WorldWideScience

Sample records for iron enrichment experiments

  1. Bacterioplankton responses to iron enrichment during the SAGE experiment

    Science.gov (United States)

    Kuparinen, J.; Hall, J.; Ellwood, M.; Safi, K.; Peloquin, J.; Katz, D.

    2011-03-01

    We studied the microbial food web in the upper 100 m of the water column in iron-limited sub-Antarctic HNLC waters south-east of New Zealand in the SAGE experiment in 2004, with focus on bacterioplankton. Samples were collected daily from inside and outside the iron enriched patch. Short term enrichment experiments were conducted on board in 4 L polycarbonate bottles with water outside the iron enriched patch to study single and combined effects of micronutrient additions on microbial food web. Low bacterial growth was recorded in the study area with community turnover times of 50 h or more during the study period. Measurements of bacterial standing stocks and production rates in the study show minor responses to the large scale iron enrichment, with increase in rates and stocks after the first enrichment and at the end of the study period after the third iron enrichment when solar radiation increased and wind mixing decreased. The average daily bacterial production rates were 31.5 and 33.7 mgCm -2 d -1 for the OUT and IN stations, respectively; thus overall there was not a significant difference between the control and the iron-enriched patch. In the bottle experiments bacterial thymidine incorporation showed responses to single iron and silicic acid enrichments and a major growth response to the combined iron and sucrose enrichments. Phytoplankton chlorophyll- a showed clear stimulation by single additions of iron and silicic acid and silicic acid enhanced the iron impact. Cobalt additions had no effect on bacteria growth and a negative effect on phytoplankton growth. Low bacterial in situ growth rates and the enrichment experiments suggest that bacteria are co-limited by iron and carbon, and that bacterial iron uptake is dependent on carbon supply by the food web. With the high iron quota (μmol Fe mol C -1) bacteria may scavenge considerable amounts of the excess iron, and thus influence the relative importance of the microbial food web as a carbon sink.

  2. Changes in the concentration of iron in different size fractions during an iron enrichment experiment in the open Southern Ocean

    NARCIS (Netherlands)

    Nishioka, Jun; Takeda, Shigenobu; Baar, Hein J.W. de; Croot, Peter L.; Boye, Marie; Laan, Patrick; Timmermans, Klaas R.

    2005-01-01

    An in situ iron enrichment experiment was carried out in the Southern Ocean Polar Frontal Zone and fertilized a patch of water within an eddy of the Antarctic Circumpolar Current (EisenEx, Nov. 2000). During the experiment, a physical speciation technique was used for iron analysis in order to under

  3. In vitro iron enrichment experiments in the Prydz Bay, the Southern Ocean: A test of the iron hypothesis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In "high nitrate, low chlorophyll" (HNLC) ocean regions, iron has been typically regarded as the limiting factor for phytoplankton production. This "iron hypothesis" needs to be tested in various oceanic environments to understand the role of iron in marine biological and biogeochemical processes. In this paper, three in vitro iron enrichment experiments were performed in Prydz Bay and at the Polar Front north of the Ross Sea, to study the role of iron on phytoplankton production. At the Polar Front of Ross Sea, iron addition significantly (P<0.05, Student’s t-test) stimulated phytoplankton growth. In Prydz Bay, however, both the iron treatments and the controls showed rapid phytoplankton growth, and no significant effect (P>0.05, Student’s t-test) as a consequence of iron addition was observed. These results confirmed the limiting role of iron in the Ross Sea and indicated that iron was not the primary factor limiting phytoplankton growth in Prydz Bay. Because the light environment for phytoplankton was enhanced in experimental bottles, light was assumed to be responsible for the rapid growth of phytoplankton in all treatments and to be the limiting factor controlling field phytoplankton growth in Prydz Bay. During the incubation experiments, nutrient consumption ratios also changed with the physiological status and the growth phases of phytoplankton cells. When phytoplankton growth was stimulated by iron addition, N was the first and Si was the last nutrient which absorption enhanced. The Si/N and Si/P consumption ratios of phytoplankton in the stationary and decay phases were significantly higher than those of rapidly growing phytoplankton. These findings were helpful for studies of the ma- rine ecosystem and biogeochemistry in Prydz Bay, and were also valuable for biogeochemical studies of carbon and nutrients in various marine environments.

  4. Experiment Research on the Enrichment of Precious Metals from Nickel-copper-iron Matte

    Institute of Scientific and Technical Information of China (English)

    FAN Xingxiang; LIU Yang; DONG Haigang; FU Guangqiang; WU Yuedong; ZHAO Jiachun; WU Xiaofeng

    2012-01-01

    According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals at home and abroad,this paper put forward the process route of enrichment of precious metals and selectively leaching of base metals from the nickel-copper-iron matte by sulfuric acid and sodium hypochlorite.The effects of particle size,leaching temperature,leaching time,amount of sulfuric acid and sodium hypochlorite on the leaching rate of nickel,cobalt,copper and iron are mainly discussed.The results show that raw material particle size has significantly effects on the leaching rate of base metals,high leaching rate of base metals and enrichment of precious metals are obtained with the suitable particle size.Through the experiments,the reasonable experiment parameters and conditions were determined as fellows:particle size of-200 to +250 mesh,leaching temperature 95℃,leaching time 5 h,sulfuric acid concentration 30%,adding amount of sodium hypochlorite 3 times of matte weight.Under these experiment parameters and conditions,the leaching rate of nickel,cobalt,copper and iron were 97.39%,96.24%,98.30% and 99.01%,respectively.The content of nickel,cobalt,copper,iron in the leaching residues was 8.15%,0.23%,1.40% and 0.24%,respectively.The content of Pt,Pd,Au,Ag and Rh in the leaching residues was 247 g/t,521 g/t,112 g/t,494 g/t and 24 g/t,respectively.The content of Pt,Pd,Au,Ag and Rh in the leaching solution was <0.0005 g/L,0.0023 g/L,0.0007 g/L,<0.0005 g/L and 0.00017 g/L,respectively.This process has advantages as follows:a small investment,simple technology,high enrichment efficiency.

