge of tropical rainfall, its associated latent heating and variability is summarized in the context of the global hydrologic cycle. Much of the tropics is covered by oceans. What land exists, is covered largely by rainforests that are only thinly populated. The only way to adequately measure the global tropical rainfall for climate and general circulation models is from space. The TRMM orbit is inclined 35' leading to good sampling in the tropics and a rapid precession to study the diurnal cycle of precipitation. The precipitation instrument complement consists of the first rain radar to be flown in space (PR), a multi-channel passive microwave sensor (TMI) and a five-channel VIS/IR (VIRS) sensor. The precipitation radar operates at a frequency of 13.6 GHz. The swath width is 220 km, with a horizontal resolution of 4 km and the vertical resolution of 250 in. The minimum detectable signal from the precipitation radar has been measured at 17 dBZ. The TMI instrument is designed similar to the SSM/I with two important changes. The 22.235 GHz water vapor absorption channel of the SSM/I was moved to 21.3 GHz in order to avoid saturation in the tropics and 10.7 GHz V&H polarized channels were added to expand the dynamic range of rainfall estimates. The resolution of the TMI varies from 4.6 km at 85 GHz to 36 km at 10.7 GHz. The visible and infrared sensor (VIRS) measures radiation at 0.63, 1.6, 3.75, 10.8 and 12.0 microns. The spatial resolution of all five VIRS channels is 2 km at nadir. In addition to the three primary rainfall instruments, TRMM will also carry a Lightning Imaging Sensor (LIS) and a Clouds and the Earth's Radiant Energy System (CERES) instrument.

  15. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

    2014-09-15

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. Copyright © 2014 the American Physiological Society.

  16. Global operational hydrological forecasts through eWaterCycle

    van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2015-04-01

    Central goal of the eWaterCycle project (www.ewatercycle.org) is the development of an operational hyper-resolution hydrological global model. This model is able to produce 14 day ensemble forecasts based on a hydrological model and operational weather data (presently NOAA's Global Ensemble Forecast System). Special attention is paid to prediction of situations in which water related issues are relevant, such as floods, droughts, navigation, hydropower generation, and irrigation stress. Near-real time satellite data will be assimilated in the hydrological simulations, which is a feature that will be presented for the first time at EGU 2015. First, we address challenges that are mainly computer science oriented but have direct practical hydrological implications. An important feature in this is the use of existing standards and open-source software to the maximum extent possible. For example, we use the Community Surface Dynamics Modeling System (CSDMS) approach to coupling models (Basic Model Interface (BMI)). The hydrological model underlying the project is PCR-GLOBWB, built by Utrecht University. This is the motor behind the predictions and state estimations. Parts of PCR-GLOBWB have been re-engineered to facilitate running it in a High Performance Computing (HPC) environment, run parallel on multiple nodes, as well as to use BMI. Hydrological models are not very CPU intensive compared to, say, atmospheric models. They are, however, memory hungry due to the localized processes and associated effective parameters. To accommodate this memory need, especially in an ensemble setting, a variation on the traditional Ensemble Kalman Filter was developed that needs much less on-chip memory. Due to the operational nature, the coupling of the hydrological model with hydraulic models is very important. The idea is not to run detailed hydraulic routing schemes over the complete globe but to have on-demand simulation prepared off-line with respect to topography and

  17. The impact of the presence on global markets of calcium carbide originating from China on other industry role players: the case of sa calcium carbide (PTY LTD

    Royce Sitshonile Mazo

    2017-12-01

    Full Text Available This research assesses how the presence of calcium carbide originating from China has impacted on the operations of other role players in the industry. SA Calcium Carbide (Pty Ltd. located in Newcastle, South Africa, was used as a case study. The study spanned all markets where the company has a footprint meaning domestically, regionally and internationally. The aim of the study was to discern the extent to which companies like SA Calcium Carbide have been affected by the presence of products from China on the global market with special focus being put on the competitiveness in terms of pricing of products. The study used a survey strategy, and was exploratory in nature. The choice of the survey strategy was motivated by the need to collect both quantitative and qualitative data in order to meet the research objectives. The data was gathered, with an 80 percent response rate, using a questionnaire method from more than 70 current SA Calcium Carbide customers both from the domestic and the export side of the business. In order to consider the different perspectives of the whole scenario, 10 companies involved in either manufacturing or trading of Chinese manufactured calcium carbide were interviewed, some face to face and some telephonically. The study revealed that current customers, who are predominantly from the African continent, buy product from SA Calcium Carbide primarily because of its high quality. It also evident from the results that the export volumes of SA Calcium Carbide were on a gradual downward trend due to loss of market share to Chinese companies

  18. The observed sensitivity of the global hydrological cycle to changes in surface temperature

    Arkin, Phillip A; Janowiak, John; Smith, Thomas M; Sapiano, Mathew R P

    2010-01-01

    Climate models project large changes in global surface temperature in coming decades that are expected to be accompanied by significant changes in the global hydrological cycle. Validation of model simulations is essential to support their use in decision making, but observing the elements of the hydrological cycle is challenging, and model-independent global data sets exist only for precipitation. We compute the sensitivity of the global hydrological cycle to changes in surface temperature using available global precipitation data sets and compare the results against the sensitivities derived from model simulations of 20th century climate. The implications of the results for the global climate observing system are discussed.

  19. The Global Carbon Cycle: It's a Small World

    Ineson, Philip; Milcu, Alexander; Subke, Jens-Arne; Wildman, Dennis; Anderson, Robert; Manning, Peter; Heinemeyer, Andreas

    2010-05-01

    Predicting future atmospheric concentrations of carbon dioxide (CO2), together with the impacts of these changes on global climate, are some of the most urgent and important challenges facing mankind. Modelling is the only way in which such predictions can be made, leading to the current generation of increasingly complex computer simulations, with associated concerns about embedded assumptions and conflicting model outputs. Alongside analysis of past climates, the GCMs currently represent our only hope of establishing the importance of potential runaway positive feedbacks linking climate change and atmospheric greenhouse gases yet the incorporation of necessary biospheric responses into GCMs markedly increases the uncertainty of predictions. Analysis of the importance of the major components of the global carbon (C) cycle reveals that an understanding of the conditions under which the terrestrial biosphere could switch from an overall carbon (C) sink to a source is critical to our ability to make future climate predictions. Here we present an alternative approach to assessing the short term biotic (plant and soil) sensitivities to elevated temperature and atmospheric CO2 through the use of a purely physical analogue. Centred on the concept of materially-closed systems containing scaled-down ratios of the global C stocks for the atmosphere, vegetation and soil we show that, in these model systems, the terrestrial biosphere is able to buffer a rise of 3oC even when coupled to very strong CO2-temperature positive feedbacks. The system respiratory response appears to be extremely well linked to temperature and is critical in deciding atmospheric concentrations of CO2. Simulated anthropogenic emissions of CO2 into the model systems showed an initial corresponding increase in atmospheric CO2 but, somewhat surprisingly, CO2 concentrations levelled off at ca. 480 p.p.m.v., despite continuing additions of CO2. Experiments were performed in which reversion of atmospheric

  20. The terrestrial carbon cycle on the regional and global scale : modeling, uncertainties and policy relevance

    Minnen, van J.G.

    2008-01-01

    Contains the chapters: The importance of three centuries of climate and land-use change for the global and regional terrestrial carbon cycle; and The terrestrial C cycle and its role in the climate change policy

  1. Global carbon cycle and possible disturbances due to man's interventions

    Pankrath, J

    1979-01-01

    Global atmospheric CO/sub 2/ concentration has increased since the beginning of reliable monitoring in 1958 at a mean rate of about 0.9 ppM CO/sub 2//y. Now, atmospheric, CO/sub 2/ concentration is at 330 ppM. From about 1860 up to 1974, man's intervention in the global carbon cycle caused a likely increase of 76.6 x 10/sup 15/ g C, corresponding to 36 ppM CO/sub 2/ in the atmosphere, if a preindustrial content of 294 ppM CO/sub 2/ or 625.3 x 10/sup 15/ g C is adopted to be valid. A further rise of atmospheric CO/sub 2/ seems to be inevitable and probably will be responsible for a climatic warming in the next several decades; therefore, a global examination of carbon reservoirs and carbon fluxes has been undertaken to determine their storage capacity for excess carbon which originated mainly from burning of fossil fuels and from land clearing. During 1860 to 1974 about 136 x 10/sup 15/ g C have been emitted into the atmosphere by fossil fuel combustion and cement production. At present, the emission rate is about 5 x 10/sup 15/ g C/y. The worldwide examination of carbon release, primarily by deforestation and soil cultivation since 1860, is estimated to be about 120 x 10/sup 15/ g C. The net transfer of carbon to the atmosphere owing to man's interference with the biosphere is now believed to be about 2.4 x 10/sup 15/ g C/y. An oceanic uptake of rougly 179 x 10/sup 15/ g C since 1860 is open to discussion. According to the chemical buffering of sea surface water only about 35.5 x 10/sup 15/ g C could have been absorbed. It is argued, however, that oceanic circulations might have been more effective in removing atmospheric excess carbon of anthropogenic origin.

  2. Finnish and Swedish business cycles in a global context

    Bergman, Ulf Michael

    2008-01-01

    This paper evaluates the decisions made by the Finnish government to join EMU and the Swedish government not to join EMU in the early 1990s. Focusing on the characteristics of business cycles during the postwar period, we find that output fluctuations in Sweden and Finland are correlated to two...... measures of the international business cycle, a European and a non-European cycle. The Finnish cycle has become more synchronized to the European cycle but less synchronized to the non-EU cycle after 1999. For Sweden we find the opposite result. The decision by the Finnish government to join EMU...

  3. eWaterCycle: A high resolution global hydrological model

    van de Giesen, Nick; Bierkens, Marc; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2014-05-01

    In 2013, the eWaterCycle project was started, which has the ambitious goal to run a high resolution global hydrological model. Starting point was the PCR-GLOBWB built by Utrecht University. The software behind this model will partially be re-engineered in order to enable to run it in a High Performance Computing (HPC) environment. The aim is to have a spatial resolution of 1km x 1km. The idea is also to run the model in real-time and forecasting mode, using data assimilation. An on-demand hydraulic model will be available for detailed flow and flood forecasting in support of navigation and disaster management. The project faces a set of scientific challenges. First, to enable the model to run in a HPC environment, model runs were analyzed to examine on which parts of the program most CPU time was spent. These parts were re-coded in Open MPI to allow for parallel processing. Different parallelization strategies are thinkable. In our case, it was decided to use watershed logic as a first step to distribute the analysis. There is rather limited recent experience with HPC in hydrology and there is much to be learned and adjusted, both on the hydrological modeling side and the computer science side. For example, an interesting early observation was that hydrological models are, due to their localized parameterization, much more memory intensive than models of sister-disciplines such as meteorology and oceanography. Because it would be deadly to have to swap information between CPU and hard drive, memory management becomes crucial. A standard Ensemble Kalman Filter (enKF) would, for example, have excessive memory demands. To circumvent these problems, an alternative to the enKF was developed that produces equivalent results. This presentation shows the most recent results from the model, including a 5km x 5km simulation and a proof of concept for the new data assimilation approach. Finally, some early ideas about financial sustainability of an operational global

  4. Assessing Students' Disciplinary and Interdisciplinary Understanding of Global Carbon Cycling

    You, Hye Sun; Marshall, Jill A.; Delgado, Cesar

    2018-01-01

    Global carbon cycling describes the movement of carbon through atmosphere, biosphere, geosphere, and hydrosphere; it lies at the heart of climate change and sustainability. To understand the global carbon cycle, students will require "interdisciplinary knowledge." While standards documents in science education have long promoted…

  5. Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP)

    Vane, Deborah

    1993-01-01

    A discussion of the objectives of the Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP) is presented in vugraph form. The objectives of GEWEX are as follows: determine the hydrological cycle by global measurements; model the global hydrological cycle; improve observations and data assimilation; and predict response to environmental change. The objectives of GCIP are as follows: determine the time/space variability of the hydrological cycle over a continental-scale region; develop macro-scale hydrologic models that are coupled to atmospheric models; develop information retrieval schemes; and support regional climate change impact assessment.

  6. Effect of rice husk ash addition on CO2 capture behavior of calcium-based sorbent during calcium looping cycle

    Li, Yingjie; Zhao, Changsui; Ren, Qiangqiang; Duan, Lunbo; Chen, Huichao; Chen, Xiaoping

    2009-01-01

    Rice husk ash/CaO was proposed as a CO 2 sorbent which was prepared by rice husk ash and CaO hydration together. The CO 2 capture behavior of rice husk ash/CaO sorbent was investigated in a twin fixed bed reactor system, and its apparent morphology, pore structure characteristics and phase variation during cyclic carbonation/calcination reactions were examined by SEM-EDX, N 2 adsorption and XRD, respectively. The optimum preparation conditions for rice husk ash/CaO sorbent are hydration temperature of 75 C, hydration time of 8 h, and mole ratio of SiO 2 in rice husk ash to CaO of 1.0. The cyclic carbonation performances of rice husk ash/CaO at these preparation conditions were compared with those of hydrated CaO and original CaO. The temperature at 660 C-710 C is beneficial to CO 2 absorption of rice husk ash/CaO, and it exhibits higher carbonation conversions than hydrated CaO and original CaO during multiple cycles at the same reaction conditions. Rice husk ash/CaO possesses better anti-sintering behavior than the other sorbents. Rice husk ash exhibits better effect on improving cyclic carbonation conversion of CaO than pure SiO 2 and diatomite. Rice husk ash/CaO maintains higher surface area and more abundant pores after calcination during the multiple cycles; however, the other sorbents show a sharp decay at the same reaction conditions. Ca 2 SiO 4 found by XRD detection after calcination of rice husk ash/CaO is possibly a key factor in determining the cyclic CO 2 capture behavior of rice husk ash/CaO. (author)

  7. Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

    Wuman Zhang

    2017-01-01

    Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

  8. Interactions of C, N, P and S biogeochemical cycles and global change

    Wollast, R.; Mackenzie, F.T.

    1993-01-01

    The biochemical cycles of carbon, nitrogen, phosphorus and sulfur are tied to each other through biological productivity and to problems of global environmental change. Both natural changes in the cycles of the elements and interference and distortion of these cycles by human activities (e.g. disturbancies by agricultural, industrial and urbanization activities) will have impacts on ecosystems and human society. (UT)

  9. Global change and biogeochemical cycles: The south Asia region

    Mitra, A.P.; DileepKumar, M.; Kumar, K.R.; Abrol, Y.P.; Kalra, N.; Velayutham, M.; Naqvi, S.W.A.

    stream_size 33 stream_content_type text/plain stream_name Global-Region_Linkage_Earth_Syst_2002_75.pdf.txt stream_source_info Global-Region_Linkage_Earth_Syst_2002_75.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  10. Dynamical analysis of the global business-cycle synchronization.

    Lopes, António M; Tenreiro Machado, J A; Huffstot, John S; Mata, Maria Eugénia

    2018-01-01

    This paper reports the dynamical analysis of the business cycles of 12 (developed and developing) countries over the last 56 years by applying computational techniques used for tackling complex systems. They reveal long-term convergence and country-level interconnections because of close contagion effects caused by bilateral networking exposure. Interconnectivity determines the magnitude of cross-border impacts. Local features and shock propagation complexity also may be true engines for local configuration of cycles. The algorithmic modeling proves to represent a solid approach to study the complex dynamics involved in the world economies.

  11. Dynamical analysis of the global business-cycle synchronization

    2018-01-01

    This paper reports the dynamical analysis of the business cycles of 12 (developed and developing) countries over the last 56 years by applying computational techniques used for tackling complex systems. They reveal long-term convergence and country-level interconnections because of close contagion effects caused by bilateral networking exposure. Interconnectivity determines the magnitude of cross-border impacts. Local features and shock propagation complexity also may be true engines for local configuration of cycles. The algorithmic modeling proves to represent a solid approach to study the complex dynamics involved in the world economies. PMID:29408909

  12. NEWS Climatology Project: The State of the Water Cycle at Continental to Global Scales

    Rodell, Matthew; LEcuyer, Tristan; Beaudoing, Hiroko Kato; Olson, Bill

    2011-01-01

    NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the NEWS Water and Energy Cycle Climatology project is to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project is a multiinstitutional collaboration with more than 20 active contributors. This presentation will describe results of the first stage of the water budget analysis, whose goal was to characterize the current state of the water cycle on mean monthly, continental scales. We examine our success in closing the water budget within the expected uncertainty range and the effects of forcing budget closure as a method for refining individual flux estimates.

  13. The Global Enery and Water Cycle Experiment Science Strategy

    Chahine, M. T.

    1997-01-01

    The distribution of water in the atmosphere and at the surface of the Earth is the most influential factor regulating our environment, not only because water is essential for life but also because through phase transitions it is the main energy source that control clouds and radiation and drives the global circulation of the atmosphere.

  14. Global guidance on environmental life cycle impact assessment indicators: Progress and case study

    Frischknecht, Rolf; Fantke, Peter; Tschümperlin, Laura

    2016-01-01

    Purpose The life cycle impact assessment (LCIA) guidance flagship project of the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative aims at providing global guidance and building scientific consensus on environmental LCIA in...

  15. Nitrogen attenuation of terrestrial carbon cycle response to global environmental factors

    Atul Jain; Xiaojuan Yang; Haroon Kheshgi; A. David McGuire; Wilfred Post; David. Kicklighter

    2009-01-01

    Nitrogen cycle dynamics have the capacity to attenuate the magnitude of global terrestrial carbon sinks and sources driven by CO2 fertilization and changes in climate. In this study, two versions of the terrestrial carbon and nitrogen cycle components of the Integrated Science Assessment Model (ISAM) are used to evaluate how variation in nitrogen...

  16. Late calcium EDTA rescues hippocampal CA1 neurons from global ischemia-induced death.

    Calderone, Agata; Jover, Teresa; Mashiko, Toshihiro; Noh, Kyung-min; Tanaka, Hidenobu; Bennett, Michael V L; Zukin, R Suzanne

    2004-11-03

    Transient global ischemia induces a delayed rise in intracellular Zn2+, which may be mediated via glutamate receptor 2 (GluR2)-lacking AMPA receptors (AMPARs), and selective, delayed death of hippocampal CA1 neurons. The molecular mechanisms underlying Zn2+ toxicity in vivo are not well delineated. Here we show the striking finding that intraventricular injection of the high-affinity Zn2+ chelator calcium EDTA (CaEDTA) at 30 min before ischemia (early CaEDTA) or at 48-60 hr (late CaEDTA), but not 3-6 hr, after ischemia, afforded robust protection of CA1 neurons in approximately 50% (late CaEDTA) to 75% (early CaEDTA) of animals. We also show that Zn2+ acts via temporally distinct mechanisms to promote neuronal death. Early CaEDTA attenuated ischemia-induced GluR2 mRNA and protein downregulation (and, by inference, formation of Zn2+-permeable AMPARs), the delayed rise in Zn2+, and neuronal death. These findings suggest that Zn2+ acts at step(s) upstream from GluR2 gene downregulation and implicate Zn2+ in transcriptional regulation and/or GluR2 mRNA stability. Early CaEDTA also blocked mitochondrial release of cytochrome c and Smac/DIABLO (second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein-binding protein with low pI), caspase-3 activity (but not procaspase-3 cleavage), p75NTR induction, and DNA fragmentation. These findings indicate that CaEDTA preserves the functional integrity of the mitochondrial outer membrane and arrests the caspase death cascade. Late injection of CaEDTA at a time when GluR2 is downregulated and caspase is activated inhibited the delayed rise in Zn2+, p75NTR induction, DNA fragmentation, and cell death. The finding of neuroprotection by late CaEDTA administration has striking implications for intervention in the delayed neuronal death associated with global ischemia.

  17. The geological carbon cycle and the global warming / climate debate

    Frank, F.

    2013-01-01

    The extensively cited seasonal carbon cycle describes the size and the annual fluxes between the temporary reservoirs (ocean, atmosphere, biosphere and soils). Compared with these large annual fluxes (approx. 200 GtC/y) the human contribution seems to be of minor amount and is currently (2011) in the range of 4-5%. However, in the geological carbon cycle, which describes the nearly equal amounts of input (volcanoes etc.) and output (sediments) into and from the temporary reservoirs, the human contribution has now reached 30-50 times the average natural level (9.5 Gt C/y versus ca. 0.2-0.3Gt C/y). In the long-term range (1-10x106y), the variable, but much smaller net imbalance between these geological sources und sinks was responsible for the atmospheric CO2-level in the last 400 My (since then comparable temporary reservoirs exist) and influenced via the various feedbacks the climate on earth. In nearly 95% of this long time the climate system was in (nearly) equilibrium conditions and changes occurred extremely slow. Whenever a certain range of higher rate of change of these driving forces were reached, it had - together with other effects - severe influence on the evolution of life, causing 5 large and many minor 'geological accidents'. Based on isotope geochemistry and a fairly good time resolution by orbitally tuned cyclostratigraphy (astrochronology) in the sedimentary record, we are able to quantify these rates of change with reasonable errors. It turns out that the present rate of change - caused by the C-based fossil energy use - is one to two orders of magnitude more rapid than these severe events (impacts excluded) in the earth system. A vast amount of data is available from the ice age cycles. Climate geology (e.g. the group of M. Sarnthein) made considerable progress in understanding the related geological/oceanic processes and proposed a reasonably constrained mass balance of CO2 during the last cycle, which could help us to understand the future

  18. Thermodynamic simulation of CO{sub 2} capture for an IGCC power plant using the calcium looping cycle

    Li, Y. [National Engineering Laboratory for Coal-Burning Pollutant Emission Reduction, Shandong University, Jinan (China); Zhao, C.; Ren, Q. [School of Energy and Environment, Southeast University, Nanjing (China)

    2011-06-15

    A CO{sub 2} capture process for an integrated gasification combined cycle (IGCC) power plant using the calcium looping cycle was proposed. The CO{sub 2} capture process using natural and modified limestone was simulated and investigated with the software package Aspen Plus. It incorporated a fresh feed of sorbent to compensate for the decay in CO{sub 2} capture activity during long-term cycles. The sorbent flow ratios have significant effect on the CO{sub 2} capture efficiency and net efficiency of the CO{sub 2} capture system. The IGCC power plant, using the modified limestone, exhibits higher CO{sub 2} capture efficiency than that using the natural limestone at the same sorbent flow ratios. The system net efficiency using the natural and modified limestones achieves 41.7% and 43.1%, respectively, at the CO{sub 2} capture efficiency of 90% without the effect of sulfation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Tropical wetlands: A missing link in the global carbon cycle?

    Sjögersten, Sofie; Black, Colin R; Evers, Stephanie; Hoyos-Santillan, Jorge; Wright, Emma L; Turner, Benjamin L

    2014-01-01

    Tropical wetlands are not included in Earth system models, despite being an important source of methane (CH4) and contributing a large fraction of carbon dioxide (CO2) emissions from land use, land use change, and forestry in the tropics. This review identifies a remarkable lack of data on the carbon balance and gas fluxes from undisturbed tropical wetlands, which limits the ability of global change models to make accurate predictions about future climate. We show that the available data on in situ carbon gas fluxes in undisturbed forested tropical wetlands indicate marked spatial and temporal variability in CO2 and CH4 emissions, with exceptionally large fluxes in Southeast Asia and the Neotropics. By upscaling short-term measurements, we calculate that approximately 90 ± 77 Tg CH4 year−1 and 4540 ± 1480 Tg CO2 year−1 are released from tropical wetlands globally. CH4 fluxes are greater from mineral than organic soils, whereas CO2 fluxes do not differ between soil types. The high CO2 and CH4 emissions are mirrored by high rates of net primary productivity and litter decay. Net ecosystem productivity was estimated to be greater in peat-forming wetlands than on mineral soils, but the available data are insufficient to construct reliable carbon balances or estimate gas fluxes at regional scales. We conclude that there is an urgent need for systematic data on carbon dynamics in tropical wetlands to provide a robust understanding of how they differ from well-studied northern wetlands and allow incorporation of tropical wetlands into global climate change models. PMID:26074666

  20. Drought and Carbon Cycling of Grassland Ecosystems under Global Change: A Review

    Tianjie Lei

    2016-10-01

    Full Text Available In recent years, the increased intensity and duration of droughts have dramatically altered the structure and function of grassland ecosystems, which have been forced to adapt to this change in climate. Combinations of global change drivers such as elevated atmospheric CO2 concentration, warming, nitrogen (N deposition, grazing, and land-use change have influenced the impact that droughts have on grassland C cycling. This influence, to some extent, can modify the relationship between droughts and grassland carbon (C cycling in the multi-factor world. Unfortunately, prior reviews have been primarily anecdotal from the 1930s to the 2010s. We investigated the current state of the study on the interactive impacts of multiple factors under drought scenarios in grassland C cycling and provided scientific advice for dealing with droughts and managing grassland C cycling in a multi-factor world. Currently, adequate information is not available on the interaction between droughts and global change drivers, which would advance our understanding of grassland C cycling responses. It was determined that future experiments and models should specifically test how droughts regulate grassland C cycling under global changes. Previous multi-factor experiments of current and future global change conditions have studied various drought scenarios poorly, including changes in precipitation frequency and amplitude, timing, and interactions with other global change drivers. Multi-factor experiments have contributed to quantifying these potential changes and have provided important information on how water affects ecosystem processes under global change. There is an urgent need to establish a systematic framework that can assess ecosystem dynamic responses to droughts under current and future global change and human activity, with a focus on the combined effects of droughts, global change drivers, and the corresponding hierarchical responses of an ecosystem.

  1. Bacteria in the greenhouse: Modeling the role of oceanic plankton in the global carbon cycle

    Ducklow, H.W.; Fasham, M.J.R.

    1992-01-01

    To plan effectively to deal with the greenhouse effect, a fundamental understanding is needed of the biogeochemical and physical machinery that cycles carbon in the global system; in addition, models are needed of the carbon cycle to project the effects of increasing carbon dioxide. In this chapter, a description is given of efforts to simulate the cycling of carbon and nitrogen in the upper ocean, concentrating on the model's treatment of marine phytoplankton, and what it reveals of their role in the biogeochemical cycling of carbon between the ocean and atmosphere. The focus is on the upper ocean because oceanic uptake appears to regulate the level of carbon dioxide in the atmosphere

  2. Global Water Cycle Diagrams Minimize Human Influence and Over-represent Water Security

    Abbott, B. W.; Bishop, K.; Zarnetske, J. P.; Minaudo, C.; Chapin, F. S., III; Plont, S.; Marçais, J.; Ellison, D.; Roy Chowdhury, S.; Kolbe, T.; Ursache, O.; Hampton, T. B.; GU, S.; Chapin, M.; Krause, S.; Henderson, K. D.; Hannah, D. M.; Pinay, G.

    2017-12-01

    The diagram of the global water cycle is the central icon of hydrology, and for many people, the point of entry to thinking about key scientific concepts such as conservation of mass, teleconnections, and human dependence on ecological systems. Because humans now dominate critical components of the hydrosphere, improving our understanding of the global water cycle has graduated from an academic exercise to an urgent priority. To assess how the water cycle is conceptualized by researchers and the general public, we analyzed 455 water cycle diagrams from textbooks, scientific articles, and online image searches performed in different languages. Only 15% of diagrams integrated human activity into the water cycle and 77% showed no sign of humans whatsoever, although representation of humans varied substantially by region (lowest in China, N. America, and Australia; highest in Western Europe). The abundance and accessibility of freshwater resources were overrepresented, with 98% of diagrams omitting water pollution and climate change, and over 90% of diagrams making no distinction for saline groundwater and lakes. Oceanic aspects of the water cycle (i.e. ocean size, circulation, and precipitation) and related teleconnections were nearly always underrepresented. These patterns held across disciplinary boundaries and through time. We explore the historical and contemporary reasons for some of these biases and present a revised version of the global water cycle based on research from natural and social sciences. We conclude that current depictions of the global water cycle convey a false sense of water security and that reintegrating humans into water cycle diagrams is an important first step towards understanding and sustaining the hydrosocial cycle.

  3. Impacts of continental arcs on global carbon cycling and climate

    Lee, C. T.; Jiang, H.; Carter, L.; Dasgupta, R.; Cao, W.; Lackey, J. S.; Lenardic, A.; Barnes, J.; McKenzie, R.

    2017-12-01

    On myr timescales, climatic variability is tied to variations in atmospheric CO2, which in turn is driven by geologic sources of CO2 and modulated by the efficiency of chemical weathering and carbonate precipitation (sinks). Long-term variability in CO2 has largely been attributed to changes in mid-ocean ridge inputs or the efficiency of global weathering. For example, the Cretaceous greenhouse is thought to be related to enhanced oceanic crust production, while the late Cenozoic icehouse is attributed to enhanced chemical weathering associated with the Himalayan orogeny. Here, we show that continental arcs may play a more important role in controlling climate, both in terms of sources and sinks. Continental arcs differ from island arcs and mid-ocean ridges in that the continental plate through which arc magmas pass may contain large amounts of sedimentary carbonate, accumulated over the history of the continent. Interaction of arc magmas with crustal carbonates via assimilation, reaction or heating can significantly add to the mantle-sourced CO2 flux. Detrital zircons and global mapping of basement rocks shows that the length of continental arcs in the Cretaceous was more than twice that in the mid-Cenozoic; maps also show many of these arcs intersected crustal carbonates. The increased length of continental arc magmatism coincided with increased oceanic spreading rates, placing convergent margins into compression, which favors continental arcs. Around 50 Ma, however, nearly all the continental arcs in Eurasia and North America terminated as India collided with Eurasia and the western Pacific rolled back, initiating the Marianas-Tonga-Kermadec intra-oceanic subduction complex and possibly leading to a decrease in global CO2 production. Meanwhile, extinct continental arcs continued to erode, resulting in regionally enhanced chemical weathering unsupported by magmatic fluxes of CO2. Continental arcs, during their magmatic lifetimes, are thus a source of CO2, driving

  4. The changing global carbon cycle: Linking plant-soil carbon dynamics to global consequences

    Chapin, F. S.; McFarland, J.; McGuire, David A.; Euskirchen, E.S.; Ruess, Roger W.; Kielland, K.

    2009-01-01

    Most current climate-carbon cycle models that include the terrestrial carbon (C) cycle are based on a model developed 40 years ago by Woodwell & Whittaker (1968) and omit advances in biogeochemical understanding since that time. Their model treats net C emissions from ecosystems as the balance between net primary production (NPP) and heterotrophic respiration (HR, i.e. primarily decomposition).

  5. The effect of calcium and vitamin D supplementation on menstrual cycle, body mass index and hyperandrogenism state of women with poly cystic ovarian syndrome

    Hatav Ghasemi Tehrani

    2014-01-01

    Full Text Available Background: Poly cystic ovary syndrome (PCOS is considered one of the most common endocrine disorders of women in reproductive age. The aim of this study was evaluating the efficacy of calcium and Vitamin D supplementation on the regularity of menstrual cycles, body mass index (BMI and hyper androgenism state of women with PCOS. Materials and Methods: In this clinical trial, 80 women with PCOS were evaluated. They randomly located in four groups receiving metformin (group 1, metformin plus calcium and Vitamin D (group 2, calcium and Vitamin D (group 3 and placebo (group 4 for 4 months. BMI, regularity of menstrual cycles, hyperandrogenism (hirsutism and acne and serum calcium and Vitamin D levels were compared in four studying groups at baseline and 4 months after the trial. Results: All studied subjects were similar at baseline (P > 0.05. After trial, the frequency of hirsutism and acne were not different among groups. Frequency regular menstrual cycle and dominant follicle were significantly higher in group 1 and 2 than others (P < 0.05. After trial, there was no significant difference with respect to BMI among groups. Conclusion: Vitamin D and calcium supplementation in addition to metformin therapy in women with PCOS could result in a better outcome in a variety of PCOS symptoms including menstrual regularity, and ovulation.

  6. A simple global carbon and energy coupled cycle model for global warming simulation: sensitivity to the light saturation effect

    Ichii, Kazuhito; Murakami, Kazutaka; Mukai, Toshikazu; Yamaguchi, Yasushi; Ogawa, Katsuro

    2003-01-01

    A simple Earth system model, the Four-Spheres Cycle of Energy and Mass (4-SCEM) model, has been developed to simulate global warming due to anthropogenic CO 2 emission. The model consists of the Atmosphere-Earth Heat Cycle (AEHC) model, the Four Spheres Carbon Cycle (4-SCC) model, and their feedback processes. The AEHC model is a one-dimensional radiative convective model, which includes the greenhouse effect of CO 2 and H 2 O, and one cloud layer. The 4-SCC model is a box-type carbon cycle model, which includes biospheric CO 2 fertilization, vegetation area variation, the vegetation light saturation effect and the HILDA oceanic carbon cycle model. The feedback processes between carbon cycle and climate considered in the model are temperature dependencies of water vapor content, soil decomposition and ocean surface chemistry. The future status of the global carbon cycle and climate was simulated up to the year 2100 based on the 'business as usual' (IS92a) emission scenario, followed by a linear decline in emissions to zero in the year 2200. The atmospheric CO 2 concentration reaches 645 ppmv in 2100 and a peak of 760 ppmv approximately in the year 2170, and becomes a steady state with 600 ppmv. The projected CO 2 concentration was lower than those of the past carbon cycle studies, because we included the light saturation effect of vegetation. The sensitivity analysis showed that uncertainties derived from the light saturation effect of vegetation and land use CO 2 emissions were the primary cause of uncertainties in projecting future CO 2 concentrations. The climate feedback effects showed rather small sensitivities compared with the impacts of those two effects. Satellite-based net primary production trends analyses can somewhat decrease the uncertainty in quantifying CO 2 emissions due to land use changes. On the other hand, as the estimated parameter in vegetation light saturation was poorly constrained, we have to quantify and constrain the effect more

  7. Integrating Natural Gas Hydrates in the Global Carbon Cycle

    David Archer; Bruce Buffett

    2011-12-31

    We produced a two-dimensional geological time- and basin-scale model of the sedimentary margin in passive and active settings, for the simulation of the deep sedimentary methane cycle including hydrate formation. Simulation of geochemical data required development of parameterizations for bubble transport in the sediment column, and for the impact of the heterogeneity in the sediment pore fluid flow field, which represent new directions in modeling methane hydrates. The model is somewhat less sensitive to changes in ocean temperature than our previous 1-D model, due to the different methane transport mechanisms in the two codes (pore fluid flow vs. bubble migration). The model is very sensitive to reasonable changes in organic carbon deposition through geologic time, and to details of how the bubbles migrate, in particular how efficiently they are trapped as they rise through undersaturated or oxidizing chemical conditions and the hydrate stability zone. The active margin configuration reproduces the elevated hydrate saturations observed in accretionary wedges such as the Cascadia Margin, but predicts a decrease in the methane inventory per meter of coastline relative to a comparable passive margin case, and a decrease in the hydrate inventory with an increase in the plate subduction rate.

  8. Advances In Understanding Global Water Cycle With Advent of GPM Mission

    Smith, Eric A.

    2002-01-01

    During the coming decade, the internationally organized Global Precipitation Measurement (GPM) Mission will take an important step in creating a global precipitation observing system from space based on an international fleet of satellites operated as a constellation. One perspective for understanding the nature of GPM is that it will be a hierarchical system of datastreams beginning with very high caliber combined dual frequency radar/passive microwave (PMW) rain-radiometer retrievals, to high caliber PMW rain-radiometer only retrievals, and then on to blends of the former datastreams with additional lower-caliber PMW-based and IR-based rain retrievals. Within the context of the now emerging global water & energy cycle (GWEC) programs of a number of research agencies throughout the world, GPM serves as a centerpiece space mission for improving our understanding of the Earth's water cycle from a global measurement perspective and on down to regional scales and below. One of the salient problems within our current understanding of the global water and energy cycle is determining whether a change in the rate of the water cycle is accompanying changes in climate, e.g., climate warming. As there are a number of ways in which to define a rate-change of the global water cycle, it is not entirely clear as to what constitutes such a determination. This paper first presents an overview of the GPM Mission and how its overriding scientific objectives for climate, weather, and hydrology flow from the anticipated improvements that are being planned for the constellation-based measuring system. Next, the paper shows how the GPM observations can be used within the framework of the oceanic and continental water budget equations to determine whether a given perturbation in precipitation is indicative of an actual rate change in the water cycle, consistent with required responses in water storage and/or water flux transport processes, or whether it is simply part of the natural

  9. Global carbon monoxide cycle: Modeling and data analysis

    Arellano, Avelino F., Jr.

    The overarching goal of this dissertation is to develop robust, spatially and temporally resolved CO sources, using global chemical transport modeling, CO measurements from Climate Monitoring and Diagnostic Laboratory (CMDL) and Measurement of Pollution In The Troposphere (MOPITT), under the framework of Bayesian synthesis inversion. To rigorously quantify the CO sources, I conducted five sets of inverse analyses, with each set investigating specific methodological and scientific issues. The first two inverse analyses separately explored two different CO observations to estimate CO sources by region and sector. Under a range of scenarios relating to inverse methodology and data quality issues, top-down estimates using CMDL CO surface and MOPITT CO remote-sensed measurements show consistent results particularly on a significantly large fossil fuel/biofuel (FFBF) emission in East Asia than present bottom-up estimates. The robustness of this estimate is strongly supported by forward and inverse modeling studies in the region particularly from TRansport and Chemical Evolution over the Pacific (TRACE-P) campaign. The use of high-resolution measurement for the first time in CO inversion also draws attention to a methodology issue that the range of estimates from the scenarios is larger than posterior uncertainties, suggesting that estimate uncertainties may be underestimated. My analyses highlight the utility of top-down approach to provide additional constraints on present global estimates by also pointing to other discrepancies including apparent underestimation of FFBF from Africa/Latin America and biomass burning (BIOM) sources in Africa, southeast Asia and north-Latin America, indicating inconsistencies on our current understanding of fuel use and land-use patterns in these regions. Inverse analysis using MOPITT is extended to determine the extent of MOPITT information and estimate monthly regional CO sources. A major finding, which is consistent with other

  10. Can we Observe and Assess Whether the Global Hydrological Cycle is "Intensifying"?

    Wood, E. F.; Sheffield, J.

    2012-12-01

    There is controversy over whether the hydrological cycle is "intensifying" (or "accelerating"), and if so how and where? Resolving this critical question is a central goal of both national (e.g. NASA's Energy and Water cycle Study: NEWS) and international (WCRP Global Energy and Water cycle Experiment: GEWEX) programs. Its resolution has significant implications for understanding changes in hydroclimatic states and variability, and in future water security at regional to global scales. Over the last decade a number of papers have addressed trends and change in specific water cycle variables with results that can best be described as inconclusive, regardless of the conclusions of specific papers. In this presentation a number of recent studies will be reviewed for their consistency in assessing whether collectively one can make conclusions regarding how the hydrologic cycle is changing. The presentation will also demonstrate a pathway for analyzing where to observe for the detection of change based on a NASA-supported, global, 1983-2009, terrestrial water cycle Earth System Data Record project being led by the author. Initial results will be presented and a discussion presented on the extent that the proposed strategy can be used to detect change in the terrestrial hydrological cycle.

  11. Different sorbents in calcium looping cycle for CO{sub 2} capture

    Luo, Cong; Zheng, Ying; Ding, Ning [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

    2013-07-01

    Cyclic CO{sub 2} capture using commercial pure micro CaCO{sub 3} and nano CaCO{sub 3} is investigated in this paper which focuses on the different characteristics two different sorbents during high temperature reactions. The results indicate that the nano CaCO{sub 3} sorbent has higher carbonation conversions and carbonation rates than the micro CaCO{sub 3} sorbent in the cyclic reactions. Furthermore, nano sorbent can retain its fast carbonation rates at the beginning dozens of seconds during each cycle. In contrast, the carbonation rates of micro sorbent diminish with the increase of cycle number. But, unfortunately, CaO derived from nano CaCO3 sorbent sinter much easily. Its grains, which are composed of numerous spherical nanocrystallites, experience dramatic morphological changes during high temperature reactions.

  12. Formulating Energy Policies Related to Fossil Fuel Use: Critical Uncertainties in the Global Carbon Cycle

    Post, W. M.; Dale, V. H.; DeAngelis, D. L.; Mann, L. K.; Mulholland, P. J.; O`Neill, R. V.; Peng, T. -H.; Farrell, M. P.

    1990-02-01

    The global carbon cycle is the dynamic interaction among the earth's carbon sources and sinks. Four reservoirs can be identified, including the atmosphere, terrestrial biosphere, oceans, and sediments. Atmospheric CO{sub 2} concentration is determined by characteristics of carbon fluxes among major reservoirs of the global carbon cycle. The objective of this paper is to document the knowns, and unknowns and uncertainties associated with key questions that if answered will increase the understanding of the portion of past, present, and future atmospheric CO{sub 2} attributable to fossil fuel burning. Documented atmospheric increases in CO{sub 2} levels are thought to result primarily from fossil fuel use and, perhaps, deforestation. However, the observed atmospheric CO{sub 2} increase is less than expected from current understanding of the global carbon cycle because of poorly understood interactions among the major carbon reservoirs.

  13. The global nitrogen cycle in the twenty-first century.

    Fowler, David; Coyle, Mhairi; Skiba, Ute; Sutton, Mark A; Cape, J Neil; Reis, Stefan; Sheppard, Lucy J; Jenkins, Alan; Grizzetti, Bruna; Galloway, James N; Vitousek, Peter; Leach, Allison; Bouwman, Alexander F; Butterbach-Bahl, Klaus; Dentener, Frank; Stevenson, David; Amann, Marcus; Voss, Maren

    2013-07-05

    Global nitrogen fixation contributes 413 Tg of reactive nitrogen (Nr) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic Nr are on land (240 Tg N yr(-1)) within soils and vegetation where reduced Nr contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer Nr contribute to nitrate (NO3(-)) in drainage waters from agricultural land and emissions of trace Nr compounds to the atmosphere. Emissions, mainly of ammonia (NH3) from land together with combustion related emissions of nitrogen oxides (NOx), contribute 100 Tg N yr(-1) to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH4NO3) and ammonium sulfate (NH4)2SO4. Leaching and riverine transport of NO3 contribute 40-70 Tg N yr(-1) to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr(-1)) to double the ocean processing of Nr. Some of the marine Nr is buried in sediments, the remainder being denitrified back to the atmosphere as N2 or N2O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of Nr in the atmosphere, with the exception of N2O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 10(2)-10(3) years), the lifetime is a few decades. In the ocean, the lifetime of Nr is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N2O that will respond very slowly to control measures on the sources of Nr from which it is produced.

  14. World's first ejector cycle for mobile refrigerators to stop global warming

    Takeuchi, Hirotsugu [Denso Corporation, Kariya (Japan); Gyoeroeg, Tibor [DENSO AUTOMOTIVE Deutschland GmbH, Eching (Germany)

    2010-07-01

    The development of energy-saving technologies is in great demand recently to stop global warming. We are committed to developing the Ejector Cycle as an energy-saving technology for refrigerators and air conditioners. The ejector, which is an energy-saving technological innovation, improves the efficiency of the refrigeration cycle by effectively using the expansion energy that is lost in the conventional vapor-compression cycle, and is applicable to almost all vapor-compression refrigerating air conditioners, thus improving the efficiency of the refrigeration cycle. Concerning the application of the Ejector Cycle in truck-transport refrigerators, we released Ejector Cycle products for large and medium-size freezer trucks, which have been favorably accepted by customers in 2003. Simultaneously we also developed the domestic water supply system using heat pump with natural refrigerant (CO{sub 2}). We developed a new Ejector Cycle, completed in 2007 a cool box which uses the refrigeration cycle of the mobile air-conditioning system to cool drinks and the commercial compact refrigerator. In 2008 a domestic water supply heat pump system using a heat pump with the natural refrigerant CO{sub 2} and the next-generation Ejector Cycle II that substantially improves performance was brought to the market. A new generation of Ejector Cycle is under development which will significantly improve the efficiency of mobile air conditioning systems (orig.)

  15. Feedback of global warming to soil carbon cycling in forest ecosystems

    Nakane, Kaneyuki

    1993-01-01

    Thus in this study the simulation of soil carbon cycling and dynamics of its storage in several types of mature forests developed from the cool-temperate to the tropics was carried out for quantitatively assessing carbon loss from the soil under several scenarios of global warming, based on the model of soil carbon cycling in forest ecosystems (Nakane et al. 1984, 1987 and Nakane 1992). (J.P.N.)

  16. Global cycle changes the rules for U.S. pulp and paper

    Peter J. Ince

    1999-01-01

    As in other industries, the fortunes of the U.S. pulp and paper industry are now closely tied to the global economy. The U.S. pulp and paper sector exhibits fairly steady production and growth trends, but its economic fortunes have become intertwined with the bglobal cyclec of supply and demand. Exposure to the global cycle has increased for the U.S. in recent decades...

  17. Should we expect financial globalization to have significant effects on business cycles?

    Iversen, Jens

    2009-01-01

    Empirical research suggests that financial globalization has insignificant effects on business cycles. Based on standard theoretical models it might be conjectured that the effects should be significant. I show that this conjecture is wrong. Theoretical effects of financial globalization can be determined to any level of precision by expanding the underlying artificial samples. In contrast, in the data the effects are imprecisely estimated because of short samples. I show that if the conclusi...

  18. Non-Linear Nitrogen Cycling and Ecosystem Calcium Depletion Along a Temperate Forest Soil Nitrogen Gradient

    Sinkhorn, E. R.; Perakis, S. S.; Compton, J. E.; Cromack, K.; Bullen, T. D.

    2007-12-01

    Understanding how N availability influences base cation stores is critical for assessing long-term ecosystem sustainability. Indices of nitrogen (N) availability and the distribution of nutrients in plant biomass, soil, and soil water were examined across ten Douglas-fir (Pseudotsuga menziesii) stands spanning a three-fold soil N gradient (0-10 cm: 0.21 - 0.69% N, 0-100 cm: 9.2 - 28.8 Mg N ha-1) in the Oregon Coast Range. This gradient is largely the consequence of historical inputs from N2-fixing red alder stands that can add 100-200 kg N ha-1 yr-1 to the ecosystem for decades. Annual net N mineralization and litterfall N return displayed non-linear relationships with soil N, increasing initially, and then decreasing as N-richness increased. In contrast, nitrate leaching from deep soils increased linearly across the soil N gradient and ranged from 0.074 to 30 kg N ha-1 yr-1. Soil exchangeable Ca, Mg, and K pools to 1 m depth were negatively related to nitrate losses across sites. Ca was the only base cation exhibiting concentration decreases in both plant and soil pools across the soil N gradient, and a greater proportion of total available ecosystem Ca was sequestered in aboveground plant biomass at high N, low Ca sites. Our work supports a hierarchical model of coupled N-Ca cycles across gradients of soil N enrichment, with microbial production of mobile nitrate anions leading to depletion of readily available Ca at the ecosystem scale, and plant sequestration promoting Ca conservation as Ca supply diminishes. The preferential storage of Ca in aboveground biomass at high N and low Ca sites, while critical for sustaining plant productivity, may also predispose forests to Ca depletion in areas managed for intensive biomass removal. Long-term N enrichment of temperate forest soils appears capable of sustaining an open N cycle and key symptoms of N-saturation for multiple decades after the cessation of elevated N inputs.

  19. The global warming potential of building materials : An application of life cycle analysis in Nepal

    Bhochhibhoya, Silu; Zanetti, Michela; Pierobon, Francesca; Gatto, Paola; Maskey, Ramesh Kumar; Cavalli, Raffaele

    2017-01-01

    This paper analyzes the global-warming potential of materials used to construct the walls of 3 building types - traditional, semimodern, and modern - in Sagarmatha National Park and Buffer Zone in Nepal, using the life-cycle assessment approach. Traditional buildings use local materials, mainly wood

  20. Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles

    Le Quéré, Corinne; Buitenhuis, Erik T.; Moriarty, Róisín

    2016-01-01

    zooplankton community, despite iron limitation of phytoplankton community growth rates. This result has implications for the representation of global biogeochemical cycles in models as zooplankton faecal pellets sink rapidly and partly control the carbon export to the intermediate and deep ocean....

  1. Consequences of the cultivation of energy crops for the global nitrogen cycle

    Bouwman, A.F.; Grinsven, van J.J.M.; Eickhout, B.

    2010-01-01

    In this paper, we assess the global consequences of implementing first- and second-generation bioenergy in the coming five decades, focusing on the nitrogen cycle. We Use a climate mitigation scenario from the Organization for Economic Cooperation and Development's (OECD) Environmental Outlook, in

  2. Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget

    Cole, J.; Prairie, Y.T.; Caraco, N.; McDowell, W.H.; Tranvil, L.; Striegl, R.G.; Duarte, C.M.; Kortelainen, P.; Downing, J.A.; Middelburg, J.J.; Melack, J.

    2007-01-01

    Because freshwater covers such a small fraction of the Earth’s surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking

  3. Solar cycle length hypothesis appears to support the IPCC on global warming

    Laut, Peter; Gundermann, Jesper

    1999-01-01

    warming from the enhanced concentrations of greenhouse gases. The "solar hypothesis" claims that solar activity causes a significant component of the global mean temperature to vary in phase opposite to the filtered solar cycle lengths. In an earlier paper we have demonstrated that for data covering...... lengths with the "corrected" temperature anomalies is substantially better than with the historical anomalies. Therefore our findings support a total reversal of the common assumption that a verification of the solar hypothesis would challenge the IPCC assessment of man-made global warming.......Since the discovery of a striking correlation between 1-2-2-2-1 filtered solar cycle lengths and the 11-year running average of Northern Hemisphere land air temperatures there have been widespread speculations as to whether these findings would rule out any significant contributions to global...

  4. Proceedings of GLOBAL 2007 conference on advanced nuclear fuel cycles and systems

    2007-01-01

    In keeping with the 12-year history of this conference, GLOBAL 2007 focuses on future nuclear energy systems and fuel cycles. With the increasing public acceptance and political endorsement of nuclear energy, it is a pivotal time for nuclear energy research. Significant advances have been made in development of advanced nuclear fuels and materials, reactor designs, partitioning, transmutation and reprocessing technologies, and waste management strategies. In concert with the technological advances, it is more important than ever to develop sensible nuclear proliferation policies, to promote sustainability, and to continue to increase international collaboration. To further these aims, GLOBAL 2007 highlights recent developments in the following areas: advanced integrated fuel cycle concepts, spent nuclear fuel reprocessing, advanced reprocessing technology, advanced fuels and materials, advanced waste management technology, novel concepts for waste disposal and repository development, advanced reactors, partitioning and transmutation, developments in nuclear non-proliferation technology, policy, and implementation, sustainability and expanded global utilization of nuclear energy, and international collaboration on nuclear energy

  5. Calcium waves.

    Jaffe, Lionel F

    2008-04-12

    Waves through living systems are best characterized by their speeds at 20 degrees C. These speeds vary from those of calcium action potentials to those of ultraslow ones which move at 1-10 and/or 10-20 nm s(-1). All such waves are known or inferred to be calcium waves. The two classes of calcium waves which include ones with important morphogenetic effects are slow waves that move at 0.2-2 microm s(-1) and ultraslow ones. Both may be propagated by cycles in which the entry of calcium through the plasma membrane induces subsurface contraction. This contraction opens nearby stretch-sensitive calcium channels. Calcium entry through these channels propagates the calcium wave. Many slow waves are seen as waves of indentation. Some are considered to act via cellular peristalsis; for example, those which seem to drive the germ plasm to the vegetal pole of the Xenopus egg. Other good examples of morphogenetic slow waves are ones through fertilizing maize eggs, through developing barnacle eggs and through axolotl embryos during neural induction. Good examples of ultraslow morphogenetic waves are ones during inversion in developing Volvox embryos and across developing Drosophila eye discs. Morphogenetic waves may be best pursued by imaging their calcium with aequorins.

  6. A Global Rapid Integrated Monitoring System for Water Cycle and Water Resource Assessment (Global-RIMS)

    Roads, John; Voeroesmarty, Charles

    2005-01-01

    The main focus of our work was to solidify underlying data sets, the data processing tools and the modeling environment needed to perform a series of long-term global and regional hydrological simulations leading eventually to routine hydrometeorological predictions. A water and energy budget synthesis was developed for the Mississippi River Basin (Roads et al. 2003), in order to understand better what kinds of errors exist in current hydrometeorological data sets. This study is now being extended globally with a larger number of observations and model based data sets under the new NASA NEWS program. A global comparison of a number of precipitation data sets was subsequently carried out (Fekete et al. 2004) in which it was further shown that reanalysis precipitation has substantial problems, which subsequently led us to the development of a precipitation assimilation effort (Nunes and Roads 2005). We believe that with current levels of model skill in predicting precipitation that precipitation assimilation is necessary to get the appropriate land surface forcing.

  7. Hydrodynamical model and experimental results of a calcium looping cycle for CO2 capture

    Lisbona, Pilar; Martínez, Ana; Romeo, Luis M.

    2013-01-01

    Highlights: ► A scaled experimental cold flow model of a dual fluidized bed facility is presented. ► Two MATLAB models are developed for the single CFB and the dual CFB facility. ► Set of experiments are carried out and used to validate the mathematical model. ► Good agreement between model and experimental tests for sCFB. ► Further work required for validating dual CFB operation. -- Abstract: High temperature looping cycles involving solid circulation, such as carbonation–calcination, play an essential role among the CO 2 capture technologies under development. The low cost and high availability of Ca-based sorbents together with the feasibility of integration between these capture systems and existing power plants lead to very competitive potential costs of avoided CO 2 , below 20 €/tonne. Optimal configurations make use of several interconnected fluidized beds. One promising configuration for Ca-based sorbents looping systems relies on the use of two circulating beds (carbonator and calciner) and two bubbling beds acting as non-mechanical valves. Fluidized beds are well characterized when operating independently since they are extensively used in industrial applications, power and chemical plants. However, the operation when two or more fluidized beds exchange solid material through non-mechanical valves is still uncertain because of the more complex pressure balance of the system. Theoretical studies based on thermo-chemical simulations and experimental studies show that minimum CO 2 capture cost is attained with large solid circulation flow between reactors. The challenge is to reach the required particle circulation in a system with a complex configuration and be able to control it. Solid internal recirculation in any of these fluidized beds would provide flexibility in its control but it will also make harder the characterization of the whole system. The aim of this work is to analyse the hydrodynamics of the system and to generate a

  8. NASA Contributions to Improve Understanding of Extreme Events in the Global Energy and Water Cycle

    Lapenta, William M.

    2008-01-01

    The U.S. Climate Change Science Program (CCSP) has established the water cycle goals of the Nation's climate change program. Accomplishing these goals will require, in part, an accurate accounting of the key reservoirs and fluxes associated with the global water and energy cycle, including their spatial and temporal variability. through integration of all necessary observations and research tools, To this end, in conjunction with NASA's Earth science research strategy, the overarching long-term NASA Energy and Water Cycle Study (NEWS) grand challenge can he summarized as documenting and enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. This challenge requires documenting and predicting trends in the rate of the Earth's water and energy cycling that corresponds to climate change and changes in the frequency and intensity of naturally occurring related meteorological and hydrologic events, which may vary as climate may vary in the future. The cycling of water and energy has obvious and significant implications for the health and prosperity of our society. The importance of documenting and predicting water and energy cycle variations and extremes is necessary to accomplish this benefit to society.

  9. Global water cycle amplifying at less than the Clausius-Clapeyron rate

    Skliris, Nikolaos; Zika, Jan D.; Nurser, George; Josey, Simon A.; Marsh, Robert

    2016-01-01

    A change in the cycle of water from dry to wet regions of the globe would have far reaching impact on humanity. As air warms, its capacity to hold water increases at the Clausius-Clapeyron rate (CC, approximately 7%?°C?1). Surface ocean salinity observations have suggested the water cycle has amplified at close to CC following recent global warming, a result that was found to be at odds with state-of the art climate models. Here we employ a method based on water mass transformation theory for...

  10. Salinity Remote Sensing and the Study of the Global Water Cycle

    Lagerloef, G. S. E.; LeVine, David M.; Chao, Y.; Colomb, F. Raul; Font, J.