  5. The CO2 system in a Redfield context during an iron enrichment experiment in the Southern Ocean

    NARCIS (Netherlands)

    Bozec, Yann; Bakker, Dorothee C.E.; Hartmann, Carmen; Thomas, Helmuth; Bellerby, Richard G.J.; Nightingale, Phil D.; Riebesell, Ulf; Watson, Andrew J.; Baar, Hein J.W. de

    2005-01-01

    In November 2000, a second iron enrichment experiment (EisenEx) was carried out in the Southern Ocean. Iron was added on the 8th of November in the centre of an eddy at 21°E, 48°S. During the cruise, the carbonate parameters dissolved inorganic carbon (DIC), fugacity of CO2 (fCO2) and pH on the hydr

  6. Responses of marine phytoplankton in iron enrichment experiments in the northern North Sea and northeast Atlantic Ocean

    NARCIS (Netherlands)

    Timmermans, Klaas R.; Gledhill, Martha; Nolting, Rob F.; Veldhuis, Marcel J.W.; Baar, Hein J.W. de; Berg, Constant M.G. van den

    1998-01-01

    Short-term iron enrichment experiments were carried out with samples collected in areas with different phytoplankton activity in the northern North Sea and northeast Atlantic Ocean in the summer of 1993. The research area was dominated by high numbers of pico-phytoplankton, up to 70,000 ml−1. Maximu

  7. The response of phytoplankton to iron enrichment in Sub-Antarctic HNLCLSi waters: Results from the SAGE experiment

    Science.gov (United States)

    Peloquin, Jill; Hall, Julie; Safi, Karl; Smith, Walker O., Jr.; Wright, Simon; van den Enden, Rick

    2011-03-01

    Areas of high nutrients and low chlorophyll a comprise nearly a third of the world's oceans, including the equatorial Pacific, the Southern Ocean and the Sub-Arctic Pacific. The SOLAS Sea- Air Gas Exchange (SAGE) experiment was conducted in late summer, 2004, off the east coast of the South Island of New Zealand. The objective was to assess the response of phytoplankton in waters with low iron and silicic acid concentrations to iron enrichment. We monitored the quantum yield of photochemistry ( Fv/ Fm) with pulse amplitude modulated fluorometry, chlorophyll a, primary productivity, and taxonomic composition. Measurements of Fv/ Fm indicated that the phytoplankton within the amended patch were relieved from iron stress ( Fv/ Fm approached 0.65). Although there was no significant difference between IN and OUT stations at points during the experiment, the eventual enhancement in chlorophyll a and primary productivity was twofold by the end of the 15-day patch occupation. However, no change in particulate carbon or nitrogen pools was detected. Enhancement in primary productivity and chlorophyll a were approximately equal for all phytoplankton size classes, resulting in a stable phytoplankton size distribution. Initial seed stocks of diatoms were extremely low, <1% of the assemblage based on HPLC pigment analysis, and did not respond to iron enrichment. The most dominant groups before and after iron enrichment were type 8 haptophytes and prasinophytes that were associated with ˜75% of chlorophyll a. Twofold enhancement of biomass estimated by flow cytometry was detected only in eukaryotic picoplankton, likely prasinophytes, type 8 haptophytes and/or pelagophytes. These results suggest that factors other than iron, such as silicic acid, light or physical disturbance limited the phytoplankton assemblage during the SAGE experiment. Furthermore, these results suggest that additional iron supply to the Sub-Antarctic under similar seasonal conditions and seed stock will most

  8. SCOR WG-131: The Legacy of in situ Iron Enrichment Experiments - Data Compilation and Modeling

    Science.gov (United States)

    Boyd, Philip W.; Bakker, Dorothee C. E.; Wg-131, Scor

    2010-05-01

    Working Group 131 (WG-131) of the Scientific Committee on Oceanic Research (SCOR) has these aims: 1) Data compilation. Assembling in a common open-access database the metadata and data of the in situ iron fertilization experiments, ranging from surface water and water column data on physical, chemical and biological parameters, to biogeochemical rate processes and incubation experiments 2) Modeling and data synthesis of specific aspects of two or more such experiments for various topics, such as physical mixing, phytoplankton productivity, overall ecosystem functioning, iron chemistry, carbon budgeting, nutrient uptake ratios, and combinations of these variables and processes. Over the last 24 months SCOR WG-131 participants, in particular Doug Mackie, have liased with Cyndy Chandler and Steve Gegg at the Biological and Chemical Oceanography Data Management Office (BCO-DMO; http://www.bco-dmo.org/home) to pull together a relational database that spans data from IronEx I in 1993 to SEEDS II in 2004. The BCO-DMO database currently contains data sets for IronEx I, IronEx II, SOIREE, SEEDS I, SEEDS II, SERIES, SOFeX-North and SOFeX-South. The BCO-DMO data base also has a link to the publicly available EisenEx data, which are stored at the World Data Center for Marine Environmental Sciences (WDC-MARE, http://www.wdc-mare.org/). We hope to launch the BCO-DMO database at a side meeting on the afternoon of Sunday 21 February 2010 before the Ocean Sciences Meeting in Portland. The relational BCO-DMO database permits intercomparisons of data, thus allowing for exciting and novel opportunities for data synthesis and modeling, from 1-dimensional simple biological models through to complex 3-dimensional models. Scientists interested in such work are invited to contact the chairs of WG-131.

  9. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron-reducing conditions

    Science.gov (United States)

    Huang, S.; Jaffé, P. R.

    2015-02-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron was measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454 pyrosequencing, and real-time quantitative PCR analysis. We be Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  10. Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron reducing conditions

    Science.gov (United States)

    Huang, S.; Jaffé, P. R.

    2014-08-01

    Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron were measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454-pyrosequencing, and real-time quantitative PCR analysis. We believe that one of the dominant microbial species in our system (an uncultured Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

  11. Southern Ocean Iron Experiment (SOFex)

    Energy Technology Data Exchange (ETDEWEB)

    Coale, Kenneth H.

    2005-07-28

    The Southern Ocean Iron Experiment (SOFeX) was an experiment decades in the planning. It's implementation was among the most complex ship operations that SIO has been involved in. The SOFeX field expedition was successful in creating and tracking two experimentally enriched areas of the Southern Ocean, one characterized by low silicic acid, one characterized by high silicic acid. Both experimental sites were replete with abundant nitrate. About 100 scientists were involved overall. The major findings of this study were significant in several ways: (1) The productivity of the southern ocean is limited by iron availability. (2) Carbon uptake and flux is therefore controlled by iron availability (3) In spite of low silicic acid, iron promotes non-silicious phytoplankton growth and the uptake of carbon dioxide. (4) The transport of fixed carbon from the surface layers proceeds with a C:N ratio that would indicate differential remineralization of nitrogen at shallow depths. (5) These finding have major implications for modeling of carbon export based on nitrate utilization. (6) The general results of the experiment indicate that, beyond other southern ocean enrichment experiments, iron inputs have a much wider impact of productivity and carbon cycling than previously demonstrated. Scientific presentations: Coale, K., Johnson, K, Buesseler, K., 2002. The SOFeX Group. Eos. Trans. AGU 83(47) OS11A-0199. Coale, K., Johnson, K. Buesseler, K., 2002. SOFeX: Southern Ocean Iron Experiments. Overview and Experimental Design. Eos. Trans. AGU 83 (47) OS22D-01. Buesseler, K.,et al. 2002. Does Iron Fertilization Enhance Carbon Sequestration? Particle flux results from the Southern Ocean Iron Experiment. Eos. Trans. AGU 83 (47), OS22D-09. Johnson, K. et al. 2002. Open Ocean Iron Fertilization Experiments From IronEx-I through SOFeX: What We Know and What We Still Need to Understand. Eos. Trans. AGU 83 (47), OS22D-12. Coale, K. H., 2003. Carbon and Nutrient Cycling During the

  12. Organic matter production response to CO2 increase in open subarctic plankton communities: Comparison of six microcosm experiments under iron-limited and -enriched bloom conditions

    Science.gov (United States)

    Yoshimura, Takeshi; Sugie, Koji; Endo, Hisashi; Suzuki, Koji; Nishioka, Jun; Ono, Tsuneo

    2014-12-01

    Increase in seawater pCO2 and the corresponding decrease in pH caused by the increasing atmospheric CO2 concentration (i.e., ocean acidification) may affect organic matter production by phytoplankton communities. Organic matter production forms the basis of marine food webs and plays a crucial role in oceanic CO2 uptake through the biological carbon pump, and hence will potentially affect future marine ecosystem dynamics. However, responses of organic matter production in open ocean plankton ecosystems to CO2 increase have not been fully examined. We conducted on-deck microcosm experiments using high nutrient, low chlorophyll (HNLC) waters in the western subarctic Pacific and oceanic Bering Sea basin in summer 2008 and 2009, respectively, to examine the impacts of elevated CO2 on particulate and dissolved organic matter (i.e., POM and DOM, respectively) production. Iron deficient natural plankton communities were incubated for 7-14 days under multiple CO2 levels with and without iron enrichments (hereafter +Fe and -Fe treatments, respectively). By combining with our previous experiments at two sites, we created a comprehensive dataset on responses of organic matter production to CO2 increase during macronutrient replete conditions in HNLC waters. Significant differences in net particulate organic carbon production among CO2 treatments were observed only in the -Fe treatments, whereas that in net dissolved organic carbon production were mainly observed in the +Fe treatments, suggesting that CO2 may affect different processes depending on the Fe nutritional status. However, impacts of CO2 were not consistent among experiments and were much smaller than the consistent positive effects of Fe enrichment. In contrast, no significant differences among the CO2 treatments were observed for organic carbon partitioning into POM and DOM, and carbon to nitrogen ratio of net produced POM. We conclude that CO2 does not play a primary role, but could have secondary effects on

  13. Iron bioavailability in humans from breakfasts enriched with iron bis-glycine chelate, phytates and polyphenols.

    Science.gov (United States)

    Layrisse, M; García-Casal, M N; Solano, L; Barón, M A; Arguello, F; Llovera, D; Ramírez, J; Leets, I; Tropper, E

    2000-09-01

    This study was conducted to determine the bioavailability of iron amino acid chelate (ferrochel) added to fortify breads prepared from either precooked corn flour or white wheat flour + cheese and margarine compared with the same basal breakfast enriched with either ferrous sulfate or iron-EDTA. The inhibitory effect of phytate and polyphenols on iron absorption from ferrochel was also tested. A total of 74 subjects were studied in five experiments. Iron absorption from ferrochel was about twice the absorption from ferrous sulfate (P: American-type coffee did not modify iron absorption significantly, whereas both espresso-type coffee and tea reduced iron absorption from ferrochel by 50% (P: < 0. 05). Ferrochel partially prevented the inhibitory effect of phytates. Because of its high solubility in aqueous solutions even at pH 6, its low interactions with food and high absorption, ferrochel is a suitable compound for food fortification.

  14. Effects of heme iron enriched peptide on iron deficiency anemia in rats.

    Science.gov (United States)

    Tang, Ning; Chen, Le-qun; Zhuang, Hong

    2014-02-01

    The present study aims to investigate whether a daily intake of heme iron enriched peptide obtained from bovine hemoglobin is effective in alleviating iron deficiency anemia (IDA). Wistar rats were randomly divided into six groups: a control group, an anemic group not treated, and anemic groups treated with FeSO4 or with the heme iron enriched peptide at low, moderate or high doses. The rats in the anemic groups were fed on a low-iron diet to establish the iron deficiency anemia model. After the model had been established, different doses of heme iron enriched peptide were given to the rats once a day via intragastric administration. After the iron supplement administration, it was observed that heme iron enriched peptide had effective restorative action returning the hemoglobin, red blood cells, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration and serum iron in IDA animals to normal values or better. In addition, compared with FeSO4, higher Fe bioavailability and fewer side effects were observed. The rats in the moderate dose group had the highest apparent Fe absorption. Moreover, in vivo antioxidant activity was also observed, enhancing the activities of antioxidant enzymes and reduced malondialdehyde levels in IDA rats. Furthermore, the heme iron enriched peptide also exhibited strong in vitro antioxidant activities. In conclusion, heme iron enriched peptide significantly alleviated iron deficiency anemia, and exhibited strong in vitro and in vivo antioxidant activities. This suggests that heme iron enriched peptide might be exploited as a safe, efficient new iron supplement.