    2007-01-01

    The SMOS and AquariusISAC-D satellite missions will begin a new era to map the global sea surface salinity (SSS) field and its variability from space within the next twothree years. They will provide critical data needed to study the interactions between the ocean circulation, global water cycle and climate. Key scientific issues to address are (1) mapping large expanses of the ocean where conventional SSS data do not yet exist, (2) understanding the seasonal and interannual SSS variations and the link to precipitation, evaporation and sea-ice patterns, (3) links between SSS and variations in the oceanic overturning circulation, (4) air-sea coupling processes in the tropics that influence El Nino, and (4) closing the marine freshwater budget. There is a growing body of oceanographic evidence in the form of salinity trends that portend significant changes in the hydrologic cycle. Over the past several decades, highlatitude oceans have become fresher while the subtropical oceans have become saltier. This change is slowly spreading into the subsurface ocean layers and may be affecting the strength of the ocean's therrnohaline overturning circulation. Salinity is directly linked to the ocean dynamics through the density distribution, and provides an important signature of the global water cycle. The distribution and variation of oceanic salinity is therefore attracting increasing scientific attention due to the relationship to the global water cycle and its influence on circulation, mixing, and climate processes. The oceans dominate the water cycle by providing 86% of global surface evaporation (E) and receiving 78% of global precipitation (P). Regional differences in E-P, land runoff, and the melting or freezing of ice affect the salinity of surface water. Direct observations of E-P over the ocean have large uncertainty, with discrepancies between the various state-of-the-art precipitation analyses of a factor of two or more in many regions. Quantifying the climatic

  11. Albedo enhancement of marine clouds to counteract global warming: impacts on the hydrological cycle

    Bala, G. [Indian Institute of Science, Divecha Center for Climate Change, Bangalore (India); Indian Institute of Science, Center for Atmospheric and Oceanic Sciences, Bangalore (India); Caldeira, Ken; Cao, Long; Ban-Weiss, George; Shin, Ho-Jeong [Carnegie Institution, Department of Global Ecology, Stanford, CA (United States); Nemani, Rama [NASA Ames Research Center, Moffett Field, CA (United States)

    2011-09-15

    Recent studies have shown that changes in solar radiation affect the hydrological cycle more strongly than equivalent CO{sub 2} changes for the same change in global mean surface temperature. Thus, solar radiation management ''geoengineering'' proposals to completely offset global mean temperature increases by reducing the amount of absorbed sunlight might be expected to slow the global water cycle and reduce runoff over land. However, proposed countering of global warming by increasing the albedo of marine clouds would reduce surface solar radiation only over the oceans. Here, for an idealized scenario, we analyze the response of temperature and the hydrological cycle to increased reflection by clouds over the ocean using an atmospheric general circulation model coupled to a mixed layer ocean model. When cloud droplets are reduced in size over all oceans uniformly to offset the temperature increase from a doubling of atmospheric CO{sub 2}, the global-mean precipitation and evaporation decreases by about 1.3% but runoff over land increases by 7.5% primarily due to increases over tropical land. In the model, more reflective marine clouds cool the atmospheric column over ocean. The result is a sinking motion over oceans and upward motion over land. We attribute the increased runoff over land to this increased upward motion over land when marine clouds are made more reflective. Our results suggest that, in contrast to other proposals to increase planetary albedo, offsetting mean global warming by reducing marine cloud droplet size does not necessarily lead to a drying, on average, of the continents. However, we note that the changes in precipitation, evaporation and P-E are dominated by small but significant areas, and given the highly idealized nature of this study, a more thorough and broader assessment would be required for proposals of altering marine cloud properties on a large scale. (orig.)

  12. In vivo and in vitro cadmium accumulation during the moult cycle of the male shore crab Carcinus maenas-interaction with calcium metabolism

    Norum, Ulrik [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)]. E-mail: ulrik@biology.sdu.dk; Bondgaard, Morten [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Pedersen, Thomas V. [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Bjerregaard, Poul [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2005-03-25

    The effect of moult stage on cadmium accumulation and distribution was investigated in vivo in male shore crabs Carcinus maenas exposed to 1 mg Cd l{sup -1} for 7 days. The accumulation of cadmium in all tissues examined was markedly higher in postmoult (A{sub 1-2} and B{sub 1-2}) compared to intermoult (C{sub 1}, C{sub 3} and C{sub 4}) and premoult (D{sub 0-3}). In addition, elevated levels of cadmium were found in gills of late premoult (D{sub 2-3}) animals. The total amount of cadmium accumulated in the tissues (haemolymph, gills, midgut gland and muscle) increased from 43 {mu}g Cd in early premoult (D{sub 0-1}) to 391 {mu}g Cd in late postmoult (B{sub 1-2}). Gills and midgut gland were the primary cadmium accumulating tissues in C{sub 4}-intermoult and premoult (D{sub 0-3}); in early postmoult (A{sub 1-2}) haemolymph and midgut gland were the main cadmium containing tissues, while midgut gland dominated in late postmoult (B{sub 1-2}) and early intermoult (C{sub 1} and C{sub 3}). A detailed account of calcium distribution in haemolymph, gills, midgut gland, muscle and exoskeleton during the moult cycle is presented. Mechanistic links between cadmium and calcium uptake in posterior gills of C{sub 4}-intermoult and early postmoult (A{sub 1-2}) crabs were explored using an in vitro gill perfusion technique. Calcium and cadmium influxes were markedly higher in postmoult compared to intermoult. No differences between intermoult and postmoult effluxes were found for either calcium or cadmium. From intermoult to postmoult net influx increased from 2.4 to 29 {mu}mol Ca{sup 2+} g{sup -1} ww{sub gill} h{sup -1} and from 0.24 to 25 nmol Cd{sup 2+} g{sup -1} ww{sub gill} h{sup -1}. The results indicate that the postmoult increase in cadmium influx is due to increased active transport of cadmium, at least partly, by accidental uptake via calcium transporting proteins. The in vitro net influx rates corresponded accurately to the observed in vivo accumulation of both cadmium

  13. In vivo and in vitro cadmium accumulation during the moult cycle of the male shore crab Carcinus maenas-interaction with calcium metabolism

    Norum, Ulrik; Bondgaard, Morten; Pedersen, Thomas V.; Bjerregaard, Poul

    2005-01-01

    The effect of moult stage on cadmium accumulation and distribution was investigated in vivo in male shore crabs Carcinus maenas exposed to 1 mg Cd l -1 for 7 days. The accumulation of cadmium in all tissues examined was markedly higher in postmoult (A 1-2 and B 1-2 ) compared to intermoult (C 1 , C 3 and C 4 ) and premoult (D 0-3 ). In addition, elevated levels of cadmium were found in gills of late premoult (D 2-3 ) animals. The total amount of cadmium accumulated in the tissues (haemolymph, gills, midgut gland and muscle) increased from 43 μg Cd in early premoult (D 0-1 ) to 391 μg Cd in late postmoult (B 1-2 ). Gills and midgut gland were the primary cadmium accumulating tissues in C 4 -intermoult and premoult (D 0-3 ); in early postmoult (A 1-2 ) haemolymph and midgut gland were the main cadmium containing tissues, while midgut gland dominated in late postmoult (B 1-2 ) and early intermoult (C 1 and C 3 ). A detailed account of calcium distribution in haemolymph, gills, midgut gland, muscle and exoskeleton during the moult cycle is presented. Mechanistic links between cadmium and calcium uptake in posterior gills of C 4 -intermoult and early postmoult (A 1-2 ) crabs were explored using an in vitro gill perfusion technique. Calcium and cadmium influxes were markedly higher in postmoult compared to intermoult. No differences between intermoult and postmoult effluxes were found for either calcium or cadmium. From intermoult to postmoult net influx increased from 2.4 to 29 μmol Ca 2+ g -1 ww gill h -1 and from 0.24 to 25 nmol Cd 2+ g -1 ww gill h -1 . The results indicate that the postmoult increase in cadmium influx is due to increased active transport of cadmium, at least partly, by accidental uptake via calcium transporting proteins. The in vitro net influx rates corresponded accurately to the observed in vivo accumulation of both cadmium and calcium. Although cadmium accumulation and distribution are clearly linked to changes in calcium requirements, cadmium

  14. Refined global methyl halide budgets with respect to rapeseed (Brassica napus) by life-cycle measurements

    Jiao, Y.; Acdan, J.; Xu, R.; Deventer, M. J.; Rhew, R. C.

    2017-12-01

    A precise quantification of global methyl halide budgets is needed to evaluate the ozone depletion potential of these compounds and to predict future changes of stratospheric ozone. However, the global budgets of methyl halides are not balanced between currently identified and quantified sources and sinks. Our study re-evaluated the methyl bromide budget from global cultivated rapeseed (Brassica napus) through life-cycle flux measurements both in the greenhouse and in the field, yielding a methyl bromide emission rate that scales globally to 1.0 - 1.2 Gg yr-1. While this indicates a globally significant source, it is much smaller than the previously widely cited value of 5 - 6 Gg yr-1(Mead et al., 2008), even taking into account the near tripling of annual global yield of rapeseed since the previous evaluation was conducted. Our study also evaluated the methyl chloride and methyl iodide emission levels from rapeseed, yielding emission rates that scale to 5.4 Gg yr-1 for methyl chloride and 1.8 Gg yr-1 of methyl iodide. The concentrations of the methyl donor SAM (S-adenosyl methionine) and the resultant product SAH (S-Adenosyl-L-homocysteine) were also analyzed to explore their role in biogenic methyl halide formation. Halide gradient incubations showed that the magnitude of methyl halide emissions from rapeseed is highly correlated to soil halide levels, thus raising the concern that the heterogeneity of soil halide contents geographically should be considered when extrapolating to global budget.

  15. Global Water Cycle Agreement in the Climate Models Assessed in the IPCC AR4

    Waliser, D.; Seo, K. -W.; Schubert, S.; Njoku, E.

    2007-01-01

    This study examines the fidelity of the global water cycle in the climate model simulations assessed in the IPCC Fourth Assessment Report. The results demonstrate good model agreement in quantities that have had a robust global observational basis and that are physically unambiguous. The worst agreement occurs for quantities that have both poor observational constraints and whose model representations can be physically ambiguous. In addition, components involving water vapor (frozen water) typically exhibit the best (worst) agreement, and fluxes typically exhibit better agreement than reservoirs. These results are discussed in relation to the importance of obtaining accurate model representation of the water cycle and its role in climate change. Recommendations are also given for facilitating the needed model improvements.

  16. Earth Without Life: A Systems Model of a Global Abiotic Nitrogen Cycle.

    Laneuville, Matthieu; Kameya, Masafumi; Cleaves, H James

    2018-03-20

    Nitrogen is the major component of Earth's atmosphere and plays important roles in biochemistry. Biological systems have evolved a variety of mechanisms for fixing and recycling environmental nitrogen sources, which links them tightly with terrestrial nitrogen reservoirs. However, prior to the emergence of biology, all nitrogen cycling was abiological, and this cycling may have set the stage for the origin of life. It is of interest to understand how nitrogen cycling would proceed on terrestrial planets with comparable geodynamic activity to Earth, but on which life does not arise. We constructed a kinetic mass-flux model of nitrogen cycling in its various major chemical forms (e.g., N 2 , reduced (NH x ) and oxidized (NO x ) species) between major planetary reservoirs (the atmosphere, oceans, crust, and mantle) and included inputs from space. The total amount of nitrogen species that can be accommodated in each reservoir, and the ways in which fluxes and reservoir sizes may have changed over time in the absence of biology, are explored. Given a partition of volcanism between arc and hotspot types similar to the modern ones, our global nitrogen cycling model predicts a significant increase in oceanic nitrogen content over time, mostly as NH x , while atmospheric N 2 content could be lower than today. The transport timescales between reservoirs are fast compared to the evolution of the environment; thus atmospheric composition is tightly linked to surface and interior processes. Key Words: Nitrogen cycle-Abiotic-Planetology-Astrobiology. Astrobiology 18, xxx-xxx.

  17. On the linkages between the global carbon-nitrogen-phosphorus cycles

    Tanaka, Katsumasa; Mackenzie, Fred; Bouchez, Julien; Knutti, Reto

    2013-04-01

    State-of-the-art earth system models used for long-term climate projections are becoming ever more complex in terms of not only spatial resolution but also the number of processes. Biogeochemical processes are beginning to be incorporated into these models. The motivation of this study is to quantify how climate projections are influenced by biogeochemical feedbacks. In the climate modeling community, it is virtually accepted that climate-Carbon (C) cycle feedbacks accelerate the future warming (Cox et al. 2000; Friedlingstein et al. 2006). It has been demonstrated that the Nitrogen (N) cycle suppresses climate-C cycle feedbacks (Thornton et al. 2009). On the contrary, biogeochemical studies show that the coupled C-N-Phosphorus (P) cycles are intimately interlinked via biosphere and the N-P cycles amplify C cycle feedbacks (Ver et al. 1999). The question as to whether the N-P cycles enhance or attenuate C cycle feedbacks is debated and has a significant implication for projections of future climate. We delve into this problem by using the Terrestrial-Ocean-aTmosphere Ecosystem Model 3 (TOTEM3), a globally-aggregated C-N-P cycle box model. TOTEM3 is a process-based model that describes the biogeochemical reactions and physical transports involving these elements in the four domains of the Earth system: land, atmosphere, coastal ocean, and open ocean. TOTEM3 is a successor of earlier TOTEM models (Ver et al. 1999; Mackenzie et al. 2011). In our presentation, we provide an overview of fundamental features and behaviors of TOTEM3 such as the mass balance at the steady state and the relaxation time scales to various types of perturbation. We also show preliminary results to investigate how the N-P cycles influence the behavior of the C cycle. References Cox PM, Betts RA, Jones CD, Spall SA, Totterdell IJ (2000) Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature, 408, 184-187. Friedlingstein P, Cox P, Betts R, Bopp L, von Bloh

  18. Updates on Modeling the Water Cycle with the NASA Ames Mars Global Climate Model

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Montmessin, F.; Brecht, A. S.; Urata, R.; Klassen, D. R.; Wolff, M. J.

    2017-01-01

    Global Circulation Models (GCMs) have made steady progress in simulating the current Mars water cycle. It is now widely recognized that clouds are a critical component that can significantly affect the nature of the simulated water cycle. Two processes in particular are key to implementing clouds in a GCM: the microphysical processes of formation and dissipation, and their radiative effects on heating/ cooling rates. Together, these processes alter the thermal structure, change the dynamics, and regulate inter-hemispheric transport. We have made considerable progress representing these processes in the NASA Ames GCM, particularly in the presence of radiatively active water ice clouds. We present the current state of our group's water cycle modeling efforts, show results from selected simulations, highlight some of the issues, and discuss avenues for further investigation.­

  19. The maximum reservoir capacity of soils for persistent organic pollutants: implications for global cycling

    Dalla Valle, M.; Jurado, E.; Dachs, J.; Sweetman, A.J.; Jones, K.C.

    2005-01-01

    The concept of maximum reservoir capacity (MRC), the ratio of the capacities of the surface soil and of the atmospheric mixed layer (AML) to hold chemical under equilibrium conditions, is applied to selected persistent organic pollutants (POPs) in the surface 'skin' (1 mm) of soils. MRC is calculated as a function of soil organic matter (SOM) content and temperature-dependent K OA and mapped globally for selected PCB congeners (PCB-28; -153; -180) and HCB, to identify regions with a higher tendency to retain POPs. It is shown to vary over many orders of magnitude, between compounds, locations and time (seasonally/diurnally). The MRC approach emphasises the very large capacity of soils as a storage compartment for POPs. The theoretical MRC concept is compared to reality and its implications for the global cycling of POPs are discussed. Sharp gradients in soil MRC can exist in mountainous areas and between the land and ocean. Exchanges between oceans and land masses via the atmosphere is likely to be an important driver to the global cycling of these compounds, and net ocean-land transfers could occur in some areas. - Major global terrestrial sinks/stores for POPs are identified and the significance of gradients between them discussed

  20. Does Global Astrocytic Calcium Signaling Participate in Awake Brain State Transitions and Neuronal Circuit Function?

    Kjaerby, Celia; Rasmussen, Rune; Andersen, Mie

    2017-01-01

    of the neuromodulators, noradrenaline and acetylcholine. Astrocytes have emerged as a new player participating in the regulation of brain activity, and have recently been implicated in brain state shifts. Astrocytes display global Ca(2+) signaling in response to activation of the noradrenergic system, but whether...... astrocytic Ca(2+) signaling is causative or correlative for shifts in brain state and neural activity patterns is not known. Here we review the current available literature on astrocytic Ca(2+) signaling in awake animals in order to explore the role of astrocytic signaling in brain state shifts. Furthermore......We continuously need to adapt to changing conditions within our surrounding environment, and our brain needs to quickly shift between resting and working activity states in order to allow appropriate behaviors. These global state shifts are intimately linked to the brain-wide release...

  1. A Time Series Analysis of Global Soil Moisture Data Products for Water Cycle Studies

    Zhan, X.; Yin, J.; Liu, J.; Fang, L.; Hain, C.; Ferraro, R. R.; Weng, F.

    2017-12-01

    Water is essential for sustaining life on our planet Earth and water cycle is one of the most important processes of out weather and climate system. As one of the major components of the water cycle, soil moisture impacts significantly the other water cycle components (e.g. evapotranspiration, runoff, etc) and the carbon cycle (e.g. plant/crop photosynthesis and respiration). Understanding of soil moisture status and dynamics is crucial for monitoring and predicting the weather, climate, hydrology and ecological processes. Satellite remote sensing has been used for soil moisture observation since the launch of the Scanning Multi-channel Microwave Radiometer (SMMR) on NASA's Nimbus-7 satellite in 1978. Many satellite soil moisture data products have been made available to the science communities and general public. The soil moisture operational product system (SMOPS) of NOAA NESDIS has been operationally providing global soil moisture data products from each of the currently available microwave satellite sensors and their blends. This presentation will provide an update of SMOPS products. The time series of each of these soil moisture data products are analyzed against other data products, such as precipitation and evapotranspiration from other independent data sources such as the North America Land Data Assimilation System (NLDAS). Temporal characteristics of these water cycle components are explored against some historical events, such as the 2010 Russian, 2010 China and 2012 United States droughts, 2015 South Carolina floods, etc. Finally whether a merged global soil moisture data product can be used as a climate data record is evaluated based on the above analyses.

  2. The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

    W. Jackson Davis

    2018-01-01

    Full Text Available We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate. We analyzed open-source databases of stable isotopes of oxygen and hydrogen as proxies for paleo-temperatures. We find that centennial-scale spectral peaks from temperature-proxy records at Vostok over the last 10,000 years occur at the same frequencies (±2.4% in three other paleoclimate records from drill sites distributed widely across the East Antarctic Plateau (EAP, and >98% of individual ACOs evaluated at Vostok match 1:1 with homologous cycles at the other three EAP drill sites and conversely. Identified ACOs summate with millennial periodicity to form the Antarctic Isotope Maxima (AIMs known to precede Dansgaard-Oeschger (D-O oscillations recorded in Greenland ice cores. Homologous ACOs recorded at the four EAP drill sites during the last glacial maximum appeared first at lower elevations nearest the ocean and centuries later on the high EAP, with latencies that exceed dating uncertainty >30-fold. ACO homologs at different drill sites became synchronous, however, during the warmer Holocene. Comparative spectral analysis suggests that the millennial-scale AIM cycle declined in period from 1500 to 800 years over the last 70 millennia. Similarly, over the last 226 millennia ACO repetition period (mean 352 years declined by half while amplitude (mean 0.67 °C approximately doubled. The period and amplitude of ACOs oscillate in phase with glacial cycles and related surface insolation associated with planetary orbital forces. We conclude that the ACO: encompasses at least the EAP; is the proximate source of D-O oscillations in the Northern Hemisphere; therefore affects global temperature; propagates with increased velocity as temperature

  3. Effects of global change during the 21st century onthe nitrogen cycle

    Fowler, D.; Steadman, C. E.; Stevenson, D.; Coyle, M.; Rees, R. M.; Skiba, U. M.; Sutton, M. A.; Cape, J. N.; Dore, A. J.; Vieno, M.; Simpson, D.; Zaehle, S.; Stocker, B. D.; Rinaldi, M.; Facchini, M. C.; Flechard, C. R.; Nemitz, E.; Twigg, M.; Erisman, J. W.; Butterbach-Bahl, K.; Galloway, J. N.

    2015-12-01

    The global nitrogen (N) cycle at the beginning of the 21st century has been shown to be strongly influenced by the inputs of reactive nitrogen (Nr) from human activities, including combustion-related NOx, industrial and agricultural N fixation, estimated to be 220 Tg N yr-1 in 2010, which is approximately equal to the sum of biological N fixation in unmanaged terrestrial and marine ecosystems. According to current projections, changes in climate and land use during the 21st century will increase both biological and anthropogenic fixation, bringing the total to approximately 600 Tg N yr-1 by around 2100. The fraction contributed directly by human activities is unlikely to increase substantially if increases in nitrogen use efficiency in agriculture are achieved and control measures on combustion-related emissions implemented. Some N-cycling processes emerge as particularly sensitive to climate change. One of the largest responses to climate in the processing of Nr is the emission to the atmosphere of NH3, which is estimated to increase from 65 Tg N yr-1 in 2008 to 93 Tg N yr-1 in 2100 assuming a change in global surface temperature of 5 °C in the absence of increased anthropogenic activity. With changes in emissions in response to increased demand for animal products the combined effect would be to increase NH3 emissions to 135 Tg N yr-1. Another major change is the effect of climate changes on aerosol composition and specifically the increased sublimation of NH4NO3 close to the ground to form HNO3 and NH3 in a warmer climate, which deposit more rapidly to terrestrial surfaces than aerosols. Inorganic aerosols over the polluted regions especially in Europe and North America were dominated by (NH4)2SO4 in the 1970s to 1980s, and large reductions in emissions of SO2 have removed most of the SO42- from the atmosphere in these regions. Inorganic aerosols from anthropogenic emissions are now dominated by NH4NO3, a volatile aerosol which contributes substantially to PM10

  4. Simulations of the global carbon cycle and anthropogenic CO{sub 2} transient. Annual report

    Sarmiento, J.L.

    1994-07-01

    This research focuses on improving the understanding of the anthropogenic carbon dioxide transient using observations and models of the past and present. In addition, an attempt is made to develop an ability to predict the future of the carbon cycle in response to continued anthropogenic perturbations and climate change. Three aspects of the anthropogenic carbon budget were investigated: (1) the globally integrated budget at the present time; (2) the time history of the carbon budget; and (3) the spatial distribution of carbon fluxes. One of the major activities of this study was the participation in the model comparison study of Enting, et al. [1994] carried out in preparation for the IPCC 1994 report.

  5. A Novel Organic Rankine Cycle System with Improved Thermal Stability and Low Global Warming Fluids

    Panesar Angad S

    2014-07-01

    Full Text Available This paper proposes a novel Organic Rankine Cycle (ORC system for long haul truck application. Rather than typical tail pipe heat recovery configurations, the proposed setup exploits the gaseous streams that are already a load on the engine cooling module. The system uses dual loops connected only by the Exhaust Gas Recirculation (EGR stream. A water blend study is conducted to identify suitable mixtures for the High Temperature (HT loop, while the Low Temperature (LT loop utilises a Low Global Warming (GWP Hydrofluoroether.

  6. Simulations of the global carbon cycle and anthropogenic CO2 transient

    Sarmiento, J.L.

    1994-01-01

    This research focuses on improving the understanding of the anthropogenic carbon dioxide transient using observations and models of the past and present. In addition, an attempt is made to develop an ability to predict the future of the carbon cycle in response to continued anthropogenic perturbations and climate change. Three aspects of the anthropogenic carbon budget were investigated: (1) the globally integrated budget at the present time; (2) the time history of the carbon budget; and (3) the spatial distribution of carbon fluxes. One of the major activities of this study was the participation in the model comparison study of Enting, et al. [1994] carried out in preparation for the IPCC 1994 report

  7. Lagged life cycle structures for food products: Their role in global marketing, their determinants and some problems in their estimation

    Baadsgaard, Allan; Gede, Mads Peter; Grunert, Klaus G.

    cycles for different product categories may be lagged (type II lag) because changes in economic and other factors will result in demands for different products. Identifying lagged life cycle structures major importance in global marketing of food products. The problems in arriving at such estimates...

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

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

    2016-01-01

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

  9. Kajian Dampak Lingkungan Global dari Kegiatan Keramba Jaring Apung melalui Life Cycle Assessment (LCA

    Tri Heru Prihadi

    2016-11-01

    Full Text Available Perubahan iklim global yang berlangsung saat ini memberikan pengaruh pada berbagai bidang, termasuk perikanan yang menyebabkan terjadinya degradasi lingkungan perairan. Hal ini berdampak pada muncul dan menyebarnya berbagai penyakit ikan, menurunnya laju pertumbuhan organisme perairan, bahkan hingga menimbulkan kematian massal ikan. Namun hal ini belum sepenuhnya dapat diatasi oleh para ilmuwan tanah air, bahkan bisa dikatakan baru sebagian kecil saja. Penerapan Best Management Practice (BMP dengan aplikasi Life Cycle Assessment (LCA akan sangat berarti dalam upaya penerapan perikanan budidaya berkelanjutan, dengan model pengelolaan kuantitatif. Dalam hal ini metode LCA secara kuantitatif merupakan pertama kalinya dilakukan di Indonesia. Penelitian ini bertujuan untuk mengetahui dan mengevaluasi kuantitas dan kategori dampak lingkungan akibat kegiatan budidaya keramba jaring apung (KJA melalui LCA. Hasil penelitian menunjukkan bahwa kegiatan budidaya di KJA menimbulkan dampak yang signifikan terhadap lingkungan perairan. Dari berbagai faktor yang berperan dalam kegiatan budidaya KJA, pakan ikan merupakan faktor yang paling dominan dalam menghasilkan dampak lingkungan global (di atas 70%, berupa pemanasan global, penurunan jumlah sumberdaya abiotik, eutrofikasi, penipisan lapisan ozon, toksisitas pada manusia, dan penurunan jumlah keanekaragaman hayati. Dari faktor pakan tersebut, unsur yang paling berpengaruh dalam menghasilkan dampak lingkungan adalah soybean Brazil dan winter wheat, sehingga perlu dicari alternatif bahan untuk mensubstitusi kedua unsur tersebut. Demikian juga faktor-faktor lainnya (seperti: polystyrene foams, drum plastik, bambu, jaring, besi, skala budidaya, dan lain-lain mempunyai peranan terhadap dampak yang ditimbulkan terhadap lingkungan perairan. Global climate change has been affecting many sectors, including fisheries causing aquatic environment degradation such as fish disease outbreaks, decreasing growth rate of fish

  10. CO{sub 2} capture efficiency and energy requirement analysis of power plant using modified calcium-based sorbent looping cycle

    Li, Y.J.; Zhao, C.S.; Chen, H.C.; Ren, Q.Q.; Duan, L.B. [Southeast University, Nanjing (China). School of Energy & Environment

    2011-03-15

    This paper examines the average carbonation conversion, CO{sub 2} capture efficiency and energy requirement for post-combustion CO{sub 2} capture system during the modified calcium-based sorbent looping cycle. The limestone modified with acetic acid solution, i.e. calcium acetate is taken as an example of the modified calcium-based sorbents. The modified limestone exhibits much higher average carbonation conversion than the natural sorbent under the same condition. The CO{sub 2} capture efficiency increases with the sorbent flow ratios. Compared with the natural limestone, much less makeup mass flow of the recycled and the fresh sorbent is needed for the system when using the modified limestone at the same CO{sub 2} capture efficiency. Achieving 0.95 of CO{sub 2} capture efficiency without sulfation, 272 kJ/mol CO{sub 2} is required in the calciner for the natural limestone, whereas only 223 kJ/mol CO{sub 2} for the modified sorbent. The modified limestone possesses greater advantages in CO{sub 2} capture efficiency and energy consumption than the natural sorbent. When the sulfation and carbonation of the sorbents take place simultaneously, more energy is required. It is significantly necessary to remove SO{sub 2} from the flue gas before it enters the carbonator in order to reduce energy consumption in the calciner.

  11. Development of a system emulating the global carbon cycle in Earth system models

    Tachiiri, K.; Hargreaves, J. C.; Annan, J. D.; Oka, A.; Abe-Ouchi, A.; Kawamiya, M.

    2010-08-01

    Recent studies have indicated that the uncertainty in the global carbon cycle may have a significant impact on the climate. Since state of the art models are too computationally expensive for it to be possible to explore their parametric uncertainty in anything approaching a comprehensive fashion, we have developed a simplified system for investigating this problem. By combining the strong points of general circulation models (GCMs), which contain detailed and complex processes, and Earth system models of intermediate complexity (EMICs), which are quick and capable of large ensembles, we have developed a loosely coupled model (LCM) which can represent the outputs of a GCM-based Earth system model, using much smaller computational resources. We address the problem of relatively poor representation of precipitation within our EMIC, which prevents us from directly coupling it to a vegetation model, by coupling it to a precomputed transient simulation using a full GCM. The LCM consists of three components: an EMIC (MIROC-lite) which consists of a 2-D energy balance atmosphere coupled to a low resolution 3-D GCM ocean (COCO) including an ocean carbon cycle (an NPZD-type marine ecosystem model); a state of the art vegetation model (Sim-CYCLE); and a database of daily temperature, precipitation, and other necessary climatic fields to drive Sim-CYCLE from a precomputed transient simulation from a state of the art AOGCM. The transient warming of the climate system is calculated from MIROC-lite, with the global temperature anomaly used to select the most appropriate annual climatic field from the pre-computed AOGCM simulation which, in this case, is a 1% pa increasing CO2 concentration scenario. By adjusting the effective climate sensitivity (equivalent to the equilibrium climate sensitivity for an energy balance model) of MIROC-lite, the transient warming of the LCM could be adjusted to closely follow the low sensitivity (with an equilibrium climate sensitivity of 4.0 K

  12. Development of a system emulating the global carbon cycle in Earth system models

    K. Tachiiri

    2010-08-01

    Full Text Available Recent studies have indicated that the uncertainty in the global carbon cycle may have a significant impact on the climate. Since state of the art models are too computationally expensive for it to be possible to explore their parametric uncertainty in anything approaching a comprehensive fashion, we have developed a simplified system for investigating this problem. By combining the strong points of general circulation models (GCMs, which contain detailed and complex processes, and Earth system models of intermediate complexity (EMICs, which are quick and capable of large ensembles, we have developed a loosely coupled model (LCM which can represent the outputs of a GCM-based Earth system model, using much smaller computational resources. We address the problem of relatively poor representation of precipitation within our EMIC, which prevents us from directly coupling it to a vegetation model, by coupling it to a precomputed transient simulation using a full GCM. The LCM consists of three components: an EMIC (MIROC-lite which consists of a 2-D energy balance atmosphere coupled to a low resolution 3-D GCM ocean (COCO including an ocean carbon cycle (an NPZD-type marine ecosystem model; a state of the art vegetation model (Sim-CYCLE; and a database of daily temperature, precipitation, and other necessary climatic fields to drive Sim-CYCLE from a precomputed transient simulation from a state of the art AOGCM. The transient warming of the climate system is calculated from MIROC-lite, with the global temperature anomaly used to select the most appropriate annual climatic field from the pre-computed AOGCM simulation which, in this case, is a 1% pa increasing CO2 concentration scenario.

    By adjusting the effective climate sensitivity (equivalent to the equilibrium climate sensitivity for an energy balance model of MIROC-lite, the transient warming of the LCM could be adjusted to closely follow the low sensitivity (with an equilibrium

  13. Partitioning the effects of Global Warming on the Hydrological Cycle with Stable Isotopes in Water Vapor

    Dee, S. G.; Russell, J. M.; Nusbaumer, J. M.; Konecky, B. L.; Buenning, N. H.; Lee, J. E.; Noone, D.

    2016-12-01

    General circulation models (GCMs) suggest that much of the global hydrological cycle's response to anthropogenic warming will be caused by increased lower-tropospheric water vapor concentrations and associated feedbacks. However, fingerprinting changes in the global hydrological cycle due to anthropogenic warming remains challenging. Held and Soden (2006) predicted that as lower-tropospheric water vapor increases, atmospheric circulation will weaken as climate warms to maintain the surface energy budget. Unfortunately, the strength of this feedback and the fallout for other branches of the hydrological cycle is difficult to constrain in situ or with GCMs alone. We demonstrate the utility of stable hydrogen isotope ratios in atmospheric water vapor to quantitatively trace changes in atmospheric circulation and convective mass flux in a warming world. We compare water isotope-enabled GCM experiments for control (present-day) CO2 vs. high CO2(2x, 4x) atmospheres in two GCMs, IsoGSM and iCAM5. We evaluate changes in the distribution of water vapor, vertical velocity (omega), and the stream function between these experiments in order to identify spatial patterns of circulation change over the tropical Pacific (where vertical motion is strong) and map the δD of water vapor associated with atmospheric warming. We also probe the simulations to isolate isotopic signatures associated with water vapor residence time, precipitation efficiency, divergence, and cloud physics. We show that there are robust mechanisms that moisten the troposphere and weaken convective mass flux, and that these mechanisms can be tracked using the δD of water vapor. Further, we find that these responses are most pronounced in the upper troposphere. These findings provide a framework to develop new metrics for the detection of global warming impacts to the hydrological cycle. Further, currently available satellite missions measure δD in the atmospheric boundary layer, the free atmosphere, or the

  14. Glacial-interglacial water cycle, global monsoon and atmospheric methane changes

    Guo, Zhengtang; Wu, Haibin [Chinese Academy of Sciences, Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Beijing (China); Zhou, Xin [Chinese Academy of Sciences, Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Beijing (China); University of Science and Technology of China, School of Earth and Space Sciences and Institute of Polar Environment, Hefei (China)

    2012-09-15

    The causes of atmospheric methane (CH{sub 4}) changes are still a major contention, in particular with regards to the relative contributions of glacial-interglacial cycles, monsoons in both hemispheres and the late Holocene human intervention. Here, we explore the CH{sub 4} signals in the Antarctic EPICA Dome C and Vostok ice records using the methods of timeseries analyses and correlate them with insolation and geological records to address these issues. The results parse out three distinct groups of CH{sub 4} signals attributable to different drivers. The first group ({proportional_to}80% variance), well tracking the marine {delta}{sup 18}O record, is attributable to glacial-interglacial modulation on the global water cycle with the effects shared by wetlands at all latitudes, from monsoonal and non-monsoonal regions in both hemispheres. The second group ({proportional_to}15% variance), centered at the {proportional_to}10-kyr semi-precession frequency, is linkable with insolation-driven tropical monsoon changes in both hemispheres. The third group ({proportional_to}5% variance), marked by millennial frequencies, is seemingly related with the combined effect of ice-volume and bi-hemispheric insolation changes at the precession bands. These results indicate that bi-hemispheric monsoon changes have been a constant driver of atmospheric CH{sub 4}. This mechanism also partially explains the Holocene CH{sub 4} reversal since {proportional_to}5 kyr BP besides the human intervention. In the light of these results, we propose that global monsoon can be regarded as a system consisting of two main integrated components, one primarily driven by the oscillations of Inter-Tropical Convergence Zone (ITCZ) in response to the low-latitude summer insolation changes, anti-phase between the two hemispheres (i.e. the ITCZ monsoon component); and another modulated by the glacial-interglacial cycles, mostly synchronous at the global scale (i.e. the glacial-interglacial monsoon

  15. Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model

    Cox, P.M.; Betts, R.A.; Jones, C.D.; Spall, S.A.; Totterdell, I.J.

    2000-01-01

    The continued increase in the atmospheric concentration of carbon dioxide due to anthropogenic emissions is predicted to lead to significant changes in climate. About half of the current emissions are being absorbed by the ocean and by land ecosystems, but this absorption is sensitive to climate as well as to atmospheric carbon dioxide concentrations, creating a feedback loop. General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO 2 concentrations from simple carbon-cycle models that do not include climate change. Here we present results from a fully coupled, three-dimensional carbon-climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century. We find that under a 'business as usual' scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, the ocean uptake rate of 5 Gt C yr -1 is balanced by the terrestrial carbon source, and atmospheric CO 2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models, resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback. (author)

  16. N2O emissions from the global agricultural nitrogen cycle – current state and future scenarios

    H. Lotze-Campen

    2012-10-01

    Full Text Available Reactive nitrogen (Nr is not only an important nutrient for plant growth, thereby safeguarding human alimentation, but it also heavily disturbs natural systems. To mitigate air, land, aquatic, and atmospheric pollution caused by the excessive availability of Nr, it is crucial to understand the long-term development of the global agricultural Nr cycle. For our analysis, we combine a material flow model with a land-use optimization model. In a first step we estimate the state of the Nr cycle in 1995. In a second step we create four scenarios for the 21st century in line with the SRES storylines. Our results indicate that in 1995 only half of the Nr applied to croplands was incorporated into plant biomass. Moreover, less than 10 per cent of all Nr in cropland plant biomass and grazed pasture was consumed by humans. In our scenarios a strong surge of the Nr cycle occurs in the first half of the 21st century, even in the environmentally oriented scenarios. Nitrous oxide (N2O emissions rise from 3 Tg N2O-N in 1995 to 7–9 in 2045 and 5–12 Tg in 2095. Reinforced Nr pollution mitigation efforts are therefore required.

  17. The Circadian Clock Modulates Global Daily Cycles of mRNA Ribosome Loading[OPEN

    Missra, Anamika; Ernest, Ben; Jia, Qidong; Ke, Kenneth

    2015-01-01

    Circadian control of gene expression is well characterized at the transcriptional level, but little is known about diel or circadian control of translation. Genome-wide translation state profiling of mRNAs in Arabidopsis thaliana seedlings grown in long day was performed to estimate ribosome loading per mRNA. The experiments revealed extensive translational regulation of key biological processes. Notably, translation of mRNAs for ribosomal proteins and mitochondrial respiration peaked at night. Central clock mRNAs are among those subject to fluctuations in ribosome loading. There was no consistent phase relationship between peak translation states and peak transcript levels. The overlay of distinct transcriptional and translational cycles can be expected to alter the waveform of the protein synthesis rate. Plants that constitutively overexpress the clock gene CCA1 showed phase shifts in peak translation, with a 6-h delay from midnight to dawn or from noon to evening being particularly common. Moreover, cycles of ribosome loading that were detected under continuous light in the wild type collapsed in the CCA1 overexpressor. Finally, at the transcript level, the CCA1-ox strain adopted a global pattern of transcript abundance that was broadly correlated with the light-dark environment. Altogether, these data demonstrate that gene-specific diel cycles of ribosome loading are controlled in part by the circadian clock. PMID:26392078

  18. Global warming potential of the sulfur-iodine process using life cycle assessment methodology

    Lattin, William C.; Utgikar, Vivek P.

    2009-01-01

    A life cycle assessment (LCA) of one proposed method of hydrogen production - thermochemical water-splitting using the sulfur-iodine cycle couple with a very high-temperature nuclear reactor - is presented in this paper. Thermochemical water-splitting theoretically offers a higher overall efficiency than high-temperature electrolysis of water because heat from the nuclear reactor is provided directly to the hydrogen generation process, instead of using the intermediate step of generating electricity. The primary heat source for the S-I cycle is an advanced nuclear reactor operating at temperatures corresponding to those required by the sulfur-iodine process. This LCA examines the environmental impact of the combined advanced nuclear and hydrogen generation plants and focuses on quantifying the emissions of carbon dioxide per kilogram of hydrogen produced. The results are presented in terms of global warming potential (GWP). The GWP of the system is 2500 g carbon dioxide-equivalent (CO 2 -eq) per kilogram of hydrogen produced. The GWP of this process is approximately one-sixth of that for hydrogen production by steam reforming of natural gas, and is comparable to producing hydrogen from wind- or hydro-electric conventional electrolysis. (author)

  19. A Review of the Stable Isotope Bio-geochemistry of the Global Silicon Cycle and Its Associated Trace Elements

    Jill N. Sutton

    2018-01-01

    Full Text Available Silicon (Si is the second most abundant element in the Earth's crust and is an important nutrient in the ocean. The global Si cycle plays a critical role in regulating primary productivity and carbon cycling on the continents and in the oceans. Development of the analytical tools used to study the sources, sinks, and fluxes of the global Si cycle (e.g., elemental and stable isotope ratio data for Ge, Si, Zn, etc. have recently led to major advances in our understanding of the mechanisms and processes that constrain the cycling of Si in the modern environment and in the past. Here, we provide background on the geochemical tools that are available for studying the Si cycle and highlight our current understanding of the marine, freshwater and terrestrial systems. We place emphasis on the geochemistry (e.g., Al/Si, Ge/Si, Zn/Si, δ13C, δ15N, δ18O, δ30Si of dissolved and biogenic Si, present case studies, such as the Silicic Acid Leakage Hypothesis, and discuss challenges associated with the development of these environmental proxies for the global Si cycle. We also discuss how each system within the global Si cycle might change over time (i.e., sources, sinks, and processes and the potential technical and conceptual limitations that need to be considered for future studies.

  20. A New Global LAI Product and Its Use for Terrestrial Carbon Cycle Estimation

    Chen, J. M.; Liu, R.; Ju, W.; Liu, Y.

    2014-12-01

    For improving the estimation of the spatio-temporal dynamics of the terrestrial carbon cycle, a new time series of the leaf area index (LAI) is generated for the global land surface at 8 km resolution from 1981 to 2012 by combining AVHRR and MODIS satellite data. This product differs from existing LAI products in the following two aspects: (1) the non-random spatial distribution of leaves with the canopy is considered, and (2) the seasonal variation of the vegetation background is included. The non-randomness of the leaf spatial distribution in the canopy is considered using the second vegetation structural parameter named clumping index (CI), which quantifies the deviation of the leaf spatial distribution from the random case. Using the MODIS Bidirectional Reflectance Distribution Function product, a global map of CI is produced at 500 m resolution. In our LAI algorithm, CI is used to convert the effective LAI obtained from mono-angle remote sensing into the true LAI, otherwise LAI would be considerably underestimated. The vegetation background is soil in crop, grass and shrub but includes soil, grass, moss, and litter in forests. Through processing a large volume of MISR data from 2000 to 2010, monthly red and near-infrared reflectances of the vegetation background is mapped globally at 1 km resolution. This new LAI product has been validated extensively using ground-based LAI measurements distributed globally. In carbon cycle modeling, the use of CI in addition to LAI allows for accurate separation of sunlit and shaded leaves as an important step in terrestrial photosynthesis and respiration modeling. Carbon flux measurements over 100 sites over the globe are used to validate an ecosystem model named Boreal Ecosystem Productivity Simulator (BEPS). The validated model is run globally at 8 km resolution for the period from 1981 to 2012 using the LAI product and other spatial datasets. The modeled results suggest that changes in vegetation structure as quantified

  1. Tropical rainforests dominate multi-decadal variability of the global carbon cycle

    Zhang, X.; Wang, Y. P.; Peng, S.; Rayner, P. J.; Silver, J.; Ciais, P.; Piao, S.; Zhu, Z.; Lu, X.; Zheng, X.

    2017-12-01

    Recent studies find that inter-annual variability of global atmosphere-to-land CO2 uptake (NBP) is dominated by semi-arid ecosystems. However, the NBP variations at decadal to multi-decadal timescales are still not known. By developing a basic theory for the role of net primary production (NPP) and heterotrophic respiration (Rh) on NBP and applying it to 100-year simulations of terrestrial ecosystem models forced by observational climate, we find that tropical rainforests dominate the multi-decadal variability of global NBP (48%) rather than the semi-arid lands (35%). The NBP variation at inter-annual timescales is almost 90% contributed by NPP, but across longer timescales is progressively controlled by Rh that constitutes the response from the NPP-derived soil carbon input (40%) and the response of soil carbon turnover rates to climate variability (60%). The NBP variations of tropical rainforests is modulated by the ENSO and the PDO through their significant influences on temperature and precipitation at timescales of 2.5-7 and 25-50 years, respectively. This study highlights the importance of tropical rainforests on the multi-decadal variability of global carbon cycle, suggesting that we need to carefully differentiate the effect of NBP long-term fluctuations associated with ocean-related climate modes on the long-term trend in land sink.

  2. Accounting for carbon cycle feedbacks in a comparison of the global warming effects of greenhouse gases

    Gillett, Nathan P; Matthews, H Damon

    2010-01-01

    Greenhouse gases other than CO 2 make a significant contribution to human-induced climate change, and multi-gas mitigation strategies are cheaper to implement than those which limit CO 2 emissions alone. Most practical multi-gas mitigation strategies require metrics to relate the climate warming effects of CO 2 and other greenhouse gases. Global warming potential (GWP), defined as the ratio of time-integrated radiative forcing of a particular gas to that of CO 2 following a unit mass emission, is the metric used in the Kyoto Protocol, and we define mean global temperature change potential (MGTP) as an equivalent metric of the temperature response. Here we show that carbon-climate feedbacks inflate the GWPs and MGTPs of methane and nitrous oxide by ∼ 20% in coupled carbon-climate model simulations of the response to a pulse of 50 x 1990 emissions, due to a warming-induced release of CO 2 from the land biosphere and ocean. The magnitude of this effect is expected to be dependent on the model, but it is not captured at all by the analytical models usually used to calculate metrics such as GWP. We argue that the omission of carbon cycle dynamics has led to a low bias of uncertain but potentially substantial magnitude in metrics of the global warming effect of other greenhouse gases, and we suggest that the carbon-climate feedback should be considered when greenhouse gas metrics are calculated and applied.

  3. Alternative "global warming" metrics in life cycle assessment: a case study with existing transportation data.

    Peters, Glen P; Aamaas, Borgar; T Lund, Marianne; Solli, Christian; Fuglestvedt, Jan S

    2011-10-15

    The Life Cycle Assessment (LCA) impact category "global warming" compares emissions of long-lived greenhouse gases (LLGHGs) using Global Warming Potential (GWP) with a 100-year time-horizon as specified in the Kyoto Protocol. Two weaknesses of this approach are (1) the exclusion of short-lived climate forcers (SLCFs) and biophysical factors despite their established importance, and (2) the use of a particular emission metric (GWP) with a choice of specific time-horizons (20, 100, and 500 years). The GWP and the three time-horizons were based on an illustrative example with value judgments and vague interpretations. Here we illustrate, using LCA data of the transportation sector, the importance of SLCFs relative to LLGHGs, different emission metrics, and different treatments of time. We find that both the inclusion of SLCFs and the choice of emission metric can alter results and thereby change mitigation priorities. The explicit inclusion of time, both for emissions and impacts, can remove value-laden assumptions and provide additional information for impact assessments. We believe that our results show that a debate is needed in the LCA community on the impact category "global warming" covering which emissions to include, the emission metric(s) to use, and the treatment of time.

  4. Simulating the Current Water Cycle with the NASA Ames Mars Global Climate Model

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Brecht, A. S.; Urata, R. A.; Montmessin, F.

    2017-12-01

    The water cycle is a critical component of the current Mars climate system, and it is now widely recognized that water ice clouds significantly affect the nature of the simulated water cycle. Two processes are key to implementing clouds in a Mars global climate model (GCM): the microphysical processes of formation and dissipation, and their radiative effects on atmospheric heating/cooling rates. Together, these processes alter the thermal structure, change the atmospheric dynamics, and regulate inter-hemispheric transport. We have made considerable progress using the NASA Ames Mars GCM to simulate the current-day water cycle with radiatively active clouds. Cloud fields from our baseline simulation are in generally good agreement with observations. The predicted seasonal extent and peak IR optical depths are consistent MGS/TES observations. Additionally, the thermal response to the clouds in the aphelion cloud belt (ACB) is generally consistent with observations and other climate model predictions. Notably, there is a distinct gap in the predicted clouds over the North Residual Cap (NRC) during local summer, but the clouds reappear in this simulation over the NRC earlier than the observations indicate. Polar clouds are predicted near the seasonal CO2 ice caps, but the column thicknesses of these clouds are generally too thick compared to observations. Our baseline simulation is dry compared to MGS/TES-observed water vapor abundances, particularly in the tropics and subtropics. These areas of disagreement appear to be a consistent with other current water cycle GCMs. Future avenues of investigation will target improving our understanding of what controls the vertical extent of clouds and the apparent seasonal evolution of cloud particle sizes within the ACB.

  5. EDITORIAL: The Earth radiation balance as driver of the global hydrological cycle

    Wild, Martin; Liepert, Beate

    2010-06-01

    Variations in the intensity of the global hydrological cycle can have far-reaching effects on living conditions on our planet. While climate change discussions often revolve around possible consequences of future temperature changes, the adaptation to changes in the hydrological cycle may pose a bigger challenge to societies and ecosystems. Floods and droughts are already today amongst the most damaging natural hazards, with floods being globally the most significant disaster type in terms of loss of human life (Jonkman 2005). From an economic perspective, changes in the hydrological cycle can impose great pressures and damages on a variety of industrial sectors, such as water management, urban planning, agricultural production and tourism. Despite their obvious environmental and societal importance, our understanding of the causes and magnitude of the variations of the hydrological cycle is still unsatisfactory (e.g., Ramanathan et al 2001, Ohmura and Wild 2002, Allen and Ingram 2002, Allan 2007, Wild et al 2008, Liepert and Previdi 2009). The link between radiation balance and hydrological cycle Globally, precipitation can be approximated by surface evaporation, since the variability of the atmospheric moisture storage is negligible. This is the case because the fluxes are an order of magnitude larger than the atmospheric storage (423 x 1012 m3 year-1 versus 13 x 1012 m3 according to Baumgartner and Reichel (1975)), the latter being determined by temperature (Clausius-Clapeyron). Hence the residence time of evaporated water in the atmosphere is not more than a few days, before it condenses and falls back to Earth in the form of precipitation. Any change in the globally averaged surface evaporation therefore implies an equivalent change in precipitation, and thus in the intensity of the global hydrological cycle. The process of evaporation requires energy, which it obtains from the surface radiation balance (also known as surface net radiation), composed of the

  6. Exploring diurnal and seasonal characteristics of global carbon cycle with GISS Model E2 GCM

    Aleinov, I. D.; Kiang, N. Y.; Romanou, A.

    2017-12-01

    The ability to properly model surface carbon fluxes on the diurnal and seasonal time scale is a necessary requirement for understanding of the global carbon cycle. It is also one of the most challenging tasks faced by modern General Circulation Models (GCMs) due to complexity of the algorithms and variety of relevant spatial and temporal scales. The observational data, though abundant, is difficult to interpret at the global scale, because flux tower observations are very sparse for large impact areas (such as Amazon and African rainforest and most of Siberia) and satellite missions often struggle to produce sufficiently high confidence data over the land and may be missing CO2 amounts near the surface due to the nature of the method. In this work we use the GISS Model E2 GCM to perform a subset of experiments proposed by the Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP) and relate the results to available observations.The GISS Model E2 GCM is currently equipped with a complete global carbon cycle algorithm. Its surface carbon fluxes are computed by the Ent Terrestrial Biosphere Model (Ent TBM) over the land with observed leaf area index of the Moderate Resolution Imaging Spectrometer (MODIS) and by the NASA Ocean Biogeochemistry Model (NOBM) over the ocean. The propagation of atmospheric CO2 is performed by a generic Model E2 tracer algorithm, which is based on a quadratic upstream method (Prather 1986). We perform a series spin-up experiments for preindustrial climate conditions and fixed preindustrial atmospheric CO2 concentration. First, we perform separate spin-up simulations each for terrestrial and ocean carbon. We then combine the spun-up states and perform a coupled spin-up simulation until the model reaches a sufficient equilibrium. We then release restrictions on CO2 concentration and allow it evolve freely, driven only by simulated surface fluxes. We then study the results of the unforced run, comparing the amplitude and the phase

  7. The contribution of weathering of the main Alpine rivers on the global carbon cycle

    Donnini, Marco; Probst, Jean-Luc; Probst, Anne; Frondini, Francesco; Marchesini, Ivan; Guzzetti, Fausto

    2013-04-01

    classification of Meybeck (1986, 1987). Then for each basin we computed Rsil weighted average considering the surface and the mean precipitation for the surface area of each lithology. Lastly, we estimated the (Ca+Mg) originating from carbonate weathering as the remaining cations after silicate correction. Depending on time-scales of the phenomena (shorter than about 1 million year i.e., correlated to the short term carbon cycle, or longer than about 1 million years i.e., correlated to the long-term carbon cycle), we considered different equations for the quantification of the atmospheric CO2 consumed by weathering (Huh, 2010). The results show the net predominance of carbonate weathering on fixing atmospheric CO2 and that, considering the long-term carbon cycle, the amount of atmospheric CO2 uptake by weathering is about one order of magnitude lower than considering the short-term carbon cycle. Moreover, considering the short-term carbon cycle, the mean CO2 consumed by Alpine basins is of the same order of magnitude of the mean CO2 consumed by weathering by the 60 largest rivers of the world estimated by Gaillardet et al. (1999). References Amiotte-Suchet, P. "Cycle Du Carbone, Érosion Chimique Des Continents Et Transfert Vers Les Océans." Sci. Géol. Mém. Strasbourg 97 (1995): 156. Amiotte-Suchet, P., and J.-L. Probst. "Origins of dissolved inorganic carbon in the Garonne river waters: seasonal and interannual variations." Sci. Géologiques Bull. Strasbourg 49, no. 1-4 (1996): 101-126. Berner, E.K., and R.A. Berner. The Global Water Cycle. Geochemistry and Environment. Prentice Halle. Engelwood Cliffs, NJ, 1987. Drever, J.L. The Geochemistry of Natural Waters. Prentice Hall, 1982. Gaillardet, J., B. Dupré, P. Louvat, and C.J. Allègre. "Global Silicate Weathering and CO2 Consumption Rates Deduced from the Chemistry of Large Rivers." Chemical Geology 159 (1999): 3-30. Garrels, R.M., and F.T. Mackenzie. Evolution of Sedimentary Rocks. New York: W.W. Nortonand, 1971. Huh, Y

  8. High resolution analysis of tropical forest fragmentation and its impact on the global carbon cycle

    Brinck, Katharina; Fischer, Rico; Groeneveld, Jürgen; Lehmann, Sebastian; Dantas de Paula, Mateus; Pütz, Sandro; Sexton, Joseph O.; Song, Danxia; Huth, Andreas

    2017-03-01

    Deforestation in the tropics is not only responsible for direct carbon emissions but also extends the forest edge wherein trees suffer increased mortality. Here we combine high-resolution (30 m) satellite maps of forest cover with estimates of the edge effect and show that 19% of the remaining area of tropical forests lies within 100 m of a forest edge. The tropics house around 50 million forest fragments and the length of the world's tropical forest edges sums to nearly 50 million km. Edge effects in tropical forests have caused an additional 10.3 Gt (2.1-14.4 Gt) of carbon emissions, which translates into 0.34 Gt per year and represents 31% of the currently estimated annual carbon releases due to tropical deforestation. Fragmentation substantially augments carbon emissions from tropical forests and must be taken into account when analysing the role of vegetation in the global carbon cycle.

  9. Proceedings of the GLOBAL 2009 congress - The Nuclear Fuel Cycle: Sustainable Options and Industrial Perspectives

    2009-06-01

    GLOBAL 2009 is the ninth bi-annual scientific world meeting on the Nuclear Fuel Cycle (NFC) that started in 1993 in Seattle. This meeting has established itself as a dedicated international forum for experts, to provide an overall review of the status and new trends of research applications and policies related to the fuel cycle. The international nuclear community is actively developing advanced processes and innovative technologies that enhance economic competitiveness of nuclear energy and ensure its sustainability, through optimized utilization of natural resources, minimization of nuclear wastes, resistance to proliferation and compliance with safety requirements. In this context, and under the profound evolutions concerning energy supply, GLOBAL 2009 is a great opportunity for sharing ideas and visions on the NFC. Special emphasis are placed on the results of the international studies for developing next generation systems. GLOBAL 2009 highlights the technical challenges and successes involved in closing the NFC and recycling long lived nuclear waste. It is also an excellent occasion to review and discuss social and regulatory aspects as well as national plans and international policies and decision affecting the future of nuclear energy. This meeting provides a forum for the exchange of the newest ideas and developments related to the initiatives at of establishing an acceptable, reliable and universal international non proliferation regime. The congress, organized by the French Nuclear Energy Society (SFEN), under the aegis of the IAEA, NEA of the OECD and the UE Commission with the basic sponsorships of ANS, ENS and AESJ, combines plenary sessions, general panel sessions, parallel sessions and technical visits. The program has full length technical papers, which are peer reviewed and published in conference proceedings. A large industrial exhibition takes place to complement the congress. The GLOBAL 2009 congress is organized in coordination with the 2009

  10. Consistency of seven different GNSS global ionospheric mapping techniques during one solar cycle

    Roma-Dollase, David; Hernández-Pajares, Manuel; Krankowski, Andrzej; Kotulak, Kacper; Ghoddousi-Fard, Reza; Yuan, Yunbin; Li, Zishen; Zhang, Hongping; Shi, Chuang; Wang, Cheng; Feltens, Joachim; Vergados, Panagiotis; Komjathy, Attila; Schaer, Stefan; García-Rigo, Alberto; Gómez-Cama, José M.