  15. Iron stress in the Pacific region of the Southern Ocean : evidence from enrichment bioassays

    NARCIS (Netherlands)

    Timmermans, Klaas; van Leeuwe, M.A.; de Jong, J.T.M.; Nolting, R.F.; Witte, H.J; van Ooyen, J; Swagerman, M.J W; Kloosterhuis, H; de Baar, H.J.W.

    1998-01-01

    The effect of iron on phytoplankton physiology in a scarcely investigated part of the Pacific region of the Southern Ocean was studied during an expedition aboard RV 'Polarstern'. Physiological effects of iron enrichments were studied during short-term bottle experiments (72 h) in high-nutrient, low

  16. Enriching Music and Language Arts Experiences

    Science.gov (United States)

    Flohr, John W.

    2006-01-01

    The article focuses on enriching music and language arts experiences of students. Music can enrich literature and language arts, poetry, theater arts, transitions, science, and math, as well as help meet special learner needs. A well-understood example of enrichment is the alphabet song. A music or classroom teacher using the alphabet song helps…

  17. Methods Development for an Unenclosed Mesoscale Iron Enrichment

    Science.gov (United States)

    1994-09-01

    Coley, R. -r. Barber, S. Lindley. A. J. Watson, K. Van Scoy, C. S. Law, M. i. Liddicoat , R. Ling. T. Stanton, J. Stockel, C. Collins, A. Anderson, R...Vol. 371, No. 6493, p 145-148, 1994. Watson, A., C. S. Law, K. A. Van Scoy, F. J. Millero, W. Yao, G. E. Friederich, M. 1. Liddicoat , R. H. Wanninkhof... Liddicoat . The In Situ Phytoplankton Response to Natural and Experimental Iron Enrichment. 1994. Iron Speciation and its Biological Availability in

  18. Effect of Iron Enriched Bread Intake on the Oxidative Stress Indices in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Sharareh Heidari

    2016-08-01

    Full Text Available Background Contrary to the proven benefits of iron, few concerns in producing the oxidative stress is remained problematic. Objectives The aim of the study was to evaluate the oxidative stress in the male Wistar rats fed bread supplemented with iron in different doses i.e., 35 (basic, 70 (two fold, 140 (four fold, and 210 mg/kg (six fold with or without NaHCO3 (250 mg/kg. Methods In this experimental study Iron, ceruloplasmin, ferritin, total iron binding capacity (TIBC, albumin, total protein, uric acid and plasma superoxide dismutase (SOD, glutathione peroxidase (GPX, catalase (CAT, malondialdehyde (MDA, and total antioxidant capacity (TAC, were evaluated in 30 rats at the first and last day of the experiment (day 30. In addition, phytic acid levels were detected in all baked breads. The data were analyzed by ANOVA and t test procedure though SPSS statistical software version 20. Results Serum iron level in rats that received basic level of iron plus NaHCO3 decreased significantly in the last day of the trial. Higher level of serum iron was seen in rats that received iron twofold, fourfold and sixfold and rats that received iron fourfold plus NaHCO3. Serum ceruloplasmin and ferritin in groups of rats that received fourfold level of iron plus NaHCO3 and rats that received iron sixfold showed a significant increase (P ≤ 0.05. Serum total protein and uric acid in rats that received basic level of iron plus NaHCO3 and rats that received twofold level of iron showed a significant decrease. Serum total protein levels in rats that received fourfold level of iron showed a significant decrease. Bread with NaHCO3 showed higher phytic acid levels than other groups. Conclusions These results indicate that oxidative stress was not induced, whereas some antioxidant activities were significantly changed in rats that received iron-enriched bread.

  19. Potential for iron enriched yeast in recovery of rats from iron deficiency

    OpenAIRE

    Kyyaly, Aref; Powell, Chris

    2015-01-01

    It is well known that iron deficiency can lead to anemia, resulting in a variety of symptoms and health issues. Negative effects can be prevented by ensuring foods with a naturally high iron content are ingested, or countered by taking nutrient supplements. As an alternative it is possible to influence the nutritional content of foods to ensure that dietary requirements are met. In this study we aimed to evaluate the potential for using iron-enriched baker’s yeast as a source of iron for cur...

  20. Preparation of iron-enriched baker's yeast and its efficiency in recovery of rats from dietary iron deficiency

    OpenAIRE

    Kyyaly, Mohammad Aref; Powell, Chris; Ramadan, Elshahat

    2015-01-01

    OBJECTIVES Iron is an important mineral, essential for the health and function of mammalian cells. Despite its key role, iron deficiency in humans is common worldwide, often leading to significant health issues within the population. The aim of this study was to evaluate the potential of using iron-enriched baker's yeast as a source of iron, especially for the protection and recovery from conditions related to anemia. METHODS Iron-enriched yeast was prepared by cultivating cells o...

  1. Iron bioavailability from cereal products enriched with Pleurotus ostreatus mushrooms in rats with induced anaemia.

    Science.gov (United States)

    Reguła, Julita; Krejpcio, Zbigniew; Staniek, Halina

    2016-06-02

    Oyster mushroom Pleurotus ostreatus is good source of iron. However, there is a limited data concerning bioavailability of iron from oyster mushroom and also cereal products containing this mushroom. The aim of this study was to assess bioavailability of iron from products with an addition of Pleurotus ostreatus in male rats with anaemia. Investigations were conducted in two stages. In the first stage iron deficiency was developed in rats. For this purpose 6 weeks old 36 male Wistar rats were fed a AIN-93M diet deficient in iron and 6 males received a standard AIN-93M diet. In the second stage of the study the assessment of Fe bioavailability from cereal products enriched with dried Pleurotus ostreatus. After experiment the animals were killed and blood and heart, liver, spleen and kidneys were collected for biochemical tests. Feeding male Wistar rats supplemented with dried Pleurotus ostreatus mushrooms diets resulted in the restitution of the systemic Fe level, as manifested by an increase of the level comparable to the control group for: iron transferrin saturation rate, haemoglobin and mean corpuscular volume. Values of hematocrit, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration in animals fed products supplemented with Pleurotus ostreatus were significantly higher compared to animals fed products with no Fe added. The highest MCV value was recorded when 20% of dried oyster mushrooms were added. Iron levels in the blood serum, the liver and kidneys in animals fed cereal products considerably exceeded values recorded at the beginning of the experiment and were similar to the control values. Product may be a valuable source of iron in the nutrition of individuals with a deficiency of this element, first of all patients with absorption and metabolism disorders, but also may add variety to the traditional daily diet.

  2. Effects of nitrate addition and iron speciation on trace element transfer in coastal food webs under phosphate and iron enrichment.

    Science.gov (United States)

    Li, Shun-Xing; Liu, Feng-Jiao; Zheng, Feng-Ying; Zuo, Yue-Gang; Huang, Xu-Guang

    2013-06-01

    Coastal organisms are often exposed to both iron enrichment and eutrophication. Trace elements transfer in coastal food webs are critical for marine life and therefore influence coastal ecosystem function and the global carbon cycle. However, how these exposures affect algal element uptake and the subsequent element transfer to marine copepods (Tigriopus japonicus) is unknown. Here we investigated the effects of nitrate addition and iron speciation (Fe (OH)3 or EDTA-Fe) on the biological uptake of Cu, Zn, and Se under phosphate and iron enrichment, using Thalassiosira weissflogii, Skeletonema costatum, and Chlorella vulgaris as model marine algae. Algal element adsorption/absorption generally increased with increasing macronutrient concentrations. Algal element assimilation efficiencies depended on iron speciation and marine algae species. Element assimilation efficiencies of copepods were significantly correlated to the intracellular element concentrations in algal cells. Element uptake and transfer were controlled by eutrophication, iron speciation, and algal species in coastal food webs.

  3. Enriched iron(III-reducing bacterial communities are shaped by carbon substrate and iron oxide mineralogy

    Directory of Open Access Journals (Sweden)

    Christopher J. Lentini

    2012-12-01

    Full Text Available Iron (Fe oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III oxides (e.g., goethite, hematite, which are poorly reduced by model dissimilatory Fe(III-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III oxides (ferrihydrite, goethite, hematite and carbon substrates (glucose, lactate, acetate along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III reduction and the well known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g. Enterobacter spp. and sulfate-reducing bacteria (e.g. Desulfovibrio spp.. Thus, changes in Fe oxide structure and resource availability may shift Fe(III-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments.

  4. Effect of high iron concentration enrichment on the phytoplankton in the Prydz Bay

    Institute of Scientific and Technical Information of China (English)

    张武昌; 孙松; 张永山; 扈传昱; 刘诚刚

    2004-01-01

    Shipboard iron enrichment phytoplankton incubations were carried out in the Prydz Bay, Antarctic, in January through to March 2002. Waters for the three incubations ( Exp 1,2 and 3 ) were collected from 20 m depth in three stations ( St. Ⅰ -1, Ⅶ-1 and Ⅶ-5 ), respectively. Although the nutrient concentrations in the surface waters of the three stations were consistently high, the Chl a concentrations varied considerably. Chl a concentrations in the 20 m depth of St. Ⅰ-1 and Ⅶ-1 werewas 2.35-2.65 for St. Ⅶ-5. There were six levels of enriched iron concentrations(control 5, 10, 20, 40 and 80 nM) in Exp 1 (6-29th, January) while three enriched iron levels (control 10 and 40 nM) were arranged in Exp 2 and 3 (both were from 20th February to 4 th March). The iron enrichments stimulated the phytoplankton growth and nutrient drawdown in Exp 1 and Exp 2. In Exp 3, phytoplankton growth and nutrient drawdown were at nearly the same rate in the control and iron enriched bottles. In Exp 1, Chl a concentrations in the bottles with 20, 40 and 80 nM iday, respectively, with a growth rate of 0.36-0.38 d-1. Chl a concentration in the day ( growth rate 0.27 d - 1 ). Phytoplankton growth rates in the control bottle and the bottle enriched with 5 nM iron were 0.13 and 0.16 d -1, respectively. In Exp 2, the Chl a growth rates were 0.13, 0.32 and 0.40 d-1 in the control bottle and bottles with 10 and 40 nM iron enrichments, respectively. It seems that 10 nM iron enrichment was not enough to stimulate the phytoplankton to reach their maximum growth rate. The result that the phytoplankton < 10 μm bloomed in Exp 1 and 2 was controversial to the "Ecumenical Iron Hypothesis" of Morel et al. ( 1991 ) that upon enrichment of iron, phytoplankton >10 μm would grow faster than phytoplankton<10 μm.

  5. Activable enriched stable isotope iron-58 for monitoring absorption rate of juvenile athletes for iron: a case study.

    Science.gov (United States)

    Qian, Qinfang; Chai, Zhifang; Feng, Weiyu; Chen, Jidi; Zhang, Peiqun; Pan, Jianxiang

    2002-09-01

    Activable enriched stable isotopes can play a unique role in studies of nutritional status, metabolism, absorption rates, and bioavailability of minerals. As a practical example, eight juvenile athletes were selected to test the absorption rates of iron during training and non-training periods by enriched stable isotope of Fe-58 (enriched degree: 51.1%) via activation analysis Fe-58 (n, gamma) Fe-59 of the collected feces samples. The results indicated that the average iron absorption rates of the juvenile athletes with and without training are 9.1 +/- 2.8 and 11.9 +/- 4.7%, respectively, which implies that the long-term endurance training with high intensity makes the iron absorption rate of athletes lower. In the meantime, the comparison of the activable enriched isotope technique with atomic absorption spectrometry was performed, which showed that the former was better than the latter in reliability and sensitivity. It is because this nuclear method can distinguish the exogenous and endogenous iron in the samples, but not for non-nuclear methods.

  6. Enriched $^{82}$Se for the LUCIFER experiment

    CERN Document Server

    Beeman, J W; Benetti, P; Cardani, L; Casali, N; Chiesa, D; Clemenza, M; Dafinei, I; Di Domizio, S; Ferroni, F; Gironi, L; Giuliani, A; Gotti, C; Laubenstein, M; Maino, M; Nagorny, S; Nisi, S; Nones, C; Orio, F; Pagnanini, L; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rusconi, C; Schäffner, K; Tomei, C; Vignati, M

    2015-01-01

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of $^{82}$Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched $^{82}$Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3% enriched $^{82}$Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of $^{232}$Th, $^{238}$U and $^{235}$U are respectively: $<$61 $\\mu$Bq/kg, $<$110 $\\mu$Bq/kg and $<$74 $\\mu$Bq/kg at 90% C.L.. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the $^{82}$...