    2018-06-01

    In the context of the International GNSS Service (IGS), several IGS Ionosphere Associated Analysis Centers have developed different techniques to provide global ionospheric maps (GIMs) of vertical total electron content (VTEC) since 1998. In this paper we present a comparison of the performances of all the GIMs created in the frame of IGS. Indeed we compare the classical ones (for the ionospheric analysis centers CODE, ESA/ESOC, JPL and UPC) with the new ones (NRCAN, CAS, WHU). To assess the quality of them in fair and completely independent ways, two assessment methods are used: a direct comparison to altimeter data (VTEC-altimeter) and to the difference of slant total electron content (STEC) observed in independent ground reference stations (dSTEC-GPS). The main conclusion of this study, performed during one solar cycle, is the consistency of the results between so many different GIM techniques and implementations.

  11. Proceedings of the GLOBAL 2009 congress - The Nuclear Fuel Cycle: Sustainable Options and Industrial Perspectives

    NONE

    2009-06-15

    GLOBAL 2009 is the ninth bi-annual scientific world meeting on the Nuclear Fuel Cycle (NFC) that started in 1993 in Seattle. This meeting has established itself as a dedicated international forum for experts, to provide an overall review of the status and new trends of research applications and policies related to the fuel cycle. The international nuclear community is actively developing advanced processes and innovative technologies that enhance economic competitiveness of nuclear energy and ensure its sustainability, through optimized utilization of natural resources, minimization of nuclear wastes, resistance to proliferation and compliance with safety requirements. In this context, and under the profound evolutions concerning energy supply, GLOBAL 2009 is a great opportunity for sharing ideas and visions on the NFC. Special emphasis are placed on the results of the international studies for developing next generation systems. GLOBAL 2009 highlights the technical challenges and successes involved in closing the NFC and recycling long lived nuclear waste. It is also an excellent occasion to review and discuss social and regulatory aspects as well as national plans and international policies and decision affecting the future of nuclear energy. This meeting provides a forum for the exchange of the newest ideas and developments related to the initiatives at of establishing an acceptable, reliable and universal international non proliferation regime. The congress, organized by the French Nuclear Energy Society (SFEN), under the aegis of the IAEA, NEA of the OECD and the UE Commission with the basic sponsorships of ANS, ENS and AESJ, combines plenary sessions, general panel sessions, parallel sessions and technical visits. The program has full length technical papers, which are peer reviewed and published in conference proceedings. A large industrial exhibition takes place to complement the congress. The GLOBAL 2009 congress is organized in coordination with the 2009

  12. Exogenous Calcium Alleviates Photoinhibition of PSII by Improving the Xanthophyll Cycle in Peanut (Arachis Hypogaea) Leaves during Heat Stress under High Irradiance

    Yang, Sha; Wang, Fang; Guo, Feng; Meng, Jing-Jing; Li, Xin-Guo; Dong, Shu-Ting; Wan, Shu-Bo

    2013-01-01

    Peanut is one of the calciphilous plants. Calcium (Ca) serves as a ubiquitous central hub in a large number of signaling pathways. The effect of exogenous calcium nitrate [Ca(NO3)2] (6 mM) on the dissipation of excess excitation energy in the photosystem II (PSII) antenna, especially on the level of D1 protein and the xanthophyll cycle in peanut plants under heat (40°C) and high irradiance (HI) (1 200 µmol m−2 s−1) stress were investigated. Compared with the control plants [cultivated in 0 mM Ca(NO3)2 medium], the maximal photochemical efficiency of PSII (Fv/Fm) in Ca2+-treated plants showed a slighter decrease after 5 h of stress, accompanied by higher non-photochemical quenching (NPQ), higher expression of antioxidative genes and less reactive oxygen species (ROS) accumulation. Meanwhile, higher content of D1 protein and higher ratio of (A+Z)/(V+A+Z) were also detected in Ca2+-treated plants under such stress. These results showed that Ca2+ could help protect the peanut photosynthetic system from severe photoinhibition under heat and HI stress by accelerating the repair of D1 protein and improving the de-epoxidation ratio of the xanthophyll cycle. Furthermore, EGTA (a chelant of Ca ion), LaCl3 (a blocker of Ca2+ channel in cytoplasmic membrane), and CPZ [a calmodulin (CaM) antagonist] were used to analyze the effects of Ca2+/CaM on the variation of (A+Z)/(V+A+Z) (%) and the expression of violaxanthin de-epoxidase (VDE). The results indicated that CaM, an important component of the Ca2+ signal transduction pathway, mediated the expression of the VDE gene in the presence of Ca to improve the xanthophyll cycle. PMID:23940721

  13. Exogenous calcium alleviates photoinhibition of PSII by improving the xanthophyll cycle in peanut (Arachis hypogaea leaves during heat stress under high irradiance.

    Sha Yang

    Full Text Available Peanut is one of the calciphilous plants. Calcium (Ca serves as a ubiquitous central hub in a large number of signaling pathways. The effect of exogenous calcium nitrate [Ca(NO32] (6 mM on the dissipation of excess excitation energy in the photosystem II (PSII antenna, especially on the level of D1 protein and the xanthophyll cycle in peanut plants under heat (40°C and high irradiance (HI (1 200 µmol m(-2 s(-1 stress were investigated. Compared with the control plants [cultivated in 0 mM Ca(NO32 medium], the maximal photochemical efficiency of PSII (Fv/Fm in Ca(2+-treated plants showed a slighter decrease after 5 h of stress, accompanied by higher non-photochemical quenching (NPQ, higher expression of antioxidative genes and less reactive oxygen species (ROS accumulation. Meanwhile, higher content of D1 protein and higher ratio of (A+Z/(V+A+Z were also detected in Ca(2+-treated plants under such stress. These results showed that Ca(2+ could help protect the peanut photosynthetic system from severe photoinhibition under heat and HI stress by accelerating the repair of D1 protein and improving the de-epoxidation ratio of the xanthophyll cycle. Furthermore, EGTA (a chelant of Ca ion, LaCl3 (a blocker of Ca(2+ channel in cytoplasmic membrane, and CPZ [a calmodulin (CaM antagonist] were used to analyze the effects of Ca(2+/CaM on the variation of (A+Z/(V+A+Z (% and the expression of violaxanthin de-epoxidase (VDE. The results indicated that CaM, an important component of the Ca(2+ signal transduction pathway, mediated the expression of the VDE gene in the presence of Ca to improve the xanthophyll cycle.

  14. Soils and Global Change in the Carbon Cycle over Geological Time

    Retallack, G. J.

    2003-12-01

    Soils play an important role in the carbon cycle as the nutrition of photosynthesized biomass. Nitrogen fixed by microbes from air is a limiting nutrient for ecosystems within the first flush of ecological succession of new ground, and sulfur can limit some components of wetland ecosystems. But over the long term, the limiting soil nutrient is phosphorus extracted by weathering from minerals such as apatite (Vitousek et al., 1997a; Chadwick et al., 1999). Life has an especially voracious appetite for common alkali (Na+ and K+) and alkaline earth (Ca2+ and Mg2+) cations, supplied by hydrolytic weathering, which is in turn amplified by biological acidification (Schwartzmann and Volk, 1991; see Chapter 5.06). These mineral nutrients fuel photosynthetic fixation and chemical reduction of atmospheric CO2 into plants and plantlike microbes, which are at the base of the food chain. Plants and photosynthetic microbes are consumed and oxidized by animals, fungi, and other respiring microbes, which release CO2, methane, and water vapor to the air. These greenhouse gases absorb solar radiation more effectively than atmospheric oxygen and nitrogen, and are important regulators of planetary temperature and albedo (Kasting, 1992). Variations in solar insolation ( Kasting, 1992), mountainous topography ( Raymo and Ruddiman, 1992), and ocean currents ( Ramstein et al., 1997) also play a role in climate, but this review focuses on the carbon cycle. The carbon cycle is discussed in detail in Volume 8 of this Treatise.The greenhouse model for global paleoclimate has proven remarkably robust (Retallack, 2002), despite new challenges ( Veizer et al., 2000). The balance of producers and consumers is one of a number of controls on atmospheric greenhouse gas balance, because CO2 is added to the air from fumaroles, volcanic eruptions, and other forms of mantle degassing (Holland, 1984). Carbon dioxide is also consumed by burial as carbonate and organic matter within limestones and other

  15. Human Impacts on the Hydrologic Cycle: Comparing Global Climate Change and Local Water Management

    Ferguson, I. M.; Maxwell, R. M.

    2010-12-01

    Anthropogenic climate change is significantly altering the hydrologic cycle at global and regional scales, with potentially devastating impacts on water resources. Recent studies demonstrate that hydrologic response to climate change will depend on local-scale feedbacks between groundwater, surface water, and land surface processes. These studies suggest that local water management practices that alter the quantity and distribution of water in the terrestrial system—e.g., groundwater pumping and irrigation—may also feed back across the hydrologic cycle, with impacts on land-atmosphere fluxes and thus weather and climate. Here we use an integrated hydrologic model to compare the impacts of large-scale climate change and local water management practices on water and energy budgets at local and watershed scales. We consider three climate scenarios (hot, hot+wet, and hot+dry) and three management scenarios (pumping only, irrigation only, and pumping+irrigation). Results demonstrate that impacts of local water management on basin-integrated groundwater storage, evapotranspiration, and stream discharge are comparable to those of changing climate conditions. However, impacts of climate change are shown to have a smaller magnitude and greater spatial extent, while impacts of pumping and irrigation are shown to have a greater magnitude but are local to areas where pumping and irrigation occur. These results have important implications regarding the scales of human impacts on both water resources and climate and the sustainability of water resources.

  16. The advanced fuel cycle facility (AFCF) role in the global nuclear energy partnership

    Griffith, Andrew

    2007-01-01

    The Global Nuclear Energy Partnership (GNEP), launched in February, 2006, proposes to introduce used nuclear fuel recycling in the United States with improved proliferation-resistance and a more effective waste management approach. This program is evaluating ways to close the fuel cycle in a manner that builds on recent laboratory breakthroughs in U.S. national laboratories and draws on international and industry partnerships. Central to moving this advanced fuel recycling technology from the laboratory to commercial implementation is a flexible research, development and demonstration facility, called the Advanced Fuel Cycle Facility (AFCF). The AFCF was introduced as one of three projects under GNEP and will provide the U.S. with the capabilities to evaluate technologies that separate used fuel into reusable material and waste in a proliferation-resistant manner. The separations technology demonstration capability is coupled with a remote transmutation fuel fabrication demonstration capability in an integrated manner that demonstrates advanced safeguard technologies. This paper will discuss the key features of AFCF and its support of the GNEP objectives. (author)

  17. Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments.

    Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

    2017-01-03

    Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO 2 (GWP bio ). In this study we calculated the GWP bio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWP bio factors ranged from 0.13-0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWP bio . Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO 2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWP bio and energy conversion efficiency. By considering the GWP bio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWP bio .

  18. Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments

    Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

    2017-01-01

    Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). In this study we calculated the GWPbio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWPbio factors ranged from 0.13–0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWPbio. Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWPbio and energy conversion efficiency. By considering the GWPbio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWPbio. PMID:28045111

  19. Seabird colonies as important global drivers in the nitrogen and phosphorus cycles.

    Otero, Xosé Luis; De La Peña-Lastra, Saul; Pérez-Alberti, Augusto; Ferreira, Tiago Osorio; Huerta-Diaz, Miguel Angel

    2018-01-23

    Seabirds drastically transform the environmental conditions of the sites where they establish their breeding colonies via soil, sediment, and water eutrophication (hereafter termed ornitheutrophication). Here, we report worldwide amounts of total nitrogen (N) and total phosphorus (P) excreted by seabirds using an inventory of global seabird populations applied to a bioenergetics model. We estimate these fluxes to be 591 Gg N y -1 and 99 Gg P y -1 , respectively, with the Antarctic and Southern coasts receiving the highest N and P inputs. We show that these inputs are of similar magnitude to others considered in global N and P cycles, with concentrations per unit of surface area in seabird colonies among the highest measured on the Earth's surface. Finally, an important fraction of the total excreted N (72.5 Gg y -1 ) and P (21.8 Gg y -1 ) can be readily solubilized, increasing their short-term bioavailability in continental and coastal waters located near the seabird colonies.

  20. Marine methane cycle simulations for the period of early global warming

    Elliott, S.; Maltrud, M.; Reagan, M.T.; Moridis, G.J.; Cameron-Smith, P.J.

    2011-01-02

    Geochemical environments, fates, and effects are modeled for methane released into seawater by the decomposition of climate-sensitive clathrates. A contemporary global background cycle is first constructed, within the framework of the Parallel Ocean Program. Input from organics in the upper thermocline is related to oxygen levels, and microbial consumption is parameterized from available rate measurements. Seepage into bottom layers is then superimposed, representing typical seabed fluid flow. The resulting CH{sub 4} distribution is validated against surface saturation ratios, vertical sections, and slope plume studies. Injections of clathrate-derived methane are explored by distributing a small number of point sources around the Arctic continental shelf, where stocks are extensive and susceptible to instability during the first few decades of global warming. Isolated bottom cells are assigned dissolved gas fluxes from porous-media simulation. Given the present bulk removal pattern, methane does not penetrate far from emission sites. Accumulated effects, however, spread to the regional scale following the modeled current system. Both hypoxification and acidification are documented. Sensitivity studies illustrate a potential for material restrictions to broaden the perturbations, since methanotrophic consumers require nutrients and trace metals. When such factors are considered, methane buildup within the Arctic basin is enhanced. However, freshened polar surface waters act as a barrier to atmospheric transfer, diverting products into the deep return flow. Uncertainties in the logic and calculations are enumerated including those inherent in high-latitude clathrate abundance, buoyant effluent rise through the column, representation of the general circulation, and bacterial growth kinetics.

  1. Marine methane cycle simulations for the period of early global warming

    Elliott, Scott; Maltrud, Mathew; Reagan, Matthew; Moridis, George; Cameron-Smith, Philip

    2011-03-01

    Geochemical environments, fates, and effects are modeled for methane released into seawater by the decomposition of climate-sensitive clathrates. A contemporary global background cycle is first constructed, within the framework of the Parallel Ocean Program. Input from organics in the upper thermocline is related to oxygen levels, and microbial consumption is parameterized from available rate measurements. Seepage into bottom layers is then superimposed, representing typical seabed fluid flow. The resulting CH4 distribution is validated against surface saturation ratios, vertical sections, and slope plume studies. Injections of clathrate-derived methane are explored by distributing a small number of point sources around the Arctic continental shelf, where stocks are extensive and susceptible to instability during the first few decades of global warming. Isolated bottom cells are assigned dissolved gas fluxes from porous-media simulation. Given the present bulk removal pattern, methane does not penetrate far from emission sites. Accumulated effects, however, spread to the regional scale following the modeled current system. Both hypoxification and acidification are documented. Sensitivity studies illustrate a potential for material restrictions to broaden the perturbations, since methanotrophic consumers require nutrients and trace metals. When such factors are considered, methane buildup within the Arctic basin is enhanced. However, freshened polar surface waters act as a barrier to atmospheric transfer, diverting products into the deep return flow. Uncertainties in the logic and calculations are enumerated including those inherent in high-latitude clathrate abundance, buoyant effluent rise through the column, representation of the general circulation, and bacterial growth kinetics.

  2. Chemistry of organic carbon in soil with relationship to the global carbon cycle

    Post, W.M. III.

    1988-01-01

    Various ecosystem disturbances alter the balances between production of organic matter and its decomposition and therefore change the amount of carbon in soil. The most severe perturbation is conversion of natural vegetation to cultivated crops. Conversion of natural vegetation to cultivated crops results in a lowered input of slowly decomposing material which causes a reduction in overall carbon levels. Disruption of soil matrix structure by cultivation leads to lowered physical protection of organic matter resulting in an increased net mineralization rate of soil carbon. Climate change is another perturbation that affects the amount and composition of plant production, litter inputs, and decomposition regimes but does not affect soil structure directly. Nevertheless, large changes in soil carbon storage are probable with anticipated CO 2 induced climate change, particularly in northern latitudes where anticipated climate change will be greatest (MacCracken and Luther 1985) and large amounts of soil organic matter are found. It is impossible, given the current state of knowledge of soil organic matter processes and transformations to develop detailed process models of soil carbon dynamics. Largely phenomenological models appear to be developing into predictive tools for understanding the role of soil organic matter in the global carbon cycle. In particular, these models will be useful in quantifying soil carbon changes due to human land-use and to anticipated global climate and vegetation changes. 47 refs., 7 figs., 2 tabs

  3. A global coal production forecast with multi-Hubbert cycle analysis

    Patzek, Tadeusz W. [Department of Petroleum and Geosystems Engineering, The University of Texas, Austin, TX 78712 (United States); Croft, Gregory D. [Department of Civil and Environmental Engineering, The University of California, Berkeley, Davis Hall, CA 94720 (United States)

    2010-08-15

    Based on economic and policy considerations that appear to be unconstrained by geophysics, the Intergovernmental Panel on Climate Change (IPCC) generated forty carbon production and emissions scenarios. In this paper, we develop a base-case scenario for global coal production based on the physical multi-cycle Hubbert analysis of historical production data. Areas with large resources but little production history, such as Alaska and the Russian Far East, are treated as sensitivities on top of this base-case, producing an additional 125 Gt of coal. The value of this approach is that it provides a reality check on the magnitude of carbon emissions in a business-as-usual (BAU) scenario. The resulting base-case is significantly below 36 of the 40 carbon emission scenarios from the IPCC. The global peak of coal production from existing coalfields is predicted to occur close to the year 2011. The peak coal production rate is 160 EJ/y, and the peak carbon emissions from coal burning are 4.0 Gt C (15 Gt CO{sub 2}) per year. After 2011, the production rates of coal and CO{sub 2} decline, reaching 1990 levels by the year 2037, and reaching 50% of the peak value in the year 2047. It is unlikely that future mines will reverse the trend predicted in this BAU scenario. (author)

  4. Insights into the diurnal cycle of global Earth outgoing radiation using a numerical weather prediction model

    Gristey, Jake J.; Chiu, J. Christine; Gurney, Robert J.; Morcrette, Cyril J.; Hill, Peter G.; Russell, Jacqueline E.; Brindley, Helen E.

    2018-04-01

    A globally complete, high temporal resolution and multiple-variable approach is employed to analyse the diurnal cycle of Earth's outgoing energy flows. This is made possible via the use of Met Office model output for September 2010 that is assessed alongside regional satellite observations throughout. Principal component analysis applied to the long-wave component of modelled outgoing radiation reveals dominant diurnal patterns related to land surface heating and convective cloud development, respectively explaining 68.5 and 16.0 % of the variance at the global scale. The total variance explained by these first two patterns is markedly less than previous regional estimates from observations, and this analysis suggests that around half of the difference relates to the lack of global coverage in the observations. The first pattern is strongly and simultaneously coupled to the land surface temperature diurnal variations. The second pattern is strongly coupled to the cloud water content and height diurnal variations, but lags the cloud variations by several hours. We suggest that the mechanism controlling the delay is a moistening of the upper troposphere due to the evaporation of anvil cloud. The short-wave component of modelled outgoing radiation, analysed in terms of albedo, exhibits a very dominant pattern explaining 88.4 % of the variance that is related to the angle of incoming solar radiation, and a second pattern explaining 6.7 % of the variance that is related to compensating effects from convective cloud development and marine stratocumulus cloud dissipation. Similar patterns are found in regional satellite observations, but with slightly different timings due to known model biases. The first pattern is controlled by changes in surface and cloud albedo, and Rayleigh and aerosol scattering. The second pattern is strongly coupled to the diurnal variations in both cloud water content and height in convective regions but only cloud water content in marine

  5. Accounting for carbon cycle feedbacks in a comparison of the global warming effects of greenhouse gases

    Gillett, Nathan P [Canadian Centre for Climate Modelling and Analysis, Environment Canada, University of Victoria, PO Box 1700, STN CSC, Victoria, BC, V8W 3V6 (Canada); Matthews, H Damon, E-mail: nathan.gillett@ec.gc.ca [Department of Geography, Planning and Environment, Concordia University, 1455 de Maisonneuve West, H 1255-26, Montreal, QC, H3G 1M8 (Canada)

    2010-07-15

    Greenhouse gases other than CO{sub 2} make a significant contribution to human-induced climate change, and multi-gas mitigation strategies are cheaper to implement than those which limit CO{sub 2} emissions alone. Most practical multi-gas mitigation strategies require metrics to relate the climate warming effects of CO{sub 2} and other greenhouse gases. Global warming potential (GWP), defined as the ratio of time-integrated radiative forcing of a particular gas to that of CO{sub 2} following a unit mass emission, is the metric used in the Kyoto Protocol, and we define mean global temperature change potential (MGTP) as an equivalent metric of the temperature response. Here we show that carbon-climate feedbacks inflate the GWPs and MGTPs of methane and nitrous oxide by {approx} 20% in coupled carbon-climate model simulations of the response to a pulse of 50 x 1990 emissions, due to a warming-induced release of CO{sub 2} from the land biosphere and ocean. The magnitude of this effect is expected to be dependent on the model, but it is not captured at all by the analytical models usually used to calculate metrics such as GWP. We argue that the omission of carbon cycle dynamics has led to a low bias of uncertain but potentially substantial magnitude in metrics of the global warming effect of other greenhouse gases, and we suggest that the carbon-climate feedback should be considered when greenhouse gas metrics are calculated and applied.

  6. Representing leaf and root physiological traits in CLM improves global carbon and nitrogen cycling predictions

    Ghimire, Bardan; Riley, William J.; Koven, Charles D.; Mu, Mingquan; Randerson, James T.

    2016-06-01

    In many ecosystems, nitrogen is the most limiting nutrient for plant growth and productivity. However, current Earth System Models (ESMs) do not mechanistically represent functional nitrogen allocation for photosynthesis or the linkage between nitrogen uptake and root traits. The current version of CLM (4.5) links nitrogen availability and plant productivity via (1) an instantaneous downregulation of potential photosynthesis rates based on soil mineral nitrogen availability, and (2) apportionment of soil nitrogen between plants and competing nitrogen consumers assumed to be proportional to their relative N demands. However, plants do not photosynthesize at potential rates and then downregulate; instead photosynthesis rates are governed by nitrogen that has been allocated to the physiological processes underpinning photosynthesis. Furthermore, the role of plant roots in nutrient acquisition has also been largely ignored in ESMs. We therefore present a new plant nitrogen model for CLM4.5 with (1) improved representations of linkages between leaf nitrogen and plant productivity based on observed relationships in a global plant trait database and (2) plant nitrogen uptake based on root-scale Michaelis-Menten uptake kinetics. Our model improvements led to a global bias reduction in GPP, LAI, and biomass of 70%, 11%, and 49%, respectively. Furthermore, water use efficiency predictions were improved conceptually, qualitatively, and in magnitude. The new model's GPP responses to nitrogen deposition, CO2 fertilization, and climate also differed from the baseline model. The mechanistic representation of leaf-level nitrogen allocation and a theoretically consistent treatment of competition with belowground consumers led to overall improvements in global carbon cycling predictions.

  7. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere

    Y. P. Wang

    2010-07-01

    Full Text Available Carbon storage by many terrestrial ecosystems can be limited by nutrients, predominantly nitrogen (N and phosphorus (P, in addition to other environmental constraints, water, light and temperature. However the spatial distribution and the extent of both N and P limitation at the global scale have not been quantified. Here we have developed a global model of carbon (C, nitrogen (N and phosphorus (P cycles for the terrestrial biosphere. Model estimates of steady state C and N pool sizes and major fluxes between plant, litter and soil pools, under present climate conditions, agree well with various independent estimates. The total amount of C in the terrestrial biosphere is 2767 Gt C, and the C fractions in plant, litter and soil organic matter are 19%, 4% and 77%. The total amount of N is 135 Gt N, with about 94% stored in the soil, 5% in the plant live biomass, and 1% in litter. We found that the estimates of total soil P and its partitioning into different pools in soil are quite sensitive to biochemical P mineralization. The total amount of P (plant biomass, litter and soil excluding occluded P in soil is 17 Gt P in the terrestrial biosphere, 33% of which is stored in the soil organic matter if biochemical P mineralization is modelled, or 31 Gt P with 67% in soil organic matter otherwise.

    This model was used to derive the global distribution and uncertainty of N or P limitation on the productivity of terrestrial ecosystems at steady state under present conditions. Our model estimates that the net primary productivity of most tropical evergreen broadleaf forests and tropical savannahs is reduced by about 20% on average by P limitation, and most of the remaining biomes are N limited; N limitation is strongest in high latitude deciduous needle leaf forests, and reduces its net primary productivity by up to 40% under present conditions.

  8. Evaluation and intercomparison of three-dimensional global marine carbon cycle models

    Caldeira, K., LLNL

    1998-07-01

    -Reimer, 1990; Sarmiento et al., 1992, Najjar et al., 1992). These twin needs for the development of marine carbon cycle models are expressed in two of the main elements of JGOFS SMP: (1) extrapolation and prediction, and (2) global and regional balances of carbon and related biologically-active substances. We propose to address these program elements through a coordinated, multi-investigator project to evaluate and intercompare several 3-D global marine carbon cycle models.

  9. Global warming implications of facade parameters: A life cycle assessment of residential buildings in Bahrain

    Radhi, Hassan, E-mail: h_alradhi@yahoo.com [Global Engineering Bureau, P.O Box 33130, Manama, Kingdom of Bahrain (Bahrain); Sharples, Stephen, E-mail: steve.sharples@liverpool.ac.uk [School of Architecture, University of Liverpool (United Kingdom)

    2013-01-15

    On a global scale, the Gulf Corporation Council Countries (GCCC), including Bahrain, are amongst the top countries in terms of carbon dioxide emissions per capita. Building authority in Bahrain has set a target of 40% reduction of electricity consumption and associated CO{sub 2} emissions to be achieved by using facade parameters. This work evaluates how the life cycle CO{sub 2} emissions of buildings are affected by facade parameters. The main focus is placed on direct and indirect CO{sub 2} emissions from three contributors, namely, chemical reactions during production processes (Pco{sub 2}), embodied energy (Eco{sub 2}) and operational energy (OPco{sub 2}). By means of the life cycle assessment (LCA) methodology, it has been possible to show that the greatest environmental impact occurs during the operational phase (80-90%). However, embodied CO{sub 2} emissions are an important factor that needs to be brought into the systems used for appraisal of projects, and hence into the design decisions made in developing projects. The assessment shows that masonry blocks are responsible for 70-90% of the total CO{sub 2} emissions of facade construction, mainly due to their physical characteristics. The highest Pco{sub 2} emissions factors are those of window elements, particularly aluminium frames. However, their contribution of CO{sub 2} emissions depends largely on the number and size of windows. Each square metre of glazing is able to increase the total CO{sub 2} emissions by almost 30% when compared with the same areas of opaque walls. The use of autoclaved aerated concrete (AAC) walls reduces the total life cycle CO{sub 2} emissions by almost 5.2% when compared with ordinary walls, while the use of thermal insulation with concrete wall reduces CO{sub 2} emissions by 1.2%. The outcome of this work offers to the building industry a reliable indicator of the environmental impact of residential facade parameters. - Highlights: Black-Right-Pointing-Pointer Life cycle

  10. Global warming implications of facade parameters: A life cycle assessment of residential buildings in Bahrain

    Radhi, Hassan; Sharples, Stephen

    2013-01-01

    On a global scale, the Gulf Corporation Council Countries (GCCC), including Bahrain, are amongst the top countries in terms of carbon dioxide emissions per capita. Building authority in Bahrain has set a target of 40% reduction of electricity consumption and associated CO 2 emissions to be achieved by using facade parameters. This work evaluates how the life cycle CO 2 emissions of buildings are affected by facade parameters. The main focus is placed on direct and indirect CO 2 emissions from three contributors, namely, chemical reactions during production processes (Pco 2 ), embodied energy (Eco 2 ) and operational energy (OPco 2 ). By means of the life cycle assessment (LCA) methodology, it has been possible to show that the greatest environmental impact occurs during the operational phase (80–90%). However, embodied CO 2 emissions are an important factor that needs to be brought into the systems used for appraisal of projects, and hence into the design decisions made in developing projects. The assessment shows that masonry blocks are responsible for 70–90% of the total CO 2 emissions of facade construction, mainly due to their physical characteristics. The highest Pco 2 emissions factors are those of window elements, particularly aluminium frames. However, their contribution of CO 2 emissions depends largely on the number and size of windows. Each square metre of glazing is able to increase the total CO 2 emissions by almost 30% when compared with the same areas of opaque walls. The use of autoclaved aerated concrete (AAC) walls reduces the total life cycle CO 2 emissions by almost 5.2% when compared with ordinary walls, while the use of thermal insulation with concrete wall reduces CO 2 emissions by 1.2%. The outcome of this work offers to the building industry a reliable indicator of the environmental impact of residential facade parameters. - Highlights: ► Life cycle carbon assessment of façade parameters. ► Greatest environmental impact occurs

  11. Insight into the Global Carbon Cycle from Assimilation of Satellite CO2 measurements

    Baker, D. F.

    2017-12-01

    A key goal of satellite CO2 measurements is to provide sufficient spatio-temporal coverage to constrain portions of the globe poorly observed by the in situ network, especially the tropical land regions. While systematic errors in both measurements and modeling remain a challenge, these satellite data are providing new insight into the functioning of the global carbon cycle, most notably across the recent 2015-16 En Niño. Here we interpret CO2 measurements from the GOSAT and OCO-2 satellites, as well as from the global in situ network (both surface sites and routine aircraft profiles), using a 4DVar-based global CO2 flux inversion across 2009-2017. The GOSAT data indicate that the tropical land regions are responsible for most of the observed global variability in CO2 across the last 8+ years. For the most recent couple of years where they overlap, the OCO-2 data give the same result, an +2 PgC/yr shift towards CO2 release in the ENSO warm phase, while disagreeing somewhat on the absolute value of the flux. The variability given by both these satellites disagrees with that given by an in situ-only inversion across the recent 2015-16 El Niño: the +2 PgC/yr shift from the satellites is double that given by the in situ data alone, suggesting that the more complete coverage is providing a more accurate view. For the current release of OCO-2 data (version 7), however, the flux results given by the OCO-2 land data (from both nadir- and glint-viewing modes) disagree significantly with those given by the ocean glint data; we examine the soon-to-be-released v8 data to assess whether these systematic retrieval errors have been reduced, and whether the corrected OCO-2 ocean data support the result from the land data. We discuss finer-scale features flux results given by the satellite data, and examine the importance of the flux prior, as well.

  12. Experimental study of the mechanisms of CO{sub 2} capture by calcium cycle under circulating fluidized bed conditions; Etude experimentale des mecanismes de capture du CO{sub 2} par cycle calcium en lit fluidise circulant

    Hoteit, A

    2006-06-15

    The work undertaken in this Thesis in partnership with department R and D of ALSTOM Power Boilers, CEMEX and the ADEME, relates to the experimental study of various phenomena associated to CO{sub 2} capture under circulating fluidized bed conditions. The size of particles, temperature and the CO{sub 2} concentration have an influence on the limestone calcination reaction. The reaction of carbonation of lime is not total. During successive cycles of calcination/carbonation, the rate of carbonation obtained with hydrated lime is increasingly higher than that obtained with the lime. Under continuously reducing conditions, the decomposition of sulphates present in the bed ashes is not total. This decomposition is total under reduction/oxidation cycles. A modeling of calcination allowed to determine the intrinsic kinetic constants of calcination and carbonation. (author)

  13. Life-cycle global warming and non-renewable energy consumption impacts of ammonia fuel

    Are, Kristian Ray Angelo; Razon, Luis; Tan, Raymond Girard

    2015-01-01

    The use of ammonia (NH 3 ) as transportation fuel had been a recent topics of research interest. NH 3 has fuel properties that are better than those of other alternative fuels, such as it high energy density and simpler storage. However, it has a low flame speed and would require to be mixed with a secondary fuel forming a dual fuel system. Moreover, current industrial methods of NH 3 production are major global warming potential (GWP) and non-renewable energy consumption (NREC) impact contributors. This study assessed the life-cycle GWP and NREC of using different NH 3 -secondary fuel mixtures. Four fuel mixtures were considered, wherein NH 3 is mixed with gasoline, diesel, hydrogen or dimethyl ether (DME). Also, our processes of NH 3 production were considered: steam reforming (SR), partial oxidation (PO), which are industrial methods and two biomass-based (alternative) processes wherein cereal straw (Salix) and cyanobacteria (Anabaena ATCC 33047) are used feedstocks. Contribution, sensitivity, and uncertainty analyses (via Monte Carlo simulation) were conducted for life-cycle interpretation. Dominance matrix tool was also employed to aid in drawing conclusions. The study concludes that the environmental impacts of NH 3 fuel are dependent on (i) NH 3 production methods and (ii) type of NH 3 fuel mixture. NH 3 -diesel fuel mixtures have lower GWP compared to pure diesel, while NH 3 -gasoline fuel mixture have higher GWP compared to pure gasoline. Because of large uncertainty of the NREC pure gasoline and pure diesel, no firm conclusion can be made about the NREC ammonia-diesel and ammonia-gasoline. If fuel mixture types are compared, NH 3 -H 2 mixtures have the lowest GWP and NREC among the four, though this would entail designing new engines. Over-all, it is shown that fuel systems involving biomass-based NH 3 have lower environmental impacts as compared to conventionally-produced NH 3 counterparts. (author)

  14. How does global biogeochemical cycle become complicated by terrestrial-aquatic interactions ?

    Nakayama, Tadanobu; Maksyutov, Shamil

    2015-04-01

    Inland water such as river and lake are now known to be important and active components of global carbon cycle though its contribution has remained uncertain due to data scarcity (Battin et al., 2009; Aufdenkampe et al., 2011). The author has developed process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama, 2008a-b, 2010, 2011a-b, 2012a-c, 2013; Nakayama and Fujita, 2010; Nakayama and Hashimoto, 2011; Nakayama and Shankman, 2013a-b; Nakayama and Watanabe, 2004, 2006, 2008a-b; Nakayama et al., 2006, 2007, 2010, 2012), which incorporates surface-groundwater interactions, includes up- and down-scaling processes between local-global scales, and can simulate iteratively nonlinear feedback between hydrologic, geomorphic, and ecological processes. In this study, NICE was coupled with various biogeochemical models to incorporate biogeochemical cycle including reaction between inorganic and organic carbons (DOC, POC, DIC, pCO2, etc.) in terrestrial and aquatic ecosystems including surface water and groundwater. The coupled model simulated CO2 evasion from inland water in global scale, was relatively in good agreement in that estimated by empirical regression model (Raymond et al., 2013). In particular, the simulated result implied importance of connectivity between terrestrial and aquatic ecosystems in addition to surface and groundwater, and hillslopes and stream channels, etc. The model further improved the accuracy of CH4 flux in wetland which is sensitive to fluctuations of shallow groundwater because the original NICE incorporates 3-D groundwater sub-model and simulates lateral subsurface flow more reasonably. This simulation system would play important role in integration of greenhouse gas budget of the biosphere, quantification of hot spots in boundless biogeochemical cycle, and bridging gap between top-down and bottom-up approaches (Cole et al., 2007; Frei et al., 2012; Kiel and Cardenas, 2014). References; Aufdenkampe, A.K., et al

  15. Global ice volume variations through the last glacial cycle simulated by a 3-D ice-dynamical model

    Bintanja, R.; Wal, R.S.W. van de; Oerlemans, J.

    2002-01-01

    A coupled ice sheet—ice shelf—bedrock model was run at 20km resolution to simulate the evolution of global ice cover during the last glacial cycle. The mass balance model uses monthly mean temperature and precipitation as input and incorporates the albedo—mass balance feedback. The model is forced

  16. Municipal solid waste conversion to transportation fuels: a life-cycle estimation of global warming potential and energy consumption

    Pressley, Phillip N.; Aziz, Tarek N.; DeCarolis, Joseph F.

    2014-01-01

    This paper utilizes life cycle assessment (LCA) methodology to evaluate the conversion of U.S. municipal solid waste (MSW) to liquid transportation fuels via gasification and Fischer-Tropsch (FT). The model estimates the cumulative energy demand and global warming potential (GWP) associated...

  17. Comparing the Life Cycle Energy Consumption, Global Warming and Eutrophication Potentials of Several Water and Waste Service Options

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG...

  18. The Policy Cycle and Vernacular Globalization: A Case Study of the Creation of Vietnam National University--Hochiminh City

    Minh Ngo, Thanh; Lingard, Bob; Mitchell, Jane

    2006-01-01

    This article examines the policy cycle and vernacular globalization in the context of higher education reform in Vietnam. Through an analysis of the development of the Vietnam National University--Hochiminh City as part of the post-1986 reconstruction of Vietnamese higher education, the article considers the complex interrelationship between…

  19. Calcium and magnesium concentrations in uterine fluid and blood serum during the estrous cycle in the bovine

    Sayed Mortaza Alavi-Shoushtari

    2012-06-01

    Full Text Available To investigate uterine and serum Ca++ and Mg++ variations during the estrous cycle in the bovine, 66 genital tracts and blood samples were collected from Urmia abattoir, Urmia, Iran. The phase of the estrous cycle was determined by examination of the structures present on ovaries and uterine tonicity. Of the collected samples, 17 were pro-estrus, 12 estrus, 14 metestrus and 23 diestrus. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. The mean ± SEM concentration of serum Ca++ in pro-estrus, estrus, metestrus and diestrus was 5.77 ± 0.69, 8.87 ± 1.83, 10.95 ± 1.52, 11.09 ± 1.08 mg dL-1, and the mean concentration of uterine fluid Ca++ was 4.40 ± 0.72, 3.15 ± 0.67, 5.89 ± 0.88, 8.63 ± 0.97 mg dL-1, respectively. The mean concentration of serum Mg++ in pro-estrus, estrus, metestrus and diestrus was 3.53 ± 0.30, 4.20 ± 0.52, 3.49 ± 0.38, 3.39 ± 0.29 mg dL-1, and mean concentration of uterine fluid Mg++ was 5.27 ± 0.42, 4.92 ± 0.60, 5.56 ± 0.30, 5.88 ± 0.36 mg dL-1, respectively. The serum and uterine fluid Ca++ in pro-estrus were significantly different from those of the metestrus and diestrus. In all stages of estrous cycle the mean concentration of serum Ca++ was higher than that in the uterine fluid. The difference between serum and uterine fluid Ca++ in estrus, metestrus and diestrus was significant. There was no significant difference between serum Mg++ content nor was it different from uterine fluid Mg++ content at any stages of estrous cycle. In all stages of estrous cycle the uterine fluid Mg++ was higher than that of the serum. These results suggest that during the estrous cycle in the cow, Ca++ is passively secreted in uterine fluids and is mostly dependent on blood serum Ca++ variations but Mg++ is secreted independently and does not follow variations in the serum concentrations.

  20. Did large animals play an important role in global biogeochemical cycling in the past?

    Doughty, C.

    2014-12-01

    In the late Pleistocene (~50-10,000 years ago), ninety-seven genera of large animals (>44kg) (megafauna) went extinct, concentrated in the Americas and Australia. The loss of megafauna had major effects on ecosystem structure, seed dispersal and land surface albedo. However, the impact of this dramatic extinction on ecosystem nutrient biogeochemistry, through the lateral transport of dung and bodies, has never been explored. Here we explore these nutrient impacts using a novel mathematical framework that analyses this lateral transport as a diffusion-like process and demonstrates that large animals play a disproportionately large role in the horizontal transfer of nutrients across landscapes. For example, we estimate that the extinction of the Amazonian megafauna led to a >98% reduction in the lateral transfer flux of the limiting nutrient phosphorus (P) with similar, though less extreme, decreases in all continents outside of Africa. This resulted in strong decreases in phosphorus availability in Eastern Amazonia away from fertile floodplains, a decline which may still be ongoing, and current P limitation in the Amazon basin may be partially a relic of an ecosystem without the functional connectedness it once had. More broadly, the Pleistocene megafaunal extinctions resulted in major and ongoing disruptions to terrestrial biogeochemical cycling at continental scales and increased nutrient heterogeneity globally.

  1. Inhibition of nitrogenase by oxygen in marine cyanobacteria controls the global nitrogen and oxygen cycles

    Berman-Frank, I.; Chen, Y.-B.; Gerchman, Y.; Dismukes, G. C.; Falkowski, P. G.

    2005-03-01

    Cyanobacterial N2-fixation supplies the vast majority of biologically accessible inorganic nitrogen to nutrient-poor aquatic ecosystems. The process, catalyzed by the heterodimeric protein complex, nitrogenase, is thought to predate that of oxygenic photosynthesis. Remarkably, while the enzyme plays such a critical role in Earth's biogeochemical cycles, the activity of nitrogenase in cyanobacteria is markedly inhibited in vivo at a post-translational level by the concentration of O2 in the contemporary atmosphere leading to metabolic and biogeochemical inefficiency in N2 fixation. We illustrate this crippling effect with data from Trichodesmium spp. an important contributor of "new nitrogen" to the world's subtropical and tropical oceans. The enzymatic inefficiency of nitrogenase imposes a major elemental taxation on diazotrophic cyanobacteria both in the costs of protein synthesis and for scarce trace elements, such as iron. This restriction has, in turn, led to a global limitation of fixed nitrogen in the contemporary oceans and provides a strong biological control on the upper bound of oxygen concentration in Earth's atmosphere.

  2. Atmospheric Carbon Dioxide and the Global Carbon Cycle: The Key Uncertainties

    Peng, T. H.; Post, W. M.; DeAngelis, D. L.; Dale, V. H.; Farrell, M. P.

    1987-12-01

    The biogeochemical cycling of carbon between its sources and sinks determines the rate of increase in atmospheric CO{sub 2} concentrations. The observed increase in atmospheric CO{sub 2} content is less than the estimated release from fossil fuel consumption and deforestation. This discrepancy can be explained by interactions between the atmosphere and other global carbon reservoirs such as the oceans, and the terrestrial biosphere including soils. Undoubtedly, the oceans have been the most important sinks for CO{sub 2} produced by man. But, the physical, chemical, and biological processes of oceans are complex and, therefore, credible estimates of CO{sub 2} uptake can probably only come from mathematical models. Unfortunately, one- and two-dimensional ocean models do not allow for enough CO{sub 2} uptake to accurately account for known releases. Thus, they produce higher concentrations of atmospheric CO{sub 2} than was historically the case. More complex three-dimensional models, while currently being developed, may make better use of existing tracer data than do one- and two-dimensional models and will also incorporate climate feedback effects to provide a more realistic view of ocean dynamics and CO{sub 2} fluxes. The instability of current models to estimate accurately oceanic uptake of CO{sub 2} creates one of the key uncertainties in predictions of atmospheric CO{sub 2} increases and climate responses over the next 100 to 200 years.

  3. Experimental study of the mechanisms of CO2 capture by calcium cycle under circulating fluidized bed conditions

    Hoteit, A.

    2006-06-01

    The work undertaken in this Thesis in partnership with department R and D of ALSTOM Power Boilers, CEMEX and the ADEME, relates to the experimental study of various phenomena associated to CO 2 capture under circulating fluidized bed conditions. The size of particles, temperature and the CO 2 concentration have an influence on the limestone calcination reaction. The reaction of carbonation of lime is not total. During successive cycles of calcination/carbonation, the rate of carbonation obtained with hydrated lime is increasingly higher than that obtained with the lime. Under continuously reducing conditions, the decomposition of sulphates present in the bed ashes is not total. This decomposition is total under reduction/oxidation cycles. A modeling of calcination allowed to determine the intrinsic kinetic constants of calcination and carbonation. (author)

  4. Derivation of a northern-hemispheric biomass map for use in global carbon cycle models

    Thurner, Martin; Beer, Christian; Santoro, Maurizio; Carvalhais, Nuno; Wutzler, Thomas; Schepaschenko, Dmitry; Shvidenko, Anatoly; Kompter, Elisabeth; Levick, Shaun; Schmullius, Christiane

    2013-04-01

    Quantifying the state and the change of the World's forests is crucial because of their ecological, social and economic value. Concerning their ecological importance, forests provide important feedbacks on the global carbon, energy and water cycles. In addition to their influence on albedo and evapotranspiration, they have the potential to sequester atmospheric carbon dioxide and thus to mitigate global warming. The current state and inter-annual variability of forest carbon stocks remain relatively unexplored, but remote sensing can serve to overcome this shortcoming. While for the tropics wall-to-wall estimates of above-ground biomass have been recently published, up to now there was a lack of similar products covering boreal and temperate forests. Recently, estimates of forest growing stock volume (GSV) were derived from ENVISAT ASAR C-band data for latitudes above 30° N. Utilizing a wood density and a biomass compartment database, a forest carbon density map covering North-America, Europe and Asia with 0.01° resolution could be derived out of this dataset. Allometric functions between stem, branches, root and foliage biomass were fitted and applied for different leaf types (broadleaf, needleleaf deciduous, needleleaf evergreen forest). Additionally, this method enabled uncertainty estimation of the resulting carbon density map. Intercomparisons with inventory-based biomass products in Russia, Europe and the USA proved the high accuracy of this approach at a regional scale (r2 = 0.70 - 0.90). Based on the final biomass map, the forest carbon stocks and densities (excluding understorey vegetation) for three biomes were estimated across three continents. While 40.7 ± 15.7 Gt of carbon were found to be stored in boreal forests, temperate broadleaf/mixed forests and temperate conifer forests contain 24.5 ± 9.4 Gt(C) and 14.5 ± 4.8 Gt(C), respectively. In terms of carbon density, most of the carbon per area is stored in temperate conifer (62.1 ± 20.7 Mg

  5. Soil carbon model alternatives for ECHAM5/JSBACH climate model: Evaluation and impacts on global carbon cycle estimates

    Thum, T.; Raisanen, P.; Sevanto, S.

    2011-01-01

    The response of soil organic carbon to climate change might lead to significant feedbacks affecting global warming. This response can be studied by coupled climate-carbon cycle models but so far the description of soil organic carbon cycle in these models has been quite simple. In this work we used...... the coupled climate-carbon cycle model ECHAM5/JSBACH (European Center/Hamburg Model 5/Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg) with two different soil carbon modules, namely (1) the original soil carbon model of JSBACH called CBALANCE and (2) a new soil carbon model Yasso07, to study...... the interaction between climate variability and soil organic carbon. Equivalent ECHAM5/JSBACH simulations were conducted using both soil carbon models, with freely varying atmospheric CO2 for the last 30 years (1977-2006). In this study, anthropogenic CO2 emissions and ocean carbon cycle were excluded. The new...

  6. A model of the solar cycle driven by the dynamo action of the global convection in the solar convection zone

    Yoshimura, H.

    1976-01-01

    Extensive numerical studies of the dynamo equations due to the global convection are presented to simulate the solar cycle and to open the way to study general stellar magnetic cycles. The dynamo equations which represent the longitudinally-averaged magnetohydrodynamical action (mean magnetohydrodynamics) of the global convection under the influence of the rotation in the solar convection zone are considered here as an initial boundary-value problem. The latitudinal and radial structure of the dynamo action consisting of a generation action due to the differential rotation and a regeneration action due to the global convection is parameterized in accordance with the structure of the rotation and of the global convection. This is done especially in such a way as to represent the presence of the two cells of the regeneration action in the radial direction in which the action has opposite signs, which is typical of the regeneration action of the global convection. The effects of the dynamics of the global convection (e.g., the effects of the stratification of the physical conditions in the solar convection zone) are presumed to be all included in those parameters used in the model and they are presumed not to alter the results drastically since these effects are only to change the structure of the regeneration action topologically. (Auth.)

  7. Initializing carbon cycle predictions from the Community Land Model by assimilating global biomass observations

    Fox, A. M.; Hoar, T. J.; Smith, W. K.; Moore, D. J.

    2017-12-01

    The locations and longevity of terrestrial carbon sinks remain uncertain, however it is clear that in order to predict long-term climate changes the role of the biosphere in surface energy and carbon balance must be understood and incorporated into earth system models (ESMs). Aboveground biomass, the amount of carbon stored in vegetation, is a key component of the terrestrial carbon cycle, representing the balance of uptake through gross primary productivity (GPP), losses from respiration, senescence and mortality over hundreds of years. The best predictions of current and future land-atmosphere fluxes are likely from the integration of process-based knowledge contained in models and information from observations of changes in carbon stocks using data assimilation (DA). By exploiting long times series, it is possible to accurately detect variability and change in carbon cycle dynamics through monitoring ecosystem states, for example biomass derived from vegetation optical depth (VOD), and use this information to initialize models before making predictions. To make maximum use of information about the current state of global ecosystems when using models we have developed a system that combines the Community Land Model (CLM) with the Data Assimilation Research Testbed (DART), a community tool for ensemble DA. This DA system is highly innovative in its complexity, completeness and capabilities. Here we described a series of activities, using both Observation System Simulation Experiments (OSSEs) and real observations, that have allowed us to quantify the potential impact of assimilating VOD data into CLM-DART on future land-atmosphere fluxes. VOD data are particularly suitable to use in this activity due to their long temporal coverage and appropriate scale when combined with CLM, but their absolute values rely on many assumptions. Therefore, we have had to assess the implications of the VOD retrieval algorithms, with an emphasis on detecting uncertainty due to

  8. Exploring global carbon turnover and radiocarbon cycling in terrestrial biosphere models

    Graven, H. D.; Warren, H.

    2017-12-01

    The uptake of carbon into terrestrial ecosystems through net primary productivity (NPP) and the turnover of that carbon through various pathways are the fundamental drivers of changing carbon stocks on land, in addition to human-induced and natural disturbances. Terrestrial biosphere models use different formulations for carbon uptake and release, resulting in a range of values in NPP of 40-70 PgC/yr and biomass turnover times of about 25-40 years for the preindustrial period in current-generation models from CMIP5. Biases in carbon uptake and turnover impact simulated carbon uptake and storage in the historical period and later in the century under changing climate and CO2 concentration, however evaluating global-scale NPP and carbon turnover is challenging. Scaling up of plot-scale measurements involves uncertainty due to the large heterogeneity across ecosystems and biomass types, some of which are not well-observed. We are developing the modelling of radiocarbon in terrestrial biosphere models, with a particular focus on decadal 14C dynamics after the nuclear weapons testing in the 1950s-60s, including the impact of carbon flux trends and variability on 14C cycling. We use an estimate of the total inventory of excess 14C in the biosphere constructed by Naegler and Levin (2009) using a 14C budget approach incorporating estimates of total 14C produced by the weapons tests and atmospheric and oceanic 14C observations. By simulating radiocarbon in simple biosphere box models using carbon fluxes from the CMIP5 models, we find that carbon turnover is too rapid in many of the simple models - the models appear to take up too much 14C and release it too quickly. Therefore many CMIP5 models may also simulate carbon turnover that is too rapid. A caveat is that the simple box models we use may not adequately represent carbon dynamics in the full-scale models. Explicit simulation of radiocarbon in terrestrial biosphere models would allow more robust evaluation of biosphere

  9. Plasma surrounding the global heliosphere at large distances controlled by the solar cycle

    Dialynas, Konstantinos; Krimigis, Stamatios; Mitchell, Donald; Decker, Robert; Roelof, Edmond

    2016-04-01

    The past decade can be characterized by a series of key, groundbreaking remote energetic neutral atom (ENA) images (INCA, IBEX) and in-situ ion (Voyager 1 & 2) observations concerning the characteristics and interactions of the heliosphere with the Local Interstellar Medium (LISM). Voyagers 1 and 2 (V1, V2) discovered the reservoir of ions and electrons that constitute the heliosheath (HS) after crossing the termination shock (TS) 35deg north and 32deg south of the ecliptic plane at 94 and 84 astronomical units (1 AU= 1.5 x108 km), respectively. The in situ measurements by each Voyager were placed in a global context by remote sensing images using ENA obtained with the Ion and Neutral Camera (INCA) onboard Cassini orbiting Saturn. The ENA images contain a 5.2-55 keV hydrogen (H) ENA region (Belt) that loops through the celestial sphere and contributes to balancing the pressure of the interstellar magnetic field (ISMF). The success of any future mission with dedicated ENA detectors (e.g. the IMAP mission), highly depends on the antecedent understanding of the details of the plasma processes in the Heliosphere as revealed by remote sensing of the plasma environment characteristics. Therefore, we address here one of the remaining and most important questions: "Where do the 5-55 keV ENAs that INCA measures come from?". We analyzed INCA all-sky maps from 2003 to 2015 and compare the solar cycle (SC) variation of the ENAs in both the nose (upstream) and anti-nose (downstream) directions with the intensities of > 30 keV ions (source of ENA through charge exchange-CE with H) measured in-situ by V1 and V2, in overlapping energy bands ~30-55 keV. ENA intensities decrease during the declining phase of SC23 by ~x3 from 2003 to 2011 but recover through 2014 (SC24); similarly, V1 and V2 ion intensities also decrease and then recover through 2014. The similarity of time profiles of remotely sensed ENA and locally measured ions are consistent with (a) ENA originating in the HS

  10. Effect of cerium oxide doping on the performance of CaO-based sorbents during calcium looping cycles.

    Wang, Shengping; Fan, Shasha; Fan, Lijing; Zhao, Yujun; Ma, Xinbin

    2015-04-21

    A series of CaO-based sorbents were synthesized through a sol-gel method and doped with different amounts of CeO2. The sorbent with a Ca/Ce molar ratio of 15:1 showed an excellent absorption capacity (0.59 gCO2/g sorbent) and a remarkable cycle durability (up to 18 cycles). The admirable capture performance of CaCe-15 was ascribed to its special morphology formed by the doping of CeO2 and the well-distributed CeO2 particles. The sorbents doped with CeO2 possessed a loose shell-connected cross-linking structure, which was beneficial for the contact between CaO and CO2. CaO and CeO2 were dispersed homogeneously, and the existence of CeO2 also decreased the grain size of CaO. The well-dispersed CeO2, which could act as a barrier, effectively prevented the CaO crystallite from growing and sintering, thus the sorbent exhibited outstanding stability. The doping of CeO2 also improved the carbonation rate of the sorbent, resulting in a high capacity in a short period of time.

  11. Crust-mantle branch of the global carbon cycle and origin of deep-seated hydrocarbons

    Sorokhtin N. O.

    2018-03-01

    Full Text Available The processes of multi-stage and polycyclic transformation and transfer of carbon in the crust and mantle have been described. The sediments drawn in the plate underthrust zones break down, become transformed and altered by metamorphic events, and part of the newly formed carbon compounds is transferred by the mantle convective currents to rift zones of the mid-oceanic ridges and carried up to the surface as hydrocarbons of various composition and carbon dioxide. This material becomes re-deposited on the sea floor as sediments forming carbonaceous and carbon-bearing units. As a result of multi-stage mechanism of physical and chemical transformations in the crust-mantle areas of the Earth hydrocarbon compounds acquire features of abiogenic origin remaining, in fact, exogenic. The revealed crust-mantle carbon cycle represents part of a global process for the cyclic carbon transfer from the atmosphere to the mantle and back. The scale of its manifestation is likely not so wide, and numerous small (mm and portions of millimeters particles of exogenic substance and dispersed carbon drawn in the plate underthrust zones form a stable geochemical tail of the crustal direction in the mantle propagating in the plane of convective currents motion. The scale of this process may be indirectly suggested by the volumes of hydrocarbon and carbon dioxide de-gassing and hydrogen in the rift systems of the Earth crust. The amount of generated hydrocarbon gases with deep-seated origin cannot form large gas and oil-and-gas fields since their significant part is transferred to the atmosphere. Just some portion of compounds may be deposited in oceanic sediments and generate gas-hydrate pools.

  12. Calcium supplements

    ... this page: //medlineplus.gov/ency/article/007477.htm Calcium supplements To use the sharing features on this page, please enable JavaScript. WHO SHOULD TAKE CALCIUM SUPPLEMENTS? Calcium is an important mineral for the ...

  13. Evaluating the Long-term Water Cycle Trends at a Global-scale using Satellite and Assimilation Datasets

    Kim, H.; Lakshmi, V.