  7. Co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron(III-reducing enrichment culture

    Directory of Open Access Journals (Sweden)

    Shiling eZheng

    2015-09-01

    Full Text Available Methanosaeta harundinacea and Methanosarcina barkeri, known as classic acetoclastic methanogens, are capable of directly accepting electrons from Geobacter metallireducens for the reduction of carbon dioxide to methane, having been revealed as direct interspecies electron transfer (DIET in the laboratory co-cultures. However, whether their co-occurrences are ubiquitous in the iron (III-reducing environments and the other species of acetoclastic methanogens such as Methanosarcina mazei are capable of DIET are still unknown. Instead of initiating the co-cultures with pure cultures, two-step cultivation was employed to selectively enrich iron (III-reducing microorganisms in a coastal gold mining river, Jiehe River, with rich iron content in the sediments. First, iron (III reducers including Geobacteraceae were successfully enriched by 3-months successive culture on amorphous Fe(III oxides as electron acceptor and acetate as electron donor. High-throughput Illumina sequencing, terminal restriction fragment length polymorphism (T-RFLP and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures actively contained the bacteria belong to Geobacteraceae and Bacilli, exclusively dominated by the archaea belong to Methanosarcinaceae. Second, the enrichment cultures including methanogens and Geobacteraceae were transferred with ethanol as alternative electron donor. Remarkably, aggregates were successively formed in the enrichments after three transfers. The results revealed by RNA-based analysis demonstrate that the co-occurrence of Methanosarcina mazei and Geobacteraceae in an iron (III-reducing enrichment culture. Furthermore, the aggregates, as close physical contact, formed in the enrichment culture, indicate that DIET could be a possible option for interspecies electron transfer in the aggregates.

  8. Fluorescence signatures of an iron-enriched phytoplankton community in the eastern equatorial Pacific Ocean

    Science.gov (United States)

    Hoge, Frank E.; Wayne Wright, C.; Swift, Robert N.; Yungel, James K.; Berry, Richard E.; Mitchell, Richard

    Laser-induced fluorescence profiles of chlorophyll and phycoerythrin pigments and chromophoric dissolved organic matter (CDOM) fluorescence acquired over an iron-enriched phytoplankton patch are compared to profiles made over adjacent, naturally occurring phytoplankton patches. A total of four airborne missions were flown during an 8 day period following the release of the iron-rich fertilizer. Analyses of the airborne laser-induced fluorescence profiles from the upper-ocean layer reveal: (1) Ship-dispersed iron enhances localized phytoplankton production in high-nutrient/low-chlorophyll regions such as found in the eastern equatorial Pacific Ocean. (2) The chlorophyll concentration within the iron-enriched phytoplankton patch exceeded levels of chlorophyll found in naturally occurring phytoplankton patches located outside the enriched region. (3) An increase in phycoerythrin fluorescence was observed within the enriched region in correspondence with the elevated chlorophyll fluorescence. However, the phycoerythrin/chlorophyll fluorescence ratio was lower within the enriched patch than in naturally occurring phytoplankton patches outside of the enriched region. (4) No above-background chromorophoric dissolved organic matter (CDOM) fluorescence was observed in the enriched patch. Elevated CDOM fluorescence was associated with some of the naturally occurring phytoplankton patches outside the enriched region, while other such phytoplankton patches showed no measurable increase in CDOM over background levels. (5) The surface layer manifestation of the patch was observed to be transported to the north and west in close agreement with the drogue positions. No elevated surface layer chlorophyll fluorescence was seen in the vicinity of the ship as it sampled the submerged fraction at the time of the 30 October and 1 November overflights. The phycoerythrin pigment fluorescence emission was insensitive to ambient cloud-induced downwelling irradiance variability, while at the

  9. Differentiation and delivery of an enriched deep mantle reservoir during iron descent to the core.

    Science.gov (United States)

    Weeraratne, D. S.; Fleck, J.; Rains, C.; McGeehee, J.; Klein, S. M.; Rincon, J. M.; Olson, P.

    2015-12-01

    Planetary interior differentiation from a bulk silicate chondrite composition is shown by geochemical studies to occur early in planetary evolution producing separated enriched and depleted mantle reservoirs with important implications for the mantle and crustal compositions that we observe today. The absence of an enriched component at the Earth's surface, however, and has lead to implications of a reservoir at the base of the mantle, but the mechanism of differentiation or downward transport of this enriched material is unknown. Here we present results from laboratory fluid dynamic experiments using liquid metal to show that metal-silicate segregation from a metal pond which forms in a magma ocean following meteorite impacts will entrain magma ocean silicate material to the base of the mantle during metal descent to the core. We model liquid iron and silicate magma using emulsified liquid metal gallium in high viscosity glucose solutions which provide the buoyancy ratios and Stokes flow regimes expected for planetary interiors. Preliminary results indicate that emulsion metal droplets sink together as a Rayleigh-Taylor instability and forms a trailing conduit of buoyant solution. Metal droplets form a pile at the base of the box where the low density solution collects, grows, and initially rises back to the surface as a thermo-chemical plume. The remaining buoyant material, which surrounds each droplet, slowly migrates upwards and rises out of the metal pile. These physical experiments scaled to planetary interiors provide important tests of purely theoretical or numerical approximations and indicate that metal-silicate segregation is consistent with rapid core formation times and contributes simultaneously to complex mantle differentiation at all depths. Our observation of entrainment of a silicate-metal conduit provides a model for differentiation and sequestration of an enriched reservoir from a magma ocean to the base of the mantle. The composition and

  10. Sensory evaluation of dairy supplements enriched with reduced iron, ferrous sulfate or ferrous fumarate.

    Science.gov (United States)

    Morales, Josefina C; Sánchez-Vargas, Elena; García-Zepeda, Rodrigo; Villalpando, Salvador

    2015-01-01

    To determine the degree of liking of the Oportunidades programme dietary supplements (DS)--purees and beverages--added with different iron salts (IS): reduced iron (RI), ferrous sulphate (FS) or ferrous fumarate (FF) during 24 weeks of storage. The DS were evaluated through a hedonic scale for aroma, flavour and colour attributes; at time zero and every eight weeks, each panel member evaluated three DS with same flavour and presentation but different IS. Seventy women participated as panel members. The chocolate and banana DS exhibited a change in preference by colour and flavour due to storage. DS with FS or RI showed the least preference by flavour and colour in the context of the three IS considered. The chocolate and neutral DS enriched with FS changed their colour and flavour. DS were, in general, well-liked; nonetheless, for purees enriched with FS and for beverages enriched with RI, the less-liked attributes were colour and flavour.