    2017-12-01

    Global-scale soil moisture and rainfall products retrieved from remotely sensed and assimilation datasets provide an effective way to monitor near surface soil moisture content and precipitation with sub-daily temporal resolution. In the present study, we employed the concept of the stored precipitation fraction Fp(f) in order to examine the long-term water cycle trends at a global-scale. The analysis was done for Fp(f) trends with the various geophysical aspects such as climate zone, land use classifications, amount of vegetation, and soil properties. Furthermore, we compared a global-scale Fp(f) using different microwave-based satellite soil moisture datasets. The Fp(f) is calculated by utilized surface soil moisture dataset from Soil Moisture Active Passive (SMAP), Soil Moisture and Ocean Salinity, Advanced Scatterometer, Advanced Microwave Scanning Radiometer 2, and precipitation information from Global Precipitation Measurement Mission and Global Land Data Assimilation System. Different results from microwave-based soil moisture dataset showed discordant results particularly over arid and highly vegetated regions. The results of this study provide us new insights of the long-term water cycle trends over different land surface areas. Thereby also highlighting the advantages of the recently available GPM and SMAP datasets for the uses in various hydrometeorological applications.

  14. The response of amino acid cycling to global change across multiple biomes: Feedbacks on soil nitrogen availability

    Brzostek, E. R.; Finzi, A. C.

    2010-12-01

    The cycling of organic nitrogen (N) in soil links soil organic matter decomposition to ecosystem productivity. Amino acids are a key pool of organic N in the soil, whose cycling is sensitive to alterations in microbial demand for carbon and N. Further, the amino acids released from the breakdown of protein by proteolytic enzymes are an important source of N that supports terrestrial productivity. The objective of this study was to measure changes in amino acid cycling in response to experimental alterations of precipitation and temperature in twelve global change experiments during the 2009 growing season. The study sites ranged from arctic tundra to xeric grasslands. The treatments experimentally increased temperature, increased or decreased precipitation, or some combination of both factors. The response of amino acid cycling to temperature and precipitation manipulations tended to be site specific, but the responses could be placed into a common framework. Changes in soil moisture drove a large response in amino acid cycling. Precipitation augmentation in xeric and mesic sites increased both amino acid pool sizes and production. However, treatments that decreased precipitation drove decreases in amino acid cycling in xeric sites, but led to increases in amino acid cycling in more mesic sites. Across sites, the response to soil warming was horizon specific. Amino acid cycling in organic rich horizons responded positively to warming, while negative responses were exhibited in lower mineral soil horizons. The variable response likely reflects a higher availability of protein substrate to sustain high rates of proteolytic enzyme activity in organic rich horizons. Overall, these results suggest that soil moisture and the availability of protein substrate may be important factors that mediate the response of amino acid cycling to predicted increases in soil temperatures.

  15. Top-down constraints on disturbance dynamics in the terrestrial carbon cycle: effects at global and regional scales

    Bloom, A. A.; Exbrayat, J. F.; van der Velde, I.; Peters, W.; Williams, M.

    2014-12-01

    Large uncertainties preside over terrestrial carbon flux estimates on a global scale. In particular, the strongly coupled dynamics between net ecosystem productivity and disturbance C losses are poorly constrained. To gain an improved understanding of ecosystem C dynamics from regional to global scale, we apply a Markov Chain Monte Carlo based model-data-fusion approach into the CArbon DAta-MOdel fraMework (CARDAMOM). We assimilate MODIS LAI and burned area, plant-trait data, and use the Harmonized World Soil Database (HWSD) and maps of above ground biomass as prior knowledge for initial conditions. We optimize model parameters based on (a) globally spanning observations and (b) ecological and dynamic constraints that force single parameter values and parameter inter-dependencies to be representative of real world processes. We determine the spatial and temporal dynamics of major terrestrial C fluxes and model parameter values on a global scale (GPP = 123 +/- 8 Pg C yr-1 & NEE = -1.8 +/- 2.7 Pg C yr-1). We further show that the incorporation of disturbance fluxes, and accounting for their instantaneous or delayed effect, is of critical importance in constraining global C cycle dynamics, particularly in the tropics. In a higher resolution case study centred on the Amazon Basin we show how fires not only trigger large instantaneous emissions of burned matter, but also how they are responsible for a sustained reduction of up to 50% in plant uptake following the depletion of biomass stocks. The combination of these two fire-induced effects leads to a 1 g C m-2 d-1reduction in the strength of the net terrestrial carbon sink. Through our simulations at regional and global scale, we advocate the need to assimilate disturbance metrics in global terrestrial carbon cycle models to bridge the gap between globally spanning terrestrial carbon cycle data and the full dynamics of the ecosystem C cycle. Disturbances are especially important because their quick occurrence may have

  16. Closing the Global Energy and Nutrient Cycles through Application of Biogas Residue to Agricultural Land – Potential Benefits and Drawback

    Veronica Arthurson

    2009-04-01

    Full Text Available Anaerobic digestion is an optimal way to treat organic waste matter, resulting in biogas and residue. Utilization of the residue as a crop fertilizer should enhance crop yield and soil fertility, promoting closure of the global energy and nutrient cycles. Consequently, the requirement for production of inorganic fertilizers will decrease, in turn saving significant amounts of energy, reducing greenhouse gas emissions to the atmosphere, and indirectly leading to global economic benefits. However, application of this residue to agricultural land requires careful monitoring to detect amendments in soil quality at the early stages.

  17. Globalization of the nuclear fuel cycle impact of developments on fuel management

    Van Den Durpel, L.; Bertel, E. [OCDE-NEA, Nuclear Development Div., 92 - Issy-les-Moulineaux (France)

    1999-07-01

    Nuclear energy will have to cope more and more with a rapid changing environment due to economic competitive pressure and the de-regulatory progress. In current economic environment, utilities will have to focus strongly on the reduction of their total generation costs, covering the fuel cycle costs, which are only partly under their control. Developments in the fuel cycle will be in the short-term rather evolutionary addressing the current needs of utilities. However, within the context of sustainable development and more and more inclusion of externalities in energy generation costs, more performing developments in the fuel cycle could become important and feasible. A life-cycle design approach of the fuel cycle will be requested in order to cover all factors in order to decrease significantly the nuclear energy generation cost to compete with other alternative fuels in the long-term. This paper will report on some of the trends one could distinguish in the fuel cycle with emphasis on cost reduction. OECD/NEA is currently conducting a study on the fuel cycle aiming to assess current and future nuclear fuel cycles according the potential for further improvement of the full added-value chain of these cycles from a mainly technological and economical perspective including environmental and social considerations. (authors)

  18. Semantic Data Integration and Ontology Use within the Global Earth Observation System of Systems (GEOSS) Global Water Cycle Data Integration System

    Pozzi, W.; Fekete, B.; Piasecki, M.; McGuinness, D.; Fox, P.; Lawford, R.; Vorosmarty, C.; Houser, P.; Imam, B.

    2008-12-01

    The inadequacies of water cycle observations for monitoring long-term changes in the global water system, as well as their feedback into the climate system, poses a major constraint on sustainable development of water resources and improvement of water management practices. Hence, The Group on Earth Observations (GEO) has established Task WA-08-01, "Integration of in situ and satellite data for water cycle monitoring," an integrative initiative combining different types of satellite and in situ observations related to key variables of the water cycle with model outputs for improved accuracy and global coverage. This presentation proposes development of the Rapid, Integrated Monitoring System for the Water Cycle (Global-RIMS)--already employed by the GEO Global Terrestrial Network for Hydrology (GTN-H)--as either one of the main components or linked with the Asian system to constitute the modeling system of GEOSS for water cycle monitoring. We further propose expanded, augmented capability to run multiple grids to embrace some of the heterogeneous methods and formats of the Earth Science, Hydrology, and Hydraulic Engineering communities. Different methodologies are employed by the Earth Science (land surface modeling), the Hydrological (GIS), and the Hydraulic Engineering Communities; with each community employing models that require different input data. Data will be routed as input variables to the models through web services, allowing satellite and in situ data to be integrated together within the modeling framework. Semantic data integration will provide the automation to enable this system to operate in near-real-time. Multiple data collections for ground water, precipitation, soil moisture satellite data, such as SMAP, and lake data will require multiple low level ontologies, and an upper level ontology will permit user-friendly water management knowledge to be synthesized. These ontologies will have to have overlapping terms mapped and linked together. so

  19. Delayed recovery of non-marine tetrapods after the end-Permian mass extinction tracks global carbon cycle

    Irmis, Randall B.; Whiteside, Jessica H.

    2011-01-01

    During the end-Permian mass extinction, marine ecosystems suffered a major drop in diversity, which was maintained throughout the Early Triassic until delayed recovery during the Middle Triassic. This depressed diversity in the Early Triassic correlates with multiple major perturbations to the global carbon cycle, interpreted as either intrinsic ecosystem or external palaeoenvironmental effects. In contrast, the terrestrial record of extinction and recovery is less clear; the effects and magn...

  20. Calcium cation enhanced cathode/electrolyte interface property of Li2FeSiO4/C cathode for lithium-ion batteries with long-cycling life

    Qu, Long; Li, Mingtao; Tian, Xiaolu; Liu, Pei; Yi, Yikun; Yang, Bolun

    2018-03-01

    Currently, the cycle performance at low rate is one of the most critical factor for realizing practical applications of Li2FeSiO4/C as a cathode of the lithium-ion batteries. To meet this challenge, calcium (Ca)-doped Li2FeSiO4/C is prepared by using the sol-gel method with soluble Li, Fe, Si and Ca sources. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy measurements are carried out to determine the crystal structures, morphologies, particle sizes and chemical valence states of the resulting products. Rietveld refinement confirms that Ca-doped Li2FeSiO4 has a monoclinic P21/n structure and that a Ca cation occupies the Fe site in the Li2FeSiO4 lattice. The grain size of Ca-doped Li2FeSiO4 is approximately 20 nm and the nanoparticles are interconnected tightly with amorphous carbon layer. As a cathode material for the lithium-ion batteries, Li2Fe0.97Ca0.03SiO4/C delivers a high discharge capacity of 186 mAh g-1 at a 0.5 C rate. Its capacity retention after the 100th cycle reaches 87%, which increases by 25 percentage points compared with Li2FeSiO4/C. The Li2Fe0.97Ca0.03SiO4/C cathode exhibits good rate performance, with corresponding discharge capacities of 170, 157, 144 and 117 mAh g-1 at 1 C, 2 C, 5 C and 10 C rates, respectively. In summary, the improvement of the electrochemical performance can be attributed to a coefficient of the strengthened crystal structure stability during Li+ deintercalation-intercalation and restrained side reactions between electrode and electrolyte.

  1. The impact of organochlorines cycling in the cryosphere on their global distribution and fate – 1. Sea ice

    Guglielmo, Francesca; Stemmler, Irene; Lammel, Gerhard

    2012-01-01

    Global fate and transport of γ-HCH and DDT was studied using a global multicompartment chemistry-transport model, MPI-MCTM, with and without a dynamic sea ice compartment. The MPI-MCTM is based on coupled ocean and atmosphere general circulation models. Sea ice hosts 7–9% of the burden of the surface ocean. Without cycling in sea ice the geographic distributions are shifted from land to sea. This shift of burdens exceeds the sea ice burden by a factor of ≈8 for γ-HCH and by a factor of ≈15 for DDT. As regional scale seasonal sea ice melting may double surface ocean contamination, a neglect of cycling in sea ice (in an otherwise unchanged model climate) would underestimate ocean exposure in high latitudes. Furthermore, it would lead to overestimates of the residence times in ocean by 40% and 33% and of the total environmental residence times, τ overall , of γ-HCH and DDT by 1.6% and 0.6%, respectively. - Highlights: ► Sea ice hosts 7–9% of the burden of γ-HCH and DDT in the surface ocean. ► Without cycling in sea ice the distributions are shifted from land to sea. ► A neglect of cycling in sea ice would underestimate ocean exposure in high latitudes. ► Persistence of γ-HCH and DDT expected enhanced in climate without sea ice. - The inclusion of cycling in sea ice is found relevant for POPs fate and transport modelling on the global scale.

  2. Development of new historical global Nitrogen fertilizer map and the evaluation of their impacts on terrestrial N cycling and the evaluation of their impacts on terrestrial N cycling

    Nishina, K.; Ito, A.; Hayashi, S.

    2015-12-01

    The use of synthetic nitrogen fertilizer was rapidly growing up after the birth of Haber-Bosch process in the early 20th century. The recent N loading derived from these sources on terrestrial ecosystems was estimated 2 times higher than biogenic N fixation in terrestrial ecosystems (Gruber et al., 2009). However, there are still large uncertainties in cumulative N impacts on terrestrial impact at global scale. In this study, to assess historical N impacts at global scale, we made a new global N fertilizer input map, which was a spatial-temporal explicit map (during 1960-2010) and considered the fraction of NH4+ and NO3- in the N fertilizer inputs. With the developed N fertilizer map, we evaluated historical N20 cycling changes by land-use changes and N depositions in N cycling using ecosystem model 'VISIT'. Prior to the downscaling processes for global N fertilizer map, we applied the statistical data imputation to FAOSTAT data due to there existing many missing data especially in developing countries. For the data imputation, we used multiple data imputation method proposed by Honaker & King (2010). The statistics of various types of synthetic fertilizer consumption are available in FAOSTAT, which can be sorted by the content of NH4+ and NO3-, respectively. To downscaling the country by country N fertilizer consumptions data to the 0.5˚x 0.5˚ grid-based map, we used historical land-use map in Earthstat (Rumankutty et al., 1999). Before the assignment of N fertilizer in each grid, we weighted the double cropping regions to be more N fertilizer input on to these regions. Using M3-Crops Data (Monfreda et al., 2008), we picked up the dominant cropping species in each grid cell. After that, we used Crop Calendar in SAGE dataset (Sacks et al., 2010) and determined schedule of N fertilizer input in each grid cell using dominant crop calendar. Base fertilizer was set to be 7 days before transplanting and second fertilizer to be 30 days after base fertilizer application

  3. Global Transition Zone Anisotropy and Consequences for Mantle Flow and Earth's Deep Water Cycle

    Beghein, C.; Yuan, K.

    2011-12-01

    The transition zone has long been at the center of the debate between multi- and single-layered convection models that directly relate to heat transport and chemical mixing throughout the mantle. It has also been suggested that the transition zone is a reservoir that collects water transported by subduction of the lithosphere into the mantle. Since water lowers mantle minerals density and viscosity, thereby modifying their rheology and melting behavior, it likely affects global mantle dynamics and the history of plate tectonics. Constraining mantle flow is therefore important for our understanding of Earth's thermochemical evolution and deep water cycle. Because it can result from deformation by dislocation creep during convection, seismic anisotropy can help us model mantle flow. It is relatively well constrained in the uppermost mantle, but its presence in the transition zone is still debated. Its detection below 250 km depth has been challenging to date because of the poor vertical resolution of commonly used datasets. In this study, we used global Love wave overtone phase velocity maps, which are sensitive to structure down to much larger depths than fundamental modes alone, and have greater depth resolution than shear wave-splitting data. This enabled us to obtain a first 3-D model of azimuthal anisotropy for the upper 800km of the mantle. We inverted the 2Ψ terms of anisotropic phase velocity maps [Visser, et al., 2008] for the first five Love wave overtones between 35s and 174s period. The resulting model shows that the average anisotropy amplitude for vertically polarized shear waves displays two main stable peaks: one in the uppermost mantle and, most remarkably, one in the lower transition zone. F-tests showed that the presence of 2Ψ anisotropy in the transition zone is required to improve the third, fourth, and fifth overtones fit. Because of parameter trade-offs, however, we cannot exclude that the anisotropy is located in the upper transition zone as

  4. Implications of a More Comprehensive Nitrogen Cycle in a Global Biogeochemical Ocean Model

    Six, K. D.; Ilyina, T.

    2016-02-01

    Nitrogen plays a crucial role for nearly all living organisms in the Earth system. Changes in the marine nitrogen cycle not only alter the marine biota, but will also have an impact on the marine carbon cycle and, in turn, on climate due to the close coupling of the carbon-nitrogen cycle. The understanding of processes and controls of the marine nitrogen cycle is therefore a prerequisite to reduce uncertainties in the prediction of future climate. Nevertheless, most ocean biogeochemical components of modern Earth system models have a rather simplistic representation of marine N-cycle mainly focusing on nitrate. Here we present results of the HAMburg Ocean Carbon Cycle model (HAMOCC) as part of the MPI-ESM which was extended by a prognostic representation of ammonium and nitrite to resolve important processes of the marine N-cycle such as nitrification and anaerobic ammonium oxidation (anammox). Additionally, we updated the production of nitrous oxide, an important greenhouse gas, allowing for two sources from oxidation of ammonium (nitrification) and from reduction of nitrite (nitrifier-denitrification) at low oxygen concentrations. Besides an extended model data comparison we discuss the following aspects of the N-cycle by model means: (1) contribution of anammox to the loss of fixed nitrogen, and (2) production and emission of marine nitrous oxide.

  5. Recent Trends of the Tropical Hydrological Cycle Inferred from Global Precipitation Climatology Project and International Satellite Cloud Climatology Project data

    Zhou, Y. P.; Xu, Kuan-Man; Sud, Y. C.; Betts, A. K.

    2011-01-01

    Scores of modeling studies have shown that increasing greenhouse gases in the atmosphere impact the global hydrologic cycle; however, disagreements on regional scales are large, and thus the simulated trends of such impacts, even for regions as large as the tropics, remain uncertain. The present investigation attempts to examine such trends in the observations using satellite data products comprising Global Precipitation Climatology Project precipitation and International Satellite Cloud Climatology Project cloud and radiation. Specifically, evolving trends of the tropical hydrological cycle over the last 20-30 years were identified and analyzed. The results show (1) intensification of tropical precipitation in the rising regions of the Walker and Hadley circulations and weakening over the sinking regions of the associated overturning circulation; (2) poleward shift of the subtropical dry zones (up to 2deg/decade in June-July-August (JJA) in the Northern Hemisphere and 0.3-0.7deg/decade in June-July-August and September-October-November in the Southern Hemisphere) consistent with an overall broadening of the Hadley circulation; and (3) significant poleward migration (0.9-1.7deg/decade) of cloud boundaries of Hadley cell and plausible narrowing of the high cloudiness in the Intertropical Convergence Zone region in some seasons. These results support findings of some of the previous studies that showed strengthening of the tropical hydrological cycle and expansion of the Hadley cell that are potentially related to the recent global warming trends.

  6. JAEA key facilities for global advanced fuel cycle R and D

    Nomura, Shigeo; Yamamoto, Ryuichi [Nuclear Fuel Cycle Engineering Labos, JAEA, 4-33 Tokai-mura, Ibaraki, 319-1194 (Japan)

    2008-07-01

    Advanced fuel cycle will be realized with the mid and long term R and D during the long-term transition period from LWR cycle to advanced reactor fuel cycle. Most of JAEA facilities have been utilized to establish the current LWR and FBR (Fast Breeder Reactor) fuel cycle by implementing evolutionary R and D. An assessment of today's state experimental facilities concerning the following research issues: reprocessing, Mox fuel fabrication, irradiation and post-irradiation examination, waste management and nuclear data measurement, is made. The revolutionary R and D requests new issues to be studied: the TRU multi-recycling, minor actinide recycling, the assessment of proliferation resistance and the assessment of cost reduction. To implement the revolutionary R and D for advanced fuel cycle, however, these facilities should be refurbished to install new machines and process equipment to provide more flexible testing parameters.

  7. Climate-induced interannual variability of marine primary and export production in three global coupled climate carbon cycle models

    B. Schneider

    2008-04-01

    Full Text Available Fully coupled climate carbon cycle models are sophisticated tools that are used to predict future climate change and its impact on the land and ocean carbon cycles. These models should be able to adequately represent natural variability, requiring model validation by observations. The present study focuses on the ocean carbon cycle component, in particular the spatial and temporal variability in net primary productivity (PP and export production (EP of particulate organic carbon (POC. Results from three coupled climate carbon cycle models (IPSL, MPIM, NCAR are compared with observation-based estimates derived from satellite measurements of ocean colour and results from inverse modelling (data assimilation. Satellite observations of ocean colour have shown that temporal variability of PP on the global scale is largely dominated by the permanently stratified, low-latitude ocean (Behrenfeld et al., 2006 with stronger stratification (higher sea surface temperature; SST being associated with negative PP anomalies. Results from all three coupled models confirm the role of the low-latitude, permanently stratified ocean for anomalies in globally integrated PP, but only one model (IPSL also reproduces the inverse relationship between stratification (SST and PP. An adequate representation of iron and macronutrient co-limitation of phytoplankton growth in the tropical ocean has shown to be the crucial mechanism determining the capability of the models to reproduce observed interactions between climate and PP.

  8. Impact of changes in river fluxes of silica on the global marine silicon cycle: a model comparison

    C. Y. Bernard

    2010-02-01

    Full Text Available The availability of dissolved silica (Si in the ocean provides a major control on the growth of siliceous phytoplankton. Diatoms in particular account for a large proportion of oceanic primary production. The original source of the silica is rock weathering, followed by transport of dissolved and biogenic silica to the coastal zone. This model study aims at assessing the sensitivity of the global marine silicon cycle to variations in the river input of silica on timescales ranging from several centuries to millennia. We compare the performance of a box model for the marine silicon cycle to that of a global biogeochemical ocean general circulation model (HAMOCC2 and 5. Results indicate that the average global ocean response to changes in river input of silica is comparable in the models on time scales up to 150 kyrs. While the trends in export production and opal burial are the same, the box model shows a delayed response to the imposed perturbations compared to the general circulation model. Results of both models confirm the important role of the continental margins as a sink for silica at the global scale. Our work also demonstrates that the effects of changes in riverine dissolved silica on ocean biogeochemistry depend on the availability of the other nutrients such as nitrogen, phosphorus and iron. The model results suggest that the effects of reduced silica inputs due to river damming are particularly pronounced in the Gulf of Bengal, Gulf of Mexico and the Amazon plume where they negatively affect opal production. While general circulation models are indispensable when assessing the spatial variation in opal export production and biogenic Si burial in the ocean, this study demonstrates that box models provide a good alternative when studying the average global ocean response to perturbations of the oceanic silica cycle (especially on longer time scales.

  9. Glass vs. Plastic: Life Cycle Assessment of Extra-Virgin Olive Oil Bottles across Global Supply Chains

    Riccardo Accorsi

    2015-03-01

    Full Text Available The environmental impacts of global food supply chains are growing with the need for their measurement and management. This paper explores the operations of a global supply chain for extra-virgin olive oil (EVOO according to a life cycle assessment (LCA methodology. The LCA assessment methodology is applied to determine the environmental impact categories associated with the bottled EVOO life cycle, focusing on packaging decisions. The proposed analysis identifies the greatest environmental stressors of the EVOO supply chain, thereby supporting strategic and operative decisions toward more efficient and environmentally-friendly operations management and packaging choices. This paper quantifies the environmental categories of the impacts of global warming potential, ozone layer depletion, non-renewable energy use, acidification, eutrophication and photochemical smog, for the observed EVOO supply chain, given alternative packaging configurations, i.e., a glass bottle vs. a plastic bottle. The observed system includes the supply of EVOO, the EVOO processing and bottling, the supply of packaging, the distribution of final products to customers, the end-of-life (EOL treatments regarding the management, recycling and the disposal of waste across a global supply chain. The findings from the LCA highlight the potential of PET bottles in reducing the environmental impact of EVOO supply chains and identifies hotspots of discussion for policy-makers, EVOO producers and consumers.

  10. Iron control on global productivity: an efficient inverse model of the ocean's coupled phosphate and iron cycles.

    Pasquier, B.; Holzer, M.; Frants, M.

    2016-02-01

    We construct a data-constrained mechanistic inverse model of the ocean's coupled phosphorus and iron cycles. The nutrient cycling is embedded in a data-assimilated steady global circulation. Biological nutrient uptake is parameterized in terms of nutrient, light, and temperature limitations on growth for two classes of phytoplankton that are not transported explicitly. A matrix formulation of the discretized nutrient tracer equations allows for efficient numerical solutions, which facilitates the objective optimization of the key biogeochemical parameters. The optimization minimizes the misfit between the modelled and observed nutrient fields of the current climate. We systematically assess the nonlinear response of the biological pump to changes in the aeolian iron supply for a variety of scenarios. Specifically, Green-function techniques are employed to quantify in detail the pathways and timescales with which those perturbations are propagated throughout the world oceans, determining the global teleconnections that mediate the response of the global ocean ecosystem. We confirm previous findings from idealized studies that increased iron fertilization decreases biological production in the subtropical gyres and we quantify the counterintuitive and asymmetric response of global productivity to increases and decreases in the aeolian iron supply.

  11. Calcium absorption

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  12. Enhancing atmospheric mercury research in China to improve the current understanding of the global mercury cycle: the need for urgent and closely coordinated efforts.

    Ci, Zhijia; Zhang, Xiaoshan; Wang, Zhangwei

    2012-06-05

    The current understanding of the global mercury (Hg) cycle remains uncertain because Hg behavior in the environment is very complicated. The special property of Hg causes the atmosphere to be the most important medium for worldwide dispersion and transformation. The source and fate of atmospheric Hg and its interaction with the surface environment are the essential topics in the global Hg cycle. Recent declining measurement trends of Hg in the atmosphere are in apparent conflict with the increasing trends in global anthropogenic Hg emissions. As the single largest country contributor of anthropogenic Hg emission, China's role in the global Hg cycle will become more and more important in the context of the decreasing man-made Hg emission from developed regions. However, much less Hg information in China is available. As a global pollutant which undergoes long-range transport and is persistence in the environment, increasing Hg knowledge in China could not only promote the Hg regulation in this country but also improve the understanding of the fundamental of the global Hg cycle and further push the abatement of this toxin on a global scale. Then the atmospheric Hg research in China may be a breakthrough for improving the current understanding of the global Hg cycle. However, due to the complex behavior of Hg in the atmosphere, a deeper understanding of the atmospheric Hg cycle in China needs greater cooperation across fields.

  13. Comparing the Life Cycle Energy Consumption, Global Warming and Eutrophication Potentials of Several Water and Waste Service Options

    Xiaobo Xue

    2016-04-01

    Full Text Available Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energy- and carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability and sensitivity were evaluated, the carbon intensity of the local electricity grid and the efficiency of electricity production by the co-digestion with the energy recovery process were the most important for determining the relative global warming potential results.

  14. The global pyrogenic carbon cycle and its impact on the level of atmospheric CO2 over past and future centuries.

    Landry, Jean-Sébastien; Matthews, H Damon

    2017-08-01

    The incomplete combustion of vegetation and dead organic matter by landscape fires creates recalcitrant pyrogenic carbon (PyC), which could be consequential for the global carbon budget if changes in fire regime, climate, and atmospheric CO 2 were to substantially affect gains and losses of PyC on land and in oceans. Here, we included global PyC cycling in a coupled climate-carbon model to assess the role of PyC in historical and future simulations, accounting for uncertainties through five sets of parameter estimates. We obtained year-2000 global stocks of (Central estimate, likely uncertainty range in parentheses) 86 (11-154), 47 (2-64), and 1129 (90-5892) Pg C for terrestrial residual PyC (RPyC), marine dissolved PyC, and marine particulate PyC, respectively. PyC cycling decreased atmospheric CO 2 only slightly between 1751 and 2000 (by 0.8 Pg C for the Central estimate) as PyC-related fluxes changed little over the period. For 2000 to 2300, we combined Representative Concentration Pathways (RCPs) 4.5 and 8.5 with stable or continuously increasing future fire frequencies. For the increasing future fire regime, the production of new RPyC generally outpaced the warming-induced accelerated loss of existing RPyC, so that PyC cycling decreased atmospheric CO 2 between 2000 and 2300 for most estimates (by 4-8 Pg C for Central). For the stable fire regime, however, PyC cycling usually increased atmospheric CO 2 (by 1-9 Pg C for Central), and only the most extreme choice of parameters maximizing PyC production and minimizing PyC decomposition led to atmospheric CO 2 decreases under RCPs 4.5 and 8.5 (by 5-8 Pg C). Our results suggest that PyC cycling will likely reduce the future increase in atmospheric CO 2 if landscape fires become much more frequent; however, in the absence of a substantial increase in fire frequency, PyC cycling might contribute to, rather than mitigate, the future increase in atmospheric CO 2 . © 2016 John Wiley & Sons Ltd.

  15. Global Change Research Related to the Earth's Energy and Hydrologic Cycle

    1998-01-01

    The Institute for Global Change Research and Education (IGCRE) is a joint initiative of the Universities Space Research Association (USRA) and the University of Alabama in Huntsville (UAH) for coordinating and facilitating research and education relevant to global environmental change. Created in 1992 with primary support from the National Aeronautics and Space Administration (NASA), IGCRE fosters participation by university, private sector and government scientists who seek to develop long-term collaborative research in global change science, focusing on the role of water and energy in the Earth's atmosphere and physical climate system. IGCRE is also chartered to address educational needs of Earth system and global change science, including the preparation of future scientists and training of primary and secondary education teachers.

  16. Cycles of selected elements in the frame of Globalization and Global Change in the environment of Tenerife (Canary Islands, Spain)

    Heidak, Markus O.; Glasmacher, Ulrich A.; Schöler, Heinfried; Trieloff, Mario; Kober, Bernd

    2010-05-01

    The Laurel Forest is an important and sensitive ecosystem with particular element cycling mechanisms. On Tenerife the distribution is straitened to some parts in the north, north-west and northeast. The NE trade wind ensures a permanently humid climate in the north. Major urban and industrial development is centred on Tenerife, and as a touristy hotspot the Island is exposed to heavy air traffic. Furthermore, the short distance to the African coastline and, therefore, to the Sahara, contribute a regular influence of African Dust emissions. In summary, Laurel Forest is exposed to different climatic conditions, variations in lithology and soils, and aerosols caused by local anthropogenic emissions, Saharan dust, and sea spray. The present study aims to understand geogenic and anthropogenic element transports of K, P, N, and organic components between soils and Laurel Forest. In addition, the element contribution from the aerosols such as the Sahara dust has to be quantified to understand the rock - soil - vegetation coupling system. The Sahara dust as one of the important aerosols has been studied by various researchers (Bustos et al., 1998; Rodrıguez, 1999; Torres et al., 2001; Viana et al., 2002). Viana et al.,(2002) quantified the impacts of African dust outbreaks for Tenerife and Gran Canaria, after the interpretation of the PM10 (thoracis particulate matter) from nineteen air quality monitoring stations. Three types of African dust contributions were identified and characterized (winter, summer and autumn-winter dust outbreaks). Collected samples with and without African dust influence proved that: (a) for the intensive winter African dust outbreaks (daily PM10 levels up to 191 mg/m3) at least 76% of the bulk PM10 levels may be attributable to dust load, whereas the anthropogenic input accounts for only 3-14% and (b) SiO2, Al2O3, Ca, K, Fe, Ti, V, Mn and Ba concentrations are excellent tracers of African origin (Viana et al., 2002).

  17. GLOBALIZATION OF ECONOMY AND GREATER CYCLES OF THE TOTAL REGIONAL PRODUCT, INFLATION AND UNEMPLOYMENT

    V.A. Belkin

    2009-06-01

    Full Text Available The process of synchronization of greater and small waves of real gross national product of the USA and a total regional product of the Chelyabinsk area is shown on the materials of economic statistics. The conclusion about defining influence of dynamics of real gross national product of the USA on the basic macroeconomic parameters of the Chelyabinsk area owing to high dependence of its economy on export of metal products is done from here. It is evidently shown, that the modern world economic crisis quite keeps within the theory of greater cycles of an economic conjuncture of N.D. Kondratyev. To greater cycles of a total regional product of the Chelyabinsk area there correspond return greater cycles of inflation and unemployment.

  18. The role of calcifying organisms in the global CO sub 2 cycle

    Kayanne, H; Miyachi, S [Geological Survey of Japan, Tsukuba (Japan)

    1991-11-01

    The increase in atmospheric CO{sub 2} is recognised as a serious problem. The coral reefs of the Japanese islands fix 2.2 kg CO{sub 2}/m per year as organic carbon and 2.1 kg CO{sub 2}/m per year as calcium carbonate. The potential CO{sub 2} fixation of the Ryukyu reefs is 1.4 per cent of CO{sub 2} emission from Japan. Technology is being established to enhance the rate of CO{sub 2} fixation. Calcareous algae also play an important role in the calcification, and the mass culture of marine unicellular coccolith former is under investigation in Japan. 4 refs., 3 boxes.

  19. A road map for the realization of global-scale thorium breeding fuel cycle by single molten-fluoride flow

    Furukawa, K.; Arakawa, K.; Erbay, L. B.

    2007-01-01

    For global survival in this century, we urgently need to launch a completely new global nuclear fission industry. To get worldwide public acceptance of nuclear energy, improvements are essential not only on safety, radio-waste management and economy but also especially nuclear proliferation resistance and safeguards. However, such global fission industry cannot replace the present fossil fuel industry in the next 50 years, unless the doubling-time of nuclear energy is less than 10 years, preferably 5-7 years. Such a doubling-time cannot be established by any kind of classical 'Fission Breeding Power Station' concept. We need a symbiotic system which couples fission power reactors with a system which can convert fertile thorium to fissile U-233, such as a spallation or D/T fusion (if and when it becomes available). For such a purpose, THORIMS-NES [Thorium Molten-Salt Nuclear Energy Synergetic System] has been proposed, which is composed of simple thermal fission power stations (FUJI) and fissile producing Accelerator Molten-Salt Breeder (AMSB). Its system functions are very ambitious, delicate and complex, but can be realized in the form of simple hardware applying the multifunctional 'single-phase molten-fluoride' circulation system. This system has no difficulties relating with 'radiation-damage', 'heat-removal' and 'chemical processing' owing to the simple 'idealistic ionic liquid' character. FUJI is size-flexible (economical even in smaller sizes), fuel self-sustaining without any continuous chemical processing and without core-graphite replacement, and AMSB is based on a single-fluid molten-salt target/blanket concept, which solves most engineering difficulties such as radiation-damage, heat-removal etc., except high-current proton accelerator development. Several AMSBs are accommodated in the regional centers (several ten sites in the world) with batch chemical processing plants including radio-waste management. The integrated thorium breeding fuel cycle is

  20. Dirac-global fits to calcium elastic scattering data in the range 21-200 MeV

    Cooper, E.D.

    1988-01-01

    We present a global relativistic optical model for p+ 40 Ca consisting of Lorentz scalar and vector potentials parametrized as a function of energy. The shapes chosen are Woods-Saxons for the real potentials, and a linear combination of Woods-Saxons and derivative Woods-Saxons for the imaginary potentials. (orig.)

  1. Calsequestrin 2 deletion causes sinoatrial node dysfunction and atrial arrhythmias associated with altered sarcoplasmic reticulum calcium cycling and degenerative fibrosis within the mouse atrial pacemaker complex1

    Glukhov, Alexey V.; Kalyanasundaram, Anuradha; Lou, Qing; Hage, Lori T.; Hansen, Brian J.; Belevych, Andriy E.; Mohler, Peter J.; Knollmann, Björn C.; Periasamy, Muthu; Györke, Sandor; Fedorov, Vadim V.

    2015-01-01

    Aims Loss-of-function mutations in Calsequestrin 2 (CASQ2) are associated with catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT patients also exhibit bradycardia and atrial arrhythmias for which the underlying mechanism remains unknown. We aimed to study the sinoatrial node (SAN) dysfunction due to loss of CASQ2. Methods and results In vivo electrocardiogram (ECG) monitoring, in vitro high-resolution optical mapping, confocal imaging of intracellular Ca2+ cycling, and 3D atrial immunohistology were performed in wild-type (WT) and Casq2 null (Casq2−/−) mice. Casq2−/− mice exhibited bradycardia, SAN conduction abnormalities, and beat-to-beat heart rate variability due to enhanced atrial ectopic activity both at baseline and with autonomic stimulation. Loss of CASQ2 increased fibrosis within the pacemaker complex, depressed primary SAN activity, and conduction, but enhanced atrial ectopic activity and atrial fibrillation (AF) associated with macro- and micro-reentry during autonomic stimulation. In SAN myocytes, CASQ2 deficiency induced perturbations in intracellular Ca2+ cycling, including abnormal Ca2+ release, periods of significantly elevated diastolic Ca2+ levels leading to pauses and unstable pacemaker rate. Importantly, Ca2+ cycling dysfunction occurred not only at the SAN cellular level but was also globally manifested as an increased delay between action potential (AP) and Ca2+ transient upstrokes throughout the atrial pacemaker complex. Conclusions Loss of CASQ2 causes abnormal sarcoplasmic reticulum Ca2+ release and selective interstitial fibrosis in the atrial pacemaker complex, which disrupt SAN pacemaking but enhance latent pacemaker activity, create conduction abnormalities and increase susceptibility to AF. These functional and extensive structural alterations could contribute to SAN dysfunction as well as AF in CPVT patients. PMID:24216388

  2. A model of the solar cycle driven by the dynamo action of the global convection in the solar convection zone

    Yoshimura, H.

    1975-01-01

    The dynamo equation which represents the longitudinally averaged magnetohydrodynamical action of the global convection influenced by the rotation in the solar convection zone is solved numerically to simulate the solar cycle as an initial boundary-value problem. The radial and latitudinal structure of the dynamo action is parametrized in accordance with the structure of the rotation, and of the global convection especially in such a way as to represent the presence of the two cells of the regeneration action in the radial direction in which the action has opposite signs, which is typical of the regeneration action of the global convection. A nonlinear process is included by assuming that part of the magnetic field energy is dissipated when the magnetic field strength exceeds some critical value; the formation of active regions and subsequent dissipations are thus simulated. By adjusting the parameters within a reasonable range, oscillatory solutions are obtained to simulate the solar cycle with the period of the right order of magnitude and with the patterns of evolution of the latitudinal distribution of the toroidal component of the magnetic field similar to the observed Butterfly Diagram of sunspots. The evolution of the latitudinal distribution of the radial component of the magnetic field shows patterns similar to the Butterfly Diagram, but having two branches of different polarity in each hemisphere. The development of the radial structure of the magnetic field associated with the solar cycle is presented. The importance of the poleward migrating branch of the Butterfly Diagram is emphasized in relation to the relative importance of the role of the latitudinal and radial shears of the differential rotation

  3. Hierarchical responses of plant–soil interactions to climate change: consequences for the global carbon cycle

    Bardgett, R.D.; Manning, P.; Morrien, E.; De Vries, F.T.

    2013-01-01

    1.Interactions between plant and soil communities play a major role in determining the impact of climate change on ecosystem functioning and the carbon cycle, and the mechanisms involved operate over a wide range of spatial and temporal scales. 2.We present a framework for understanding the

  4. Sudomotor and vasomotor activity during the menstrual cycle with global heating.

    Petrofsky, Jerrold; Lee, Haneul; Khowailed, Iman Akef

    2017-07-01

    Many studies have reported that there are changes in sympathetic activity throughout the menstrual cycle as there are oestrogen receptor in the hypothalamus and all other parts of the sympathetic nervous system. The purpose of this study was to see whether there were variations in sympathetic activity, skin vasomotor and sweat gland sudomotor rhythms during the menstrual cycle. Eight young female subjects with a regular menstrual cycle participated in the study. Subjects were tested once during the follicular phase and once during the luteal phase. Skin blood flow and sweat rate were significantly higher in the luteal phase compared with the follicular phase (p < .05), but the frequency and magnitude of sudomotor and vasomotor rhythms were significantly greater in the follicular phase (p < .05). In contrast, spectral data showed less sympathetic activity in the luteal phase. A significant finding here is that the sudomotor rhythm of sweat glands is altered by the menstrual cycle. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  5. Is There Really a Global Business Cycle? : A Dynamic Factor Model with Stochastic Factor Selection

    T. Berger (Tino); L.C.G. Pozzi (Lorenzo)

    2016-01-01

    textabstractWe investigate the presence of international business cycles in macroeconomic aggregates (output, consumption, investment) using a panel of 60 countries over the period 1961-2014. The paper presents a Bayesian stochastic factor selection approach for dynamic factor models with

  6. Diurnal Cycling Transcription Factors of Pineapple Revealed by Genome-Wide Annotation and Global Transcriptomic Analysis.

    Sharma, Anupma; Wai, Ching Man; Ming, Ray; Yu, Qingyi

    2017-09-01

    Circadian clock provides fitness advantage by coordinating internal metabolic and physiological processes to external cyclic environments. Core clock components exhibit daily rhythmic changes in gene expression, and the majority of them are transcription factors (TFs) and transcription coregulators (TCs). We annotated 1,398 TFs from 67 TF families and 80 TCs from 20 TC families in pineapple, and analyzed their tissue-specific and diurnal expression patterns. Approximately 42% of TFs and 45% of TCs displayed diel rhythmic expression, including 177 TF/TCs cycling only in the nonphotosynthetic leaf tissue, 247 cycling only in the photosynthetic leaf tissue, and 201 cycling in both. We identified 68 TF/TCs whose cycling expression was tightly coupled between the photosynthetic and nonphotosynthetic leaf tissues. These TF/TCs likely coordinate key biological processes in pineapple as we demonstrated that this group is enriched in homologous genes that form the core circadian clock in Arabidopsis and includes a STOP1 homolog. Two lines of evidence support the important role of the STOP1 homolog in regulating CAM photosynthesis in pineapple. First, STOP1 responds to acidic pH and regulates a malate channel in multiple plant species. Second, the cycling expression pattern of the pineapple STOP1 and the diurnal pattern of malate accumulation in pineapple leaf are correlated. We further examined duplicate-gene retention and loss in major known circadian genes and refined their evolutionary relationships between pineapple and other plants. Significant variations in duplicate-gene retention and loss were observed for most clock genes in both monocots and dicots. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  7. Implementation of methane cycling for deep time, global warming simulations with the DCESS Earth System Model (Version 1.2)

    Shaffer, Gary; Villanueva, Esteban Fernández; Rondanelli, Roberto

    2017-01-01

    Geological records reveal a number of ancient, large and rapid negative excursions of carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth System over a short duration. These injections may have forced strong global warming events, sometimes....... With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, time scales and locations of methane injections driving specific, observed deep time, global warming events......., or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth System models should include a comprehensive treatment of methane cycling but such a treatment...

  8. Uncertainty propagation in life cycle assessment of biodiesel versus diesel: global warming and non-renewable energy.

    Hong, Jinglan

    2012-06-01

    Uncertainty information is essential for the proper use of life cycle assessment and environmental assessments in decision making. To investigate the uncertainties of biodiesel and determine the level of confidence in the assertion that biodiesel is more environmentally friendly than diesel, an explicit analytical approach based on the Taylor series expansion for lognormal distribution was applied in the present study. A biodiesel case study demonstrates the probability that biodiesel has a lower global warming and non-renewable energy score than diesel, that is 92.3% and 93.1%, respectively. The results indicate the level of confidence in the assertion that biodiesel is more environmentally friendly than diesel based on the global warming and non-renewable energy scores. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Globally important nitrous oxide emissions from croplands induced by freeze-thaw cycles

    Wagner-Riddle, Claudia; Congreves, Katelyn A.; Abalos Rodriguez, Diego; Berg, Aaron A.; Brown, Shannon E.; Ambadan, Jaison Thomas; Gao, Xiaopeng; Tenuta, Mario

    2017-01-01

    Seasonal freezing induces large thaw emissions of nitrous oxide, a trace gas that contributes to stratospheric ozone destruction and atmospheric warming. Cropland soils are by far the largest anthropogenic source of nitrous oxide. However, the global contribution of seasonal freezing to nitrous

  10. Vulnerability of permafrost carbon to climate change: implications for the global carbon cycle

    Edward A.G. Schuur; James Bockheim; Josep G. Canadell; Eugenie Euskirchen; Christopher B. Field; Sergey V. Goryachkin; Stefan Hagemann; Peter Kuhry; Peter M. Lafleur; Hanna Lee; Galina Mazhitova; Frederick E. Nelson; Annette Rinke; Vladimir E. Romanovsky; Nikolay Shiklomanov; Charles Tarnocai; Sergey Venevsky; Jason G. Vogel; Sergei A. Zimov

    2008-01-01

    Thawing permafrost and the resulting microbial decomposition of previously frozen organic carbon (C) is one of the most significant potential feedbacks from terrestrial ecosystems to the atmosphere in a changing climate. In this article we present an overview of the global permafrost C pool and of the processes that might transfer this C into the atmosphere, as well as...

  11. Calcium - ionized

    ... diuretics Thrombocytosis (high platelet count) Tumors Vitamin A excess Vitamin D excess Lower-than-normal levels may be due to: Hypoparathyroidism Malabsorption Osteomalacia Pancreatitis Renal failure Rickets Vitamin D deficiency Alternative Names Free calcium; Ionized calcium ...

  12. Calcium Carbonate

    ... Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  13. The Martian hydrologic cycle - Effects of CO2 mass flux on global water distribution

    James, P. B.

    1985-01-01

    The Martian CO2 cycle, which includes the seasonal condensation and subsequent sublimation of up to 30 percent of the planet's atmosphere, produces meridional winds due to the consequent mass flux of CO2. These winds currently display strong seasonal and hemispheric asymmetries due to the large asymmetries in the distribution of insolation on Mars. It is proposed that asymmetric meridional advection of water vapor on the planet due to these CO2 condensation winds is capable of explaining the observed dessication of Mars' south polar region at the current time. A simple model for water vapor transport is used to verify this hypothesis and to speculate on the effects of changes in orbital parameters on the seasonal water cycle.

  14. Evolution of the global water cycle on Mars: The geological evidence

    Baker, V. R.; Gulick, V. C.

    1993-01-01

    The geological evidence for active water cycling early in the history of Mars (Noachian geological system or heavy bombardment) consists almost exclusively of fluvial valley networks in the heavily cratered uplands of the planet. It is commonly assumed that these landforms required explanation by atmospheric processes operating above the freezing point of water and at high pressure to allow rainfall and liquid surface runoff. However, it has also been documented that nearly all valley networks probably formed by subsurface outflow and sapping erosion involving groundwater outflow prior to surface-water flow. The prolonged ground-water flow also requires extensive water cycling to maintain hydraulic gradients, but is this done via rainfall recharge, as in terrestrial environments?

  15. Regional and global environmental behaviour of radionuclides from the nuclear fuel cycle

    1983-02-01

    The operation of nuclear fuel cycle facilities entails the discharge of radioactive effluents to both the atmosphere and aquatic environment. These effluents may contain radionuclides which may be subject of concern for their long-range environmental consequences, in particular, in assessing the health detriment to populations in regions beyond the local environment. The present document reviews information on radionuclides, their environmental pathways and processes and related models and summarizes experiences and studies in this field

  16. Consistency of Estimated Global Water Cycle Variations Over the Satellite Era

    Robertson, F. R.; Bosilovich, M. G.; Roberts, J. B.; Reichle, R. H.; Adler, R.; Ricciardulli, L.; Berg, W.; Huffman, G. J.

    2013-01-01

    Motivated by the question of whether recent indications of decadal climate variability and a possible "climate shift" may have affected the global water balance, we examine evaporation minus precipitation (E-P) variability integrated over the global oceans and global land from three points of view-remotely sensed retrievals / objective analyses over the oceans, reanalysis vertically-integrated moisture convergence (MFC) over land, and land surface models forced with observations-based precipitation, radiation and near-surface meteorology. Because monthly variations in area-averaged atmospheric moisture storage are small and the global integral of moisture convergence must approach zero, area-integrated E-P over ocean should essentially equal precipitation minus evapotranspiration (P-ET) over land (after adjusting for ocean and land areas). Our analysis reveals considerable uncertainty in the decadal variations of ocean evaporation when integrated to global scales. This is due to differences among datasets in 10m wind speed and near-surface atmospheric specific humidity (2m qa) used in bulk aerodynamic retrievals. Precipitation variations, all relying substantially on passive microwave retrievals over ocean, still have uncertainties in decadal variability, but not to the degree present with ocean evaporation estimates. Reanalysis MFC and P-ET over land from several observationally forced diagnostic and land surface models agree best on interannual variations. However, upward MFC (i.e. P-ET) reanalysis trends are likely related in part to observing system changes affecting atmospheric assimilation models. While some evidence for a low-frequency E-P maximum near 2000 is found, consistent with a recent apparent pause in sea-surface temperature (SST) rise, uncertainties in the datasets used here remain significant. Prospects for further reducing uncertainties are discussed. The results are interpreted in the context of recent climate variability (Pacific Decadal

  17. Global patterns and substrate-based mechanisms of the terrestrial nitrogen cycle.

    Niu, Shuli; Classen, Aimée T; Dukes, Jeffrey S; Kardol, Paul; Liu, Lingli; Luo, Yiqi; Rustad, Lindsey; Sun, Jian; Tang, Jianwu; Templer, Pamela H; Thomas, R Quinn; Tian, Dashuan; Vicca, Sara; Wang, Ying-Ping; Xia, Jianyang; Zaehle, Sönke

    2016-06-01

    Nitrogen (N) deposition is impacting the services that ecosystems provide to humanity. However, the mechanisms determining impacts on the N cycle are not fully understood. To explore the mechanistic underpinnings of N impacts on N cycle processes, we reviewed and synthesised recent progress in ecosystem N research through empirical studies, conceptual analysis and model simulations. Experimental and observational studies have revealed that the stimulation of plant N uptake and soil retention generally diminishes as N loading increases, while dissolved and gaseous losses of N occur at low N availability but increase exponentially and become the dominant fate of N at high loading rates. The original N saturation hypothesis emphasises sequential N saturation from plant uptake to soil retention before N losses occur. However, biogeochemical models that simulate simultaneous competition for soil N substrates by multiple processes match the observed patterns of N losses better than models based on sequential competition. To enable better prediction of terrestrial N cycle responses to N loading, we recommend that future research identifies the response functions of different N processes to substrate availability using manipulative experiments, and incorporates the measured N saturation response functions into conceptual, theoretical and quantitative analyses. © 2016 John Wiley & Sons Ltd/CNRS.

  18. The carbon cycle in a land surface model: modelling, validation and implementation at a global scale; Cycle du carbone dans un modele de surface continentale: modelisation, validation et mise en oeuvre a l'echelle globale

    Gibelin, A.L

    2007-05-15

    ISBA-A-gs is an option of the CNRM land surface model ISBA which allows for the simulation of carbon exchanges between the terrestrial biosphere and the atmosphere. The model was implemented for the first time at the global scale as a stand-alone model. Several global simulations were performed to assess the sensitivity of the turbulent fluxes and Leaf Area Index to a doubling of the CO{sub 2} atmospheric concentration, and to the climate change simulated by the end of the 21. century. In addition, a new option of ISBA, referred to as ISBA-CC, was developed in order to simulate a more detailed ecosystem respiration by separating the autotrophic respiration and the heterotrophic respiration. The vegetation dynamics and the carbon fluxes were validated at a global scale using satellite datasets, and at a local scale using data from 26 sites of the FLUXNET network. All these results show that the model is sufficiently realistic to be coupled with a general circulation model, in order to account for interactions between the terrestrial biosphere, the atmosphere and the carbon cycle. (author)

  19. The carbon cycle in a land surface model: modelling, validation and implementation at a global scale; Cycle du carbone dans un modele de surface continentale: modelisation, validation et mise en oeuvre a l'echelle globale

    Gibelin, A L

    2007-05-15

    ISBA-A-gs is an option of the CNRM land surface model ISBA which allows for the simulation of carbon exchanges between the terrestrial biosphere and the atmosphere. The model was implemented for the first time at the global scale as a stand-alone model. Several global simulations were performed to assess the sensitivity of the turbulent fluxes and Leaf Area Index to a doubling of the CO{sub 2} atmospheric concentration, and to the climate change simulated by the end of the 21. century. In addition, a new option of ISBA, referred to as ISBA-CC, was developed in order to simulate a more detailed ecosystem respiration by separating the autotrophic respiration and the heterotrophic respiration. The vegetation dynamics and the carbon fluxes were validated at a global scale using satellite datasets, and at a local scale using data from 26 sites of the FLUXNET network. All these results show that the model is sufficiently realistic to be coupled with a general circulation model, in order to account for interactions between the terrestrial biosphere, the atmosphere and the carbon cycle. (author)

  20. Sensible heat has significantly affected the global hydrological cycle over the historical period.

    Myhre, G; Samset, B H; Hodnebrog, Ø; Andrews, T; Boucher, O; Faluvegi, G; Fläschner, D; Forster, P M; Kasoar, M; Kharin, V; Kirkevåg, A; Lamarque, J-F; Olivié, D; Richardson, T B; Shawki, D; Shindell, D; Shine, K P; Stjern, C W; Takemura, T; Voulgarakis, A

    2018-05-15

    Globally, latent heating associated with a change in precipitation is balanced by changes to atmospheric radiative cooling and sensible heat fluxes. Both components can be altered by climate forcing mechanisms and through climate feedbacks, but the impacts of climate forcing and feedbacks on sensible heat fluxes have received much less attention. Here we show, using a range of climate modelling results, that changes in sensible heat are the dominant contributor to the present global-mean precipitation change since preindustrial time, because the radiative impact of forcings and feedbacks approximately compensate. The model results show a dissimilar influence on sensible heat and precipitation from various drivers of climate change. Due to its strong atmospheric absorption, black carbon is found to influence the sensible heat very differently compared to other aerosols and greenhouse gases. Our results indicate that this is likely caused by differences in the impact on the lower tropospheric stability.

  1. The global re-cycling of persistent organic pollutants is strongly retarded by soils

    Ockenden, W.A.; Breivik, Knut; Meijer, S.N.; Steinnes, Eiliv; Sweetman, A.J.; Jones, K.C

    2003-01-01

    C-rich soils of the northern hemisphere appear to be serving as sinks for POPs and preventing their transfer to the Arctic. - 'Persistent organic pollutants' (POPs) are semi-volatile, mobile in the environment and bioaccumulate. Their toxicity and propensity for long-range atmospheric transport (LRAT) has led to international bans/restrictions on their use/release. LRAT of POPs may occur by a 'single hop' or repeated temperature-driven air-surface exchange. It has been hypothesised that this will result in global fractionation and distillation - with condensation and accumulation in polar regions. Polychlorinated biphenyls (PCBs)--industrial chemicals banned/restricted in the 1970s - provide a classic illustration of POP behaviour. A latitudinally-segmented global PCB inventory has been produced, which shows that {approx}86% of the 1.3x10{sup 6} tonnes produced was used in the temperate industrial zone of the northern hemisphere. A global survey of background surface soils gives evidence for 'fractionation' of PCBs. More significantly, however, very little of the total inventory has 'made the journey' via primary emission and/or air-surface exchange and LRAT out of the heavily populated source regions, in the 70 years since PCBs were first produced. Soils generally occlude PCBs, especially soils with dynamic turnover of C/bioturbation/burial mechanisms. This limits the fraction of PCBs available for repeated air-soil exchange. The forested soils of the northern hemisphere, and other C-rich soils, appear to be playing an important role in 'protecting' the Arctic from the advective supply of POPs. Whilst investigations on POPs in remote environments are important, it is imperative that researchers also seek to better understand their release from sources, persistence in source regions, and the significant loss mechanisms/global sinks of these compounds, if they wish to predict future trends.

  2. The global re-cycling of persistent organic pollutants is strongly retarded by soils

    Ockenden, W.A.; Breivik, Knut; Meijer, S.N.; Steinnes, Eiliv; Sweetman, A.J.; Jones, K.C.

    2003-01-01

    C-rich soils of the northern hemisphere appear to be serving as sinks for POPs and preventing their transfer to the Arctic. - 'Persistent organic pollutants' (POPs) are semi-volatile, mobile in the environment and bioaccumulate. Their toxicity and propensity for long-range atmospheric transport (LRAT) has led to international bans/restrictions on their use/release. LRAT of POPs may occur by a 'single hop' or repeated temperature-driven air-surface exchange. It has been hypothesised that this will result in global fractionation and distillation - with condensation and accumulation in polar regions. Polychlorinated biphenyls (PCBs)--industrial chemicals banned/restricted in the 1970s - provide a classic illustration of POP behaviour. A latitudinally-segmented global PCB inventory has been produced, which shows that ∼86% of the 1.3x10 6 tonnes produced was used in the temperate industrial zone of the northern hemisphere. A global survey of background surface soils gives evidence for 'fractionation' of PCBs. More significantly, however, very little of the total inventory has 'made the journey' via primary emission and/or air-surface exchange and LRAT out of the heavily populated source regions, in the 70 years since PCBs were first produced. Soils generally occlude PCBs, especially soils with dynamic turnover of C/bioturbation/burial mechanisms. This limits the fraction of PCBs available for repeated air-soil exchange. The forested soils of the northern hemisphere, and other C-rich soils, appear to be playing an important role in 'protecting' the Arctic from the advective supply of POPs. Whilst investigations on POPs in remote environments are important, it is imperative that researchers also seek to better understand their release from sources, persistence in source regions, and the significant loss mechanisms/global sinks of these compounds, if they wish to predict future trends

  3. Atmospheric redistribution of reactive nitrogen and phosphorus by wildfires and implications for global carbon cycling

    Randerson, J. T.; Xu, L.; Wiggins, E. B.; Chen, Y.; Riley, W. J.; Mekonnen, Z. A.; Pellegrini, A.; Mahowald, N. M.