  11. Final Activity Report: The Effects of Iron Complexing Ligands on the Long Term Ecosystem Response to Iron Enrichment of HNLC waters

    Energy Technology Data Exchange (ETDEWEB)

    Trick, Charles Gordon [Western University

    2013-07-30

    Substantial increases in the concentrations of the stronger of two Fe(III) complexing organic ligand classes measured during the mesoscale Fe enrichment studies IronEx II and SOIREE appeared to sharply curtailed Fe availability to diatoms and thus limited the efficiency of carbon sequestration to the deep. Detailed observations during IronEx II (equatorial Pacific Ocean) and SOIREE (Southern Ocean –Pacific sector) indicate that the diatoms began re-experiencing Fe stress even though dissolved Fe concentrations remained elevated in the patch. This surprising outcome likely is related to the observed increased concentrations of strong Fe(III)-complexing ligands in seawater. Preliminary findings from other studies indicate that diatoms may not readily obtain Fe from these chemical species whereas Fe bound by strong ligands appears to support growth of cyanobacteria and nanoflagellates. The difficulty in assessing the likelihood of these changes with in-situ mesoscale experiments is the extended monitoring period needed to capture the long-term trajectory of the carbon cycle. A more detailed understanding of Fe complexing ligand effects on long-term ecosystem structure and carbon cycling is essential to ascertain not only the effect of Fe enrichment on short-term carbon sequestration in the oceans, but also the potential effect of Fe enrichment in modifying ecosystem structure and trajectory.

  12. Surface reactions of iron - enriched smectites: adsorption and transformation of hydroxy fatty acids and phenolic acids

    Science.gov (United States)

    Polubesova, Tamara; Olshansky, Yaniv; Eldad, Shay; Chefetz, Benny

    2014-05-01

    Iron-enriched smectites play an important role in adsorption and transformation of soil organic components. Soil organo-clay complexes, and in particular humin contain hydroxy fatty acids, which are derived from plant biopolymer cutin. Phenolic acids belong to another major group of organic acids detected in soil. They participate in various soil processes, and are of concern due to their allelopathic activity. We studied the reactivity of iron-enriched smectites (Fe(III)-montmorillonite and nontronite) toward both groups of acids. We used fatty acids- 9(10),16-dihydroxypalmitic acid (diHPA), isolated from curtin, and 9,10,16-trihydroxypalmitic acid (triHPA); the following phenolic acids were used: ferulic, p-coumaric, syringic, and vanillic. Adsorption of both groups of acids was measured. The FTIR spectra of fatty acid-mineral complexes indicated inner-sphere complexation of fatty acids with iron-enriched smectites (versus outer-sphere complexation with Ca(II)-montmorillonite). The LC-MS results demonstrated enhanced esterification of fatty acids on the iron-enriched smectite surfaces (as compared to Ca(II)-montmorillonite). This study suggests that fatty acids can be esterified on the iron-enriched smectite surfaces, which results in the formation of stable organo-mineral complexes. These complexes may serve as a model for the study of natural soil organo-clay complexes and humin. The reaction of phenolic acids with Fe(III)-montmorillonite demonstrated their oxidative transformation by the mineral surfaces, which was affected by molecular structure of acids. The following order of their transformation was obtained: ferulic >syringic >p-coumaric >vanillic. The LC-MS analysis demonstrated the presence of dimers, trimers, and tetramers of ferulic acid on the surface of Fe(III)-montmorillonite. Oxidation and transformation of ferulic acid were more intense on the surface of Fe(III)-montmorillonite as compared to Fe(III) in solution due to stronger complexation on

  13. EFFICIENCY OF THE LIQUID HYDROCARBONS USAGE IN THE ENRICHMENT PROCESS OF IRON ORE

    OpenAIRE

    SHKURENOK V.; PANOVA A.; AKYLBEK B.; OSTANINA N.

    2012-01-01

    This work proposes the liquid hydrocarbon reductant (LHR) usage in the process of iron ore opening-up to a metallurgic range. Calcination process optimization of Lisakovsk gravity-magnetic concentrate (LGMC) was performed by the planning of experiments using Seidel – Gauss method. Iron content in the concentrate increases from 47,6 % to 54,17 % in optimal conditions.

  14. EFFICIENCY OF THE LIQUID HYDROCARBONS USAGE IN THE ENRICHMENT PROCESS OF IRON ORE

    Directory of Open Access Journals (Sweden)

    SHKURENOK V.

    2012-01-01

    Full Text Available This work proposes the liquid hydrocarbon reductant (LHR usage in the process of iron ore opening-up to a metallurgic range. Calcination process optimization of Lisakovsk gravity-magnetic concentrate (LGMC was performed by the planning of experiments using Seidel – Gauss method. Iron content in the concentrate increases from 47,6 % to 54,17 % in optimal conditions.