    2017-12-01

    Fires are an important process regulating the redistribution of nutrients within terrestrial ecosystems. Frequently burning ecosystems such as savannas are a net source of N and P to the atmosphere each year, with atmospheric transport and dry and wet deposition increasing nutrient availability in downwind ecosystems and over the open ocean. Transport of N and P aerosols from savanna fires within the Hadley circulation contributes to nutrient deposition over tropical forests, yielding an important cross-biome nutrient transfer. Pyrodenitrification of reactive N increases with fire temperature and modified combustion efficiency, generating a global net biospheric loss of approximately 14 Tg N per year. Here we analyze atmospheric N and P redistribution using the Global Fire Emissions Database version 4s and the Accelerated Climate Modeling for Energy earth system model. We synthesize literature estimates of N and P concentrations in fire-emitted aerosols and ecosystem mass balance measurements to help constrain model estimates of these biosphere-atmosphere fluxes. In our analysis, we estimate the fraction of terrestrial net primary production (NPP) that is sustained by fire-emitted P and reactive N from upwind ecosystems. We then evaluate how recent global declines in burned area in savanna and grassland ecosystems may be changing nutrient availability in downwind ecosystems.

  4. Global patterns and substrate-based mechanisms of the terrestrial nitrogen cycle

    Niu, Shuli; Classen, Aimee Taylor; Dukes, Jeffrey S.

    2016-01-01

    availability but increase exponentially and become the dominant fate of N at high loading rates. The original N saturation hypothesis emphasises sequential N saturation from plant uptake to soil retention before N losses occur. However, biogeochemical models that simulate simultaneous competition for soil N...... substrates by multiple processes match the observed patterns of N losses better than models based on sequential competition. To enable better prediction of terrestrial N cycle responses to N loading, we recommend that future research identifies the response functions of different N processes to substrate...

  5. Planetary Biology and Microbial Ecology: Molecular Ecology and the Global Nitrogen cycle

    Nealson, Molly Stone (Editor); Nealson, Kenneth H. (Editor)

    1993-01-01

    This report summarizes the results of the Planetary Biology and Molecular Ecology's summer 1991 program, which was held at the Marine Biological Laboratory in Woods Hole, Massachusetts. The purpose of the interdisciplinary PBME program is to integrate, via lectures and laboratory work, the contributions of university and NASA scientists and student interns. The goals of the 1991 program were to examine several aspects of the biogeochemistry of the nitrogen cycle and to teach the application of modern methods of molecular genetics to field studies of organisms. Descriptions of the laboratory projects and protocols and abstracts and references of the lectures are presented.

  6. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison

    2009-01-01

    Calcium cycling plays a key role in the health and productivity of red spruce forests in the northeastern US. A portion of the flowpath of calcium within forests includes translocation as Ca2+ in sapwood and accumulation as crystals of calcium oxalate in foliage. Concentrations of Ca in these tree tissues have been used as markers of...

  7. Nuclear fuel cycle industry. A responsible approach supporting non proliferation efforts in global perspective

    Jorant, Caroline

    2005-01-01

    This paper presents the reasons why and the manner in which nuclear industry is a stakeholder in non proliferation efforts. It then presents some recent proposals on multinational approaches to the fuel cycle industry and offers some comments and an industry view on these issues. A parallel is established with fundamental concepts in the field of radiation protection. Our industry, involved in 'nuclear technology development' (activities) qualified of 'sensitive' from a non proliferation standpoint, has major interests at stake in the evolution of the international non proliferation regime and is genuinely committed to the spreading of a non proliferation culture. The international community and in particular the nuclear community have been recently reflecting on ways to strengthen the non-proliferation regime in reaction to new threats or the perception thereof. Multilateral approaches regarding the nuclear fuel cycle are being discussed or proposed in this regard. Our approach as an industrial may be illustrated using the three basic principles developed in the field of radiation protection, namely limitation, justification and optimization. a) an overall limitation of sensitive facilities worldwide may be judicious, b) however no prohibition should be imposed if justified needs can be demonstrated on objective criteria, c) optimized used for existing facilities should be promoted through strengthened guarantees of supply where it may be necessary. (author)

  8. Inter-model variability and biases of the global water cycle in CMIP3 coupled climate models

    Liepert, Beate G; Previdi, Michael

    2012-01-01

    Observed changes such as increasing global temperatures and the intensification of the global water cycle in the 20th century are robust results of coupled general circulation models (CGCMs). In spite of these successes, model-to-model variability and biases that are small in first order climate responses, however, have considerable implications for climate predictability especially when multi-model means are used. We show that most climate simulations of the 20th and 21st century A2 scenario performed with CMIP3 (Coupled Model Inter-comparison Project Phase 3) models have deficiencies in simulating the global atmospheric moisture balance. Large biases of only a few models (some biases reach the simulated global precipitation changes in the 20th and 21st centuries) affect the multi-model mean global moisture budget. An imbalanced flux of −0.14 Sv exists while the multi-model median imbalance is only −0.02 Sv. Moreover, for most models the detected imbalance changes over time. As a consequence, in 13 of the 18 CMIP3 models examined, global annual mean precipitation exceeds global evaporation, indicating that there should be a ‘leaking’ of moisture from the atmosphere whereas for the remaining five models a ‘flooding’ is implied. Nonetheless, in all models, the actual atmospheric moisture content and its variability correctly increases during the course of the 20th and 21st centuries. These discrepancies therefore imply an unphysical and hence ‘ghost’ sink/source of atmospheric moisture in the models whose atmospheres flood/leak. The ghost source/sink of moisture can also be regarded as atmospheric latent heating/cooling and hence as positive/negative perturbation of the atmospheric energy budget or non-radiative forcing in the range of −1 to +6 W m −2 (median +0.1 W m −2 ). The inter-model variability of the global atmospheric moisture transport from oceans to land areas, which impacts the terrestrial water cycle, is also quite high and ranges

  9. Albedo enhancement over land to counteract global warming: impacts on hydrological cycle

    Bala, Govindasamy; Nag, Bappaditya [Indian Institute of Science, Divecha Center for Climate Change and Center for Atmospheric and Oceanic Sciences, Bangalore (India)

    2012-09-15

    A recent modelling study has shown that precipitation and runoff over land would increase when the reflectivity of marine clouds is increased to counter global warming. This implies that large scale albedo enhancement over land could lead to a decrease in runoff over land. In this study, we perform simulations using NCAR CAM3.1 that have implications for Solar Radiation Management geoengineering schemes that increase the albedo over land. We find that an increase in reflectivity over land that mitigates the global mean warming from a doubling of CO{sub 2} leads to a large residual warming in the southern hemisphere and cooling in the northern hemisphere since most of the land is located in northern hemisphere. Precipitation and runoff over land decrease by 13.4 and 22.3%, respectively, because of a large residual sinking motion over land triggered by albedo enhancement over land. Soil water content also declines when albedo over land is enhanced. The simulated magnitude of hydrological changes over land are much larger when compared to changes over oceans in the recent marine cloud albedo enhancement study since the radiative forcing over land needed (-8.2 W m{sup -2}) to counter global mean radiative forcing from a doubling of CO{sub 2} (3.3 W m{sup -2}) is approximately twice the forcing needed over the oceans (-4.2 W m{sup -2}). Our results imply that albedo enhancement over oceans produce climates closer to the unperturbed climate state than do albedo changes on land when the consequences on land hydrology are considered. Our study also has important implications for any intentional or unintentional large scale changes in land surface albedo such as deforestation/afforestation/reforestation, air pollution, and desert and urban albedo modification. (orig.)

  10. Quantification of the "global" authigenic carbonate δ13C value and implications for carbon cycling

    Loyd, S. J.

    2017-12-01

    Relationships among early Earth ocean chemistry, atmospheric chemistry and the evolution/radiation of life have been inferred from carbon isotope compositions (δ13C) of marine carbonates. Under steady-state conditions, the isotope compositions of marine carbonates reflect both the amount and δ13C of carbon entering and leaving the oceans. Recently the traditional "two-output" (marine carbonate and organic matter) mass-balance equation has been modified to include a third, authigenic carbonate output term. However, the formation mechanisms of authigenic carbonates remain poorly understood, particularly from a global prospective. The utility of the new mass-balance approach will be limited until authigenic carbonates are better characterized (e.g., through δ13C analyses). Authigenic carbonates form largely as a result of 1) the respiratory degradation of organic matter (e.g., sulfate reduction), 2) the oxidation of methane and 3) the production of methane. These major reaction pathways can produce authigenic carbonates with highly variable δ13C compositions (δ13Cac). Spatiotemporal variation in the extent and prevalence of different pathways therefore exert a first order control on "global" δ13Cac. Here, values are compiled from new and existing data sets and a modern, global δ13Cac is calculated. When calculated as an average of all data or an averaged mean of individual sites, this value is very similar to normal marine sedimentary organic matter. This finding suggests that marine sediments behave largely as closed systems in the context of organic matter degradation and carbonate authigenesis. In addition, the lack of significant difference between authigenic and organic δ13C implies that these two mass-balance output terms can be considered collectively in more recent time intervals. It may be appropriate to separate these two terms when characterizing more ancient settings when redox characteristics promoted more reducing organic matter degradation

  11. Transcriptional Orchestration of the Global Cellular Response of a Model Pennate Diatom to Diel Light Cycling under Iron Limitation.

    Sarah R Smith

    2016-12-01

    Full Text Available Environmental fluctuations affect distribution, growth and abundance of diatoms in nature, with iron (Fe availability playing a central role. Studies on the response of diatoms to low Fe have either utilized continuous (24 hr illumination or sampled a single time of day, missing any temporal dynamics. We profiled the physiology, metabolite composition, and global transcripts of the pennate diatom Phaeodactylum tricornutum during steady-state growth at low, intermediate, and high levels of dissolved Fe over light:dark cycles, to better understand fundamental aspects of genetic control of physiological acclimation to growth under Fe-limitation. We greatly expand the catalog of genes involved in the low Fe response, highlighting the importance of intracellular trafficking in Fe-limited diatoms. P. tricornutum exhibited transcriptomic hallmarks of slowed growth leading to prolonged periods of cell division/silica deposition, which could impact biogeochemical carbon sequestration in Fe-limited regions. Light harvesting and ribosome biogenesis transcripts were generally reduced under low Fe while transcript levels for genes putatively involved in the acquisition and recycling of Fe were increased. We also noted shifts in expression towards increased synthesis and catabolism of branched chain amino acids in P. tricornutum grown at low Fe whereas expression of genes involved in central core metabolism were relatively unaffected, indicating that essential cellular function is protected. Beyond the response of P. tricornutum to low Fe, we observed major coordinated shifts in transcript control of primary and intermediate metabolism over light:dark cycles which contribute to a new view of the significance of distinctive diatom pathways, such as mitochondrial glycolysis and the ornithine-urea cycle. This study provides new insight into transcriptional modulation of diatom physiology and metabolism across light:dark cycles in response to Fe availability

  12. Global guidance on environmental life cycle impact assessment indicators: impacts of climate change, fine particulate matter formation, water consumption and land use

    Jolliet, Olivier; Antón, Assumpció; Boulay, Anne-Marie

    2018-01-01

    of water consumption on human health assesses the DALYs from malnutrition caused by lack of water for irrigated food production. Land use impacts: CFs representing global potential species loss from land use are proposed as interim recommendation suitable to assess biodiversity loss due to land use......Purpose: Guidance is needed on best-suited indicators to quantify and monitor the man-made impacts on human health, biodiversity and resources. Therefore, the UNEP-SETAC Life Cycle Initiative initiated a global consensus process to agree on an updated overall life cycle impact assessment (LCIA...... are recommended: (a) The global warming potential 100 years (GWP 100) represents shorter term impacts associated with rate of change and adaptation capacity, and (b) the global temperature change potential 100 years (GTP 100) characterizes the century-scale long term impacts, both including climate-carbon cycle...

  13. Future mobility case studies. Life cycle assessments of BEVs and ICVs with a global perspective

    Ma, Hongrui; Riera-Palou, Xavier; Tait, Nigel [Shell Global Solutions (United Kingdom), Chester (United Kingdom). Shell Technology Center Thornton; Balthasar, Felix; Warnecke, Wolfgang [Shell Global Solutions (Deutschland) GmbH, Hamburg (Germany). PAE-Labor

    2012-11-01

    To highlight the potential risks associated with simplification, we present a relevant case study on electric vehicles, where the outcome of the analysis changes substantially with the methodological/system boundary choices made. Electric vehicles have increasingly gained worldwide interest as one of the most promising potential long-term solutions to sustainable personal mobility; in particular, battery electric vehicles (BEVs) offer zero tailpipe emissions enabling them not only to reduce transport GHG emissions but also to reduce other regulated emissions (e.g. smog). However, their true ability to contribute to GHG emissions reductions can only be properly assessed by comparing a full life cycle assessment of their GHG emissions with a similar assessment for conventional internal combustion vehicles (ICVs). In this study, we have carried out an analysis for vehicles typical of those expected to be introduced in 2012 in Western Europe, the U.S. and China, taking into account the impact of three important factors: (a) like-forlike vehicle comparison and effect of real-world driving conditions, (b) accounting for the GHG emissions associated with meeting the additional electricity demand for charging the batteries, and (c) the GHG emissions associated with the vehicle life cycle (e.g. manufacture and disposal, etc). We find that BEVs can deliver significant GHG savings compared to ICVs providing that the grid GHG intensity used to charge the batteries is sufficiently low. In particular, BEVs perform best relative to ICVs in terms of GHG emissions in low speed (e.g. urban) driving and when lightly loaded with weight and auxiliaries. However, vehicle life cycle emissions are higher for BEVs than ICVs due to the GHG emissions associated with battery manufacture. Furthermore, our analysis illustrates that it is inappropriate to draw general conclusions about the relative GHG performance of BEVs and ICVs without due reference to the context - such relative performance

  14. Characterization factors for global warming in life cycle assessment based on damages to humans and ecosystems.

    De Schryver, An M; Brakkee, Karin W; Goedkoop, Mark J; Huijbregts, Mark A J

    2009-03-15

    Human and ecosystem health damage due to greenhouse gas (GHG) emissions is generally poorly quantified in the life cycle assessment of products, preventing an integrated comparison of the importance of GHGs with other stressor types, such as ozone depletion and acidifying emissions. In this study, we derived new characterization factors for 63 GHGs that quantify the impact of an emission change on human and ecosystem health damage. For human health damage, the Disability Adjusted Life Years (DALYs) per unit emission related to malaria, diarrhea, malnutrition, drowning, and cardiovascular diseases were quantified. For ecosystem health damage, the Potentially Disappeared Fraction (PDF) over space and time of various species groups, including plants, butterflies, birds, and mammals, per unit emission was calculated. The influence of value choices in the modeling procedure was analyzed by defining three coherent scenarios, based on Cultural theory perspectives. It was found that the characterization factor for human health damage by carbon dioxide (CO2) ranges from 1.1 x 10(-2) to 1.8 x 10(+1) DALY per kton of emission, while the characterization factor for ecosystem damage by CO2 ranges from 5.4 x 10(-2) to 1.2 x 10(+1) disappeared fraction of species over space and time ((km2 x year)/kton), depending on the scenario chosen. The characterization factor of a GHG can change up to 4 orders of magnitude, depending on the scenario. The scenario-specific differences are mainly explained by the choice for a specific time horizon and stresses the importance of dealing with value choices in the life cycle impact assessment of GHG emissions.

  15. Globalization

    Tulio Rosembuj

    2006-12-01

    Full Text Available There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

  16. Globalization

    Tulio Rosembuj

    2006-01-01

    There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

  17. The global distribution of thermospheric odd nitrogen for solstice conditions during solar cycle minimum

    Gerard, J.-C.; Roble, R. G.; Rusch, D. W.; Stewart, A. I.

    1984-01-01

    A two-dimensional model of odd nitrogen in the thermosphere and upper mesosphere is described. The global distributions of nitric oxide and atomic nitrogen are calculated for the solstice period for quiet and moderate magnetic activity during the solar minimum period. The effect of thermospheric transport by winds is investigated along with the importance of particle-induced ionization in the auroral zones. The results are compared with rocket and satellite measurements, and the sensitivity of the model to eddy diffusion and neutral winds is investigated. Downward fluxes of NO into the mesosphere are given, and their importance for stratospheric ozone is discussed. The results show that the summer-to-winter pole meridional circulation transports both NO and N(S-4) across the solar terminator into the polar night region where there is a downward vertical transport toward the mesosphere. The model shows that odd nitrogen densities at high winter latitudes are entirely controlled by particle precipitation and transport processes.

  18. Global Precipitation Measurement (GPM) Spacecraft Lithium Ion Battery Micro-Cycling Investigation

    Dakermanji, George; Lee, Leonine; Spitzer, Thomas

    2016-01-01

    The Global Precipitation Measurement (GPM) spacecraft was jointly developed by NASA and JAXA. It is a Low Earth Orbit (LEO) spacecraft launched on February 27, 2014. The power system is a Direct Energy Transfer (DET) system designed to support 1950 watts orbit average power. The batteries use SONY 18650HC cells and consist of three 8s by 84p batteries operated in parallel as a single battery. During instrument integration with the spacecraft, large current transients were observed in the battery. Investigation into the matter traced the cause to the Dual-Frequency Precipitation Radar (DPR) phased array radar which generates cyclical high rate current transients on the spacecraft power bus. The power system electronics interaction with these transients resulted in the current transients in the battery. An accelerated test program was developed to bound the effect, and to assess the impact to the mission.

  19. Association between cadmium and calcium uptake and distribution during the moult cycle of female shore crabs, Carcinus maenas: an in vivo study

    Bondgaard, Morten; Bjerregaard, Poul

    2005-01-01

    Net influxes into the haemolymph and tissue distribution of 45 Ca and 109 Cd were studied in vivo in female Carcinus maenas at different moult stages. Net influxes of 45 Ca and 109 Cd from water were higher in postmoult (A and B) C. maenas than in C 3 - and C 4 -intermoult crabs and the net influx of calcium was higher in C 3 -intermoult crabs than in C 4 -intermoult crabs. The net influxes of 45 Ca and 109 Cd increased in postmoult C. maenas with decreasing external calcium concentrations at constant salinity. At all external calcium concentrations a significant correlation existed between 45 Ca and 109 Cd accumulated in the haemolymph of individual animals. In vivo exposure of postmoult C. maenas to external lanthanum decreased the 45 Ca and 109 Cd uptake rates to 30 and 10%, respectively, of the control values. About 30% of injected 109 Cd were found in the midgut gland, 10-20% in the gills and only a few (1-2) percent was lost to the seawater 24 h after injection. No major variations in tissue distribution of 109 Cd were observed between moult stages in these tissues. Premoult crabs retained more cadmium in the haemolymph 24 h after injection than other moult stages, and postmoult crabs retained more in muscle. Between 20 and 40% of the injected 45 Ca were excreted to the water, while only a few percent of the injected 45 Ca were found in the soft tissues 24 h after injection. Large moult stage variations, however, were observed in the tissue distribution of internalised 45 Ca. This study demonstrates that cadmium and calcium uptakes are elevated in postmoult C. maenas. The results indicate that cadmium and calcium in this stage are taken up via Ca 2+ -channels located in the apical membrane of gill epithelium cells. When internalised, however, cadmium and calcium are metabolised in fundamentally different ways, determined by the chemical properties and biological significance of the two metals

  20. Trends of 13C/12C ratios in pinyon tree rings of the American Southwest and the global carbon cycle

    Leavitt, S.W.; Long, A.

    1986-01-01

    An accurate atmospheric 13 C/ 12 C chronology can provide important constraints to models of the global carbon cycle. Trees accumulate carbon from atmospheric CO 2 into growth rings and offer potential for 13 C/ 12 C reconstructions, but results have not been reproducible. This paper presents δ 13 C curves from 5 sites, representing 20 pinyon (Pinus edulis) trees, where cores of 4 trees from each site have been pooled into a composite sample. Isotopic analysis of cellulose in 5-yr ring groups produces curves with a general trend of decreasing δ 13 C after 1800, but with pronounced short-term fluctuations superimposed upon the trend. Evidence indicates the fluctuations are strongly related to moisture availability (drought). A mean curve of the 5 δ 13 C chronologies from which the fossil-fuel component is subtracted suggests a substantial biospheric CO 2 contribution to the atmosphere since 1800

  1. The Challenges of Developing a Framework for Global Water Cycle Monitoring and Prediction (Alfred Wegener Medal Lecture)

    Wood, Eric F.

    2014-05-01

    The Global Earth Observation System of Systems (GEOSS) Water Strategy ("From Observations to Decisions") recognizes that "water is essential for ensuring food and energy security, for facilitating poverty reduction and health security, and for the maintenance of ecosystems and biodiversity", and that water cycle data and observations are critical for improved water management and water security - especially in less developed regions. The GEOSS Water Strategy has articulated a number of goals for improved water management, including flood and drought preparedness, that include: (i) facilitating the use of Earth Observations for water cycle observations; (ii) facilitating the acquisition, processing, and distribution of data products needed for effective management; (iii) providing expertise, information systems, and datasets to the global, regional, and national water communities. There are several challenges that must be met to advance our capability to provide near real-time water cycle monitoring, early warning of hydrological hazards (floods and droughts) and risk assessment under climate change, regionally and globally. Current approaches to monitoring and predicting hydrological hazards are limited in many parts of the world, and especially in developing countries where national capacity is limited and monitoring networks are inadequate. This presentation describes the developments at Princeton University towards a seamless monitoring and prediction framework at all time scales that allows for consistent assessment of water variability from historic to current conditions, and from seasonal and decadal predictions to climate change projections. At the center of the framework is an experimental, global water cycle monitoring and seasonal forecast system that has evolved out of regional and continental systems for the US and Africa. The system is based on land surface hydrological modeling that is driven by satellite remote sensing precipitation to predict

  2. How do persistent organic pollutants be coupled with biogeochemical cycles of carbon and nutrients in terrestrial ecosystems under global climate change?

    Teng, Ying [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation; Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Xu, Zhihong; Reverchon, Frederique [Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Luo, Yongming [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation

    2012-03-15

    Global climate change (GCC), especially global warming, has affected the material cycling (e.g., carbon, nutrients, and organic chemicals) and the energy flows of terrestrial ecosystems. Persistent organic pollutants (POPs) were regarded as anthropogenic organic carbon (OC) source, and be coupled with the natural carbon (C) and nutrient biogeochemical cycling in ecosystems. The objective of this work was to review the current literature and explore potential coupling processes and mechanisms between POPs and biogeochemical cycles of C and nutrients in terrestrial ecosystems induced by global warming. Global warming has caused many physical, chemical, and biological changes in terrestrial ecosystems. POPs environmental fate in these ecosystems is controlled mainly by temperature and biogeochemical processes. Global warming may accelerate the re-emissions and redistribution of POPs among environmental compartments via soil-air exchange. Soil-air exchange is a key process controlling the fate and transportation of POPs and terrestrial ecosystem C at regional and global scales. Soil respiration is one of the largest terrestrial C flux induced by microbe and plant metabolism, which can affect POPs biotransformation in terrestrial ecosystems. Carbon flow through food web structure also may have important consequences for the biomagnification of POPs in the ecosystems and further lead to biodiversity loss induced by climate change and POPs pollution stress. Moreover, the integrated techniques and biological adaptation strategy help to fully explore the coupling mechanisms, functioning and trends of POPs and C and nutrient biogeochemical cycling processes in terrestrial ecosystems. There is increasing evidence that the environmental fate of POPs has been linked with biogeochemical cycles of C and nutrients in terrestrial ecosystems under GCC. However, the relationships between POPs and the biogeochemical cycles of C and nutrients are still not well understood. Further

  3. Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

    Norwood, Zack; Kammen, Daniel

    2012-12-01

    We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of 0.25 kWh-1 electricity and 0.03 kWh-1 thermal, for a system with a life cycle global warming potential of ˜80 gCO2eq kWh-1 of electricity and ˜10 gCO2eq kWh-1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of 1.40 m-3, water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that 0.40-1.90 m-3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions.

  4. Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

    Norwood, Zack; Kammen, Daniel

    2012-01-01

    We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of $0.25 kWh −1 electricity and $0.03 kWh −1 thermal, for a system with a life cycle global warming potential of ∼80 gCO 2 eq kWh −1 of electricity and ∼10 gCO 2 eq kWh −1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of $1.40 m −3 , water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that $0.40–$1.90 m −3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions. (letter)

  5. Global solar magetic field organization in the extended corona: influence on the solar wind speed and density over the cycle.

    Réville, V.; Velli, M.; Brun, S.

    2017-12-01

    The dynamics of the solar wind depends intrinsically on the structure of the global solar magnetic field, which undergoes fundamental changes over the 11yr solar cycle. For instance, the wind terminal velocity is thought to be anti-correlated with the expansion factor, a measure of how the magnetic field varies with height in the solar corona, usually computed at a fixed height (≈ 2.5 Rȯ, the source surface radius which approximates the distance at which all magnetic field lines become open). However, the magnetic field expansion affects the solar wind in a more detailed way, its influence on the solar wind properties remaining significant well beyond the source surface: we demonstrate this using 3D global MHD simulations of the solar corona, constrained by surface magnetograms over half a solar cycle (1989-2001). For models to comply with the constraints provided by observed characteristics of the solar wind, namely, that the radial magnetic field intensity becomes latitude independent at some distance from the Sun (Ulysses observations beyond 1 AU), and that the terminal wind speed is anti-correlated with the mass flux, they must accurately describe expansion beyond the solar wind critical point (even up to 10Rȯ and higher in our model). We also show that near activity minimum, expansion in the higher corona beyond 2.5 Rȯ is actually the dominant process affecting the wind speed. We discuss the consequences of this result on the necessary acceleration profile of the solar wind, the location of the sonic point and of the energy deposition by Alfvén waves.

  6. Global Warming, New Climate, New Atmospheric Circulation and New Water Cycle in North Africa

    Karrouk, M. S.

    2017-12-01

    Global warming has now reached the energetic phase of H2O's return to the ground after the saturation of the atmosphere in evaporation since the 80s and 90s of the last century, which were characterized by severe droughts, mainly in Africa.This phase is the result of the accumulation of thermal energy exchanges in the Earth-Ocean-Atmosphere system that resulted in the thrust reversal of the energy balance toward the poles. This situation is characterized by a new thermal distribution: above the ocean, the situation is more in surplus compared to the mainland, or even opposite when the balance is negative on the land, and in the atmosphere, warm thermal advection easily reach the North Pole (planetary crests), as well as cold advection push deep into North Africa and the Gulf of Mexico (planetary valleys: Polar Vortex).This "New Ground Energy Balance" establishes a "New Meridian Atmospheric Circulation (MAC)" with an undulating character throughout the year, including the winter characterized by intense latitudinal very active energy exchanges between the surplus areas (tropical) and the deficit (polar) on the one hand, and the atmosphere, the ocean and the continent on the other.The excess radiation balance increases the potential evaporation of the atmosphere and provides a new geographical distribution of Moisture and Water worldwide: the excess water vapor is easily converted by cold advection (Polar Vortex) to heavy rains that cause floods or snow storms that paralyze the normal functioning of human activities, which creates many difficulties for users and leaves damage and casualties, but ensures water availability missing since a long time in many parts of the world, in Africa, Europe and America.The new thermal distribution reorganizes the geography of atmospheric pressure: the ocean energy concentration is transmitted directly to the atmosphere, and the excess torque is pushed northward. The Azores anticyclone is strengthened and is a global lock by the

  7. The role of industrial nitrogen in the global nitrogen biogeochemical cycle

    Gu, Baojing; Chang, Jie; Min, Yong; Ge, Ying; Zhu, Qiuan; Galloway, James N.; Peng, Changhui

    2013-01-01

    Haber-Bosch nitrogen (N) has been increasingly used in industrial products, e.g., nylon, besides fertilizer. Massive numbers of species of industrial reactive N (Nr) have emerged and produced definite consequences but receive little notice. Based on a comprehensive inventory, we show that (1) the industrial N flux has increased globally from 2.5 to 25.4 Tg N yr−1 from 1960 through 2008, comparable to the NOx emissions from fossil fuel combustion; (2) more than 25% of industrial products (primarily structural forms, e.g., nylon) tend to accumulate in human settlements due to their long service lives; (3) emerging Nr species define new N-assimilation and decomposition pathways and change the way that Nr is released to the environment; and (4) the loss of these Nr species to the environment has significant negative human and ecosystem impacts. Incorporating industrial Nr into urban environmental and biogeochemical models could help to advance urban ecology and environmental sciences. PMID:23999540

  8. Ecosystem services and biogeochemical cycles on a global scale: valuation of water, carbon and nitrogen processes

    Watanabe, Marcos D.B.; Ortega, Enrique

    2011-01-01

    Ecosystem services (ES) are provided by healthy ecosystems and are fundamental to support human life. However, natural systems have been degraded all over the world and the process of degradation is partially attributed to the lack of knowledge regarding the economic benefits associated with ES, which usually are not captured in the market. To valuate ES without using conventional approaches, such as the human's willingness-to-pay for ecosystem goods and services, this paper uses a different method based on Energy Systems Theory to estimate prices for biogeochemical flows that affect ecosystem services by considering their emergy content converted to equivalent monetary terms. Ecosystem services related to water, carbon and nitrogen biogeochemical flows were assessed since they are connected to a range of final ecosystem services including climate regulation, hydrological regulation, food production, soil formation and others. Results in this paper indicate that aquifer recharge, groundwater flow, carbon dioxide sequestration, methane emission, biological nitrogen fixation, nitrous oxide emission and nitrogen leaching/runoff are the most critical biogeochemical flows in terrestrial systems. Moreover, monetary values related to biogeochemical flows on a global scale could provide important information for policymakers concerned with payment mechanisms for ecosystem services and costs of greenhouse gas emissions.

  9. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    Herdiwijaya, Dhani, E-mail: dhani@as.itb.ac.id [Astronomy Research Division and Bosscha Observatory, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia); Arif, Johan [Geology Research Division, Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia); Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi [Astronomy Study Program, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung, Indonesia 40132 (Indonesia)

    2015-09-30

    Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth’s climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the activities of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between solar forcing energy to the Earth’s global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low solar activity.

  10. On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

    Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi

    2015-09-01

    Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth's climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the activities of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between solar forcing energy to the Earth's global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low solar activity.

  11. Characterization of Anammox Hydrazine Dehydrogenase, a Key N2-producing Enzyme in the Global Nitrogen Cycle.

    Maalcke, Wouter J; Reimann, Joachim; de Vries, Simon; Butt, Julea N; Dietl, Andreas; Kip, Nardy; Mersdorf, Ulrike; Barends, Thomas R M; Jetten, Mike S M; Keltjens, Jan T; Kartal, Boran

    2016-08-12

    Anaerobic ammonium-oxidizing (anammox) bacteria derive their energy for growth from the oxidation of ammonium with nitrite as the electron acceptor. N2, the end product of this metabolism, is produced from the oxidation of the intermediate, hydrazine (N2H4). Previously, we identified N2-producing hydrazine dehydrogenase (KsHDH) from the anammox organism Kuenenia stuttgartiensis as the gene product of kustc0694 and determined some of its catalytic properties. In the genome of K. stuttgartiensis, kustc0694 is one of 10 paralogs related to octaheme hydroxylamine (NH2OH) oxidoreductase (HAO). Here, we characterized KsHDH as a covalently cross-linked homotrimeric octaheme protein as found for HAO and HAO-related hydroxylamine-oxidizing enzyme kustc1061 from K. stuttgartiensis Interestingly, the HDH trimers formed octamers in solution, each octamer harboring an amazing 192 c-type heme moieties. Whereas HAO and kustc1061 are capable of hydrazine oxidation as well, KsHDH was highly specific for this activity. To understand this specificity, we performed detailed amino acid sequence analyses and investigated the catalytic and spectroscopic (electronic absorbance, EPR) properties of KsHDH in comparison with the well defined HAO and kustc1061. We conclude that HDH specificity is most likely derived from structural changes around the catalytic heme 4 (P460) and of the electron-wiring circuit comprising seven His/His-ligated c-type hemes in each subunit. These nuances make HDH a globally prominent N2-producing enzyme, next to nitrous oxide (N2O) reductase from denitrifying microorganisms. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Globalization

    Andru?cã Maria Carmen

    2013-01-01

    The field of globalization has highlighted an interdependence implied by a more harmonious understanding determined by the daily interaction between nations through the inducement of peace and the management of streamlining and the effectiveness of the global economy. For the functioning of the globalization, the developing countries that can be helped by the developed ones must be involved. The international community can contribute to the institution of the development environment of the gl...

  13. The evolution of the global selenium cycle: Secular trends in Se isotopes and abundances

    Stüeken, E. E.; Buick, R.; Bekker, A.; Catling, D.; Foriel, J.; Guy, B. M.; Kah, L. C.; Machel, H. G.; Montañez, I. P.; Poulton, S. W.

    2015-08-01

    The Earth's surface has undergone major transitions in its redox state over the past three billion years, which have affected the mobility and distribution of many elements. Here we use Se isotopic and abundance measurements of marine and non-marine mudrocks to reconstruct the evolution of the biogeochemical Se cycle from ∼3.2 Gyr onwards. The six stable isotopes of Se are predominantly fractionated during redox reactions under suboxic conditions, which makes Se a potentially valuable new tool for identifying intermediate stages from an anoxic to a fully oxygenated world. δ82/78Se shows small fractionations of mostly less than 2‰ throughout Earth's history and all are mass-dependent within error. In the Archean, especially after 2.7 Gyr, we find an isotopic enrichment in marine (+0.37 ± 0.27‰) relative to non-marine samples (-0.28 ± 0.67‰), paired with increasing Se abundances. Student t-tests show that these trends are statistically significant. Although we cannot completely rule out the possibility of volcanic Se addition, these trends may indicate the onset of oxidative weathering on land, followed by non-quantitative reduction of Se oxyanions during fluvial transport. The Paleoproterozoic Great Oxidation Event (GOE) is not reflected in the marine δ82/78Se record. However, we find a major inflection in the secular δ82/78Se trend during the Neoproterozoic, from a Precambrian mean of +0.42 ± 0.45‰ to a Phanerozoic mean of -0.19 ± 0.59‰. This drop probably reflects the oxygenation of the deep ocean at this time, stabilizing Se oxyanions throughout the water column. Since then, reduction of Se oxyanions has likely been restricted to anoxic basins and diagenetic environments in sediments. In light of recent Cr isotope data, it is likely that oxidative weathering before the Neoproterozoic produced Se oxyanions in the intermediate redox state SeIV, whereas the fully oxidized species SeVI became more abundant after the Neoproterozoic rise of

  14. Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle.

    Gundale, Michael J; From, Fredrik; Bach, Lisbet H; Nordin, Annika

    2014-01-01

    It is proposed that increases in anthropogenic reactive nitrogen (Nr ) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long-term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long-term (14-year) stand-scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha(-1)  yr(-1) ) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low-level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A (15) N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg(-1)  N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition. © 2013 John Wiley & Sons Ltd.

  15. The ocean quasi-homogeneous layer model and global cycle of carbon dioxide in system of atmosphere-ocean

    Glushkov, Alexander; Glushkov, Alexander; Loboda, Nataliya; Khokhlov, Valery; Serbov, Nikoly; Svinarenko, Andrey

    The purpose of this paper is carrying out the detailed model of the CO2 global turnover in system of "atmosphere-ocean" with using the ocean quasi-homogeneous layer model. Practically all carried out models are functioning in the average annual regime and accounting for the carbon distribution in bio-sphere in most general form (Glushkov et al, 2003). We construct a modified model for cycle of the carbon dioxide, which allows to reproduce a season dynamics of carbon turnover in ocean with account of zone ocean structure (up quasi-homogeneous layer, thermocline and deepest layer). It is taken into account dependence of the CO2 transfer through the bounder between atmosphere and ocean upon temperature of water and air, wind velocity, buffer mechanism of the CO2 dissolution. The same program is realized for atmosphere part of whole system. It is obtained a tempo-ral and space distribution for concentration of non-organic carbon in ocean, partial press of dissolute CO2 and value of exchange on the border between atmosphere and ocean. It is estimated a role of the wind intermixing of the up ocean layer. The increasing of this effect leads to increasing the plankton mass and further particles, which are transferred by wind, contribute to more quick immersion of microscopic shells and organic material. It is fulfilled investigation of sen-sibility of the master differential equations system solutions from the model parameters. The master differential equa-tions system, describing a dynamics of the CO2 cycle, is numerically integrated by the four order Runge-Cutt method under given initial values of valuables till output of solution on periodic regime. At first it is indicated on possible real-zation of the chaos scenario in system. On our data, the difference of the average annual values for the non-organic car-bon concentration in the up quasi-homogeneous layer between equator and extreme southern zone is 0.15 mol/m3, be-tween the equator and extreme northern zone is 0

  16. Development of Low Global Warming Potential Refrigerant Solutions for Commercial Refrigeration Systems using a Life Cycle Climate Performance Design Tool

    Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Vineyard, Edward Allan [ORNL

    2012-01-01

    Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, direct emissions related to refrigerant leakage and indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications to provide lower Global Warming Potential (GWP) refrigerant solutions with improved LCCP compared to baseline systems. The LCCP design tool accounts for system performance, ambient temperature, and system load; system performance is evaluated using a validated vapor compression system simulation tool while ambient temperature and system load are devised from a widely used building energy modeling tool (EnergyPlus). The LCCP design tool also accounts for the change in hourly electricity emission rate to yield an accurate prediction of indirect emissions. The analysis shows that conventional commercial refrigeration system life cycle emissions are largely due to direct emissions associated with refrigerant leaks and that system efficiency plays a smaller role in the LCCP. However, as a transition occurs to low GWP refrigerants, the indirect emissions become more relevant. Low GWP refrigerants may not be suitable for drop-in replacements in conventional commercial refrigeration systems; however some mixtures may be introduced as transitional drop-in replacements. These transitional refrigerants have a significantly lower GWP than baseline refrigerants and as such, improved LCCP. The paper concludes with a brief discussion on the tradeoffs between refrigerant GWP, efficiency and capacity.

  17. New era of satellite chlorophyll fluorescence and soil moisture observations leads to advances in the predictive understanding of global terrestrial coupled carbon-water cycles

    Qiu, B.; Xue, Y.; Fisher, J.; Guo, W.

    2017-12-01

    The terrestrial carbon cycle and water cycle are coupled through a multitude of connected processes among soil, roots, leaves, and the atmosphere. The strength and sensitivity of these couplings are not yet well known at the global scale, which contributes to uncertainty in predicting the terrestrial water and carbon budgets. For the first time, we now have synchronous, high fidelity, global-scale satellite observations of critical terrestrial carbon and water cycle components: sun-induced chlorophyll fluorescence (SIF) and soil moisture. We used these observations within the framework of a well-established global terrestrial biosphere model (Simplified Simple Biosphere Model version 2.0, SSiB2) to investigate carbon-water coupling processes. We updated SSiB2 to include a mechanistic representation of SIF and tested the sensitivity of model parameters to improve the simulation of both SIF and soil moisture with the ultimate objective of improving the first-order terrestrial carbon component, gross primary production (GPP). Although several vegetation parameters, such as leaf area index (LAI) and green leaf fraction, improved the simulated SIF, and several soil parameters, such as hydraulic conductivity, improved simulated soil moisture, their effects were mainly limited to their respective cycles. One parameter emerged as the key coupler between the carbon and water cycles: the wilting point. Updates to the wilting point significantly improved the simulations for both soil moisture and SIF, as well as GPP. This study demonstrates the value of synchronous global measurements of the terrestrial carbon and water cycles in improving the understanding of coupled carbon-water cycles.

  18. Regionalized life cycle impact assessment of air pollution on the global scale: Damage to human health and vegetation

    van Zelm, Rosalie; Preiss, Philipp; van Goethem, Thomas; Van Dingenen, Rita; Huijbregts, Mark

    2016-06-01

    We developed regionalized characterization factors (CFs) for human health damage from particulate matter (PM2.5) and ozone, and for damage to vegetation from ozone, at the global scale. These factors can be used in the impact assessment phase of an environmental life cycle assessment. CFs express the overall damage of a certain pollutant per unit of emission of a precursor, i.e. primary PM2.5, nitrogen oxides (NOx), ammonia (NH3), sulfur dioxide (SO2) and non-methane volatile organic compounds (NMVOCs). The global chemical transport model TM5 was used to calculate intake fractions of PM2.5 and ozone for 56 world regions covering the whole globe. Furthermore, region-specific effect and damage factors were derived, using mortality rates, background concentrations and years of life lost. The emission-weighted world average CF for primary PM2.5 emissions is 629 yr kton-1, varying up to 3 orders of magnitude over the regions. Larger CFs were obtained for emissions in central Asia and Europe, and smaller factors in Australia and South America. The world average CFs for PM2.5 from secondary aerosols, i.e. NOx, NH3, and SO2, is 67.2 to 183.4 yr kton-1. We found that the CFs for ozone human health damage are 2-4 orders of magnitude lower compared to the CFs for damage due to primary PM2.5 and PM2.5 precursor emissions. Human health damage due to the priority air pollutants considered in this study was 1.7·10-2 yr capita-1 worldwide in year 2010, with primary PM2.5 emissions as the main contributor (62%). The emission-weighted world average CF for ecosystem damage due to ozone was 2.5 km2 yr kton-1 for NMVOCs and 8.7 m2 yr kg-1 for NOx emissions, varying 2-3 orders of magnitude over the regions. Ecosystem damage due to the priority air pollutants considered in this study was 1.6·10-4 km2 capita-1 worldwide in 2010, with NOx as the main contributor (72%). The spatial range in CFs stresses the importance of including spatial variation in life cycle impact assessment of

  19. Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies.

    Hertwich, Edgar G; Gibon, Thomas; Bouman, Evert A; Arvesen, Anders; Suh, Sangwon; Heath, Garvin A; Bergesen, Joseph D; Ramirez, Andrea; Vega, Mabel I; Shi, Lei

    2015-05-19

    Decarbonization of electricity generation can support climate-change mitigation and presents an opportunity to address pollution resulting from fossil-fuel combustion. Generally, renewable technologies require higher initial investments in infrastructure than fossil-based power systems. To assess the tradeoffs of increased up-front emissions and reduced operational emissions, we present, to our knowledge, the first global, integrated life-cycle assessment (LCA) of long-term, wide-scale implementation of electricity generation from renewable sources (i.e., photovoltaic and solar thermal, wind, and hydropower) and of carbon dioxide capture and storage for fossil power generation. We compare emissions causing particulate matter exposure, freshwater ecotoxicity, freshwater eutrophication, and climate change for the climate-change-mitigation (BLUE Map) and business-as-usual (Baseline) scenarios of the International Energy Agency up to 2050. We use a vintage stock model to conduct an LCA of newly installed capacity year-by-year for each region, thus accounting for changes in the energy mix used to manufacture future power plants. Under the Baseline scenario, emissions of air and water pollutants more than double whereas the low-carbon technologies introduced in the BLUE Map scenario allow a doubling of electricity supply while stabilizing or even reducing pollution. Material requirements per unit generation for low-carbon technologies can be higher than for conventional fossil generation: 11-40 times more copper for photovoltaic systems and 6-14 times more iron for wind power plants. However, only two years of current global copper and one year of iron production will suffice to build a low-carbon energy system capable of supplying the world's electricity needs in 2050.

  20. Does the correlation between solar cycle lengths and Northern Hemisphere land temperatures rule out any significant global warming from greenhouse gases?

    Laut, Peter; Gundermann, Jesper

    1998-01-01

    Since the discovery of a striking correlation between solar cycle lengths and Northern Hemisphere land temperatures there have been widespread speculations as to whether these findings would rule out any significant contributions to global warming from the enhanced concentrations of greenhouse...... gases. The present analysis shows that a similar degree of correlation is obtained when testing the solar data against a couple of fictitious temperature series representing different global warming trends. Therefore, the correlation cannot be used to estimate the magnitude of a possible contribution...... to global warming from human activities, nor to rule out a sizable contribution from that source....

  1. Simulation of global sulfate distribution and the influence of effective cloud drop radii with a coupled photochemistry-sulfur cycle model

    Roelofs, G.J.; Lelieveld, J.; Ganzeveld, L.N.

    1998-01-01

    A sulfur cycle model is coupled to a global chemistry-climate model. The simulated surface sulfate concentrations are generally within a factor of 2 of observed concentrations, and display a realistic seasonality for most background locations. However, the model tends to underestimate sulfate and

  2. Diazotroph-Bacterial Community Structure of Root Nodules Account for Two-Fold Differences in Plant Growth: Consequences for Global Biogeochemical Cycles

    Williams, M. A.

    2016-12-01

    The bacterial communities that inhabit and function as mutualists in the nodules of soybean, a major worldwide crop, are a fundamental determinant of plant growth and global nitrogen and carbon cycles. Unfertilized soybean can derive up to 90% of its nitrogen through bacterial-driven diazotrophy. It was the goal of the research in this study to assess whether different bacterial taxa (e.g. Bradyrhizobia spp.) differ in their soybean growth supportive role, which could then feedback to alter global biogeochemical cycling. Using 16S rRNA and NifH genes, nodule bacterial communities were shown to vary across 9 different cultivars of soybean, and that the variation between cultivars were highly correlated to plant yield (97 to 188 bu/Ha) and nitrogen. The relative abundances of gene sequences associated with the closest taxonomic match (NCBI), indicated that several taxa were (r= 0.76) negatively (e.g. Bradyrhizobium sp Ec3.3) or (r= 0.84) positively (e.g. Bradyrhizobium elkanii WSM 2783) correlated with plant yield. Other non-Rhizobiaceae taxa, such as Rhodopseudomonas spp. were also prevalent and correlated with plant yield. Soybeans and other leguminous crops will become increasingly important part of world food production, soil fertility and global biogeochemical cycles with rising population and food demand. The study demonstrates the importance of plant-microbial feedbacks driving plant growth but also ramifications for global cycling of nitrogen and carbon.

  3. Modeling cumulative effects in life cycle assessment: the case of fertilizer in wheat production contributing to the global warming potential.

    Laratte, Bertrand; Guillaume, Bertrand; Kim, Junbeum; Birregah, Babiga

    2014-05-15

    This paper aims at presenting a dynamic indicator for life cycle assessment (LCA) measuring cumulative impacts over time of greenhouse gas (GHG) emissions from fertilizers used for wheat cultivation and production. Our approach offers a dynamic indicator of global warming potential (GWP), one of the most used indicator of environmental impacts (e.g. in the Kyoto Protocol). For a case study, the wheat production in France was selected and considered by using data from official sources about fertilizer consumption and production of wheat. We propose to assess GWP environmental impact based on LCA method. The system boundary is limited to the fertilizer production for 1 ton of wheat produced (functional unit) from 1910 to 2010. As applied to wheat production in France, traditional LCA shows a maximum GWP impact of 500 kg CO2-eq for 1 ton of wheat production, whereas the GWP impact of wheat production over time with our approach to dynamic LCA and its cumulative effects increases to 18,000 kg CO2-eq for 1 ton of wheat production. In this paper, only one substance and one impact assessment indicator are presented. However, the methodology can be generalized and improved by using different substances and indicators. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Polycyclic aromatic hydrocarbons in soils of the central Tibetan Plateau, China: Distribution, sources, transport and contribution in global cycling

    Yuan, Guo-Li; Wu, Li-Juan; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

    2015-01-01

    Forty-four soil samples were collected across the central Tibetan Plateau (CTP) at altitudes between 3711 m and 5352 m, and their polycyclic aromatic hydrocarbons (PAHs) contents were measured to be from 0.43 to 26.66 ng/g. The main sources of PAHs were identified for each of four sub-areas, and their concentrations in soils were determined to be mainly influenced by local sources. Along a 600 km sampling trajectory from Lhasa, which served as the biggest local source, the concentrations of PAHs decreased logarithmically with increasing distances from the source. Meanwhile, the fractional proportions of PAHs were observed to change logarithmically according to the transport distances. Conclusively, PAHs from local sources were transported within the CTP and dominated PAHs concentrations in the soils, but few of them were transported outside the CTP. In global cycling, the soils in the CTP mainly serve as background and a “sink” for PAHs. - Highlights: • Main sources of PAHs were identified for each of four sub-areas in CTP. • Local sources dominated PAHs in soils but rarely transported outside CTP. • The PAHs in soils changed logarithmically according to the distances from source. • It is first revealed how the local PAH sources influenced PAHs in the soils of CTP. - Local sources dominated PAHs concentrations in the soils of CTP but rarely transported outside, and PAHs in soils changed logarithmically according to the transported distances

  5. Normalisation in product life cycle assessment: an LCA of the global and European economic systems in the year 2000.

    Sleeswijk, Anneke Wegener; van Oers, Lauran F C M; Guinée, Jeroen B; Struijs, Jaap; Huijbregts, Mark A J

    2008-02-01

    In the methodological context of the interpretation of environmental life cycle assessment (LCA) results, a normalisation study was performed. 15 impact categories were accounted for, including climate change, acidification, eutrophication, human toxicity, ecotoxicity, depletion of fossil energy resources, and land use. The year 2000 was chosen as a reference year, and information was gathered on two spatial levels: the global and the European level. From the 860 environmental interventions collected, 48 interventions turned out to account for at least 75% of the impact scores of all impact categories. All non-toxicity related, emission dependent impacts are fully dominated by the bulk emissions of only 10 substances or substance groups: CO(2), CH(4), SO(2), NO(x), NH(3), PM(10), NMVOC, and (H)CFCs emissions to air and emissions of N- and P-compounds to fresh water. For the toxicity-related emissions (pesticides, organics, metal compounds and some specific inorganics), the availability of information was still very limited, leading to large uncertainty in the corresponding normalisation factors. Apart from their usefulness as a reference for LCA studies, the results of this study stress the importance of efficient measures to combat bulk emissions and to promote the registration of potentially toxic emissions on a more comprehensive scale.

  6. Calcium Electroporation

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  7. Dynamic model of the global iodine cycle for the estimation of dose to the world population from releases of iodine-129 to the environment

    Kocher, D.C.

    1979-11-01

    A dynamic linear compartment model of the global iodine cycle has been developed for the purpose of estimating long-term doses and dose commitments to the world population from releases of 129 I to the environment. The environmental compartments assumed in the model comprise the atmosphere, hydrosphere, lithosphere, and terrestrial biosphere. The global transport of iodine is described by means of time-invariant fractional transfer rates between the environmental compartments. The fractional transfer rates for 129 I are determined primarily from available data on compartment inventories and fluxes for naturally occurring stable iodine and from data on the global hydrologic cycle. The dose to the world population is estimated from the calculated compartment inventories of 129 I, the known compartment inventories of stable iodine, a pathway analysis of the intake of iodine by a reference individual, dose conversion factors for inhalation and ingestion, and an estimate of the world population. For an assumed constant population of 12.21 billion beyond the year 2075, the estimated population dose commitment is 2 x 10 5 man-rem/Ci. The sensitivity of the calculated doses to variations in some of the parameters in the model for the global iodine cycle is investigated. A computer code written to calculate global compartment inventories and dose rates and population doses is described and documented

  8. Globalization

    Plum, Maja

    Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA...

  9. Globalization

    F. Gerard Adams

    2008-01-01

    The rapid globalization of the world economy is causing fundamental changes in patterns of trade and finance. Some economists have argued that globalization has arrived and that the world is “flat†. While the geographic scope of markets has increased, the author argues that new patterns of trade and finance are a result of the discrepancies between “old†countries and “new†. As the differences are gradually wiped out, particularly if knowledge and technology spread worldwide, the t...

  10. Calcium addition in straw gasification

    Risnes, H.; Fjellerup, Jan Søren; Henriksen, Ulrik Birk

    2003-01-01

    The present work focuses on the influence of calcium addition in gasification. The inorganic¿organic element interaction as well as the detailed inorganic¿inorganic elements interaction has been studied. The effect of calcium addition as calcium sugar/molasses solutions to straw significantly...... affected the ash chemistry and the ash sintering tendency but much less the char reactivity. Thermo balance test are made and high-temperature X-ray diffraction measurements are performed, the experimental results indicate that with calcium addition major inorganic¿inorganic reactions take place very late...... in the char conversion process. Comprehensive global equilibrium calculations predicted important characteristics of the inorganic ash residue. Equilibrium calculations predict the formation of liquid salt if sufficient amounts of Ca are added and according to experiments as well as calculations calcium binds...

  11. Effects of Seawater Acidification on the Liffe Cycle and Fitness of Opossum Shrimp Population

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known se...

  12. Effects of Seawater Acidification on the Life Cycle and fitness of Opossum Shrimp Populations

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known ph...

  13. The Search for Eight Glacial Cycles of Deep-Water Temperatures and Global ice Volume From the Southern Hemisphere

    Ferretti, P.; Elderfield, H.; Greaves, M.; McCave, N.

    2007-12-01

    It has been recently suggested "a substantial portion of the marine 100-ky cycle that has been object of so much attention over the past quarter of a century is, in reality, a deep-water temperature signal and not an ice volume signal" (Shackleton, 2000). There are currently few records available of deep-water temperature variations during the Pleistocene and most of our understanding is inferred from the oxygen isotopic composition (δ18O) of benthic foraminifera from deep-sea sediments. However, variations in benthic δ18O reflect some combination of local to regional changes in water mass properties (largely deep- water temperature) as well as global changes in seawater δ18O (δ18Osw) resulting from the growth and decay of continental ice. Recent studies suggest that benthic foraminiferal Mg/Ca may be useful in reconstructing deep-water temperature changes, but the application of this method to benthic species has been hampered by a number of unresolved issues, such as uncertainties related to the calibration for benthic Mg at the coldest temperatures. Here we present deep-sea Mg/Ca and δ18O records for the past eight glacial cycles in benthic foraminiferal ( Uvigerina spp.) calcite from a marine sediment core recovered in the mid Southern latitudes. Ocean Drilling Program Site 1123 was retrieved from Chatham Rise, east of New Zealand in the Southwest Pacific Ocean (3290 m water depth). This site lies under the Deep Western Boundary Current (DWBC) that flows into the Pacific Ocean, and is responsible for most of the deep water in that ocean; DWBC strength is directly related to processes occurring around Antarctica. Temperatures derived via pore fluid modeling of the last glacial maximum are available from Site 1123 and represent an important tool to constrain deep-water temperatures estimates using Mg/Ca. In selected time slices, we measured B/Ca ratios in Uvigerina in order to gain information on the deep-water carbonate saturation state and have data of Mg

  14. Carbon cost of plant nitrogen acquisition: global carbon cycle impact from an improved plant nitrogen cycle in the Community Land Model.

    Shi, Mingjie; Fisher, Joshua B; Brzostek, Edward R; Phillips, Richard P

    2016-03-01

    Plants typically expend a significant portion of their available carbon (C) on nutrient acquisition - C that could otherwise support growth. However, given that most global terrestrial biosphere models (TBMs) do not include the C cost of nutrient acquisition, these models fail to represent current and future constraints to the land C sink. Here, we integrated a plant productivity-optimized nutrient acquisition model - the Fixation and Uptake of Nitrogen Model - into one of the most widely used TBMs, the Community Land Model. Global plant nitrogen (N) uptake is dynamically simulated in the coupled model based on the C costs of N acquisition from mycorrhizal roots, nonmycorrhizal roots, N-fixing microbes, and retranslocation (from senescing leaves). We find that at the global scale, plants spend 2.4 Pg C yr(-1) to acquire 1.0 Pg N yr(-1) , and that the C cost of N acquisition leads to a downregulation of global net primary production (NPP) by 13%. Mycorrhizal uptake represented the dominant pathway by which N is acquired, accounting for ~66% of the N uptake by plants. Notably, roots associating with arbuscular mycorrhizal (AM) fungi - generally considered for their role in phosphorus (P) acquisition - are estimated to be the primary source of global plant N uptake owing to the dominance of AM-associated plants in mid- and low-latitude biomes. Overall, our coupled model improves the representations of NPP downregulation globally and generates spatially explicit patterns of belowground C allocation, soil N uptake, and N retranslocation at the global scale. Such model improvements are critical for predicting how plant responses to altered N availability (owing to N deposition, rising atmospheric CO2 , and warming temperatures) may impact the land C sink. © 2015 John Wiley & Sons Ltd.

  15. Correction for non-rigid movement artefacts in calcium imaging using local-global optical flow and PCA-based templates

    Brazhe, A.; Fordsmann, J.; Lauritzen, M.

    2017-01-01

    correction of calcium timelapse imaging data is accurate, can represent non-rigid image distortions, robust to noisy data and allows for fast registration of large videos. The implementation is open-source and is programmed in Python, which provides for easy access and merging into downstream image...

  16. Characterization of waterborne nitrogen emissions for marine eutrophication modelling in life cycle impact assessment at the damage level and global scale

    Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

    2017-01-01

    Current life cycle impact assessment (LCIA) methods lack a consistent and globally applicable characterization model relating nitrogen (N, as dissolved inorganic nitrogen, DIN) enrichment of coastal waters to the marine eutrophication impacts at the endpoint level. This paper introduces a method...... to calculate spatially explicit characterization factors (CFs) at endpoint and damage to ecosystems levels, for waterborne nitrogen emissions, reflecting their hypoxia-related marine eutrophication impacts, modelled for 5772 river basins of the world....

  17. Get Enough Calcium

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... women, don't get enough calcium. How much calcium do I need every day? Women: If you ...

  18. Calcium - urine

    ... Female urinary tract Male urinary tract Calcium urine test References Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier; ...

  19. The global marine phosphorus cycle: Response to climate change and feedbacks on ocean biogeochemistry. Geologica Ultraiectina (329)

    Tsandev, I.

    2010-01-01

    This thesis focuses on the marine phosphorus (P) cycle and its response to changing environmental conditions, particularly those associated with glacial-interglacial cycles of the late Pleistocene and Ocean Anoxic Events in the Cretaceous. From a box model of the ocean phosphorus, organic carbon and

  20. Simulation analysis of the possibility of introducing massive renewable energy and nuclear fuel cycle in the scenario to halve global CO2 emissions by the year 2050

    Hosoya, Yoshifumi; Komiyama, Ryoichi; Fujii, Yasumasa

    2011-01-01

    There is growing attention to the regulation of greenhouse gas (GHG) emissions to mitigate the global warming. Hence, the target of 50% reduction of global GHG emissions by the year 2050 has been investigated in this paper. The authors have been revising the regionally disaggregated world energy model which is formulated as a large scale linear optimization model from the aspect of nuclear and photovoltaic power generation technologies. This paper explains the structure of the revised world energy model considering the intermittent characteristics of photovoltaic power generation derived from the changes in weather conditions. And also this paper shows the simulation results to halve global CO 2 emissions by the year 2050 and evaluates the long-term technological options such as nuclear fuel cycle and renewable energies. Finally the authors discuss the future step for extensive revision of the energy model. (author)

  1. International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). 2011 Progress Report. Enhancing Global Nuclear Energy Sustainability

    NONE

    2012-05-15

    When INPRO was established in 2000, some key characteristics and main objectives for the project were determined and remain basically unchanged to this day: to help ensure that nuclear energy is available to contribute to satisfying energy needs in the 21st century in a sustainable manner and to bring together technology holders, technology users and other stakeholders to consider jointly the national and international actions required to achieve desired innovations in nuclear reactors and fuel cycles. I wish to use the occasion of this INPRO Progress Report to review some of the key highlights of the past year and share with you my views and vision of INPRO's future. The ''Great East Japan Earthquake and Tsunami'' and the resulting accident at TEPCO's Fukushima Daiichi nuclear power plant occurred on 11 March 2011. In response to this accident and at the request of its Member States, the IAEA drafted an Action Plan which defines a programme of work o strengthen the global nuclear safety framework. The activities proposed in the Action Plan are meant to be implemented in the near term, to assess the safety of operating nuclear power plants n the light of lessons learned from the Fukushima Daiichi accident. The assessment covers both technical elements, specifically the design of nuclear power plants with regard to site specific extreme natural hazards, and institutional elements, such as the effectiveness of regulatory bodies, operating organizations and the international legal framework in regard to the implementation of IAEA Safety tandards and Conventions. The lessons learned in the medium and long terms will also be reflected n a periodic update of the design requirements for nuclear power plants, international safety tandards, regulations issued by national supervisory authorities, operational procedures, emergency planning and safety assessment methodologies. INPRO has a long term perspective and provides an assessment of the whole nuclear system. Ensuring

  2. International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). 2011 Progress Report. Enhancing Global Nuclear Energy Sustainability

    2012-05-01

    When INPRO was established in 2000, some key characteristics and main objectives for the project were determined and remain basically unchanged to this day: to help ensure that nuclear energy is available to contribute to satisfying energy needs in the 21st century in a sustainable manner and to bring together technology holders, technology users and other stakeholders to consider jointly the national and international actions required to achieve desired innovations in nuclear reactors and fuel cycles. I wish to use the occasion of this INPRO Progress Report to review some of the key highlights of the past year and share with you my views and vision of INPRO's future. The ''Great East Japan Earthquake and Tsunami'' and the resulting accident at TEPCO's Fukushima Daiichi nuclear power plant occurred on 11 March 2011. In response to this accident and at the request of its Member States, the IAEA drafted an Action Plan which defines a programme of work o strengthen the global nuclear safety framework. The activities proposed in the Action Plan are meant to be implemented in the near term, to assess the safety of operating nuclear power plants n the light of lessons learned from the Fukushima Daiichi accident. The assessment covers both technical elements, specifically the design of nuclear power plants with regard to site specific extreme natural hazards, and institutional elements, such as the effectiveness of regulatory bodies, operating organizations and the international legal framework in regard to the implementation of IAEA Safety tandards and Conventions. The lessons learned in the medium and long terms will also be reflected n a periodic update of the design requirements for nuclear power plants, international safety tandards, regulations issued by national supervisory authorities, operational procedures, emergency planning and safety assessment methodologies. INPRO has a long term perspective and provides an assessment of the whole nuclear system. Ensuring

  3. Top-down constraints on disturbance dynamics in the terrestrial carbon cycle: effects at global and regional scales

    Bloom, A. A.; Exbrayat, J. F.; van der Velde, I.; Peters, W.; Williams, M.

    2014-01-01

    Large uncertainties preside over terrestrial carbon flux estimates on a global scale. In particular, the strongly coupled dynamics between net ecosystem productivity and disturbance C losses are poorly constrained. To gain an improved understanding of ecosystem C dynamics from regional to global

  4. Temporary Service? A Global Perspective on Domestic Work and the Life Cycle from Pre-Industrial Times to the Present

    Nederveen Meerkerk, van E.J.V.

    2017-01-01

    In recent years, labor history has taken a “global turn”, increasingly focusing on labor relations in the non-Western world. This article aims to challenge existing perceptions of the history of domestic work in Europe from a global labor history perspective by comparing them with the histories of

  5. GEOTRACES – An international study of the global marine biogeochemical cycles of trace elements and their isotopes

    Henderson, G.M.; Anderson, R.F.; Adkins, J.; Andersson, P.; Boyle, E.A.; Cutter, Greg; Baar, H. de; Eisenhauer, Anton; Frank, Martin; Francois, R.; Orians, Kristin; Gamo, T.; German, C.; Jenkins, W.; Moffett, J.

    2007-01-01

    Trace elements serve important roles as regulators of ocean processes including marine ecosystem dynamics and carbon cycling. The role of iron, for instance, is well known as a limiting micronutrient in the surface ocean. Several other trace elements also play crucial roles in ecosystem function and their supply therefore controls the structure, and possibly the productivity, of marine ecosystems. Understanding the biogeochemical cycling of these micronutrients requires knowledge of their div...

  6. Regulation of cardiomyocyte autophagy by calcium.

    Shaikh, Soni; Troncoso, Rodrigo; Criollo, Alfredo; Bravo-Sagua, Roberto; García, Lorena; Morselli, Eugenia; Cifuentes, Mariana; Quest, Andrew F G; Hill, Joseph A; Lavandero, Sergio

    2016-04-15

    Calcium signaling plays a crucial role in a multitude of events within the cardiomyocyte, including cell cycle control, growth, apoptosis, and autophagy. With respect to calcium-dependent regulation of autophagy, ion channels and exchangers, receptors, and intracellular mediators play fundamental roles. In this review, we discuss calcium-dependent regulation of cardiomyocyte autophagy, a lysosomal mechanism that is often cytoprotective, serving to defend against disease-related stress and nutrient insufficiency. We also highlight the importance of the subcellular distribution of calcium and related proteins, interorganelle communication, and other key signaling events that govern cardiomyocyte autophagy. Copyright © 2016 the American Physiological Society.

  7. Calcium biogeochemical cycle at the beech tree-soil solution interface from the Strengbach CZO (NE France): insights from stable Ca and radiogenic Sr isotopes

    Schmitt, Anne-Désirée; Gangloff, Sophie; Labolle, François; Chabaux, François; Stille, Peter

    2017-09-01

    Calcium (Ca) is the fourth most abundant element in mineral nutrition and plays key physiological and structural roles in plant metabolism. At the soil-water-plant scale, stable Ca isotopes are a powerful tool for the identification of plant-mineral interactions and recycling via vegetation. Radiogenic Sr isotopes are often used as tracers of Ca sources and mixtures of different reservoirs. In this study, stable Ca and radiogenic Sr are combined and analysed in several organs from two beech trees that were collected in June and September in the Strengbach critical zone observatory (CZO) (NE France) and in corresponding soil solutions. At the beech-tree scale, this study confirms the field Ca adsorption (i.e., physico-chemical mechanism and not vital effects) on carboxyl acid groups of pectin in the apoplasm of small roots. The analysis of the xylem sap and corresponding organs shows that although the Strengbach CZO is nutrient-poor, Ca seems to be non-limiting for tree-growth. Different viscosities of xylem sap between the stemwood and branches or leaves can explain δ44/40Ca values in different tree-organs. The bark and phloem 40Ca-enrichments could be due to Ca-oxalate precipitation in the bark tissues and in the phloem. The results from this study regarding the combination of these two isotopic systems show that the isotopic signatures of the roots are dominated by Ca fractionation mechanisms and Sr, and thus Ca, source variations. In contrast, translocation mechanisms are only governed by Ca fractionation processes. This study showed that at the root-soil solution interface, litter degradation was not the main source of Ca and Sr and that the soil solutions are not the complement of uptake by roots for samples from the 2011/2013 period. The opposite is observed for older samples. These observations indicate the decreasing contribution of low radiogenic Sr fluxes, such as recycling, alimenting the soil solutions. Such reduced importance of nutrient uptake and

  8. Calcium paradox and calcium entry blockers

    Ruigrok, T.J.C.; Slade, A.M.; Nayler, W.G.; Meijler, F.L.

    1984-01-01

    Reperfusion of isolated hearts with calcium-containing solution after a short period of calcium-free perfusion results in irreversible cell damage (calcium paradox). This phenomenon is characterized by an excessive influx of calcium into the cells, the rapid onset of myocardial contracture,

  9. Summertime calcium carbonate undersaturation in shelf waters of the western Arctic Ocean – how biological processes exacerbate the impact of ocean acidification

    N. R. Bates; M. I. Orchowska; R. Garley; J. T. Mathis

    2013-01-01

    The Arctic Ocean accounts for only 4% of the global ocean area, but it contributes significantly to the global carbon cycle. Recent observations of seawater CO2-carbonate chemistry in shelf waters of the western Arctic Ocean, primarily in the Chukchi Sea, from 2009 to 2011 indicate that bottom waters are seasonally undersaturated with respect to calcium carbonate (CaCO3) minerals, particularly aragonite. Nearly 40% of sampled bottom waters on the shelf have saturation states...

  10. The impact of organochlorines cycling in the cryosphere on global distributions and fate – 2. Land ice and temporary snow cover

    Hofmann, Lorenz; Stemmler, Irene; Lammel, Gerhard

    2012-01-01

    Global fate and transport of γ-HCH and DDT was studied using a global multicompartment chemistry-transport model, MPI-MCTM, with and without inclusion of land ice (in Antarctica and Greenland) or snow cover (dynamic). MPI-MCTM is based on coupled ocean and atmosphere general circulation models. After a decade of simulation 4.2% γ-HCH and 2.3% DDT are stored in land ice and snow. Neglection of land ice and snow in modelling would underestimate the total environmental residence time, τ ov , of γ-HCH and overestimate τ ov for DDT, both on the order of 1% and depending on actual compartmental distribution. Volatilisation of DDT from boreal, seasonally snow covered land is enhanced throughout the year, while volatilisation of γ-HCH is only enhanced during the snow-free season. Including land ice and snow cover in modelling matters in particular for the Arctic, where higher burdens are predicted to be stored. - Highlights: ► Land ice and snow hosts 2–4% of the global environmental burden of γ-HCH and DDT. ► Inclusion of land ice and snow cover matters for global environmental residence time. ► Including of land ice and snow cover matters in particular for the Arctic. - The inclusion of cycling in temporary snow cover and land ice in the model is found relevant for predicted POPs multicompartmental distribution and fate in the Arctic and on the global scale.

  11. A probabilistic assessment of calcium carbonate export and dissolution in the modern ocean

    Battaglia Gianna; Steinacher Marco; Joos Fortunat

    2016-01-01

    The marine cycle of calcium carbonate (CaCO3) is an important element of the carbon cycle and co-governs the distribution of carbon and alkalinity within the ocean. However, CaCO3 export fluxes and mechanisms governing CaCO3 dissolution are highly uncertain. We present an observationally constrained, probabilistic assessment of the global and regional CaCO3 budgets. Parameters governing pelagic CaCO3 export fluxes and dissolution rates are sampled using a Monte Carlo sche...

  12. Regional distribution and losses of end-of-life steel throughout multiple product life cycles-Insights from the global multiregional MaTrace model.

    Pauliuk, Stefan; Kondo, Yasushi; Nakamura, Shinichiro; Nakajima, Kenichi

    2017-01-01

    Substantial amounts of post-consumer scrap are exported to other regions or lost during recovery and remelting, and both export and losses pose a constraint to desires for having regionally closed material cycles. To quantify the challenges and trade-offs associated with closed-loop metal recycling, we looked at the material cycles from the perspective of a single material unit and trace a unit of material through several product life cycles. Focusing on steel, we used current process parameters, loss rates, and trade patterns of the steel cycle to study how steel that was originally contained in high quality applications such as machinery or vehicles with stringent purity requirements gets subsequently distributed across different regions and product groups such as building and construction with less stringent purity requirements. We applied MaTrace Global, a supply-driven multiregional model of steel flows coupled to a dynamic stock model of steel use. We found that, depending on region and product group, up to 95% of the steel consumed today will leave the use phase of that region until 2100, and that up to 50% can get lost in obsolete stocks, landfills, or slag piles until 2100. The high losses resulting from business-as-usual scrap recovery and recycling can be reduced, both by diverting postconsumer scrap into long-lived applications such as buildings and by improving the recovery rates in the waste management and remelting industries. Because the lifetimes of high-quality (cold-rolled) steel applications are shorter and remelting occurs more often than for buildings and infrastructure, we found and quantified a tradeoff between low losses and high-quality applications in the steel cycle. Furthermore, we found that with current trade patterns, reduced overall losses will lead to higher fractions of secondary steel being exported to other regions. Current loss rates, product lifetimes, and trade patterns impede the closure of the steel cycle.

  13. Development of TRU transmuters for optimization of the global fuel cycle. Final Report for the NERI Project

    Lee, John C.

    2009-01-01

    This final report summarizes the research activities during the entire performance period of the NERI grant, including the extra 9 months granted under a no-cost time extension. Building up on the 14 quarterly reports submitted through October 2008, we present here an overview of the research accomplishments under the five tasks originally proposed in July 2004, together with citations for publications resulting from the project. The AFCI-NERI project provided excellent support for two undergraduate and 10 graduates students at the University of Michigan during a period of three years and nine months. Significant developments were achieved in three areas: (1) Efficient deterministic fuel cycle optimization algorithms both for PWR and SFR configurations, (2) Efficient search algorithm for PWR equilibrium cycles, and (3) Simplified Excel-based script for dynamic fuel cycle analysis of diverse cycles. The project resulted in a total of 8 conference papers and three journal papers, including two that will be submitted shortly. Three pending publications are attached to the report

  14. The links between global carbon, water and nutrient cycles in an urbanizing world — the case of coastal eutrophication

    Kroeze, C.; Hofstra, N.; Ivens, W.; Löhr, A.; Strokal, M.; Wijnen, van J.

    2013-01-01

    The natural cycles of carbon (C), nitrogen (N), phosphorus (P) and water have been disturbed substantially by human activities. Urbanizing coastal drainage basins and large river deltas are located at the interface of freshwater and coastal components of the larger earth system and the process of

  15. How important are intertidal ecosystems for global biogeochemical cycles? Molecular and isotopic evidence for major outwelling of photo-bleached dissolved organic matter from mangroves.

    Dittmar, T.; Cooper, W. T.; Koch, B. P.; Kattner, G.

    2006-05-01

    Organic matter, which is dissolved in low concentrations in the vast waters of the oceans, contains a total amount of carbon similar to atmospheric carbon dioxide. To understand global biogeochemical cycles it is crucial to quantify the sources of marine dissolved organic carbon (DOC). We investigated the impact of mangroves, the dominant intertidal vegetation of the tropics, on marine DOC inventories. Stable carbon- isotopes, ultrahigh-resolution mass spectrometry (FTICRMS), lignin-derived phenols and proton nuclear magnetic resonance spectroscopy showed that mangroves are the main source of terrigenous DOC on the shelf off Northern Brazil. Sunlight efficiently destroyed aromatic molecules during transport offshore, removing about one third of mangrove-derived DOC. The remainder was refractory and may thus be distributed over the oceans. On a global scale, we estimate that mangroves account for more than 10 percent of the terrestrially- derived, refractory DOC transported to the ocean, while they cover less than 0.1 percent of the continents' surface.

  16. Combined oxygen- and carbon-isotope records through the Early Jurassic: multiple global events and two modes of carbon-cycle/temperature coupling

    Hesselbo, Stephen P.; Korte, Christoph

    2010-01-01

    , to the extent that meaningful comparisons between these events can begin to be made. Here we present new carbon and oxygen isotope data from mollusks (bivalves and belemnites) and brachiopods collected through the marine Early Jurassic succession of NE England, including the Sinemurian-Plienbachian boundary...... GSSP. All materials have been screened by chemical analysis and scanning electron microscopy to check for diagenetic alteration. Analysis of carbon isotopes from marine calcite is supplemented by analysis of carbon-isotope values from fossil wood collected through the same section. It is demonstrated...... that both long-term and short-term carbon-isotope shifts from the UK Early Jurassic represent global changes in carbon cycle balances. The Sinemurian-Pliensbachian boundary event is an event of global significance and shows several similarities to the Toarcian OAE (relative sea-level change, carbon-isotope...

  17. Implementation of methane cycling for deep time, global warming simulations with the DCESS Earth System Model (Version 1.2)

    Shaffer, Gary; Villanueva, Esteban Fernández; Rondanelli, Roberto

    2017-01-01

    Geological records reveal a number of ancient, large and rapid negative excursions of carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth System over a short duration. These injections may have forced strong global warming events, sometimes....... With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, time scales and locations of methane injections driving specific, observed deep time, global warming events....

  18. Retrieval Assimilation and Modeling of Atmospheric Water Vapor from Ground- and Space-Based GPS Networks: Investigation of the Global and Regional Hydrological Cycles

    Dickey, Jean O.

    1999-01-01

    Uncertainty over the response of the atmospheric hydrological cycle (particularly the distribution of water vapor and cloudiness) to anthropogenic forcing is a primary source of doubt in current estimates of global climate sensitivity, which raises severe difficulties in evaluating its likely societal impact. Fortunately, a variety of advanced techniques and sensors are beginning to shed new light on the atmospheric hydrological cycle. One of the most promising makes use of the sensitivity of the Global Positioning System (GPS) to the thermodynamic state, and in particular the water vapor content, of the atmosphere through which the radio signals propagate. Our strategy to derive the maximum benefit for hydrological studies from the rapidly increasing GPS data stream will proceed in three stages: (1) systematically analyze and archive quality-controlled retrievals using state-of-the-art techniques; (2) employ both currently available and innovative assimilation procedures to incorporate these determinations into advanced regional and global atmospheric models and assess their effects; and (3) apply the results to investigate selected scientific issues of relevance to regional and global hydrological studies. An archive of GPS-based estimation of total zenith delay (TZD) data and water vapor where applicable has been established with expanded automated quality control. The accuracy of the GPS estimates is being monitored; the investigation of systematic errors is ongoing using comparisons with water vapor radiometers. Meteorological packages have been implemented. The accuracy and utilization of the TZD estimates has been improved by implementing a troposphere gradient model. GPS-based gradients have been validated as real atmospheric moisture gradients, establishing a link between the estimated gradients and the passage of weather fronts. We have developed a generalized ray tracing inversion scheme that can be used to analyze occultation data acquired from space

  19. Understanding the Global Water and Energy Cycle Through Assimilation of Precipitation-Related Observations: Lessons from TRMM and Prospects for GPM

    Hou, Arthur; Zhang, Sara; daSilva, Arlindo; Li, Frank; Atlas, Robert (Technical Monitor)

    2002-01-01

    Understanding the Earth's climate and how it responds to climate perturbations relies on what we know about how atmospheric moisture, clouds, latent heating, and the large-scale circulation vary with changing climatic conditions. The physical process that links these key climate elements is precipitation. Improving the fidelity of precipitation-related fields in global analyses is essential for gaining a better understanding of the global water and energy cycle. In recent years, research and operational use of precipitation observations derived from microwave sensors such as the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager and Special Sensor Microwave/Imager (SSM/I) have shown the tremendous potential of using these data to improve global modeling, data assimilation, and numerical weather prediction. We will give an overview of the benefits of assimilating TRMM and SSM/I rain rates and discuss developmental strategies for using space-based rainfall and rainfall-related observations to improve forecast models and climate datasets in preparation for the proposed multi-national Global Precipitation Mission (GPM).

  20. Regionalization of land use impact models for life cycle assessment: Recommendations for their use on the global scale and their applicability to Brazil

    Pavan, Ana Laura Raymundo, E-mail: laurarpavan@gmail.com [Center for Water Resource and Environmental Studies, São Carlos School of Engineering, University of São Paulo, Av. Trabalhador São-Carlense 400, São Carlos 13566-590, SP (Brazil); Ometto, Aldo Roberto [Center for Water Resource and Environmental Studies, São Carlos School of Engineering, University of São Paulo, Av. Trabalhador São-Carlense 400, São Carlos 13566-590, SP (Brazil); Department of Production Engineering, São Carlos School of Engineering, University of São Paulo, Av. Trabalhador São-Carlense 400, São Carlos 13566-590, SP (Brazil)

    2016-09-15

    Life Cycle Assessment (LCA) is the main technique for evaluate the environmental impacts of product life cycles. A major challenge in the field of LCA is spatial and temporal differentiation in Life Cycle Impact Assessment (LCIA) methods, especially impacts resulting from land occupation and land transformation. Land use characterization modeling has advanced considerably over the last two decades and many approaches have recently included crucial aspects such as geographic differentiation. Nevertheless, characterization models have so far not been systematically reviewed and evaluated to determine their applicability to South America. Given that Brazil is the largest country in South America, this paper analyzes the main international characterization models currently available in the literature, with a view to recommending regionalized models applicable on a global scale for land use life cycle impact assessments, and discusses their feasibility for regionalized assessment in Brazil. The analytical methodology involves classification based on the following criteria: midpoint/endpoint approach, scope of application, area of data collection, biogeographical differentiation, definition of recovery time and reference situation; followed by an evaluation of thirteen scientific robustness and environmental relevance subcriteria. The results of the scope of application are distributed among 25% of the models developed for the European context, and 50% have a global scope. There is no consensus in the literature about the definition of parameters such biogeographical differentiation and reference situation, and our review indicates that 35% of the models use ecoregion division while 40% use the concept of potential natural vegetation. Four characterization models show high scores in terms of scientific robustness and environmental relevance. These models are recommended for application in land use life cycle impact assessments, and also to serve as references for the

  1. The impact of the Cretaceous-Paleogene (K-Pg) mass extinction event on the global sulfur cycle: Evidence from Seymour Island, Antarctica

    Witts, James D.; Newton, Robert J.; Mills, Benjamin J. W.; Wignall, Paul B.; Bottrell, Simon H.; Hall, Joanna L. O.; Francis, Jane E.; Alistair Crame, J.

    2018-06-01

    The Cretaceous-Paleogene (K-Pg) mass extinction event 66 million years ago led to large changes to the global carbon cycle, primarily via a decrease in primary or export productivity of the oceans. However, the effects of this event and longer-term environmental changes during the Late Cretaceous on the global sulfur cycle are not well understood. We report new carbonate associated sulfate (CAS) sulfur isotope data derived from marine macrofossil shell material from a highly expanded high latitude Maastrichtian to Danian (69-65.5 Ma) succession located on Seymour Island, Antarctica. These data represent the highest resolution seawater sulfate record ever generated for this time interval, and are broadly in agreement with previous low-resolution estimates for the latest Cretaceous and Paleocene. A vigorous assessment of CAS preservation using sulfate oxygen, carbonate carbon and oxygen isotopes and trace element data, suggests factors affecting preservation of primary seawater CAS isotopes in ancient biogenic samples are complex, and not necessarily linked to the preservation of original carbonate mineralogy or chemistry. Primary data indicate a generally stable sulfur cycle in the early-mid Maastrichtian (69 Ma), with some fluctuations that could be related to increased pyrite burial during the 'mid-Maastrichtian Event'. This is followed by an enigmatic +4‰ increase in δ34SCAS during the late Maastrichtian (68-66 Ma), culminating in a peak in values in the immediate aftermath of the K-Pg extinction which may be related to temporary development of oceanic anoxia in the aftermath of the Chicxulub bolide impact. There is no evidence of the direct influence of Deccan volcanism on the seawater sulfate isotopic record during the late Maastrichtian, nor of a direct influence by the Chicxulub impact itself. During the early Paleocene (magnetochron C29R) a prominent negative excursion in seawater δ34S of 3-4‰ suggests that a global decline in organic carbon burial

  2. Global sensitivity analysis of computer-aided molecular design problem for the development of novel working fluids for power cycles

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    2016-01-01

    This study compares two methods for global sensitivity analysis as a new approach for the identification and ranking of target properties in molecular design problems: A modified Morris Screening technique and Monte Carlo based standard regression. The two methodologies are highlighted in a case ...

  3. Importance of food waste pre-treatment efficiency for global warming potential in life cycle assessment of anaerobic digestion systems

    Carlsson, My; Naroznova, Irina; Møller, Jacob

    2015-01-01

    treatment of the refuse. The objective of this study was to investigate how FW pre-treatment efficiency impacts the environmental performance of waste management, with respect to global warming potential (GWP). The modeling tool EASETECH was used to perform consequential LCA focusing on the impact...

  4. Connection of stratospheric QBO with global atmospheric general circulation and tropical SST. Part I: methodology and composite life cycle

    Huang, Bohua; Kinter, James L. [George Mason University, Department of Atmospheric, Oceanic, and Earth Sciences, College of Science, Fairfax, VA (United States); Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Hu, Zeng-Zhen [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Climate Prediction Center (suite 605), NCEP/NWS/NOAA, Camp Springs, MD (United States); Wu, Zhaohua [Florida State University, Department of Earth, Ocean, and Atmospheric Science, and Center for Ocean-Atmospheric Prediction Studies, Tallahassee, FL (United States); Kumar, Arun [Climate Prediction Center (suite 605), NCEP/NWS/NOAA, Camp Springs, MD (United States)

    2012-01-15

    The stratospheric quasi-biennial oscillation (QBO) and its association with the interannual variability in the stratosphere and troposphere, as well as in tropical sea surface temperature anomalies (SSTA), are examined in the context of a QBO life cycle. The analysis is based on the ERA40 and NCEP/NCAR reanalyses, radiosonde observations at Singapore, and other observation-based datasets. Both reanalyses reproduce the QBO life cycle and its associated variability in the stratosphere reasonably well, except that some long-term changes are detected only in the NCEP/NCAR reanalysis. In order to separate QBO from variability on other time scales and to eliminate the long-term changes, a scale separation technique [Ensemble Empirical Mode Decomposition (EEMD)] is applied to the raw data. The QBO component of zonal wind anomalies at 30 hPa, extracted using the EEMD method, is defined as a QBO index. Using this index, the QBO life cycle composites of stratosphere and troposphere variables, as well as SSTA, are constructed and examined. The composite features in the stratosphere are generally consistent with previous investigations. The correlations between the QBO and tropical Pacific SSTA depend on the phase in a QBO life cycle. On average, cold (warm) SSTA peaks about half a year after the maximum westerlies (easterlies) at 30 hPa. The connection of the QBO with the troposphere seems to be associated with the differences of temperature anomalies between the stratosphere and troposphere. While the anomalies in the stratosphere propagate downward systematically, some anomalies in the troposphere develop and expand vertically. Therefore, it is possible that the temperature difference between the troposphere and stratosphere may alter the atmospheric stability and tropical deep convection, which modulates the Walker circulation and SSTA in the equatorial Pacific Ocean. (orig.)

  5. Connection of stratospheric QBO with global atmospheric general circulation and tropical SST. Part I: methodology and composite life cycle

    Huang, Bohua; Hu, Zeng-Zhen; Kinter, James L.; Wu, Zhaohua; Kumar, Arun

    2012-01-01

    The stratospheric quasi-biennial oscillation (QBO) and its association with the interannual variability in the stratosphere and troposphere, as well as in tropical sea surface temperature anomalies (SSTA), are examined in the context of a QBO life cycle. The analysis is based on the ERA40 and NCEP/NCAR reanalyses, radiosonde observations at Singapore, and other observation-based datasets. Both reanalyses reproduce the QBO life cycle and its associated variability in the stratosphere reasonably well, except that some long-term changes are detected only in the NCEP/NCAR reanalysis. In order to separate QBO from variability on other time scales and to eliminate the long-term changes, a scale separation technique [Ensemble Empirical Mode Decomposition (EEMD)] is applied to the raw data. The QBO component of zonal wind anomalies at 30 hPa, extracted using the EEMD method, is defined as a QBO index. Using this index, the QBO life cycle composites of stratosphere and troposphere variables, as well as SSTA, are constructed and examined. The composite features in the stratosphere are generally consistent with previous investigations. The correlations between the QBO and tropical Pacific SSTA depend on the phase in a QBO life cycle. On average, cold (warm) SSTA peaks about half a year after the maximum westerlies (easterlies) at 30 hPa. The connection of the QBO with the troposphere seems to be associated with the differences of temperature anomalies between the stratosphere and troposphere. While the anomalies in the stratosphere propagate downward systematically, some anomalies in the troposphere develop and expand vertically. Therefore, it is possible that the temperature difference between the troposphere and stratosphere may alter the atmospheric stability and tropical deep convection, which modulates the Walker circulation and SSTA in the equatorial Pacific Ocean.

  6. Calcium blood test

    ... page: //medlineplus.gov/ency/article/003477.htm Calcium blood test To use the sharing features on this page, please enable JavaScript. The calcium blood test measures the level of calcium in the blood. ...

  7. Calcium source (image)

    Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

  8. Calcium Pyrophosphate Deposition (CPPD)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  9. Calcium carbonate overdose

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Products that contain calcium carbonate are certain: Antacids (Tums, Chooz) Mineral supplements Hand lotions Vitamin and mineral supplements Other products may also contain ...

  10. Calcium and bones (image)

    Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

  11. Calcium hydroxide poisoning

    Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

  12. H2O and CO2 devolatilization in subduction zones: implications for the global water and carbon cycles (Invited)

    van Keken, P. E.; Hacker, B. R.; Syracuse, E. M.; Abers, G. A.

    2010-12-01

    Subduction of sediments and altered oceanic crust functions as a major carbon sink. Upon subduction the carbon may be released by progressive metamorphic reactions, which can be strongly enhanced by free fluids. Quantification of the CO2 release from subducting slabs is important to determine the provenance of CO2 that is released by the volcanic arc and to constrain the flux of carbon to the deeper mantle. In recent work we used a global set of high resolution thermal models of subduction zones to predict the flux of H2O from the subducting slab (van Keken, Hacker, Syracuse, Abers, Subduction factory 4: Depth-dependent flux of H2O from subducting slabs worldwide, J. Geophys. Res., under review) which provides a new estimate of the dehydration efficiency of the global subducting system. It was found that mineralogically bound water can pass efficiently through old and fast subduction zones (such as in the western Pacific) but that warm subduction zones (such as Cascadia) see nearly complete dehydration of the subducting slab. The top of the slab is sufficiently hot in all subduction zones that the upper crust dehydrates significantly. The degree and depth of dehydration is highly diverse and strongly depends on (p,T) and bulk rock composition. On average about one third of subducted H2O reaches 240 km depth, carried principally and roughly equally in the gabbro and peridotite sections. The present-day global flux of H2O to the deep mantle translates to an addition of about one ocean mass over the age of the Earth. We extend the slab devolatilization work to carbon by providing an update to Gorman et al. (Geochem. Geophys. Geosyst, 2006), who quantified the effects of free fluids on CO2 release. The thermal conditions were based on three end-member subduction zones with linear interpolation to provide a global CO2 flux. We use the new high resolution and global set of models to provide higher resolution predictions for the provenance and pathways of CO2 release to

  13. Global Solar Magnetic Field Organization in the Outer Corona: Influence on the Solar Wind Speed and Mass Flux Over the Cycle

    Réville, Victor; Brun, Allan Sacha

    2017-11-01

    The dynamics of the solar wind depends intrinsically on the structure of the global solar magnetic field, which undergoes fundamental changes over the 11-year solar cycle. For instance, the wind terminal velocity is thought to be anti-correlated with the expansion factor, a measure of how the magnetic field varies with height in the solar corona, usually computed at a fixed height (≈ 2.5 {R}⊙ , the source surface radius that approximates the distance at which all magnetic field lines become open). However, the magnetic field expansion affects the solar wind in a more detailed way, its influence on the solar wind properties remaining significant well beyond the source surface. We demonstrate this using 3D global magnetohydrodynamic (MHD) simulations of the solar corona, constrained by surface magnetograms over half a solar cycle (1989-2001). A self-consistent expansion beyond the solar wind critical point (even up to 10 {R}⊙ ) makes our model comply with observed characteristics of the solar wind, namely, that the radial magnetic field intensity becomes latitude independent at some distance from the Sun, and that the mass flux is mostly independent of the terminal wind speed. We also show that near activity minimum, the expansion in the higher corona has more influence on the wind speed than the expansion below 2.5 {R}⊙ .

  14. Calcium in Urine Test

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Calcium, Serum; Calcium and Phosphates, Urine; ...

  15. Transcellular transport of calcium

    Terepka, A R; Coleman, J R; Armbrecht, H J; Gunter, T E

    1976-01-01

    Studies of two calcium transporting epithelia, embryonic chick chorioallantoic membrane and the small intestine of rat and chick, have strongly suggested that the transfer of calcium across a cell involves processes distinctly different from intracellular calcium ion regulation. In the proposed model, transcellular calcium transport is considered as a specialized process developed only by certain cells in those tissues charged with bulk transfer of calcium. The overall effect of the endocytotic mechanism is bulk calcium movement across a cell, protection of mitochondria from exposure to high concentrations of calcium, and the avoidance of wide and potentially toxic fluctuations in cytosol ionic calcium levels. (MFB)

  16. The aerial fertilization effect of CO sub 2 and its implications for global carbon cycling and maximum greenhouse warming

    Idso, S B [US Water Conservation Laboratory, Phoenix, AZ (USA)

    1991-07-01

    The author observes that the CO{sub 2} sequestering ability of the world's plant life should increase with the rising CO{sub 2} content of the atmosphere. The enhanced cyclic variation of atmospheric CO{sub 2} in the Northern Hemisphere is seen to be a result of the CO{sub 2} fertilization effect. Trees are responsible for about two-thirds of global photosynthesis. It is calculated that a 300 ppm increase in atmospheric CO{sub 2} produces a 182 per cent increase in the mean productivity of the world's forests. Global warming yet to be faced will not be much more than that which has already occurred. The rising CO{sub 2} content of the atmosphere provides a strong impetus for forest expansion, and a solution to any problems its continued upward trend might produce by intensifying the major mechanisms for its removal. 22 refs., 1 fig.

  17. An initial study on modeling the global thermal and fast reactor fuel cycle mass flow using Vensim

    Brinton, Samuel

    2008-01-01

    This study concentrated on modeling the construction and decommissioning rates of five major facilities comprising the nuclear fuel cycle: (1) current LWRs with a 60-year service life, (2) new LWRs burning MOX fuel, (3) new LWRs to replace units in the current fleet, (4) new FRs to be added to the fleet, and (5) new spent fuel reprocessing facilities. This is a mass flow mode starting from uranium ore and following it to spent forms. The visual dynamic modeling program Vensim was used to create a system of equations and variables to track the mass flows from enrichment, fabrication, burn-up, and the back-end of the fuel cycle. The scenarios considered provide estimates of the uranium ore requirements, quantities of LLW and HLW production, and the number of reprocessing facilities necessary to reduce recently reported levels of spent fuel inventory. Preliminary results indicate that the entire national spent fuel inventory produced in the next 100 years can be reprocessed with a reprocessing plant built every 11 years (small capacity) or even as low as every 23 years (large capacity). (authors)

  18. Global and regional effects of land-use change on climate in 21. century simulations with interactive carbon cycle

    Boysen, L.R.; Brovkin, V.; Pongratz, J.; Gayler, V.; Arora, V.K.; Cadule, P.; Noblet-Ducoudre, N. de; Kato, E.

    2014-01-01

    Bio-geophysical (BGP) and biogeochemical (BGC) effects of land-use and land cover change (LULCC) are separated at the global and regional scales in new interactive CO 2 simulations for the 21. century. Results from four earth system models (ESMs) are analyzed for the future RCP8.5 scenario from simulations with and without land-use and land cover change (LULCC), contributing to the Land-Use and Climate, Identification of robust impacts (LUCID) project. Over the period 2006-2100, LULCC causes the atmospheric CO 2 concentration to increase by 12, 22, and 66 ppm in CanESM2, MIROC-ESM, and MPI-ESM-LR, respectively. Statistically significant changes in global near-surface temperature are found in three models with a BGC induced global mean annual warming between 0.07 and 0.23 K. BGP-induced responses are simulated by three models in areas of intense LULCC of varying sign and magnitude (between -0.47 and 0.10 K). Modifications of the land carbon pool by LULCC are disentangled in accordance with processes that can lead to increases and decreases in this carbon pool. Global land carbon losses due to LULCC are simulated by all models: 218, 57, 35 and 34 Gt C by MPI-ESM-LR, MIROC-ESM, IPSL-CM5A-LR and CanESM2, respectively. On the contrary, the CO 2 -fertilization effect caused by elevated atmospheric CO 2 concentrations due to LULCC leads to a land carbon gain of 39 Gt C in MPI-ESM-LR and is almost negligible in the other models. A substantial part of the spread in models' responses to LULCC is attributed to the differences in implementation of LULCC (e.g., whether pastures or crops are simulated explicitly) and the simulation of specific processes. Simple idealized experiments with clear protocols for implementing LULCC in ESMs are needed to increase the understanding of model responses and the statistical significance of results, especially when analyzing the regional-scale impacts of LULCC. (authors)

  19. Global and regional effects of land-use change on climate in 21st century simulations with interactive carbon cycle

    L. R. Boysen

    2014-09-01

    Full Text Available Biogeophysical (BGP and biogeochemical (BGC effects of land-use and land cover change (LULCC are separated at the global and regional scales in new interactive CO2 simulations for the 21st century. Results from four earth system models (ESMs are analyzed for the future RCP8.5 scenario from simulations with and without land-use and land cover change (LULCC, contributing to the Land-Use and Climate, IDentification of robust impacts (LUCID project. Over the period 2006–2100, LULCC causes the atmospheric CO2 concentration to increase by 12, 22, and 66 ppm in CanESM2, MIROC-ESM, and MPI-ESM-LR, respectively. Statistically significant changes in global near-surface temperature are found in three models with a BGC-induced global mean annual warming between 0.07 and 0.23 K. BGP-induced responses are simulated by three models in areas of intense LULCC of varying sign and magnitude (between −0.47 and 0.10 K. Modifications of the land carbon pool by LULCC are disentangled in accordance with processes that can lead to increases and decreases in this carbon pool. Global land carbon losses due to LULCC are simulated by all models: 218, 57, 35 and 34 Gt C by MPI-ESM-LR, MIROC-ESM, IPSL-CM5A-LR and CanESM2, respectively. On the contrary, the CO2-fertilization effect caused by elevated atmospheric CO2 concentrations due to LULCC leads to a land carbon gain of 39 Gt C in MPI-ESM-LR and is almost negligible in the other models. A substantial part of the spread in models' responses to LULCC is attributed to the differences in implementation of LULCC (e.g., whether pastures or crops are simulated explicitly and the simulation of specific processes. Simple idealized experiments with clear protocols for implementing LULCC in ESMs are needed to increase the understanding of model responses and the statistical significance of results, especially when analyzing the regional-scale impacts of LULCC.

  20. Performance optimization of low-temperature power generation by supercritical ORCs (organic Rankine cycles) using low GWP (global warming potential) working fluids

    Le, Van Long; Feidt, Michel; Kheiri, Abdelhamid; Pelloux-Prayer, Sandrine

    2014-01-01

    This paper presents the system efficiency optimization scenarios of basic and regenerative supercritical ORCs (organic Rankine cycles) using low-GWP (global warming potential) organic compounds as working fluid. A more common refrigerant, i.e. R134a, was also employed to make the comparison. A 150-°C, 5-bar-pressurized hot water is used to simulate the heat source medium. Power optimization was equally performed for the basic configuration of supercritical ORC. Thermodynamic performance comparison of supercritical ORCs using different working fluids was achieved by ranking method and exergy analysis method. The highest optimal efficiency of the system (η sys ) is always obtained with R152a in both basic (11.6%) and regenerative (13.1%) configurations. The highest value of optimum electrical power output (4.1 kW) is found with R1234ze. By using ranking method and considering low-GWP criterion, the best working fluids for system efficiency optimization of basic and regenerative cycles are R32 and R152a, respectively. The best working fluid for net electrical power optimization of basic cycle is R1234ze. Although CO 2 has many desirable environmental and safety properties (e.g. zero ODP (Ozone Depletion Potential), ultra low-GWP, non toxicity, non flammability, etc.), the worst thermodynamic performance is always found with the cycle using this compound as working fluid. - Highlights: • Performance optimizations were carried out for the supercritical ORCs using low-GWP working fluids. • Heat regeneration was used to improve the system efficiency of the supercritical ORC. • Thermodynamic performances of supercritical ORCs at the optima were evaluated by ranking method and exergy analysis

  1. Coordination cycles

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  2. Intensified Vegetation Water Use due to Soil Calcium Leaching under Acid Deposition

    Lanning, M.; Wang, L.; Scanlon, T. M.; Vadeboncoeur, M. A.; Adams, M. B.; Epstein, H. E.; Druckenbrod, D.

    2017-12-01

    Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. Nitrate and sulfate deposition from fossil fuel burning has caused significant soil acidification, leading to the leaching of soil base cations. From a physiological perspective, plants require various soil cations as signaling and regulatory ions as well as integral parts of structural molecules; a depletion of soil cations can cause reduced productivity and abnormal responses to environmental change. A deficiency in calcium could also potentially prolong stomatal opening, leading to increased transpiration until enough calcium had been acquired to stimulate stomatal closure. Based on the plant physiology and the nature of acidic deposition, we hypothesize that depletion of the soil calcium supply, induced by acid deposition, would intensify vegetation water use at the watershed scale. We tested this hypothesis by analyzing a long-term and unique data set (1989-2012) of soil lysimeter data along with stream flow and evapotranspiration data at the Fernow Experimental Forest. We show that depletion of soil calcium by acid deposition can intensify vegetation water use ( 10% increase in evapotranspiration and depletion in soil water) for the first time. These results are critical to understanding future water availability, biogeochemical cycles, and surficial energy flux and may help reduce uncertainties in terrestrial biosphere models.

  3. AdS solutions in gauge supergravities and the global anomaly for the product of complex two-cycles

    Bytsenko, A.A. [Universidade Estadual de Londrina, Departamento de Fisica, Caixa Postal 6001, Londrina-Parana (Brazil); Elizalde, E. [Universitat Autonoma de Barcelona, Consejo Superior de Investigaciones Cientificas (ICE/CSIC) and Institut d' Estudis Espacials de Catalunya (IEEC), Facultat de Ciencies, Bellaterra (Barcelona) (Spain)

    2011-03-15

    Cohomological methods are applied for the special set of solutions corresponding to rotating branes in arbitrary dimensions, AdS black holes (which can be embedded in ten or eleven dimensions), and gauge supergravities. A new class of solutions is proposed, the Hilbert modular varieties, which consist of the 2n-fold product of the two-spaces H{sup n} /{gamma} (where H{sup n} denotes the product of n upper half-planes, H {sup 2}, equipped with the co-compact action of {gamma} is contained in SL(2, R){sup n}) and (H {sup n}){sup *}/{gamma} (where (H {sup 2}){sup *}=H {sup 2}{gamma} and {gamma} is a congruence subgroup of SL(2, R) {sup n}). The cohomology groups of the Hilbert variety, which inherit a Hodge structure (in the sense of Deligne), are analyzed, as well as bifiltered sequences, weight and Hodge filtrations, and it is argued that the torsion part of the cuspidal cohomology is involved in the global anomaly condition. Indeed, in the presence of the cuspidal part, all cohomology classes can be mapped to the boundary of the space and the cuspidal contribution can be involved in the global anomaly condition. (orig.)

  4. The enigmatic SAR202 cluster up close: shedding light on a globally distributed dark ocean lineage involved in sulfur cycling.

    Mehrshad, Maliheh; Rodriguez-Valera, Francisco; Amoozegar, Mohammad Ali; López-García, Purificación; Ghai, Rohit

    2018-03-01

    The dark ocean microbiota represents the unknown majority in the global ocean waters. The SAR202 cluster belonging to the phylum Chloroflexi was the first microbial lineage discovered to specifically inhabit the aphotic realm, where they are abundant and globally distributed. The absence of SAR202 cultured representatives is a significant bottleneck towards understanding their metabolic capacities and role in the marine environment. In this work, we use a combination of metagenome-assembled genomes from deep-sea datasets and publicly available single-cell genomes to construct a genomic perspective of SAR202 phylogeny, metabolism and biogeography. Our results suggest that SAR202 cluster members are medium sized, free-living cells with a heterotrophic lifestyle, broadly divided into two distinct clades. We present the first evidence of vertical stratification of these microbes along the meso- and bathypelagic ocean layers. Remarkably, two distinct species of SAR202 cluster are highly abundant in nearly all deep bathypelagic metagenomic datasets available so far. SAR202 members metabolize multiple organosulfur compounds, many appear to be sulfite-oxidizers and are predicted to play a major role in sulfur turnover in the dark water column. This concomitantly suggests an unsuspected availability of these nutrient sources to allow for the high abundance of these microbes in the deep sea.

  5. Local systems, global impacts. Using life cycle assessment to analyse the potential and constraints of industrial symbioses

    Sokka, L.

    2011-08-15

    Human activities extract and displace different substances and materials from the earthAEs crust, thus causing various environmental problems, such as climate change, acidification and eutrophication. As problems have become more complicated, more holistic measures that consider the origins and sources of pollutants have been called for. Industrial ecology is a field of science that forms a comprehensive framework for studying the interactions between the modern technological society and the environment. Industrial ecology considers humans and their technologies to be part of the natural environment, not separate from it. Industrial operations form natural systems that must also function as such within the constraints set by the biosphere. Industrial symbiosis (IS) is a central concept of industrial ecology. Industrial symbiosis studies look at the physical flows of materials and energy in local industrial systems. In an ideal IS, waste material and energy are exchanged by the actors of the system, thereby reducing the consumption of virgin material and energy inputs and the generation of waste and emissions. Companies are seen as part of the chains of suppliers and consumers that resemble those of natural ecosystems. The aim of this study was to analyse the environmental performance of an industrial symbiosis based on pulp and paper production, taking into account life cycle impacts as well. Life Cycle Assessment (LCA) is a tool for quantitatively and systematically evaluating the environmental aspects of a product, technology or service throughout its whole life cycle. Moreover, the Natural Step Sustainability Principles formed a conceptual framework for assessing the environmental performance of the case study symbiosis (Paper 1). The environmental performance of the case study symbiosis was compared to four counterfactual reference scenarios in which the actors of the symbiosis operated on their own. The research methods used were process-based life cycle

  6. Implementation of methane cycling for deep-time global warming simulations with the DCESS Earth system model (version 1.2)

    Shaffer, Gary; Fernández Villanueva, Esteban; Rondanelli, Roberto; Olaf Pepke Pedersen, Jens; Malskær Olsen, Steffen; Huber, Matthew

    2017-11-01

    Geological records reveal a number of ancient, large and rapid negative excursions of the carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth system over a short duration. These injections may have forced strong global warming events, sometimes accompanied by mass extinctions such as the Triassic-Jurassic and end-Permian extinctions 201 and 252 million years ago, respectively. In many cases, evidence points to methane as the dominant form of injected carbon, whether as thermogenic methane formed by magma intrusions through overlying carbon-rich sediment or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth system models for addressing such events should include a comprehensive treatment of methane cycling but such a treatment has often been lacking. Here we implement methane cycling in the Danish Center for Earth System Science (DCESS) model, a simplified but well-tested Earth system model of intermediate complexity. We use a generic methane input function that allows variation in input type, size, timescale and ocean-atmosphere partition. To be able to treat such massive inputs more correctly, we extend the model to deal with ocean suboxic/anoxic conditions and with radiative forcing and methane lifetimes appropriate for high atmospheric methane concentrations. With this new model version, we carried out an extensive set of simulations for methane inputs of various sizes, timescales and ocean-atmosphere partitions to probe model behavior. We find that larger methane inputs over shorter timescales with more methane dissolving in the ocean lead to ever-increasing ocean anoxia with consequences for ocean life and global carbon cycling. Greater methane input directly to the atmosphere leads to more warming and, for example, greater carbon dioxide release

  7. Implementation of methane cycling for deep-time global warming simulations with the DCESS Earth system model (version 1.2

    G. Shaffer

    2017-11-01

    Full Text Available Geological records reveal a number of ancient, large and rapid negative excursions of the carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth system over a short duration. These injections may have forced strong global warming events, sometimes accompanied by mass extinctions such as the Triassic-Jurassic and end-Permian extinctions 201 and 252 million years ago, respectively. In many cases, evidence points to methane as the dominant form of injected carbon, whether as thermogenic methane formed by magma intrusions through overlying carbon-rich sediment or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth system models for addressing such events should include a comprehensive treatment of methane cycling but such a treatment has often been lacking. Here we implement methane cycling in the Danish Center for Earth System Science (DCESS model, a simplified but well-tested Earth system model of intermediate complexity. We use a generic methane input function that allows variation in input type, size, timescale and ocean–atmosphere partition. To be able to treat such massive inputs more correctly, we extend the model to deal with ocean suboxic/anoxic conditions and with radiative forcing and methane lifetimes appropriate for high atmospheric methane concentrations. With this new model version, we carried out an extensive set of simulations for methane inputs of various sizes, timescales and ocean–atmosphere partitions to probe model behavior. We find that larger methane inputs over shorter timescales with more methane dissolving in the ocean lead to ever-increasing ocean anoxia with consequences for ocean life and global carbon cycling. Greater methane input directly to the atmosphere leads to more warming and, for example

  8. Calcium sensing in exocytosis

    Gustavsson, Natalia; Wu, Bingbing; Han, Weiping

    2012-01-01

    an increase in intracellular calcium levels. Besides the triggering role, calcium signaling modulates the precise amount and kinetics of vesicle release. Thus, it is a central question to understand the molecular machineries responsible for calcium sensing in exocytosis. Here we provide an overview of our...... current understanding of calcium sensing in neurotransmitter release and hormone secretion....

  9. Calcium fluoride

    King, C.W.; Nestor, O.H.

    1989-01-01

    A new process for producing large, single, oriented crystals of calcium fluoride (CaF 2 ) has been developed which overcomes the limitations of current growing methods. This process has been reduced to practice and has yielded oriented crystals 17.5 x 17.5 x 5 cm 3 . Currently nearing completion is a system for producing 35 x 35 x 7.5 cm 3 single crystals. A scale up to one-meter-square is considered feasible. This crystal growing process makes possible the fabrication of very large CaF 2 windows. Suitability for very high power lasers, however, requires attention to properties beyond mere size. A process to generate higher purity growth stock (starting material) was also developed. The additional purification of the growth stock contributes to lower bulk absorption, the absence of color centers and increased radiation hardness. Also identified were several specific impurities which correlate with radiation hardness. A correlation was found between color centers induced by laser radiation and ionizing radiation. Other CaF 2 crystal properties such as tensile strength, absorption and laser damage thresholds were studied and are discussed

  10. Development of an advanced eco-hydrologic and biogeochemical coupling model aimed at clarifying the missing role of inland water in the global biogeochemical cycle

    Nakayama, Tadanobu

    2017-04-01

    Recent research showed that inland water including rivers, lakes, and groundwater may play some role in carbon cycling, although its contribution has remained uncertain due to limited amount of reliable data available. In this study, the author developed an advanced model coupling eco-hydrology and biogeochemical cycle (National Integrated Catchment-based Eco-hydrology (NICE)-BGC). This new model incorporates complex coupling of hydrologic-carbon cycle in terrestrial-aquatic linkages and interplay between inorganic and organic carbon during the whole process of carbon cycling. The model could simulate both horizontal transports (export from land to inland water 2.01 ± 1.98 Pg C/yr and transported to ocean 1.13 ± 0.50 Pg C/yr) and vertical fluxes (degassing 0.79 ± 0.38 Pg C/yr, and sediment storage 0.20 ± 0.09 Pg C/yr) in major rivers in good agreement with previous researches, which was an improved estimate of carbon flux from previous studies. The model results also showed global net land flux simulated by NICE-BGC (-1.05 ± 0.62 Pg C/yr) decreased carbon sink a little in comparison with revised Lund-Potsdam-Jena Wetland Hydrology and Methane (-1.79 ± 0.64 Pg C/yr) and previous materials (-2.8 to -1.4 Pg C/yr). This is attributable to CO2 evasion and lateral carbon transport explicitly included in the model, and the result suggests that most previous researches have generally overestimated the accumulation of terrestrial carbon and underestimated the potential for lateral transport. The results further implied difference between inverse techniques and budget estimates suggested can be explained to some extent by a net source from inland water. NICE-BGC would play an important role in reevaluation of greenhouse gas budget of the biosphere, quantification of hot spots, and bridging the gap between top-down and bottom-up approaches to global carbon budget.

  11. Assessment of Anthropogenic and Climatic Impacts on the Global Carbon Cycle Using a 3-D Model Constrained by Isotopic Carbon Measurements and Remote Sensing of Vegetation

    Keeling, Charles D.; Piper, S. C.

    1998-01-01

    Our original proposal called for improved modeling of the terrestrial biospheric carbon cycle, specifically using biome-specific process models to account for both the energy and water budgets of plant growth, to facilitate investigations into recent changes in global atmospheric CO2 abundance and regional distribution. The carbon fluxes predicted by these models were to be incorporated into a global model of CO2 transport to establish large-scale regional fluxes of CO2 to and from the terrestrial biosphere subject to constraints imposed by direct measurements of atmospheric CO2 and its 13C/12C isotopic ratio. Our work was coordinated with a NASA project (NASA NAGW-3151) at the University of Montana under the direction of Steven Running, and was partially funded by the Electric Power Research Institute. The primary objective of this project was to develop and test the Biome-BGC model, a global biological process model with a daily time step which simulates the water, energy and carbon budgets of plant growth. The primary product, the unique global gridded daily land temperature, and the precipitation data set which was used to drive the process model is described. The Biome-BGC model was tested by comparison with a simpler biological model driven by satellite-derived (NDVI) Normalized Difference Vegetation Index and (PAR) Photosynthetically Active Radiation data and by comparison with atmospheric CO2 observations. The simple NDVI model is also described. To facilitate the comparison with atmospheric CO2 observations, a three-dimensional atmospheric transport model was used to produce predictions of atmospheric CO2 variations given CO2 fluxes owing to (NPP) Net Primary Productivity and heterotrophic respiration that were produced by the Biome-BGC model and by the NDVI model. The transport model that we used in this project, and errors associated with transport simulations, were characterized by a comparison of 12 transport models.

  12. Evolution of the Toarcian (Early Jurassic) carbon-cycle and global climatic controls on local sedimentary processes (Cardigan Bay Basin, UK)

    Xu, Weimu; Ruhl, Micha; Jenkyns, Hugh C.; Leng, Melanie J.; Huggett, Jennifer M.; Minisini, Daniel; Ullmann, Clemens V.; Riding, James B.; Weijers, Johan W. H.; Storm, Marisa S.; Percival, Lawrence M. E.; Tosca, Nicholas J.; Idiz, Erdem F.; Tegelaar, Erik W.; Hesselbo, Stephen P.

    2018-02-01

    The late Early Jurassic Toarcian Stage represents the warmest interval of the Jurassic Period, with an abrupt rise in global temperatures of up to ∼7 °C in mid-latitudes at the onset of the early Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma). The T-OAE, which has been extensively studied in marine and continental successions from both hemispheres, was marked by the widespread expansion of anoxic and euxinic waters, geographically extensive deposition of organic-rich black shales, and climatic and environmental perturbations. Climatic and environmental processes following the T-OAE are, however, poorly known, largely due to a lack of study of stratigraphically well-constrained and complete sedimentary archives. Here, we present integrated geochemical and physical proxy data (high-resolution carbon-isotope data (δ13 C), bulk and molecular organic geochemistry, inorganic petrology, mineral characterisation, and major- and trace-element concentrations) from the biostratigraphically complete and expanded entire Toarcian succession in the Llanbedr (Mochras Farm) Borehole, Cardigan Bay Basin, Wales, UK. With these data, we (1) construct the first high-resolution biostratigraphically calibrated chemostratigraphic reference record for nearly the complete Toarcian Stage, (2) establish palaeoceanographic and depositional conditions in the Cardigan Bay Basin, (3) show that the T-OAE in the hemipelagic Cardigan Bay Basin was marked by the occurrence of gravity-flow deposits that were likely linked to globally enhanced sediment fluxes to continental margins and deeper marine (shelf) basins, and (4) explore how early Toarcian (tenuicostatum and serpentinum zones) siderite formation in the Cardigan Bay Basin may have been linked to low global oceanic sulphate concentrations and elevated supply of iron (Fe) from the hinterland, in response to climatically induced changes in hydrological cycling, global weathering rates and large-scale sulphide and evaporite deposition.

  13. Global Studies of the Sulfur Cycle Including the Influence of DMS and Fossil Fuel Sulfur on Climate and Climate Change

    Penner, Joyce E.

    1998-01-01

    The indirect effect of anthropogenic aerosols, wherein aerosol particles are thought to increase cloud droplet concentrations and cloud lifetime, is the most uncertain component of climate forcing over the past 100 years. Here, for the first time, we use a mechanistic treatment of droplet nucleation and a prognostic treatment of the number of cloud droplets to study the indirect aerosol effect from changes in carbonaceous and sulfate aerosols. Cloud droplet nucleation is parameterized as a function of total aerosol number concentration, updraft velocity and a shape parameter, which takes into account the mechanism, of sulfate aerosol formation, while cloud droplet number depends on the nucleation as well as on droplet sinks. Whereas previous treatments have predicted annual average indirect effects between -1 and -2 W/sq m, we obtain an indirect aerosol effect between -0.14 W/sq m and -0.42 W/sq m in the global mean.

  14. An assessment of NASA master directory/catalog interoperability for interdisciplinary study of the global water cycle

    Peuquet, Donna J.

    1991-01-01

    The most important issue facing science is understanding global change; the causes, the processes involved and their consequences. The key to success in this massive Earth science research effort will depend on efficient identification and access to the most data available across the atmospheric, oceanographic, and land sciences. Current mechanisms used by earth scientists for accessing these data fall far short of meeting this need. Scientists must as a result frequently rely on a priori knowledge and informal person to person networks to find relevant data. The Master Directory/Catalog Interoperability Program (MC/CI) undertaken by NASA is an important step in overcoming these problems. The stated goal of the MD project is to enable researchers to efficiently identify, locate, and obtain access to space and Earth science data.

  15. On the shape and properties of the global heliosphere over the Solar Cycle with Voyager/LECP ions and Cassini/INCA ENAs

    Dialynas, Konstantinos; Krimigis, Stamatios; Mitchell, Donald; Decker, Robert; Roelof, Edmond

    2017-04-01

    Voyager 1 (V1) and Voyager 2 (V2) have crossed the termination shock in 2004 (V1) and 2007(V2) and traversing the Heliosheath (HS) in the upstream (nose) hemisphere, while the Ion and Neutral Camera (INCA) on Cassini enables Energetic Neutral Atom (ENA) images of the celestial sphere that place the local ion measurements by each Voyager in a global context. We present an analysis of 5.2-55 keV ENA global images of the HS and 28-53 keV in-situ ions over an 11-year period (2003-2014) that corresponds to the declining phase of solar cycle 23 (SC23) and onset of SC24. The measurements reveal a coherent decrease and recovery between ENA in the global heliosphere and in-situ ions at V1/V2 during this time period, in overlapping energy bands, establishing that the HS ions are the source of >28 keV ENA. The similarity in the overall appearance of the images throughout the INCA energy range (5.2-55 keV), reveals that the source of ENAs at 5.2 keV ENA and ion variations with the Solar Sunspot Numbers (SSN) and solar wind parameters indicates that the Heliosphere responds promptly, within 2-3 years, to outward propagating solar wind changes in both the nose and anti-nose (tail) directions following the Solar Cycle (SC) phases. A detailed latitudinal examination of the global ENA emissions, verifies that the peak intensities between the nose and anti-nose directions are nearly similar, the power law ENA spectral index (γ) is largely the same near the equator in both the nose and anti-nose directions and displays similar spatial dependence with latitude. The totality of the ENA and in situ ion observations, together with the V1 measurement of a 0.5 nT interstellar magnetic field (ISMF) and recent modeling, suggest a "bubble-shape" heliosphere, i.e with little substantial tail-like feature. These observations are essential in determining the context for the measurements anticipated by the forthcoming IMAP mission.

  16. Reversible and irreversible impacts of greenhouse gas emissions in multi-century projections with the NCAR global coupled carbon cycle-climate model

    Froelicher, Thomas L.; Joos, Fortunat [University of Bern, Climate and Environmental Physics, Physics Institute, Bern (Switzerland); University of Bern, Oeschger Centre for Climate Change Research, Bern (Switzerland)

    2010-12-15

    The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification, and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500. The reversibility and irreversibility of impacts is quantified by comparing anthropogenically-forced regional changes with internal, unforced climate variability. We show that the influence of historical emissions and of non-CO{sub 2} agents is largely reversible on the regional scale. Forced changes in surface temperature and precipitation become smaller than internal variability for most land and ocean grid cells in the absence of future carbon emissions. In contrast, continued carbon emissions over the 21st century cause irreversible climate change on centennial to millennial timescales in most regions and impacts related to ocean acidification and sea level rise continue to aggravate for centuries even if emissions are stopped in year 2100. Undersaturation of the Arctic surface ocean with respect to aragonite, a mineral form of calcium carbonate secreted by marine organisms, is imminent and remains widespread. The volume of supersaturated water providing habitat to calcifying organisms is reduced from preindustrial 40 to 25% in 2100 and to 10% in 2300 for the high emission case. We conclude that emission trading schemes, related to the Kyoto Process, should not permit trading between emissions of relatively short-lived agents and CO{sub 2} given the irreversible impacts of anthropogenic carbon emissions. (orig.)

  17. EVOLUTION OF THE GLOBAL TEMPERATURE STRUCTURE OF THE SOLAR CORONA DURING THE MINIMUM BETWEEN SOLAR CYCLES 23 AND 24

    Nuevo, Federico A.; Vasquez, Alberto M. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA) and FCEN (UBA), CC 67-Suc 28, Ciudad de Buenos Aires (Argentina); Huang Zhenguang; Frazin, Richard; Manchester, Ward B. IV; Jin Meng [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-08-10

    The combination of differential emission measure tomography with extrapolation of the photospheric magnetic field allows determination of the electron density and electron temperature along individual magnetic field lines. This is especially useful in quiet-Sun (QS) plasmas where individual loops cannot otherwise be identified. In Paper I, this approach was applied to study QS plasmas during Carrington rotation (CR) 2077 at the minimum between solar cycles (SCs) 23 and 24. In that work, two types of QS coronal loops were identified: ''up'' loops in which the temperature increases with height, and ''down'' loops in which the temperature decreases with height. While the first ones were expected, the latter ones were a surprise and, furthermore, were found to be ubiquitous in the low-latitude corona. In the present work, we extend the analysis to 11 CRs around the last solar minimum. We found that the ''down'' population, always located at low latitudes, was maximum at the time when the sunspot number was minimum, and the number of down loops systematically increased during the declining phase of SC-23 and diminished during the rising phase of SC-24. ''Down'' loops are found to have systematically larger values of {beta} than do ''up'' loops. These discoveries are interpreted in terms of excitation of Alfven waves in the photosphere, and mode conversion and damping in the low corona.

  18. A global prospective of income distribution and its effect on life cycle assessment of municipal solid waste management: a review.

    Yadav, Pooja; Samadder, S R

    2017-04-01

    This study reviewed the municipal solid waste (MSW) composition, the management practices, and the use of life cycle assessment (LCA) tool for MSW management (MSWM) options in the various income group countries. LCA studies require inventory data, which is difficult to procure for any country including higher income group countries, and this issue gets compounded in low-income and lower middle-income group countries, which limits the implementation of LCA. This paper compared the use of LCA for MSWM between high-income and low-income group countries and also highlights the gap in using LCA for MSWM. A very limited number of LCA studies on MSWM were found for low-income group countries in comparison to high-income group countries. The study also provided a critical discussion on the challenges in applications of LCA in MSWM for better solid waste management in low-income and lower middle-income group countries. The study will help in taking up LCA studies in low-income countries to improve the overall MSWM efficiency.

  19. EVOLUTION OF THE GLOBAL TEMPERATURE STRUCTURE OF THE SOLAR CORONA DURING THE MINIMUM BETWEEN SOLAR CYCLES 23 AND 24

    Nuevo, Federico A.; Vásquez, Alberto M.; Huang Zhenguang; Frazin, Richard; Manchester, Ward B. IV; Jin Meng

    2013-01-01

    The combination of differential emission measure tomography with extrapolation of the photospheric magnetic field allows determination of the electron density and electron temperature along individual magnetic field lines. This is especially useful in quiet-Sun (QS) plasmas where individual loops cannot otherwise be identified. In Paper I, this approach was applied to study QS plasmas during Carrington rotation (CR) 2077 at the minimum between solar cycles (SCs) 23 and 24. In that work, two types of QS coronal loops were identified: ''up'' loops in which the temperature increases with height, and ''down'' loops in which the temperature decreases with height. While the first ones were expected, the latter ones were a surprise and, furthermore, were found to be ubiquitous in the low-latitude corona. In the present work, we extend the analysis to 11 CRs around the last solar minimum. We found that the ''down'' population, always located at low latitudes, was maximum at the time when the sunspot number was minimum, and the number of down loops systematically increased during the declining phase of SC-23 and diminished during the rising phase of SC-24. ''Down'' loops are found to have systematically larger values of β than do ''up'' loops. These discoveries are interpreted in terms of excitation of Alfvén waves in the photosphere, and mode conversion and damping in the low corona

  20. The Role of External Inputs and Internal Cycling in Shaping the Global Ocean Cobalt Distribution: Insights From the First Cobalt Biogeochemical Model

    Tagliabue, Alessandro; Hawco, Nicholas J.; Bundy, Randelle M.; Landing, William M.; Milne, Angela; Morton, Peter L.; Saito, Mak A.

    2018-04-01

    Cobalt is an important micronutrient for ocean microbes as it is present in vitamin B12 and is a co-factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state-of-the-art three-dimensional global ocean biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom-water oxygen conditions. The basin-scale distribution of cobalt supplied from margins is facilitated by the activity of manganese-oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and global ocean, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper ocean and the ocean interior. Our model highlights key regions of the ocean where biological activity may be most sensitive to cobalt availability.

  1. The Role of Heterotrophic Microbial Communities in Estuarine C Budgets and the Biogeochemical C Cycle with Implications for Global Warming: Research Opportunities and Challenges.

    Anderson, O Roger

    2016-05-01

    Estuaries are among the most productive and economically important marine ecosystems at the land-ocean interface and contribute significantly to exchange of CO2 with the atmosphere. Estuarine microbial communities are major links in the biogeochemical C cycle and flow of C in food webs from primary producers to higher consumers. Considerable attention has been given to bacteria and autotrophic eukaryotes in estuarine ecosystems, but less research has been devoted to the role of heterotrophic eukaryotic microbes. Current research is reviewed here on the role of heterotrophic eukaryotic microbes in C biogeochemistry and ecology of estuaries, with particular attention to C budgets, trophodynamics, and the metabolic fate of C in microbial communities. Some attention is given to the importance of these processes in climate change and global warming, especially in relation to sources and sinks of atmospheric CO2 , while also documenting the current paucity of research on the role of eukaryotic microbes that contribute to this larger question of C biogeochemistry and the environment. Some recommendations are made for future directions of research and opportunities of applying newer technologies and analytical approaches to a more refined analysis of the role of C in estuarine microbial community processes and the biogeochemical C cycle. © 2015 The Author Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

  2. International conference on the safety and security of radioactive sources: Towards a global system for the continuous control of sources throughout their life cycle. Contributed papers

    2005-01-01

    The objective of the conference is to promote a wide exchange of information on key issues relating to the safety and security of radioactive sources, including: drawing up an inventory; finding a solution without delay to situations resulting from past activities; preparing for the future by defining a global cooperative approach to the continuous control of radioactive sources during their life cycle. It is expected that the conference will foster a better understanding of the risks posed by these sources from the point of view of radiation safety and the threat associated with some of them in the event of malevolent use, and will help in finding ways of reducing the likelihood of the occurrence of a radiological incident or accident, or of a malevolent act. It is also expected to identify the preparedness and response measures that are necessary and to facilitate a common understanding on the feasibility of creating a sustainable global system for ensuring the safety and security of radioactive sources

  3. Life cycle inventory analysis of regenerative thermal oxidation of air emissions from oriented strand board facilities in Minnesota - a perspective of global climate change

    Nicholson, W.J. [Potlatch Corp., San Francisco, CA (United States)

    1997-12-31

    Life cycle inventory analysis has been applied to the prospective operation of regenerative thermal oxidation (RTO) technology at oriented strand board plants at Bemidji (Line 1) and Cook, Minnesota. The net system destruction of VOC`s and carbon monoxide, and at Cook a small quantity of particulate, has a very high environmental price in terms of energy and water use, global warming potential, sulfur and nitrogen oxide emissions, solids discharged to water, and solid waste deposited in landfills. The benefit of VOC destruction is identified as minor in terms of ground level ozone at best and possibly slightly detrimental. Recognition of environmental tradeoffs associated with proposed system changes is critical to sound decision-making. There are more conventional ways to address carbon monoxide emissions than combustion in RTO`s. In an environment in which global warming is a concern, fuel supplemental combustion for environmental control does not appear warranted. Consideration of non-combustion approaches to address air emission issues at the two operations is recommended. 1 ref., 5 tabs.

  4. International conference on the safety and security of radioactive sources: Towards a global system for the continuous control of sources throughout their life cycle. Contributed papers

    NONE

    2005-07-01

    The objective of the conference is to promote a wide exchange of information on key issues relating to the safety and security of radioactive sources, including: drawing up an inventory; finding a solution without delay to situations resulting from past activities; preparing for the future by defining a global cooperative approach to the continuous control of radioactive sources during their life cycle. It is expected that the conference will foster a better understanding of the risks posed by these sources from the point of view of radiation safety and the threat associated with some of them in the event of malevolent use, and will help in finding ways of reducing the likelihood of the occurrence of a radiological incident or accident, or of a malevolent act. It is also expected to identify the preparedness and response measures that are necessary and to facilitate a common understanding on the feasibility of creating a sustainable global system for ensuring the safety and security of radioactive sources.

  5. Atomic layer deposition of calcium oxide and calcium hafnium oxide films using calcium cyclopentadienyl precursor

    Kukli, Kaupo; Ritala, Mikko; Sajavaara, Timo; Haenninen, Timo; Leskelae, Markku

    2006-01-01

    Calcium oxide and calcium hafnium oxide thin films were grown by atomic layer deposition on borosilicate glass and silicon substrates in the temperature range of 205-300 o C. The calcium oxide films were grown from novel calcium cyclopentadienyl precursor and water. Calcium oxide films possessed refractive index 1.75-1.80. Calcium oxide films grown without Al 2 O 3 capping layer occurred hygroscopic and converted to Ca(OH) 2 after exposure to air. As-deposited CaO films were (200)-oriented. CaO covered with Al 2 O 3 capping layers contained relatively low amounts of hydrogen and re-oriented into (111) direction upon annealing at 900 o C. In order to examine the application of CaO in high-permittivity dielectric layers, mixtures of Ca and Hf oxides were grown by alternate CaO and HfO 2 growth cycles at 230 and 300 o C. HfCl 4 was used as a hafnium precursor. When grown at 230 o C, the films were amorphous with equal amounts of Ca and Hf constituents (15 at.%). These films crystallized upon annealing at 750 o C, showing X-ray diffraction peaks characteristic of hafnium-rich phases such as Ca 2 Hf 7 O 16 or Ca 6 Hf 19 O 44 . At 300 o C, the relative Ca content remained below 8 at.%. The crystallized phase well matched with rhombohedral Ca 2 Hf 7 O 16 . The dielectric films grown on Si(100) substrates possessed effective permittivity values in the range of 12.8-14.2

  6. Ocean acidification over the next three centuries using a simple global climate carbon-cycle model: projections and sensitivities

    Hartin, Corinne A.; Bond-Lamberty, Benjamin; Patel, Pralit; Mundra, Anupriya

    2016-08-01

    Continued oceanic uptake of anthropogenic CO2 is projected to significantly alter the chemistry of the upper oceans over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of ocean acidification, limiting our ability to assess the impacts and probabilities of ocean changes. In this study we examine the ability of Hector v1.1, a reduced-form global model, to project changes in the upper ocean carbonate system over the next three centuries, and quantify the model's sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representative Concentration Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that ocean acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude oceans (< 55°). The model projects low-latitude surface ocean pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (ΩAr) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of ocean acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector's carbonate system. Of the parameters tested, changes in [H+] are most sensitive to parameters that directly affect atmospheric CO2 concentrations – Q10 (terrestrial respiration temperature response) as well as changes in ocean circulation, while changes in ΩAr saturation levels are sensitive to changes in ocean salinity and Q10. We conclude that Hector is a robust tool well suited for rapid ocean acidification

  7. Nutrient cycling for biomass: Interactive proteomic/transcriptomic networks for global carbon management processes within poplar-mycorrhizal interactions

    Cseke, Leland [Univ. of Alabama, Huntsville, AL (United States)

    2016-08-30

    free living conditions. Together, the assembled team of experts completed all of the planned milestones set forth in this project. In addition to the planned approaches, several lines of exciting new research have also evolved during the course of this project that involved FTIR Imaging using the National Synchrotron Light Source at BNL. A summary of the approaches used in this project and key highlights are as follows: Having the right combination of microbes associated with plants is largely responsible for the plant’s ability to mine nutrients from the soil and to develop a strong “immune system”. Our current chemically focused and intensive culture tends to forget that plants obtain nutrients in two ways: (1) via water soluble chemical nutrients and (2) via the activity of acquired microbial symbionts. In healthy natural ecosystems, chemical nutrients are always in low abundance because the organisms within that system have already locked such nutrients away within the biological system itself. Thus, in nature it is the biological sources of nutrients and the microbes that have the capacity to mine those nutrients for their plant hosts that actually control the terrestrial nutrient cycles on this planet. Thus, a new push in the future may very well be to use our skills at elucidating complex patterns to strategically guide soil microbe communities to do what we want, essentially allowing nature to do the work of figuring out what is most efficient and effective for human needs. However, the findings of this project and other work in our lab lead to the hypothesis that the specific soil community composition is less important than the emergent properties of those communities. So, additional research into what soil communities are effective and how they are established will be key in developing human understanding of how to manipulate biological systems to meet human needs without causing undue damage to our environment.

  8. Calcium microdomains near R-type calcium channels control the induction of presynaptic LTP at parallel fiber to Purkinje cell synapses

    Myoga, Michael H.; Regehr, Wade G.

    2011-01-01

    R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium-calmodulin sensitive potassium channel that in turn regulates postsynaptic hippocampal LTP. Here we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic LTP at parallel fiber to Purkinje cell synapses in the cerebellum (PF-LTP), which is mediated by calcium/calmodulin-stimulated adenylyl cyclases. Although most presynaptic calcium influx is through N-type and P/Q-type calcium channels, blocking these channels does not disrupt PF-LTP, but blocking R-type calcium channels does. Moreover, global calcium signaling cannot account for the calcium dependence of PF-LTP because R-type channels contribute modestly to overall calcium entry. These findings indicate that within presynaptic terminals, R-type calcium channels produce calcium microdomains that evoke presynaptic LTP at moderate frequencies that do not greatly increase global calcium levels,. PMID:21471358

  9. Environments of ocean and primary productivity during the late Quaternary. Millenial-scale large and abrupt climatic changes (global system dynamics in response to Dansgaard-Oeschger cycles); Daiyonki koki no kaiyo kankyo to seibutsu seisan. Suhyaku-susennen scale no kyugekina kiko hendo (Dansgaard-Oeschger cycle ni taisuru chikyu system no oto)

    Tada, R. [The University of Tokyo, Tokyo (Japan)

    1998-04-25

    Abrupt and steep climate changes of the millennial scale as represented by the Dansgaard-Oeschger cycle (D-O cycle) and the behavior of the global surface layer system in their wake are outlined. The D-DO cycle is the abrupt and steep climate changes that are recorded in the Greenland continental ice sheet, and is grasped most typically as changes in the oxygen isotopic ratio in the ice. Studies reveal that the D-O cycle is a global episode that accompanied interaction between various subsystems constituting the global surface layer system. It is believed that in the D-O cycle there were changes not only in temperature but also in aridity/moisture and in the sea level, and probabilities are high that there was a great local variation in the way the changes took effect. The possibility has now become lower that the D-O cycle occurred in the interglacial epoch in the high latitude belt in the northern hemisphere, yet it remains likely that the climate changes driving the D-O cycle continued in the low latitude belt. 57 refs., 8 figs.

  10. Calcium and magnesium determination

    Bhattacharya, S.K.

    1982-01-01

    The roles of calcium and magnesium in human health and disease have been extensively studied. Calcium and magnesium have been determined in biological specimens by atomic absorption spectroscopy using stiochiometric nitrous oxide-acetylene flame

  11. Fenoprofen calcium overdose

    ... page: //medlineplus.gov/ency/article/002649.htm Fenoprofen calcium overdose To use the sharing features on this page, please enable JavaScript. Fenoprofen calcium is a type of medicine called a nonsteroidal ...

  12. Calcium channel blocker overdose

    ... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used ...

  13. Calcium and Mitosis

    Hepler, P.

    1983-01-01

    Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

  14. Calcium en cardioplegie

    Ruigrok, T.J.C.; Meijler, F.L.

    1985-01-01

    Coronary perfusion with a calcium-free solution, followed by reperfusion with a calcium containing solution, may result in acute myocardial cell death and in irreversible loss of the e1ectrical and mechanical activity of the heart. This phenomenon is known as the calcium paradox. A number of

  15. Immobilization of calcium sulfate contained in demolition waste

    Ambroise, J.; Pera, J.

    2008-01-01

    This paper presents the results of a laboratory study undertaken to examine the treatment of demolition waste containing calcium sulfate by means of calcium sulfoaluminate clinker (CSA). The quantity of CSA necessary to entirely consume calcium sulfate was determined. Using infrared spectrometry analysis and X-ray diffraction, it was shown that calcium sulfate was entirely consumed when the ratio between CSA and calcium sulfate was 4. Standard sand was polluted by 4% calcium sulfate. Two solutions were investigated: ·either global treatment of sand by CSA, ·or immobilization of calcium sulfate by CSA, followed by the introduction of this milled mixture in standard sand. Regardless of the type of treatment, swelling was almost stabilized after 28 days of immersion in water

  16. A Geometry-Based Cycle Slip Detection and Repair Method with Time-Differenced Carrier Phase (TDCP for a Single Frequency Global Position System (GPS + BeiDou Navigation Satellite System (BDS Receiver

    Chuang Qian

    2016-12-01

    Full Text Available As the field of high-precision applications based on carriers continues to expand, the development of low-cost, small, modular receivers and their application in diverse scenarios and situations with complex data quality has increased the requirements of carrier-phase data preprocessing. A new geometry-based cycle slip detection and repair method based on Global Position System (GPS + BeiDou Navigation Satellite System (BDS is proposed. The method uses a Time-differenced Carrier Phase (TDCP model, which eliminates the Inner-System Bias (ISB between GPS and BDS, and it is conducive to the effective combination of GPS and BDS. It avoids the interference of the noise of the pseudo-range with cycle slip detection, while the cycle slips are preserved as integers. This method does not limit the receiver frequency number, and it is applicable to single-frequency data. The process is divided into two steps to detect and repair cycle slip. The first step is cycle slip detection, using the Improved Local Analysis Method (ILAM to find satellites that have cycle slips; The second step is to repair the cycle slips, including estimating the float solution of changes in ambiguities at the satellites that have cycle slips with the least squares method and the integer solution of the cycle slips by rounding. In the process of rounding, in addition to the success probability, a decimal test is carried out to validate the result. Finally, experiments with filed test data are carried out to prove the effectiveness of this method. The results show that the detectable cycle slips number with GPS + BDS is much greater than that with GPS. The method can also detect the non-integer outliers while fixing the cycle slip. The maximum decimal bias in repair is less than that with GPS. It implies that this method takes full advantages of multi-system.

  17. Calcium absorption and achlorhydria

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  18. Measurement of Iodine-129 concentration in environmental water samples around Fukushima area - Role of river system in the global iodine cycle

    Matsuzaki, Hiroyuki; Tokuyama, Hironori; Miyake, Yasuto; Honda, Maki; Yamagata, Takeyasu; Muramatsu, Yasuyuki

    2013-04-01

    According to Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, vast amount of radioactive nuclides including radioactive iodine were spilled out into the environment. There is no question about that detailed observation of distribution of radioactive nuclides and evaluation of the radiation exposure of residents is extremely important. On the other hand, from the view of an elemental dynamics in the environment, this event can be considered as a spike of the radioactive isotope. It is also the case for the iodine. A rare isotope Iodine-129 was widely distributed in a very short time by the FDNPP accident. Iodine-129 directly landing on the soil surface had been trapped in the upper layer of the soil and the depth profile should indicate the migration in and the interaction with the soil. If Iodine-129 was trapped in the woods, it seems to take rather longer time to landing on the ground. Either way, a certain portion of the Iodine-129 should be moving downward and finally washed out by the groundwater or river with a certain rate and transported into the sea. The concentration of Iodine-129 in environmental water samples taken from rivers and ponds are considered to reflect the iodine transportation process by the fluvial system. For the detailed discussion of the role of the fluvial system in the global iodine cycle, Iodine-129 concentration of various water samples collected from Fukushima area was measured by means of Accelerator Mass Spectrometry. The results ranged from 3E06 atoms/L to 3E09 atoms/L. Samples from Abukuma area (South West of FDNPP) showed lower concentration. On the other hand, samples collected from North West part (Iitate village and Minami Soma region) showed higher concentration (more than 1E8 atoms/L). Delayed enhancement of Iodine-129 concentration over a year in river systems surrounded by woods was also observed which is considered to correspond to the delayed release from the woods.

  19. Calcium channel blocker poisoning

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  20. Dengue and Calcium

    Shivanthan, Mitrakrishnan C; Rajapakse, Senaka

    2014-01-01

    Dengue is potentially fatal unless managed appropriately. No specific treatment is available and the mainstay of treatment is fluid management with careful monitoring, organ support, and correction of metabolic derangement. Evidence with regards to the role of calcium homeostasis in dengue is limited. Low blood calcium levels have been demonstrated in dengue infection and hypocalcemia maybe more pronounced in more severe forms. The cause of hypocalcemia is likely to be multifactorial. Calcium...

  1. Calcium Channel Blockers

    ... Certain calcium channel blockers interact with grapefruit products. Kaplan NM, et al. Treatment of hypertension: Drug therapy. In: Kaplan's Clinical Hypertension. 11th ed. Philadelphia, Pa.: Wolters Kluwer ...

  2. Product life cycle management as contribution for a sustainable management - EXPO 2000 - Global Dialogue 'Science and Technology - Thinking for the Future'; Produkt Life Cycle Management als Beitrag fuer ein nachhaltiges Wirtschaften - EXPO 2000 - Global Dialogue 'Science and Technology - Thinking the Future'. Schlussbericht

    Westkaemper, E.; Hieber, M.; Dauensteiner, A.; Fengler, R.; Mannuss, O.; Niemann, J.; Stolz, M.

    2001-04-01

    Within the context of the project the IFF Stuttgart develops Life Cycle Management (LCM) concepts for heating systems and machine-tools, which where presented within the World Exhibition EXPO 2000. The Vaillant GmbH, manufacturer of heating systems, cooperates with the IFF in order to develop the prototype of an LCM controlled system. At the World Exhibition it was possible to control a complete heating system via the Internet and in this way to, say, monitor temperatures, switch on and off the pumps, fix errors or eliminate malfunctions. IFF has developed and realized a remote control of all parameters of the system, which may be controlled via Internet, e-mail or using the software program HZClient. In addition, an Internet-based software was developed, which will support customers to choose the heating system suited best for their individual needs. Finally, Life Cycle Costing (LCC) calculations for machine tools has presented demonstrating the proposed LCC approach in the sphere of capital goods. Therefore, the IFF has developed an interactive simulation tool which allows the economically oriented inspection of product life cycles and generates its overall economic result. The results of the project are transferable particularly on heating-systems of different manufactures. (orig.) [German] Das IFF Stuttgart entwickelte im Vorhaben Life Cycle Management-Konzepte am Beispiel von Heizungsanlagen und Werkzeugmaschinen, die den Besuchern des 'Global Dialogues' auf der EXPO 2000 vorgestellt wurden. In Kooperation des Heizungsherstellers Vaillant GmbH und dem Fraunhofer IPA wurde ein Prototyp einer nach dem LCM gesteuerten Heizungsanlage entwickelt. Hierzu hat das IFF Stuttgart die Fernsteuerung eines modernen Gas-Wandheizgeraetes realisiert. Saemtliche Parameter der Heizung koennen somit per Internet, Softwareprogramm sowie per E-Mail gesteuert werden. Ausserdem wurde ein web-basiertes Programm entwickelt, das Kunden bei ihrer Entscheidung ueber die fuer

  3. Research on the general analytical method of fossil fuel cycle from a viewpoint of the global environment. 3; Chikyu kankyo kara mita sogoteki kaseki nenryo cycle bunseki hyoka shuho no chosa. 3

    NONE

    1996-03-01

    The general analysis/assessment method of a fossil fuel cycle was studied. Seven kinds of power generation plants such as LNG cycle and coal cycle ones, and four kinds of transport and treatment systems of recovered CO2 such as ocean and underground systems were studied as case studies on life cycle analysis. As data necessary for life cycle analysis, the database was constructed which stores the facilities and operational energy required for a total energy system from mining of fossil fuel to treatment of recovered CO2, and the quantity of environmental waste such as CO2 emission. As a result, the decrease rate of energy balance defined as ratio of input energy to power plant output was estimated to be 14-43% and 20-60% in LNG cycle and coal cycle, respectively. Even if the recovery rate of CO2 in power plants reached 80-90%, reduction of total CO2 emission was limited to only 20-40% because of CO2 emission during mining, liquefaction and transport of fuel. 168 refs., 48 figs., 102 tabs.

  4. Acidosis and Urinary Calcium Excretion

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibi...

  5. Calcium D-saccharate

    Garcia, André Castilho; Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

    2016-01-01

    Molar conductivity of saturated aqueous solutions of calcium d-saccharate, used as a stabilizer of beverages fortified with calcium d-gluconate, increases strongly upon dilution, indicating complex formation between calcium and d-saccharate ions, for which, at 25 °C, Kassoc = 1032 ± 80, ΔHassoc......° = -34 ± 6 kJ mol-1, and ΔSassoc° = -55 ± 9 J mol-1 K-1, were determined electrochemically. Calcium d-saccharate is sparingly soluble, with a solubility product, Ksp, of (6.17 ± 0.32) × 10-7 at 25 °C, only moderately increasing with the temperature: ΔHsol° = 48 ± 2 kJ mol-1, and ΔSassoc° = 42 ± 7 J mol-1...... K-1. Equilibria in supersaturated solutions of calcium d-saccharate seem only to adjust slowly, as seen from calcium activity measurements in calcium d-saccharate solutions made supersaturated by cooling. Solutions formed by isothermal dissolution of calcium d-gluconate in aqueous potassium d...

  6. Global Carbon Budget 2017

    Le Quere, Corinne; Andrew, Robbie M.; Friedlingstein, Pierre; Sitch, Stephen; Pongratz, Julia; Manning, Andrew C.; Korsbakken, Jan Ivar; Peters, Glen P.; Canadell, Josep G.; Jackson, Robert B.; Boden, Thomas A.; Tans, Pieter P.; Andrews, Oliver D.; Arora, Vivek K.; Bakker, Dorothee C. E.; Barbero, Leticia; Becker, Meike; Betts, Richard A.; Bopp, Laurent; Chevallier, Frederic; Chini, Louise P.; Ciais, Philippe; Cosca, Catherine E.; Cross, Jessica; Currie, Kim; Gasser, Thomas; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Houghton, Richard A.; Hunt, Christopher W.; Hurtt, George; Ilyina, Tatiana; Jain, Atul K.; Kato, Etsushi; Kautz, Markus; Keeling, Ralph F.; Goldewijk, Kees Klein; Koertzinger, Arne; Landschuetzer, Peter; Lefevre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lima, Ivan; Lombardozzi, Danica; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M. S.; Munro, David R.; Nabel, Julia E. M. S.; Nakaoka, Shin-ichiro; Nojiri, Yukihiro; Padin, X. Antonio; Peregon, Anna; Pfeil, Benjamin; Pierrot, Denis; Poulter, Benjamin; Rehder, Gregor; Reimer, Janet; Roedenbeck, Christian; Schwinger, Jorg; Seferian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Tian, Hanqin; Tilbrook, Bronte; Tubiello, Francesco N.; van der Laan-Luijkx, Ingrid T.; van der Werf, Guido R.; van Heuven, Steven; Viovy, Nicolas; Vuichard, Nicolas; Walker, Anthony P.; Watson, Andrew J.; Wiltshire, Andrew J.; Zaehle, Soenke; Zhu, Dan

    2018-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere - the "global carbon budget" - is important to better understand the global carbon cycle, support the development of climate policies, and project

  7. Calcium metabolism in birds.

    de Matos, Ricardo

    2008-01-01

    Calcium is one of the most important plasma constituents in mammals and birds. It provides structural strength and support (bones and eggshell) and plays vital roles in many of the biochemical reactions in the body. The control of calcium metabolism in birds is highly efficient and closely regulated in a number of tissues, primarily parathyroid gland, intestine, kidney, and bone. The hormones with the greatest involvement in calcium regulation in birds are parathyroid hormone, 1,25-dihydroxyvitamin D(3) (calcitriol), and estrogen, with calcitonin playing a minor and uncertain role. The special characteristics of calcium metabolism in birds, mainly associated with egg production, are discussed, along with common clinical disorders secondary to derangements in calcium homeostasis.

  8. Calcium stable isotope geochemistry

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  9. Calcium stable isotope geochemistry

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  10. Dietary Calcium Intake in Sample of School Age Children in City of Rabat, Morocco

    Amina Bouziani

    2018-01-01

    Full Text Available Calcium is an important mineral playing a vital role to maintain bone health. Calcium intake is considered as one of the most important determinants to assess the calcium status and to evaluate the calcium deficiency in the human body. Our study aims at estimating calcium intake in a sample of children and adolescent to be used in the global strategy to reduce calcium deficiency disorders in Morocco. Thus, 131 children and adolescents were recruited from public schools at Rabat and its regions in the framework of a descriptive cross-sectional study. For each participant, anthropometric parameters were measured. Calcium status was assessed by 24 h dietary recall. Food frequency questionnaire was used to evaluate children’s nutritional habits and to assess the consumption of calcium-rich food. Overall, the mean calcium intake was 522.0 ± 297.0 mg/day, and 85.5% of subjects highlighted calcium deficiency, with no significant difference between boys and girls. Calcium intake was significantly different according to age groups, and high consumption of calcium was found in subjects aged from 14 to 18 years (776.86 ±290.07 mg/day, giving evidence of the low calcium status of the studied population. Daily food intake and food frequency analysis showed that bread, vegetables, and fruits are the most consumed food and the main source of daily calcium intake. Consumption of dairy products, considered as the best source of calcium, is lower and represents only 14% of total calcium intake. Our study clearly showed that calcium status is very lower in Moroccan children and adolescents and a large proportion of this population have inadequate calcium intake. Hence, there’s an urgent need of specific strategies, including children sensitisation and nutritional education, to increase calcium intake and therefore reduce calcium deficiency disorders impacting the whole body during childhood and in adult age.

  11. HYPERTHERMIA, INTRACELLULAR FREE CALCIUM AND CALCIUM IONOPHORES

    STEGE, GJJ; WIERENGA, PK; KAMPINGA, HH; KONINGS, AWT

    1993-01-01

    It is shown that heat-induced increase of intracellular calcium does not correlate with hyperthermic cell killing. Six different cell lines were investigated; in four (EAT, HeLa S3, L5178Y-R and L5178Y-S) heat treatments killing 90% of the cells did not affect the levels of intracellular free

  12. Temporary service? : A global perspective on domestic work and the life cycle from pre-industrial times to the present day

    van Nederveen Meerkerk, E.J.V.

    2017-01-01

    In recent years, labor history has taken a “global turn” and the focus has increasingly been on labor relations in the non-Western context. This article aims to challenge existing perceptions of the history of domestic work in Europe from a global labor history perspective, by comparing as well as

  13. DIHYDROPYRIDINE CALCIUM- CHANNELBLOCKERSFOR ...

    Furthermore, the controversy over the role of calci~-channel blockers as first-line ..... group trials while fully accounting for placebo effects as well as interindividual ..... Reducing calcium overload in the ischemic brain. N Engl JMed. 1999; 341 ...

  14. Calcium and Your Child

    ... calcium-set tofu edamame (soybeans) broccoli, collard greens, kale, chard, Chinese cabbage, and other leafy greens almonds ... more dark green, leafy vegetables (such as broccoli, kale, collard greens, or Chinese cabbage) with meals. Kids ...

  15. Carbonate-silicate cycle models of the long-term carbon cycle, carbonate accumulation in the oceans, and climate

    Caldeira, K.G.

    1991-01-01

    Several models of the long-term carbon cycle, incorporating models of the carbonate-silicate cycle, were developed and utilized to investigate issues relating to global climate and the causes and consequences of changes in calcium carbonate accumulation in the oceans. Model results indicate that the marked mid-Cretaceous (120 Ma) global warming could be explained by increased rates of release of carbon dioxide from subduction-zone metamorphism and mid-ocean-ridges, in conjunction with paleogeographic factors. Since the mid-Cretaceous, the primary setting for calcium carbonate accumulation in the oceans has shifted from shallow-water to deep-water environments. Model results suggest that this shift could have major consequences for the carbonate-silicate cycle and climate, and lead to significant increases in the flux of metamorphic carbon dioxide to the atmosphere. Increases in pelagic carbonate productivity, and decreases in tropical shallow-water area available for neritic carbonate accumulation, have both been proposed as the primary cause of this shift. Two lines of evidence developed here (one involving a statistical analysis of Tertiary carbonate-accumulation and oxygen-isotope data, and another based on modeling the carbonate-silicate cycle and ocean chemistry) suggest that a decrease in tropical shallow-water area was more important than increased pelagic productivity in explaining this shift. Model investigations of changes in ocean chemistry at the Cretaceous/Tertiary (K/T) boundary (66 Ma) indicate that variations in deep-water carbonate productivity may affect shallow-water carbonate accumulation rates through a mechanism involving surface-water carbonate-ion concentration. In the aftermath of the K/T boundary event, deep-water carbonate production and accumulation were significantly reduced as a result of the extinction of calcareous plankton

  16. Discovery and Development of Calcium Channel Blockers

    Théophile Godfraind

    2017-05-01

    Full Text Available In the mid 1960s, experimental work on molecules under screening as coronary dilators allowed the discovery of the mechanism of calcium entry blockade by drugs later named calcium channel blockers. This paper summarizes scientific research on these small molecules interacting directly with L-type voltage-operated calcium channels. It also reports on experimental approaches translated into understanding of their therapeutic actions. The importance of calcium in muscle contraction was discovered by Sidney Ringer who reported this fact in 1883. Interest in the intracellular role of calcium arose 60 years later out of Kamada (Japan and Heibrunn (USA experiments in the early 1940s. Studies on pharmacology of calcium function were initiated in the mid 1960s and their therapeutic applications globally occurred in the the 1980s. The first part of this report deals with basic pharmacology in the cardiovascular system particularly in isolated arteries. In the section entitled from calcium antagonists to calcium channel blockers, it is recalled that drugs of a series of diphenylpiperazines screened in vivo on coronary bed precontracted by angiotensin were initially named calcium antagonists on the basis of their effect in depolarized arteries contracted by calcium. Studies on arteries contracted by catecholamines showed that the vasorelaxation resulted from blockade of calcium entry. Radiochemical and electrophysiological studies performed with dihydropyridines allowed their cellular targets to be identified with L-type voltage-operated calcium channels. The modulated receptor theory helped the understanding of their variation in affinity dependent on arterial cell membrane potential and promoted the terminology calcium channel blocker (CCB of which the various chemical families are introduced in the paper. In the section entitled tissue selectivity of CCBs, it is shown that characteristics of the drug, properties of the tissue, and of the stimuli are

  17. Calcium binding by dietary fibre

    James, W.P.T.; Branch, W.J.; Southgate, D.A.T.

    1978-01-01

    Dietary fibre from plants low in phytate bound calcium in proportion to its uronic-acid content. This binding by the non-cellulosic fraction of fibre reduces the availability of calcium for small-intestinal absorption, but the colonic microbial digestion of uronic acids liberates the calcium. Thus the ability to maintain calcium balance on high-fibre diets may depend on the adaptive capacity on the colon for calcium. (author)

  18. A model of propagating calcium-induced calcium release mediated by calcium diffusion

    Backx, P. H.; de Tombe, P. P.; van Deen, J. H.; Mulder, B. J.; ter Keurs, H. E.

    1989-01-01

    The effect of sudden local fluctuations of the free sarcoplasmic [Ca++]i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium

  19. [Calcium suppletion for patients who use gastric acid inhibitors: calcium citrate or calcium carbonate?].

    Jonge, H.J. de; Gans, R.O.; Huls, G.A.

    2012-01-01

    Various calcium supplements are available for patients who have an indication for calcium suppletion. American guidelines and UpToDate recommend prescribing calcium citrate to patients who use antacids The rationale for this advice is that water-insoluble calcium carbonate needs acid for adequate

  20. TWO NOVEL PARAMETERS TO EVALUATE THE GLOBAL COMPLEXITY OF THE SUN'S MAGNETIC FIELD AND TRACK THE SOLAR CYCLE

    Zhao, L.; Landi, E. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48105 (United States); Gibson, S. E., E-mail: lzh@umich.edu [NCAR/HAO, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2013-08-20

    Since the unusually prolonged and weak solar minimum between solar cycles 23 and 24 (2008-2010), the sunspot number is smaller and the overall morphology of the Sun's magnetic field is more complicated (i.e., less of a dipole component and more of a tilted current sheet) compared with the same minimum and ascending phases of the previous cycle. Nearly 13 yr after the last solar maximum ({approx}2000), the monthly sunspot number is currently only at half the highest value of the past cycle's maximum, whereas the polar magnetic field of the Sun is reversing (north pole first). These circumstances make it timely to consider alternatives to the sunspot number for tracking the Sun's magnetic cycle and measuring its complexity. In this study, we introduce two novel parameters, the standard deviation (SD) of the latitude of the heliospheric current sheet (HCS) and the integrated slope (SL) of the HCS, to evaluate the complexity of the Sun's magnetic field and track the solar cycle. SD and SL are obtained from the magnetic synoptic maps calculated by a potential field source surface model. We find that SD and SL are sensitive to the complexity of the HCS: (1) they have low values when the HCS is flat at solar minimum, and high values when the HCS is highly tilted at solar maximum; (2) they respond to the topology of the HCS differently, as a higher SD value indicates that a larger part of the HCS extends to higher latitude, while a higher SL value implies that the HCS is wavier; (3) they are good indicators of magnetically anomalous cycles. Based on the comparison between SD and SL with the normalized sunspot number in the most recent four solar cycles, we find that in 2011 the solar magnetic field had attained a similar complexity as compared to the previous maxima. In addition, in the ascending phase of cycle 24, SD and SL in the northern hemisphere were on the average much greater than in the southern hemisphere, indicating a more tilted and wavier

  1. Constraining the cause of the end-Guadalupian extinction with coupled records of carbon and calcium isotopes

    Jost, A. B.; Mundil, R.; He, B.; Brown, S. T.; Altiner, D.; Sun, Y.; DePaolo, D. J.; Payne, J.

    2013-12-01

    A negative δ13C excursion in carbonate sediments from Guadalupian (Middle Permian) and Lopingian (Late Permian) stratigraphic sections has been interpreted to result from a large carbon cycle disturbance during end-Guadalupian extinction event (ca. 260 Ma). However, the carbon isotope data alone are insufficient to uniquely determine the type and magnitude of perturbations to the global carbon cycle. The carbon and calcium cycles are coupled via CaCO3 burial, so changes in calcium isotopes can be used to constrain the cause of a carbon isotope excursion. In this study, we present coupled carbon and calcium isotope records from three Guadalupian-Lopingian (G/L) sections in China and Turkey. Isotope records among our studied sections are inconsistent in both their δ13C and δ44/40Ca records. Similar inconsistencies in δ13C among sections occur across previously published datasets. Sections with large (>3‰) changes in δ13C either show evidence for diagenetic alteration or do not show δ13C and δ44/40Ca changes consistent with severe volcanic degassing from Emeishan or methane clathrate destabilization. We conclude that the large isotopic changes are more likely the result of local burial conditions or diagenetic effects, rather than a large carbon cycle disturbance. Perturbations to the global carbon and calcium cycles appear to have been much smaller across the G/L transition than across the subsequent Permian-Triassic boundary. This finding is consistent with recent paleobiological data showing that the end-Guadalupian extinction was much less severe than previously believed, and was indistinguishable in magnitude from background intervals. However, selective extinction of marine animals with passive respiratory physiology indicates that the G/L extinction cannot simply be due to background extinction or sampling failure, and that it was triggered by some environmental event. Therefore, any environmental event must have been small enough to not generate large

  2. Calcium in plant cells

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  3. Freeway Driving Cycle Construction Based on Real-Time Traffic Information and Global Optimal Energy Management for Plug-In Hybrid Electric Vehicles

    Hongwen He

    2017-11-01

    Full Text Available This paper presents a freeway driving cycle (FDC construction method based on traffic information. A float car collected different type of roads in California and we built a velocity fragment database. We selected a real freeway driving cycle (RFDC and established the corresponding time traffic information tensor model by using the data in California Department of Transportation performance measure system (PeMS. The correlation of road velocity in the time dimension and spatial dimension are analyzed. According to the average velocity of road sections at different times, the kinematic fragments are stochastically selected in the velocity fragment database to construct a real-time FDC of each section. The comparison between construction freeway driving cycle (CFDC and real freeway driving cycle (RFDC show that the CFDC well reflects the RFDC characteristic parameters. Compared to its application in plug-in electric hybrid vehicle (PHEV optimal energy management based on a dynamic programming (DP algorithm, CFDC and RFDC fuel consumption are similar within approximately 5.09% error, and non-rush hour fuel economy is better than rush hour 3.51 (L/100 km at non-rush hour, 4.29 (L/km at rush hour. Moreover, the fuel consumption ratio can be up to 13.17% in the same CFDC at non-rush hour.

  4. The Dynamics of Interfirm Networks along the Industry Life Cycle: The Case of the Global Video Game Industry 1987-2007

    Balland, P.M.A.; Vaan, M. de; Boschma, R.

    2013-01-01

    In this article, we study the formation of network ties between firms along the life cycle of a creative industry. We focus on three mechanisms that drive network formation: (i) network endogeneity which stresses a path-dependent change originating from previous network structures, (ii) five

  5. Major Findings of the IAEA/INPRO Collaborative Project on Global Architectures of Innovative Nuclear Energy Systems with Thermal and Fast Reactors and a Closed Nuclear Fuel Cycle

    Kuznetsov, V.; Fesenko, G.; Kriachko, M.; Dixon, B.; Hayashi, H.; Usanov, V.

    2013-01-01

    GAINS objectives: Rationale: • Increasing interest in MSs in joint modelling of global and regional trends in nuclear power taking into account technical innovations and multilateral cooperation; • Modelling of the kind requires agreed methodological platform to analyse transition strategies from the present to future nuclear energy system (NES). Overall objectives: Address technical & institutional issues of developing a global architecture for the sustainable NES in the 21st century: • develop a framework (common methodological platform, databases, assumptions & boundary conditions); • perform sample studies; • indicate potential areas for application of GAINS framework

  6. Assessing offsets between the δ13C of sedimentary components and the global exogenic carbon pool across early Paleogene carbon cycle perturbations

    Sluijs, A.; Dickens, G.R.

    2012-01-01

    Negative stable carbon isotope excursions (CIEs) across the Paleocene–Eocene thermal maximum (PETM; ∼56 Ma) range between 2‰ and 7‰, even after discounting sections with truncated records. Individual carbon isotope records differ in shape and magnitude from variations in the global exogenic carbon

  7. Viral lysis of photosynthesizing microbes as a mechanism for calcium carbonate nucleation in seawater

    Lisle, John T.; Robbins, Lisa L.

    2016-01-01

    Removal of carbon through the precipitation and burial of calcium carbonate in marine sediments constitutes over 70% of the total carbon on Earth and is partitioned between coastal and pelagic zones. The precipitation of authigenic calcium carbonate in seawater, however, has been hotly debated because despite being in a supersaturated state, there is an absence of persistent precipitation. One of the explanations for this paradox is the geochemical conditions in seawater cannot overcome the activation energy barrier for the first step in any precipitation reaction; nucleation. Here we show that virally induced rupturing of photosynthetic cyanobacterial cells releases cytoplasmic-associated bicarbonate at concentrations ~23-fold greater than in the surrounding seawater, thereby shifting the carbonate chemistry toward the homogenous nucleation of one or more of the calcium carbonate polymorphs. Using geochemical reaction energetics, we show the saturation states (Ω) in typical seawater for calcite (Ω = 4.3), aragonite (Ω = 3.1), and vaterite (Ω = 1.2) are significantly elevated following the release and diffusion of the cytoplasmic bicarbonate (Ωcalcite = 95.7; Ωaragonite = 68.5; Ωvaterite = 25.9). These increases in Ω significantly reduce the activation energy for nuclei formation thresholds for all three polymorphs, but only vaterite nucleation is energetically favored. In the post-lysis seawater, vaterite's nuclei formation activation energy is significantly reduced from 1.85 × 10−17 J to 3.85 × 10−20 J, which increases the nuclei formation rate from highly improbable (nucleation of calcium carbonate in seawater describes a mechanism through which the initial step in the production of carbonate sediments may proceed. It also presents an additional role of photosynthesizing microbes and their viruses in marine carbon cycles and reveals these microorganisms are a collective repository for concentrated and reactive dissolved inorganic carbon (DIC

  8. Movement of calcium signals and calcium-binding proteins: firewalls, traps and tunnels.

    Barrow, S L; Sherwood, M W; Dolman, N J; Gerasimenko, O V; Voronina, S G; Tepikin, A V

    2006-06-01

    In the board game 'Snakes and Ladders', placed on the image of a pancreatic acinar cell, calcium ions have to move from release sites in the secretory region to the nucleus. There is another important contraflow - from calcium entry channels in the basal part of the cell to ER (endoplasmic reticulum) terminals in the secretory granule region. Both transport routes are perilous as the messenger can disappear in any place on the game board. It can be grabbed by calcium ATPases of the ER (masquerading as a snake but functioning like a ladder) and tunnelled through its low buffering environment, it can be lured into the whirlpools of mitochondria uniporters and forced to regulate the tricarboxylic acid cycle, and it can be permanently placed inside the matrix of secretory granules and released only outside the cell. The organelles could trade calcium (e.g. from the ER to mitochondria and vice versa) almost depriving this ion the light of the cytosol and noble company of cytosolic calcium buffers. Altogether it is a rich and colourful story.

  9. Calcium ferrite formation from the thermolysis of calcium tris (maleato)

    For preparing calcium ferrite, calcium tris (maleato) ferrate(III) precursor was prepared by mixing aqueous solutions of iron(III) maleate, calcium maleate and maleic acid. Various physico-chemical techniques i.e. TG, DTG, DTA, Mössbauer, XRD, IR etc have been used to study the decomposition behaviour from ambient to ...

  10. ALM-FATES: Using dynamic vegetation and demography to capture changes in forest carbon cycling and competition at the global scale

    Holm, J. A.; Knox, R. G.; Koven, C.; Riley, W. J.; Bisht, G.; Fisher, R.; Christoffersen, B. O.; Dietze, M.; Chambers, J. Q.

    2017-12-01

    The inclusion of dynamic vegetation demography in Earth System Models (ESMs) has been identified as a critical step in moving ESMs towards more realistic representations of plant ecology and the processes that govern climatically important fluxes of carbon, energy, and water. Successful application of dynamic vegetation models, and process-based approaches to simulate plant demography, succession, and response to disturbances without climate envelopes at the global scale is a challenging endeavor. We integrated demographic processes using the Functionally-Assembled Terrestrial Ecosystem Simulator (FATES) in the newly developed ACME Land Model (ALM). We then use an ALM-FATES globally gridded simulation for the first time to investigate plant functional type (PFT) distributions and dynamic turnover rates. Initial global simulations successfully include six interacting and competing PFTs (ranging from tropical to boreal, evergreen, deciduous, needleleaf and broadleaf); including more PFTs is planned. Global maps of net primary productivity, leaf area index, and total vegetation biomass by ALM-FATES matched patterns and values when compared to CLM4.5-BGC and MODIS estimates. We also present techniques for PFT parameterization based on the Predictive Ecosystem Analyzer (PEcAn), field based turnover rates, improved PFT groupings based on trait-tradeoffs, and improved representation of multiple canopy positions. Finally, we applied the improved ALM-FATES model at a central Amazon tropical and western U.S. temperate sites and demonstrate improvements in predicted PFT size- and age-structure and regional distribution. Results from the Amazon tropical site investigate the ability and magnitude of a tropical forest to act as a carbon sink by 2100 with a doubling of CO2, while results from the temperate sites investigate the response of forest mortality with increasing droughts.

  11. A sensor for calcium uptake

    Collins, Sean; Meyer, Tobias

    2011-01-01

    Mitochondria — the cell’s power plants — increase their energy production in response to calcium signals in the cytoplasm. A regulator of the elusive mitochondrial calcium channel has now been identified. PMID:20844529

  12. Children's Bone Health and Calcium

    ... Twitter Pinterest Email Print Children's Bone Health and Calcium: Condition Information What is bone health and how ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  13. Calcium – how and why?

    Unknown

    biological processes because of its unusual physical and chemical properties. 1. History of calcium ... cellular roles of calcium has established the importance of this ion ..... Ca2+ ion, for example in regulating enzyme activity (Price. 1975 ...

  14. Carbon cycle

    Jaeger, J; Halbritter, G; Neumann-Hauf, G

    1982-05-01

    This report contains a review of literature on the subjects of the carbon cycle, the increase of the atmospheric CO/sub 2/ concentration and the possible impacts of an increased CO/sub 2/ concentration on the climate. In addition to this survey, the report discusses the questions that are still open and the resulting research needs. During the last twenty years a continual increase of the atmospheric carbon dioxide concentration by about 1-2 ppm per years has been observed. In 1958 the concentration was 315 ppm and this increased to 336 ppm in 1978. A rough estimate shows that the increase of the atmospheric carbon dioxide concentration is about half of the amount of carbon dioxide added to the atmosphere by the combustion of fossil fuels. Two possible sinks for the CO/sub 2/ released into the atmosphere are known: the ocean and the biota. The role of the biota is, however, unclear, since it can act both as a sink and as a source. Most models of the carbon cycle are one-dimensional and cannot be used for accurate predictions. Calculations with climate models have shown that an increased atmospheric CO/sub 2/ concentration leads to a warming of the earth's surface and lower atmosphere. Calculations show that a doubling of the atmospheric CO/sub 2/-concentration would lead to a net heating of the lower atmosphere and earth's surface by a global average of about 4 W m/sup -2/. Greater uncertainties arise in estimating the change in surface temperature resulting from this change in heating rate. It is estimated that the global average annual surface temperature would change between 1.5 and 4.5 K. There are, however, latitudinal and seasonal variations of the impact of increased CO/sub 2/ concentration. Other meteorological variables (e.g. precipitation, wind speed etc.) would also be changed. It appears that the impacts of the other products of fossil fuel combustion are unlikely to counteract the impacts of CO/sub 2/ on the climate.

  15. Solar Imagery - Chromosphere - Calcium

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of full-disk images of the sun in Calcium (Ca) II K wavelength (393.4 nm). Ca II K imagery reveal magnetic structures of the sun from about 500...

  16. Antenatal calcium intake in Malaysia.

    Mahdy, Zaleha Abdullah; Basri, Hashimah; Md Isa, Zaleha; Ahmad, Shuhaila; Shamsuddin, Khadijah; Mohd Amin, Rahmah

    2014-04-01

    To determine the adequacy of antenatal calcium intake in Malaysia, and the influencing factors. A cross-sectional study was conducted among postnatal women who delivered in two tertiary hospitals. Data were collected from antenatal cards, hospital documents and diet recall on daily milk and calcium intake during pregnancy. SPSS version 19.0 was used for statistical analyses. A total of 150 women were studied. The total daily calcium intake was 834 ± 43 mg (mean ± standard error of the mean), but the calcium intake distribution curve was skewed to the right with a median intake of 725 mg daily. When calcium intake from milk and calcium supplements was excluded, the daily dietary calcium intake was only 478 ± 25 mg. Even with inclusion of milk and calcium supplements, more than a third (n=55 or 36.7%) of the women consumed less than 600 mg calcium in their daily diet. The adequacy of daily calcium intake was not influenced by maternal age, ethnicity, income or maternal job or educational status as well as parity. The daily dietary calcium intake of the Malaysian antenatal population is far from adequate without the addition of calcium supplements and milk. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  17. The Plasma Membrane Calcium Pump

    Rasmussen, H.

    1983-01-01

    Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

  18. Uranium, its impact on the national and global energy mix; and its history, distribution, production, nuclear fuel-cycle, future, and relation to the environment

    Finch, Warren Irvin

    1997-01-01

    The many aspects of uranium, a heavy radioactive metal used to generate electricity throughout the world, are briefly described in relatively simple terms intended for the lay reader. An adequate glossary of unfamiliar terms is given. Uranium is a new source of electrical energy developed since 1950, and how we harness energy from it is explained. It competes with the organic coal, oil, and gas fuels as shown graphically. Uranium resources and production for the world are tabulated and discussed by country and for various energy regions in the United States. Locations of major uranium deposits and power reactors in the United States are mapped. The nuclear fuel-cycle of uranium for a typical light-water reactor is illustrated at the front end-beginning with its natural geologic occurrence in rocks through discovery, mining, and milling; separation of the scarce isotope U-235, its enrichment, and manufacture into fuel rods for power reactors to generate electricity-and at the back end-the reprocessing and handling of the spent fuel. Environmental concerns with the entire fuel cycle are addressed. The future of the use of uranium in new, simplified, 'passively safe' reactors for the utility industry is examined. The present resource assessment of uranium in the United States is out of date, and a new assessment could aid the domestic uranium industry.

  19. To Which Degree Does Sector Specific Standardization Make Life Cycle Assessments Comparable?—The Case of Global Warming Potential of Smartphones

    Anders S. G. Andrae

    2014-11-01

    Full Text Available Here attributional life cycle assessments (LCAs for the same smartphone model are presented by two different organizations (Orange, OGE and Huawei, HuW and the effect of different modeling approach is analyzed. A difference of around 32% (29.6 kg and 39.2 kg for CO2e baseline scores is found using same study object and sector specific LCA standard, however, different metrics, emission intensities, and LCA software programs. The CO2e difference is reduced to 12% (29.9 kg and 33.5 kg when OGE use HuW metrics for use phase power consumption and total mass, and when HuW use OGE metrics for gold mass and silicon die area. Further, a probability test confirms that present baseline climate change results, for one specific study object modeled with two largely different and independent LCA modeling approaches, are comparable if both use the European Telecommunications Standard Institute (ETSI LCA standard. The general conclusion is that the ETSI LCA standard strongly facilitates comparable CC results for technically comparable smartphone models. Moreover, thanks to the reporting requirements of ETSI LCA standard, a clear understanding of the differences between LCA modeling approaches is obtained. The research also discusses the magnitude of the CO2e reduction potential in the life cycle of smartphones.

  20. The Effects of Calcium-Vitamin D and Metformin on Polycystic Ovary Syndrome: A Pilot Study

    Batool Rashidi

    2009-06-01

    Conclusion: The effects of metformin and calcium-vitamin D in regulating the menstrual cycle suggest that they could also be effective for the treatment of anovulation and oligomenorrhea, with possible consequences for pregnancy rates in PCOS patients.

  1. A novel assessment of the role of land-use and land-cover change in the global carbon cycle, using a new Dynamic Global Vegetation Model version of the CABLE land surface model

    Haverd, Vanessa; Smith, Benjamin; Nieradzik, Lars; Briggs, Peter; Canadell, Josep

    2017-04-01

    In recent decades, terrestrial ecosystems have sequestered around 1.2 PgC y-1, an amount equivalent to 20% of fossil-fuel emissions. This land carbon flux is the net result of the impact of changing climate and CO2 on ecosystem productivity (CO2-climate driven land sink ) and deforestation, harvest and secondary forest regrowth (the land-use change (LUC) flux). The future trajectory of the land carbon flux is highly dependent upon the contributions of these processes to the net flux. However their contributions are highly uncertain, in part because the CO2-climate driven land sink and LUC components are often estimated independently, when in fact they are coupled. We provide a novel assessment of global land carbon fluxes (1800-2015) that integrates land-use effects with the effects of changing climate and CO2 on ecosystem productivity. For this, we use a new land-use enabled Dynamic Global Vegetation Model (DGVM) version of the CABLE land surface model, suitable for use in attributing changes in terrestrial carbon balance, and in predicting changes in vegetation cover and associated effects on land-atmosphere exchange. In this model, land-use-change is driven by prescribed gross land-use transitions and harvest areas, which are converted to changes in land-use area and transfer of carbon between pools (soil, litter, biomass, harvested wood products and cleared wood pools). A novel aspect is the treatment of secondary woody vegetation via the coupling between the land-use module and the POP (Populations Order Physiology) module for woody demography and disturbance-mediated landscape heterogeneity. Land-use transitions to and from secondary forest tiles modify the patch age distribution within secondary-vegetated tiles, in turn affecting biomass accumulation and turnover rates and hence the magnitude of the secondary forest sink. The resulting secondary forest patch age distribution also influences the magnitude of the secondary forest harvest and clearance fluxes

  2. A Study of the Abundance and 13C/12C Ratio of Atmospheric Carbon Dioxide to Advance the Scientific Understanding of Terrestrial Processes Regulating the Global Carbon Cycle

    Stephen C. Piper

    2005-10-15

    The primary goal of our research program, consistent with the goals of the U.S. Climate Change Science Program and funded by the terrestrial carbon processes (TCP) program of DOE, has been to improve understanding of changes in the distribution and cycling of carbon among the active land, ocean and atmosphere reservoirs, with particular emphasis on terrestrial ecosystems. Our approach is to systematically measure atmospheric CO2 to produce time series data essential to reveal temporal and spatial patterns. Additional measurements of the 13C/12C isotopic ratio of CO2 provide a basis for distinguishing organic and inorganic processes. To pursue the significance of these patterns further, our research also involved interpretations of the observations by models, measurements of inorganic carbon in sea water, and of CO2 in air near growing land plants.

  3. Life cycle assessment (LCA) as a decision-suppport tool for the evaluation of environmental impacts of site remediation on the global, regional and local scale

    Lemming, Gitte; Bulle, C.; Margni, Manuele

    2010-01-01

    Life cycle assessment (LCA) was used to compare the environment al impacts of three alternatives for remediating a TCE-contaminated site: (i) enhanced reductive dechlorination (ERD); (ii) in situ thermal desorption (ISTD) and (iii) excavation with off-site soil treatment. In addition......, the remediation alternatives were compared to a no action scenario, where only monitoring and natural attenuation takes place. A numerical reactive fracture model was used to predict the timeframes for the ERD and the no action scenarios. Moreover, the model was used to estimate the mass discharge of TCE...... of the LCA showed that of the three remediation methods compared, the ERD had the lowest total environmental impacts, even though it had significant primary impacts due to its long timeframe. The environmental impacts of ERD were comparable or only slightly higher than those of the no action scenario. ISTD...

  4. Voltage-Gated Calcium Channels

    Zamponi, Gerald Werner

    Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

  5. Calcium-deficiency assessment and biomarker identification by an integrated urinary metabonomics analysis

    2013-01-01

    Background Calcium deficiency is a global public-health problem. Although the initial stage of calcium deficiency can lead to metabolic alterations or potential pathological changes, calcium deficiency is difficult to diagnose accurately. Moreover, the details of the molecular mechanism of calcium deficiency remain somewhat elusive. To accurately assess and provide appropriate nutritional intervention, we carried out a global analysis of metabolic alterations in response to calcium deficiency. Methods The metabolic alterations associated with calcium deficiency were first investigated in a rat model, using urinary metabonomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and multivariate statistical analysis. Correlations between dietary calcium intake and the biomarkers identified from the rat model were further analyzed to confirm the potential application of these biomarkers in humans. Results Urinary metabolic-profiling analysis could preliminarily distinguish between calcium-deficient and non-deficient rats after a 2-week low-calcium diet. We established an integrated metabonomics strategy for identifying reliable biomarkers of calcium deficiency using a time-course analysis of discriminating metabolites in a low-calcium diet experiment, repeating the low-calcium diet experiment and performing a calcium-supplement experiment. In total, 27 biomarkers were identified, including glycine, oxoglutaric acid, pyrophosphoric acid, sebacic acid, pseudouridine, indoxyl sulfate, taurine, and phenylacetylglycine. The integrated urinary metabonomics analysis, which combined biomarkers with regular trends of change (types A, B, and C), could accurately assess calcium-deficient rats at different stages and clarify the dynamic pathophysiological changes and molecular mechanism of calcium deficiency in detail. Significant correlations between calcium intake and two biomarkers, pseudouridine (Pearson

  6. When Product Life Cycle Meets Customer Activity Cycle

    Tan, Adrian Ronald

    2007-01-01

    Manufacturing companies have traditionally focused their efforts on designing, developing and producing products to offer on the market. Today global competition and demands for greater company responsibility of products throughout their entire life cycle are driving manufacturing companies to sh...

  7. Contribution of fish to the marine inorganic carbon cycle.

    Wilson, R W; Millero, F J; Taylor, J R; Walsh, P J; Christensen, V; Jennings, S; Grosell, M

    2009-01-16

    Oceanic production of calcium carbonate is conventionally attributed to marine plankton (coccolithophores and foraminifera). Here we report that marine fish produce precipitated carbonates within their intestines and excrete these at high rates. When combined with estimates of global fish biomass, this suggests that marine fish contribute 3 to 15% of total oceanic carbonate production. Fish carbonates have a higher magnesium content and solubility than traditional sources, yielding faster dissolution with depth. This may explain up to a quarter of the increase in titratable alkalinity within 1000 meters of the ocean surface, a controversial phenomenon that has puzzled oceanographers for decades. We also predict that fish carbonate production may rise in response to future environmental changes in carbon dioxide, and thus become an increasingly important component of the inorganic carbon cycle.

  8. Calcium, essential for health

    Martínez de Victoria, Emilio

    2016-07-12

    Calcium (Ca) is the most abundant mineral element in our body. It accounts for about 2% of body weight. The functions of calcium are: a) functions skeletal and b) regulatory functions. Bone consists of a protein matrix that mineralizes mainly with calcium (the most abundant), phosphate and magnesium, for it is essential an adequate dietary intake of Ca, phosphorus and vitamin D. The ionic Ca (Ca2+) is essential to maintain and / or perform different specialized functions of, virtually, all body cells cellular. Because of its important functions Ca2+ must be closely regulated, keeping plasma concentrations within narrow ranges. For this reason there is an accurate response against hypocalcemia or hypercalcemia in which the parathormone, calcitriol, calcitonin and vitamin K are involved. Ca intakes in the Spanish population are low in a significant percentage of the older adult’s population, especially in women. The main source of Ca in the diet is milk and milk derivatives. Green leafy vegetables, fruits and legumes can be important sources of Ca in a Mediterranean dietary pattern. The bioavailability of dietary Ca depends on physiological and dietary factors. Physiological include age, physiological status (gestation and lactation) Ca and vitamin D status and disease. Several studies relate Ca intake in the diet and various diseases, such as osteoporosis, cancer, cardiovascular disease and obesity.

  9. Models of calcium signalling

    Dupont, Geneviève; Kirk, Vivien; Sneyd, James

    2016-01-01

    This book discusses the ways in which mathematical, computational, and modelling methods can be used to help understand the dynamics of intracellular calcium. The concentration of free intracellular calcium is vital for controlling a wide range of cellular processes, and is thus of great physiological importance. However, because of the complex ways in which the calcium concentration varies, it is also of great mathematical interest.This book presents the general modelling theory as well as a large number of specific case examples, to show how mathematical modelling can interact with experimental approaches, in an interdisciplinary and multifaceted approach to the study of an important physiological control mechanism. Geneviève Dupont is FNRS Research Director at the Unit of Theoretical Chronobiology of the Université Libre de Bruxelles;Martin Falcke is head of the Mathematical Cell Physiology group at the Max Delbrück Center for Molecular Medicine, Berlin;Vivien Kirk is an Associate Professor in the Depar...

  10. Sulfur cycle

    LokaBharathi, P.A.

    Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

  11. Importance of disturbance history on net primary productivity in the world's most productive forests and implications for the global carbon cycle.

    Volkova, Liubov; Roxburgh, Stephen H; Weston, Christopher J; Benyon, Richard G; Sullivan, Andrew L; Polglase, Philip J

    2018-05-14

    Analysis of growth and biomass turnover in natural forests of Eucalyptus regnans, the world's tallest angiosperm, reveals it is also the world's most productive forest type, with fire disturbance an important mediator of net primary productivity (NPP). A comprehensive empirical database was used to calculate the averaged temporal pattern of NPP from regeneration to 250 years age. NPP peaks at 23.1 ± 3.8 (95% interquantile range) Mg C ha -1  year -1 at age 14 years, and declines gradually to about 9.2 ± 0.8 Mg C ha -1  year -1 at 130 years, with an average NPP over 250 years of 11.4 ± 1.1 Mg C ha -1  year -1 , a value similar to the most productive temperate and tropical forests around the world. We then applied the age-class distribution of E. regnans resulting from relatively recent historical fires to estimate current NPP for the forest estate. Values of NPP were 40% higher (13 Mg C ha -1  year -1 ) than if forests were assumed to be at maturity (9.2 Mg C ha -1  year -1 ). The empirically derived NPP time series for the E. regnans estate was then compared against predictions from 21 global circulation models, showing that none of them had the capacity to simulate a post-disturbance peak in NPP, as found in E. regnans. The potential importance of disturbance impacts on NPP was further tested by applying a similar approach to the temperate forests of conterminous United States and of China. Allowing for the effects of disturbance, NPP summed across both regions was on average 11% (or 194 Tg C/year) greater than if all forests were assumed to be in a mature state. The results illustrate the importance of accounting for past disturbance history and growth stage when estimating forest primary productivity, with implications for carbon balance modelling at local to global scales. © 2018 John Wiley & Sons Ltd.

  12. Determination of percent calcium carbonate in calcium chromate

    Middleton, H.W.

    1979-01-01

    The precision, accuracy and reliability of the macro-combustion method is superior to the Knorr alkalimetric method, and it is faster. It also significantly reduces the calcium chromate waste accrual problem. The macro-combustion method has been adopted as the official method for determination of percent calcium carbonate in thermal battery grade anhydrous calcium chromate and percent calcium carbonate in quicklime used in the production of calcium chromate. The apparatus and procedure can be used to measure the percent carbonate in inorganic materials other than calcium chromate. With simple modifications in the basic apparatus and procedure, the percent carbon and hydrogen can be measured in many organic material, including polymers and polymeric formulations. 5 figures, 5 tables

  13. Oxalate secretion by ectomycorrhizal Paxillus involutus is mineral-specific and controls calcium weathering from minerals

    Schmalenberger, A.; Duran, A. L.; Bray, A. W.; Bridge, J.; Bonneville, S.; Benning, L. G.; Romero-Gonzalez, M. E.; Leake, J. R.; Banwart, S. A.

    2015-01-01

    Trees and their associated rhizosphere organisms play a major role in mineral weathering driving calcium fluxes from the continents to the oceans that ultimately control long-term atmospheric CO2 and climate through the geochemical carbon cycle. Photosynthate allocation to tree roots and their mycorrhizal fungi is hypothesized to fuel the active secretion of protons and organic chelators that enhance calcium dissolution at fungal-mineral interfaces. This was tested using 14CO2 supplied to shoots of Pinus sylvestris ectomycorrhizal with the widespread fungus Paxillus involutus in monoxenic microcosms, revealing preferential allocation by the fungus of plant photoassimilate to weather grains of limestone and silicates each with a combined calcium and magnesium content of over 10 wt.%. Hyphae had acidic surfaces and linear accumulation of weathered calcium with secreted oxalate, increasing significantly in sequence: quartz, granite mineral-specific oxalate exudation in ectomycorrhizal weathering to dissolve calcium bearing minerals, thus contributing to the geochemical carbon cycle. PMID:26197714

  14. Calcium oxalate stone and gout.

    Marickar, Y M Fazil

    2009-12-01

    Gout is well known to be produced by increased uric acid level in blood. The objective of this paper is to assess the relationship between gout and calcium oxalate stone formation in the humans. 48 patients with combination of gout and calcium oxalate stone problem were included. The biochemical values of this group were compared with 38 randomly selected uric acid stone patients with gout, 43 stone patients with gout alone, 100 calcium oxalate stone patients without gout and 30 controls, making a total of 259 patients. Various biochemical parameters, namely serum calcium, phosphorus and uric acid and 24-h urine calcium, phosphorus, uric acid, oxalate, citrate and magnesium were analysed. ANOVA and Duncan's multiple-range tests were performed to assess statistical significance of the variations. The promoters of stone formation, namely serum calcium (P stone patients and gouty calcium oxalate stone patients compared to the non-gouty patients and controls. Urine oxalate (P stones patients. The inhibitor urine citrate (P stone gouty patients, followed by the gouty uric acid stone formers and gouty calcium oxalate stone patients. The high values of promoters, namely uric acid and calcium in the gouty stone patients indicate the tendency for urinary stone formation in the gouty stone patients. There is probably a correlation between gout and calcium oxalate urinary stone. We presume this mechanism is achieved through the uric acid metabolism. The findings point to the summation effect of metabolic changes in development of stone disease.

  15. Calcium Signaling in Taste Cells

    Medler, Kathryn F.

    2014-01-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. PMID:25450977

  16. The potential of fission nuclear power in resolving global climate change under the constraints of nuclear fuel resources and once-through fuel cycles

    Knapp, Vladimir; Pevec, Dubravko; Matijevic, Mario

    2010-01-01

    Nuclear fission is receiving new attention as a developed source of carbon-free energy. A much larger number of nuclear reactors would be needed for a major impact on carbon emission. The crucial question is whether it can be done without increasing the risk of nuclear proliferation. Specifically, can a larger nuclear share in world energy production, well above the present 6%, be achieved in the next few decades without adding the proliferation-sensitive technologies of reprocessing spent fuel and recycling plutonium to the problems of the unavoidable use of enrichment technology? The answer depends on the available uranium resources. We first looked for the maximum possible nuclear build-up in the 2025-2065 period under the constraints of the estimated uranium resources and the use of once-through nuclear fuel technology. Our results show that nuclear energy without reprocessing could reduce carbon emission by 39.6% of the total reduction needed to bring the WEO 2009 Reference Scenario prediction of total GHG emissions in 2065 to the level of the WEO 450 Scenario limiting global temperature increase to 2 deg. C. The less demanding strategy of the nuclear replacement of all non-CCS coal power plants retiring during the 2025-2065 period would reduce emission by 26.1%.

  17. EDDY RESOLVING NUTRIENT ECODYNAMICS IN THE GLOBAL PARALLEL OCEAN PROGRAM AND CONNECTIONS WITH TRACE GASES IN THE SULFUR, HALOGEN AND NMHC CYCLES

    S. CHU; S. ELLIOTT

    2000-08-01

    Ecodynamics and the sea-air transfer of climate relevant trace gases are intimately coupled in the oceanic mixed layer. Ventilation of species such as dimethyl sulfide and methyl bromide constitutes a key linkage within the earth system. We are creating a research tool for the study of marine trace gas distributions by implementing coupled ecology-gas chemistry in the high resolution Parallel Ocean Program (POP). The fundamental circulation model is eddy resolving, with cell sizes averaging 0.15 degree (lat/long). Here we describe ecochemistry integration. Density dependent mortality and iron geochemistry have enhanced agreement with chlorophyll measurements. Indications are that dimethyl sulfide production rates must be adjusted for latitude dependence to match recent compilations. This may reflect the need for phytoplankton to conserve nitrogen by favoring sulfurous osmolytes. Global simulations are also available for carbonyl sulfide, the methyl halides and for nonmethane hydrocarbons. We discuss future applications including interaction with atmospheric chemistry models, high resolution biogeochemical snapshots and the study of open ocean fertilization.

  18. The acid and alkalinity budgets of weathering in the Andes-Amazon system: Insights into the erosional control of global biogeochemical cycles

    Torres, Mark A.; West, A. Joshua; Clark, Kathryn E.; Paris, Guillaume; Bouchez, Julien; Ponton, Camilo; Feakins, Sarah J.; Galy, Valier; Adkins, Jess F.

    2016-09-01

    The correlation between chemical weathering fluxes and denudation rates suggests that tectonic activity can force variations in atmospheric pCO2 by modulating weathering fluxes. However, the effect of weathering on pCO2 is not solely determined by the total mass flux. Instead, the effect of weathering on pCO2 also depends upon the balance between 1) alkalinity generation by carbonate and silicate mineral dissolution and 2) sulfuric acid generation by the oxidation of sulfide minerals. In this study, we explore how the balance between acid and alkalinity generation varies with tectonic uplift to better understand the links between tectonics and the long-term carbon cycle. To trace weathering reactions across the transition from the Peruvian Andes to the Amazonian foreland basin, we measured a suite of elemental concentrations (Na, K, Ca, Mg, Sr, Si, Li, SO4, and Cl) and isotopic ratios (87Sr/86Sr and δ34S) on both dissolved and solid phase samples. Using an inverse model, we quantitatively link systematic changes in solute geochemistry with elevation to downstream declines in sulfuric acid weathering as well as the proportion of cations sourced from silicates. With a new carbonate-system framework, we show that weathering in the Andes Mountains is a CO2 source whereas foreland weathering is a CO2 sink. These results are consistent with the theoretical expectation that the ratio of sulfide oxidation to silicate weathering increases with increasing erosion. Altogether, our results suggest that the effect of tectonically-enhanced weathering on atmospheric pCO2 is strongly modulated by sulfide mineral oxidation.

  19. Effects of gender, digit ratio, and menstrual cycle on intrinsic brain functional connectivity: A whole-brain, voxel-wise exploratory study using simultaneous local and global functional connectivity mapping.

    Donishi, Tomohiro; Terada, Masaki; Kaneoke, Yoshiki

    2018-01-01

    Gender and sex hormones influence brain function, but their effects on functional network organization within the brain are not yet understood. We investigated the influence of gender, prenatal sex hormones (estimated by the 2D:4D digit ratio), and the menstrual cycle on the intrinsic functional network organization of the brain (as measured by 3T resting-state functional MRI (rs-fMRI)) using right-handed, age-matched university students (100 males and 100 females). The mean (± SD ) age was 20.9 ± 1.5 (range: 18-24) years and 20.8 ± 1.3 (range: 18-24) years for males and females, respectively. Using two parameters derived from the normalized alpha centrality analysis (one for local and another for global connectivity strength), we created mean functional connectivity strength maps. There was a significant difference between the male mean map and female mean map in the distributions of network properties in almost all cortical regions and the basal ganglia but not in the medial parietal, limbic, and temporal regions and the thalamus. A comparison between the mean map for the low 2D:4D digit ratio group (indicative of high exposure to testosterone during the prenatal period) and that for the high 2D:4D digit ratio group revealed a significant difference in the network properties of the medial parietal region for males and in the temporal region for females. The menstrual cycle affected network organization in the brain, which varied with the 2D:4D digit ratio. Most of these findings were reproduced with our other datasets created with different preprocessing steps. The results suggest that differences in gender, prenatal sex hormone exposure, and the menstrual cycle are useful for understanding the normal brain and investigating the mechanisms underlying the variable prevalence and symptoms of neurological and psychiatric diseases.

  20. Relação cálcio:fósforo disponível e níveis de fitase para poedeiras semipesadas no primeiro e segundo ciclos de postura Calcium:available phosphorus ratio and phytase levels for semi heavy laying hens in the first and second posture cycle

    José Humberto Vilar da Silva

    2008-12-01

    ções deficientes em fósforo disponível com 600 UF melhora o peso dos ovos no segundo ciclo de postura.Two experiments were carried out to investigate the calcium (Ca:available phosphorus (aP ratio and the level of phytase in the first and second posture cycle. In the first posture cycle, 128 birds were distributed to a 3 × 2 + 1 factorial arrangement, composed of three Ca:aP ratio [14:1 (4.2% Ca and 0.30% aP, 12:1 (3.5% Ca and 0.30% aP, and 9:1 (3.5% Ca and 0.38% aP], two levels of phytase (0 and 600 Phytase Units - PU and a Ca:aP control [11:1 (4.2% Ca and 0.38% aP]. In the second posture cycle, 240 birds were distributed to a 2 × 2 × 2 factorial arrangement, composed of two Ca (3.5 and 4.2%, two aP (0.30 and 0.38% levels and two phytase levels (0 and 600 PU. In the first posture cycle, among birds fed diets without phytase, the greater eggs weight was obtained with 9:1 Ca:aP ratio and the smaller, with 12:1 Ca:aP ratio. The best eggs mass and feed conversion by eggs mass (FCEM were observed in birds fed a diet with 14:1 Ca:Pd ratio and worse, with the ration with 12:1 Ca:aP ratio. In birds fed diet with phytase, the best FCEM was obtained with 12:1 Ca:aP ratio and worse, with 9:1 Ca:aP ratio. In the second posture cycle, the diet consumption decreased with increasing levels of calcium (3.5 to 4.2%, available phosphorus (0.30 to 0.38% and phytase (0 to 600 PU. Feed conversion by eggs mass or per dozen eggs improved, respectively, with increasing levels of available phosphorus and phytase, while specific gravity improved with the increase of dietary calcium level. For laying hens in the first posture cycle, it is recommended 14:1 (4.2% Ca:0.30% Pd ratio without phytase and 12:1 (3.5% Ca:0.30% Pd ratio with 600 PU and, for birds in the second posture cycle, it is recommended 14:1 (4.2% Ca and 0.38% Pd ratio. The supplementation of diets deficient in available phosphorus with 600 PU improves egg weight in the second posture cycle.

  1. Cardiovascular Effects of Calcium Supplements

    Ian R. Reid

    2013-07-01

    Full Text Available Calcium supplements reduce bone turnover and slow the rate of bone loss. However, few studies have demonstrated reduced fracture incidence with calcium supplements, and meta-analyses show only a 10% decrease in fractures, which is of borderline statistical and clinical significance. Trials in normal older women and in patients with renal impairment suggest that calcium supplements increase the risk of cardiovascular disease. To further assess their safety, we recently conducted a meta-analysis of trials of calcium supplements, and found a 27%–31% increase in risk of myocardial infarction, and a 12%–20% increase in risk of stroke. These findings are robust because they are based on pre-specified analyses of randomized, placebo-controlled trials and are consistent across the trials. Co-administration of vitamin D with calcium does not lessen these adverse effects. The increased cardiovascular risk with calcium supplements is consistent with epidemiological data relating higher circulating calcium concentrations to cardiovascular disease in normal populations. There are several possible pathophysiological mechanisms for these effects, including effects on vascular calcification, vascular cells, blood coagulation and calcium-sensing receptors. Thus, the non-skeletal risks of calcium supplements appear to outweigh any skeletal benefits, and are they appear to be unnecessary for the efficacy of other osteoporosis treatments.

  2. SIGNIFICANCE OF THE CALCIUM DEFICIT IN PEDIATRICS AND WAYS TO CORRECT IT

    O.A. Gromova

    2007-01-01

    Full Text Available Calcium takes an active part in provision and development of the motion function (tractions, transmission of the neural impulse, muscle reactions to the neural excitement, change of the hormone activity, realizing together with adenylate cyclase. But no less important is the calcium role in participation of the supporting tissue buildup, organization of the integral child's skeletal system, in which there is 99% of the body calcium. This is a sort of depot, in which the element is in the dynamic equilibrium with its level in blood. The skeletal system acts as a buffer to support the stable level of the calcium circulation in the course of the entire life cycle. The calcium deficit among children should fully be treated, frequently conducting therapy of the accompanied pathology of the gastrointestinal tract, liver and intestinal dysbiosis. We should exclude the hereditary pathology of the calcium exchange. For the usual growth of the human body and prevention of the senile osteoporosis, the necessary amount of calcium consumption should be provided from the very childhood of a person. For the prevention and treatment of the calcium deficit among children, we use specific calcium medications together with phosphorus, magnesium, microelements and vitamins tested in clinical practice and approved by the union of pediatricians of Russia.Key words: calcium, deficit of major mineral elements, treatment, prevention, children.

  3. SR calcium handling and calcium after-transients in a rabbit model of heart failure

    Baartscheer, Antonius; Schumacher, Cees A.; Belterman, Charly N. W.; Coronel, Ruben; Fiolet, Jan W. T.

    2003-01-01

    Objective: After-depolarization associated arrhythmias are frequently observed in heart failure and associated with spontaneous calcium release from sarcoplasmic reticulum (SR), calcium after-transients. We hypothesize that disturbed SR calcium handling underlies calcium after-transients in heart

  4. Effects of dietary bread crust Maillard reaction products on calcium and bone metabolism in rats.

    Roncero-Ramos, Irene; Delgado-Andrade, Cristina; Haro, Ana; Ruiz-Roca, Beatriz; Morales, Francisco J; Navarro, María Pilar

    2013-06-01

    Maillard reaction products (MRP) consumption has been related with the development of bone degenerative disorders, probably linked to changes in calcium metabolism. We aimed to investigate the effects of MRP intake from bread crust on calcium balance and its distribution, and bone metabolism. During 88 days, rats were fed control diet or diets containing bread crust as source of MRP, or its soluble high molecular weight, soluble low molecular weight or insoluble fractions (bread crust, HMW, LMW and insoluble diets, respectively). In the final week, a calcium balance was performed, then animals were sacrified and some organs removed to analyse calcium levels. A second balance was carried out throughout the experimental period to calculate global calcium retention. Biochemical parameters and bone metabolism markers were measured in serum or urine. Global calcium bioavailability was unmodified by consumption of bread crust or its isolate fractions, corroborating the previously described low affinity of MRP to bind calcium. Despite this, a higher calcium concentration was found in femur due to smaller bones having a lower relative density. The isolate consumption of the fractions altered some bone markers, reflecting a situation of increased bone resorption or higher turnover; this did not take place in the animals fed the bread crust diet. Thus, the bread crust intake does not affect negatively calcium bioavailability and bone metabolism.

  5. Global Carbon Budget 2016

    Le Quéré, Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Ivar Korsbakken, Jan; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian A; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M S; Munro, David R.; Nabel, Julia E M S; Nakaoka, Shin Ichiro; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; Van Der Laan-Luijkx, Ingrid T.; Van Der Werf, Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

    2016-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere-the "global carbon budget"-is important to better understand the global carbon cycle, support the development of climate policies, and project future

  6. Global Carbon Budget 2016

    Quéré, Le Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Korsbakken, Jan Ivar; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M.S.; Munro, David R.; Nabel, Julia E.M.S.; Nakaoka, S.; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; Laan-Luijkx, van der Ingrid T.; Werf, van der Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

    2016-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project

  7. 21 CFR 573.240 - Calcium periodate.

    2010-04-01

    ... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...

  8. 21 CFR 573.260 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium silicate. 573.260 Section 573.260 Food and... Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely used as an anticaking agent in animal feed, provided that the amount of calcium silicate does not...

  9. Viral lysis of photosynthesizing microbes as a mechanism for calcium carbonate nucleation in seawater

    Lisle, John T.; Robbins, Lisa L.

    2016-01-01

    Removal of carbon through the precipitation and burial of calcium carbonate in marine sediments constitutes over 70% of the total carbon on Earth and is partitioned between coastal and pelagic zones. The precipitation of authigenic calcium carbonate in seawater, however, has been hotly debated because despite being in a supersaturated state, there is an absence of persistent precipitation. One of the explanations for this paradox is the geochemical conditions in seawater cannot overcome the activation energy barrier for the first step in any precipitation reaction; nucleation. Here we show that virally induced rupturing of photosynthetic cyanobacterial cells releases cytoplasmic-associated bicarbonate at concentrations ~23-fold greater than in the surrounding seawater, thereby shifting the carbonate chemistry toward the homogenous nucleation of one or more of the calcium carbonate polymorphs. Using geochemical reaction energetics, we show the saturation states (Ω) in typical seawater for calcite (Ω = 4.3), aragonite (Ω = 3.1), and vaterite (Ω = 1.2) are significantly elevated following the release and diffusion of the cytoplasmic bicarbonate (Ωcalcite = 95.7; Ωaragonite = 68.5; Ωvaterite = 25.9). These increases in Ω significantly reduce the activation energy for nuclei formation thresholds for all three polymorphs, but only vaterite nucleation is energetically favored. In the post-lysis seawater, vaterite's nuclei formation activation energy is significantly reduced from 1.85 × 10−17 J to 3.85 × 10−20 J, which increases the nuclei formation rate from highly improbable (seawater describes a mechanism through which the initial step in the production of carbonate sediments may proceed. It also presents an additional role of photosynthesizing microbes and their viruses in marine carbon cycles and reveals these microorganisms are a collective repository for concentrated and reactive dissolved inorganic carbon (DIC) that is currently not accounted for

  10. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt... FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.330 Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may...

  11. The Effects of Dietary Calcium and/or Iron Deficiency upon Murine Intestinal Calcium Binding Protein Activity and Calcium Absorption

    McDonald, Catherine M.

    1980-01-01

    Iron deficiency has been shown to impair calcium absorption, leading to decreased bone mass. Vitamin D3-dependent calcium binding protein (CaBP) has been demonstrated to be necessary for the active transport of calcium in the intestine of numerous species. Iron deficiency might affect the activity of the calcium binding protein. Four experimental diets were formulated as follows: Diet 1, iron adequate, calcium adequate; Diet 2, iron deficient, calcium adequate; Diet 3, iron adequate, calci...

  12. Alternative ORC bottoming cycles FOR combined cycle power plants

    Chacartegui, R.; Sanchez, D.; Munoz, J.M.; Sanchez, T.

    2009-01-01

    In this work, low temperature Organic Rankine Cycles are studied as bottoming cycle in medium and large scale combined cycle power plants. The analysis aims to show the interest of using these alternative cycles with high efficiency heavy duty gas turbines, for example recuperative gas turbines with lower gas turbine exhaust temperatures than in conventional combined cycle gas turbines. The following organic fluids have been considered: R113, R245, isobutene, toluene, cyclohexane and isopentane. Competitive results have been obtained for toluene and cyclohexane ORC combined cycles, with reasonably high global efficiencies. The paper is structured in four main parts. A review of combined cycle and ORC cycle technologies is presented, followed by a thermodynamic analysis of combined cycles with commercial gas turbines and ORC low temperature bottoming cycles. Then, a parametric optimization of an ORC combined cycle plant is performed in order to achieve a better integration between these two technologies. Finally, some economic considerations related to the use of ORC in combined cycles are discussed.

  13. Calcium, vitamin D, and your bones

    ... page: //medlineplus.gov/ency/patientinstructions/000490.htm Calcium, vitamin D, and your bones To use the sharing ... and maintain strong bones. How Much Calcium and Vitamin D do I Need? Amounts of calcium are ...

  14. Calcium Supplements: Do Men Need Them Too?

    ... Lifestyle Nutrition and healthy eating Should men take calcium supplements? Answers from Katherine Zeratsky, R.D., L. ... Most healthy men don't need to take calcium supplements. Calcium is important for men for optimal ...

  15. Calcium transport in turtle bladder

    Sabatini, S.; Kurtzman, N.A.

    1987-01-01

    Unidirectional 45 Ca fluxes were measured in the turtle bladder under open-circuit and short-circuit conditions. In the open-circuited state net calcium flux (J net Ca ) was secretory (serosa to mucosa). Ouabain reversed J net Ca to an absorptive flux. Amiloride reduced both fluxes such that J net Ca was not significantly different from zero. Removal of mucosal sodium caused net calcium absorption; removal of serosal sodium caused calcium secretion. When bladders were short circuited, J net Ca decreased to approximately one-third of control value but remained secretory. When ouabain was added under short-circuit conditions, J net Ca was similar in magnitude and direction to ouabain under open-circuited conditions (i.e., absorptive). Tissue 45 Ca content was ≅30-fold lower when the isotope was placed in the mucosal bath, suggesting that the apical membrane is the resistance barrier to calcium transport. The results obtained in this study are best explained by postulating a Ca 2+ -ATPase on the serosa of the turtle bladder epithelium and a sodium-calcium antiporter on the mucosa. In this model, the energy for calcium movement would be supplied, in large part, by the Na + -K + -ATPase. By increasing cell sodium, ouabain would decrease the activity of the mucosal sodium-calcium exchanger (or reverse it), uncovering active calcium transport across the serosa

  16. Calcium chromate process related investigations

    Dillard, B.M.

    1979-01-01

    A pilot plant for production of calcium chromate has been scaled up to a small production facility at the General Electric Neutron Devices Department. In preparation for this scale-up, the process and final product were studied in order to evaluate problems not considered previously. The variables and processes studied included: (1) the determination of optimum drying temperature and time for product analysis; (2) the effect of the grade of lime used as the precipitating agent on the purity of the calcium chromate; (3) product purity when calcium chromate is precipitated by the addition of ammonium chromate to slaked lime; (4) the reagents best suited for cleaning calcium chromate spills; and (5) methods for determining hydroxide ion concentration in calcium chromate. The optimum drying time for the product before analysis is four hours at 600 0 C. Gases evolved at various temperatures during the drying process were carbon dioxide and water vapor. Technical grade lime produced calcium chromate of the highest purity. Both nitric and acetic acids were efficient dissolvers of calcium chromate spills. Direct titration of hydroxide ion with sulfuric acid gave an average recovery of 93% for samples spiked with calcium hydroxide. 1 figure, 17 tables

  17. closed cycle solar refrigeration with the calcium chloride system

    user

    1986-09-01

    Sep 1, 1986 ... condenser with porous sandcrete wall, which produced condenser water temperatures varying from ... generation and condensation. .... during this heat up period amounted to 40 - 50% ... would be transferred to the absorbent.

  18. Whole-genome analysis of mRNA decay in Plasmodium falciparum reveals a global lengthening of mRNA half-life during the intra-erythrocytic development cycle.

    Shock, Jennifer L; Fischer, Kael F; DeRisi, Joseph L

    2007-01-01

    The rate of mRNA decay is an essential element of post-transcriptional regulation in all organisms. Previously, studies in several organisms found that the specific half-life of each mRNA is precisely related to its physiologic role, and plays an important role in determining levels of gene expression. We used a genome-wide approach to characterize mRNA decay in Plasmodium falciparum. We found that, globally, rates of mRNA decay increase dramatically during the asexual intra-erythrocytic developmental cycle. During the ring stage of the cycle, the average mRNA half-life was 9.5 min, but this was extended to an average of 65 min during the late schizont stage of development. Thus, a major determinant of mRNA decay rate appears to be linked to the stage of intra-erythrocytic development. Furthermore, we found specific variations in decay patterns superimposed upon the dominant trend of progressive half-life lengthening. These variations in decay pattern were frequently enriched for genes with specific cellular functions or processes. Elucidation of Plasmodium mRNA decay rates provides a key element for deciphering mechanisms of genetic control in this parasite, by complementing and extending previous mRNA abundance studies. Our results indicate that progressive stage-dependent decreases in mRNA decay rate function are a major determinant of mRNA accumulation during the schizont stage of intra-erythrocytic development. This type of genome-wide change in mRNA decay rate has not been observed in any other organism to date, and indicates that post-transcriptional regulation may be the dominant mechanism of gene regulation in P. falciparum.

  19. Calcium-responsive contractility during fertilization in sea urchin eggs.

    Stack, Christianna; Lucero, Amy J; Shuster, Charles B

    2006-04-01

    Fertilization triggers a reorganization of oocyte cytoskeleton, and in sea urchins, there is a dramatic increase in cortical F-actin. However, the role that myosin II plays during fertilization remains largely unexplored. Myosin II is localized to the cortical cytoskeleton both before and after fertilization and to examine myosin II contractility in living cells, Lytechinus pictus eggs were observed by time-lapse microscopy. Upon sperm binding, a cell surface deflection traversed the egg that was followed by and dependent on the calcium wave. The calcium-dependence of surface contractility could be reproduced in unfertilized eggs, where mobilization of intracellular calcium in unfertilized eggs under compression resulted in a marked contractile response. Lastly, inhibition of myosin II delayed absorption of the fertilization cone, suggesting that myosin II not only responds to the same signals that activate eggs but also participates in the remodeling of the cortical actomyosin cytoskeleton during the first zygotic cell cycle. (c) 2006 Wiley-Liss, Inc.

  20. Calcium carbonate production response to future ocean warming and acidification

    A. J. Pinsonneault

    2012-06-01

    Full Text Available Anthropogenic carbon dioxide (CO2 emissions are acidifying the ocean, affecting calcification rates in pelagic organisms, and thereby modifying the oceanic carbon and alkalinity cycles. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO2 and the resulting climate change. At the same time, ocean warming caused by rising CO2 is expected to drive increased growth rates of all pelagic organisms, including calcifiers. It thus remains unclear whether anthropogenic CO2 emissions will ultimately increase or decrease pelagic calcification rates. Here, we assess the importance of this uncertainty by introducing a dependence of calcium carbonate (CaCO3 production on calcite saturation state (ΩCaCO3 in an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of several variants of this dependence on global ocean carbon cycling between 1800 and 3500 under two different CO2 emissions scenarios. Introducing a calcification-saturation state dependence has a significant effect on the vertical and surface horizontal alkalinity gradients, as well as on the removal of alkalinity from the ocean through CaCO3 burial. These changes result in an additional oceanic uptake of carbon when calcification depends on ΩCaCO3 (of up to 270 Pg C, compared to the case where calcification does not depend on acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500. Different versions of the model produced varying results, and narrowing this range of uncertainty will require better understanding of both temperature and acidification effects on pelagic calcifiers. Nevertheless, our results suggest that alkalinity observations can be used

  1. Evolution of the Calcium Paradigm: The Relation between Vitamin D, Serum Calcium and Calcium Absorption

    Borje E. Christopher Nordin

    2010-09-01

    Full Text Available Osteoporosis is the index disease for calcium deficiency, just as rickets/osteomalacia is the index disease for vitamin D deficiency, but there is considerable overlap between them. The common explanation for this overlap is that hypovitaminosis D causes malabsorption of calcium which then causes secondary hyperparathyroidism and is effectively the same thing as calcium deficiency. This paradigm is incorrect. Hypovitaminosis D causes secondary hyperparathyroidism at serum calcidiol levels lower than 60 nmol/L long before it causes malabsorption of calcium because serum calcitriol (which controls calcium absorption is maintained until serum calcidiol falls below 20 nmol/L. This secondary hyperparathyroidism, probably due to loss of a “calcaemic” action of vitamin D on bone first described in 1957, destroys bone and explains why vitamin D insufficiency is a risk factor for osteoporosis. Vitamin D thus plays a central role in the maintenance of the serum (ionised calcium, which is more important to the organism than the preservation of the skeleton. Bone is sacrificed when absorbed dietary calcium does not match excretion through the skin, kidneys and bowel which is why calcium deficiency causes osteoporosis in experimental animals and, by implication, in humans.

  2. Bcl-2 overexpression: effects on transmembrane calcium movement

    Rangaswami, Arun A.; Premack, Brett; Walleczek, Jan; Killoran, Pamela; Gardner, Phyllis; Knox, Susan J.

    1996-01-01

    Purpose/Objective: High levels of expression of the proto-oncogene bcl-2 and its 26 kD protein product Bcl-2 have been correlated with the inhibition of apoptosis and the increased resistance of tumor cells to cytotoxic drugs and ionizing radiation. Unfortunately, the specific mechanism of action of Bcl-2 remains poorly understood. In the studies described here, the role of intracellular calcium fluxes and plasma membrane calcium cycling in the induction of apoptosis, and the effect of Bcl-2 expression on the modulation of transmembrane calcium fluxes following treatment of cells with cytotoxic agents were studied. The relationship between intracellular calcium release, capacitive calcium entry, and the plasma membrane potential were also investigated. Materials and Methods: Human B-cell lymphoma (PW) and human promyelocytic leukemia (HL60) cell lines were transfected with Bcl-2 and a control vector. The Bcl-2 transfectants over expressed the Bcl-2 onco-protein and were more resistant to irradiation than the control cells. Cells were loaded with fluorescent indicators indo-1 and fura-2 AM to quantify the cytosolic calcium concentration and subsequent calcium responses to a variety of cytotoxic stimuli, including the microsomal ATPase inhibitor, thapsigargin, using fluorometric measurements. Comparisons of resting and stimulated cytosolic calcium concentrations were made between the parental, neomycin control, and bcl-2 transfected cells. In order to determine the actual calcium influx rate, cells were loaded with either indo-1 or fura-2 and then exposed to 0.1 mM extracellular manganese, which enters the cells through calcium influx channels and quenches the fluorescent signal in proportion to the calcium influx rate. In order to determine the role of the membrane potential in driving calcium influx, cells were treated with either 0.1 μM Valinomycin or isotonic potassium chloride to either hyper polarize or depolarize the resting membrane potential, and the

  3. Theory of limit cycles

    Ye, Yan-Qian; Lo, Chi Y

    1986-01-01

    Over the past two decades the theory of limit cycles, especially for quadratic differential systems, has progressed dramatically in China as well as in other countries. This monograph, updating the 1964 first edition, includes these recent developments, as revised by eight of the author's colleagues in their own areas of expertise. The first part of the book deals with limit cycles of general plane stationary systems, including their existence, nonexistence, stability, and uniqueness. The second section discusses the global topological structure of limit cycles and phase-portraits of quadratic systems. Finally, the last section collects important results that could not be included under the subject matter of the previous two sections or that have appeared in the literature very recently. The book as a whole serves as a reference for college seniors, graduate students, and researchers in mathematics and physics.

  4. The mechanical environment modulates intracellular calcium oscillation activities of myofibroblasts.

    Charles Godbout

    Full Text Available Myofibroblast contraction is fundamental in the excessive tissue remodeling that is characteristic of fibrotic tissue contractures. Tissue remodeling during development of fibrosis leads to gradually increasing stiffness of the extracellular matrix. We propose that this increased stiffness positively feeds back on the contractile activities of myofibroblasts. We have previously shown that cycles of contraction directly correlate with periodic intracellular calcium oscillations in cultured myofibroblasts. We analyze cytosolic calcium dynamics using fluorescent calcium indicators to evaluate the possible impact of mechanical stress on myofibroblast contractile activity. To modulate extracellular mechanics, we seeded primary rat subcutaneous myofibroblasts on silicone substrates and into collagen gels of different elastic modulus. We modulated cell stress by cell growth on differently adhesive culture substrates, by restricting cell spreading area on micro-printed adhesive islands, and depolymerizing actin with Cytochalasin D. In general, calcium oscillation frequencies in myofibroblasts increased with increasing mechanical challenge. These results provide new insight on how changing mechanical conditions for myofibroblasts are encoded in calcium oscillations and possibly explain how reparative cells adapt their contractile behavior to the stresses occurring in normal and pathological tissue repair.

  5. Global perspective on the nuclear fuel cycle

    Wilcox, W.J. Jr.

    1977-01-01

    This review presents a general picture of the status of the various enrichment technologies around the world, reviews who is doing what, and gives a general idea of how the market for enrichment services is shaping up

  6. Glacial cycles

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...... to simulate glacial cycles accurately. Also, results suggest that non-linear 10 dynamics, threshold effects, and/or free oscillations may not play an overriding role in glacial cycles....

  7. Fuel cycles

    Hawley, N.J.

    1983-05-01

    AECL publications, from the open literature, on fuels and fuel cycles used in CANDU reactors are listed in this bibliography. The accompanying index is by subject. The bibliography will be brought up to date periodically

  8. Calcium and Calcium Supplements: Achieving the Right Balance

    ... may have on heart attack risk. A similar controversy surrounds calcium and prostate cancer. Some studies have ... your agreement to the Terms and Conditions and Privacy Policy linked below. Terms and Conditions Privacy Policy ...

  9. Calcium signals in olfactory neurons.

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  10. Global patterns of organic carbon export and sequestration in the ocean (Arne Richter Award for Outstanding Young Scientists)

    Henson, S.; Sanders, R.; Madsen, E.; Le Moigne, F.; Quartly, G.

    2012-04-01

    A major term in the global carbon cycle is the ocean's biological carbon pump which is dominated by sinking of small organic particles from the surface ocean to its interior. Here we examine global patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface ocean, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep ocean. This is achieved through extrapolating from in situ estimates of particulate organic carbon export to the global scale using satellite-derived data. Global scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper ocean, but uncorrelated with calcium carbonate export flux. We hypothesise that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper ocean, rather than the availability of calcium carbonate for ballasting. Finally, our estimate of global integrated carbon export is only 50% of previous estimates. The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains incomplete.

  11. Why Calcium? How Calcium Became the Best Communicator*

    Carafoli, Ernesto; Krebs, Joachim

    2016-01-01

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations,...

  12. Isomorfic Substitutions of Calcium by Strontium in Calcium Hydroxyapatite

    Christensen, Hilbert

    1962-12-01

    By means of homogeneous precipitation it has been possible to synthesize crystalline solid solutions of calcium strontium hydroxyapatite from aqueous solutions. The lattice constants for the solid solutions were measured in the range Ca 9 Sr(PO 4 ) 6 (OH) 2 - CaSr 9 (PO 4 ) 6 (OH) 2 . The investigations show that the discrimination of strontium against calcium is considerably smaller than reported elsewhere (1). Strontium is preferentially built into the c-axis direction of the apatite lattice

  13. Influence of dietary calcium on bone calcium utilization

    Farmer, M.; Roland, D.A. Sr.; Clark, A.J.

    1986-01-01

    In Experiment 1, 10 microCi 45 Ca/day were administered to 125 hens for 10 days. Hens were then allocated to five treatments with calcium levels ranging from .08 to 3.75% of the diet. In Experiment 2, hens with morning oviposition times were randomly allocated to 11 treatments that were periods of time postoviposition ranging from 6 hr to 24 hr, in 2-hr increments (Experiment 2). At the end of each 2-hr period, eggs from 25 hens were removed from the uterus. The 18-, 20-, and 22-hr treatments were replicated three times. In Experiment 3, hens were fed either ad libitum or feed was withheld the last 5 or 6 hr before oviposition. In Experiment 4, hens were fed 10 microCi of 45 Ca for 15 days to label skeletal calcium. Hens were divided into two groups and fed a .08 or 3.75% calcium diet for 2 days. On the second day, 25 hens fed the 3.75% calcium diet were intubated with 7 g of the same diet containing .5 g calcium at 1700, 2100, 0100, 0500, and 0700 hr. The measurements used were egg weight, shell weight, and 45 Ca content of the egg shell. Results indicated a significant linear or quadratic regression of dietary calcium levels on 45 Ca accumulation in eggshells and eggshell weight (Experiment 1). As the calcium level of the diet increased, eggshell weight increased and 45 Ca recovery decreased. Utilization of skeletal calcium for shell formation ranged from 28 to 96%. In Experiment 2, the rate of shell calcification was not constant throughout the calcification process but varied significantly

  14. 21 CFR 172.410 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

  15. A Crash Course in Calcium Channels.

    Zamponi, Gerald W

    2017-12-20

    Much progress has been made in understanding the molecular physiology and pharmacology of calcium channels. Recently, there have been tremendous advances in learning about calcium channel structure and function through crystallography and cryo-electron microscopy studies. Here, I will give an overview of our knowledge about calcium channels, and highlight two recent studies that give important insights into calcium channel structure.

  16. Calcium-sensing beyond neurotransmitters

    Gustavsson, Natalia; Han, Weiping

    2009-01-01

    Neurotransmitters, neuropeptides and hormones are released through the regulated exocytosis of SVs (synaptic vesicles) and LDCVs (large dense-core vesicles), a process that is controlled by calcium. Synaptotagmins are a family of type 1 membrane proteins that share a common domain structure. Most....... Also, we discuss potential roles of synaptotagmins in non-traditional endocrine systems....... synaptotagmins are located in brain and endocrine cells, and some of these synaptotagmins bind to phospholipids and calcium at levels that trigger regulated exocytosis of SVs and LDCVs. This led to the proposed synaptotagmin-calcium-sensor paradigm, that is, members of the synaptotagmin family function...... as calcium sensors for the regulated exocytosis of neurotransmitters, neuropeptides and hormones. Here, we provide an overview of the synaptotagmin family, and review the recent mouse genetic studies aimed at understanding the functions of synaptotagmins in neurotransmission and endocrine-hormone secretion...

  17. Calcium phosphates for biomedical applications

    Maria Canillas

    2017-05-01

    Full Text Available The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies.

  18. Functions of vitamin D / Calcium

    First page Back Continue Last page Overview Graphics. Excitation-contraction coupling,. Cardiac functions. Hormonal secretion. Control of enzymatic reactions. Mitotic division. Maintenance of cell integrity. Ciliary motility. Notes: Calcium is a vital second messenger.

  19. Calcium signals in planetary embryos

    Morbidelli, Alessandro

    2018-03-01

    The calcium-isotope composition of planetary bodies in the inner Solar System correlates with the masses of such objects. This finding could have implications for our understanding of how the Solar System formed.

  20. Calcium homeostasis in diabetes mellitus.

    Ahn, Changhwan; Kang, Ji-Houn; Jeung, Eui-Bae

    2017-09-30

    Diabetes mellitus (DM) is becoming a lifestyle-related pandemic disease. Diabetic patients frequently develop electrolyte disorders, especially diabetic ketoacidosis or nonketotic hyperglycemic hyperosmolar syndrome. Such patients show characteristic potassium, magnesium, phosphate, and calcium depletion. In this review, we discuss a homeostatic mechanism that links calcium and DM. We also provide a synthesis of the evidence in favor or against this linking mechanism by presenting recent clinical indications, mainly from veterinary research. There are consistent results supporting the use of calcium and vitamin D supplementation to reduce the risk of DM. Clinical trials support a marginal reduction in circulating lipids, and some meta-analyses support an increase in insulin sensitivity, following vitamin D supplementation. This review provides an overview of the calcium and vitamin D disturbances occurring in DM and describes the underlying mechanisms. Such elucidation will help indicate potential pathophysiology-based precautionary and therapeutic approaches and contribute to lowering the incidence of DM.