  15. Iron enriched Saccharomyces cerevisiae maintains its fermenting power and bakery properties

    Directory of Open Access Journals (Sweden)

    Fernanda Gaensly

    2011-12-01

    Full Text Available Iron is an essential micronutrient in the metabolism of almost all living organisms; however, its deficiency is well documented especially in pregnant women and in children. Iron salts as a dietary supplement have low bioavailability and can cause gastrointestinal discomforts. Iron enriched yeasts can provide a supplementation of this micronutrient to the diet because this mineral has a better bioavailability when bonded to yeast cell macromolecules. These yeasts can be used as feed supplement for human and animals and also as baker's yeast. Baker's yeast Saccharomyces cerevisiae was cultivated in a reactor employing yeast media supplemented with 497 mg ferrous sulfate.L-1, and the resultant biomass incorporated 8 mg Fe.g-1 dry matter. This biomass maintained its fermenting power regarding both water displace measurement through carbonic dioxide production and bakery characteristics. The bread produced using the yeast obtained by cultivation in yeast media supplemented with iron presented six times more iron than the bread produced using the yeast obtained by cultivation without iron supplementation.

  16. Iron opacity experiments for the solar interior

    Science.gov (United States)

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; Hansen, S. B.; Blancard, C.; Cosse, Ph.; Faussurier, G.; Gilleron, F.; Pain, J.-C.; Pradhan, A. K.; Orban, C.; Pinsonneault, M.; Nahar, S. N.; Iglesias, C. A.; Wilson, B.; Colgan, J.; Fontes, C.; Kilcrease, D.; Sherrill, M.; Macfarlane, J. J.; Golovkin, I.; Mancini, R. C.

    2014-10-01

    Iron opacity experiments near solar interior conditions are performed at SNL Z-machine to better constrain solar models. The SNL opacity science platform satisfies the many challenging requirements for opacity measurements and successfully determines iron opacities at multiple conditions. We found that the agreement between the modeled opacity and the measured opacity deteriorates as Te and ne are raised to approach solar interior conditions. While the inaccuracy of the modeled opacity partially resolves the solar abundance problem, the announcement of such discrepancies has a high impact on the astrophysics, atomic physics, and high energy density physics, and thus more scrutiny on the potential experimental flaws is critical. We report the synthetic investigation for potential sources of systematic uncertainties in the experiments. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

  17. Assessing the effects of iron enrichment across holobiont compartments reveals reduced microbial nitrogen fixation in the Red Sea coral Pocillopora verrucosa

    KAUST Repository

    Radecker, Nils

    2017-07-31

    The productivity of coral reefs in oligotrophic tropical waters is sustained by an efficient uptake and recycling of nutrients. In reef-building corals, the engineers of these ecosystems, this nutrient recycling is facilitated by a constant exchange of nutrients between the animal host and endosymbiotic photosynthetic dinoflagellates (zooxanthellae), bacteria, and other microbes. Due to the complex interactions in this so-called coral holobiont, it has proven difficult to understand the environmental limitations of productivity in corals. Among others, the micronutrient iron has been proposed to limit primary productivity due to its essential role in photosynthesis and bacterial processes. Here, we tested the effect of iron enrichment on the physiology of the coral Pocillopora verrucosa from the central Red Sea during a 12-day experiment. Contrary to previous reports, we did not see an increase in zooxanthellae population density or gross photosynthesis. Conversely, respiration rates were significantly increased, and microbial nitrogen fixation was significantly decreased. Taken together, our data suggest that iron is not a limiting factor of primary productivity in Red Sea corals. Rather, increased metabolic demands in response to iron enrichment, as evidenced by increased respiration rates, may reduce carbon (i.e., energy) availability in the coral holobiont, resulting in reduced microbial nitrogen fixation. This decrease in nitrogen supply in turn may exacerbate the limitation of other nutrients, creating a negative feedback loop. Thereby, our results highlight that the effects of iron enrichment appear to be strongly dependent on local environmental conditions and ultimately may depend on the availability of other nutrients.

  18. The Role of Enriched Microbial Consortium on Iron-Reducing Bioaugmentation in Sediments.

    Science.gov (United States)

    Pan, Yuanyuan; Yang, Xunan; Xu, Meiying; Sun, Guoping

    2017-01-01

    Microbial iron reduction is an important biogeochemical process and involved in various engineered processes, including the traditional clay dyeing processes. Bioaugmentation with iron reducing bacteria (IRB) is generally considered as an effective method to enhance the activity of iron reduction. However, limited information is available about the role of IRB on bioaugmentation. To reveal the roles of introduced IRB on bioaugmentation, an IRB consortium enriched with ferric citrate was inoculated into three Fe(II)-poor sediments which served as the pigments for Gambiered Guangdong silk dyeing. After bioaugmentation, the dyeabilities of all sediments met the demands of Gambiered Guangdong silk through increasing the concentration of key agent [precipitated Fe(II)] by 35, 27, and 61%, respectively. The microbial community analysis revealed that it was the minor species but not the dominant ones in the IRB consortium that promoted the activity of iron reduction. Meanwhile, some indigenous bacteria with the potential of iron reduction, such as Clostridium, Anaeromyxobacter, Bacillus, Pseudomonas, Geothrix, and Acinetobacter, were also stimulated to form mutualistic interaction with introduced consortium. Interestingly, the same initial IRB consortium led to the different community successions among the three sediments and there was even no common genus increasing or decreasing synchronously among the potential IRB of all bioaugmented sediments. The Mantel and canonical correspondence analysis showed that different physiochemical properties of sediments influenced the microbial community structures. This study not only provides a novel bioremediation method for obtaining usable sediments for dyeing Gambiered Guangdong silk, but also contributes to understanding the microbial response to IRB bioaugmentation.

  19. A new method to measure iron absorption from the enrichment of 57Fe and 58Fe in young erythroid cells

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muys, T.; Pellegrom, H.; Bruyntjes, J.P.; Dokkum, W. van; Spanhaak, S.; Schaafsma, G.

    1998-01-01

    Iron absorption can be measured by the incorporation of stable iron isotopes into erythrocytes, 14 days after isotope administration. The disadvantage of this method is the high dose of isotopes needed to obtain a sufficient enrichment. Therefore, in this study cell fractions rich in young erythroid

  20. Enriching the Student Experience Through a Collaborative Cultural Learning Model.

    Science.gov (United States)

    McInally, Wendy; Metcalfe, Sharon; Garner, Bonnie

    2015-01-01

    This article provides a knowledge and understanding of an international, collaborative, cultural learning model for students from the United States and Scotland. Internationalizing the student experience has been instrumental for student learning for the past eight years. Both countries have developed programs that have enriched and enhanced the overall student learning experience, mainly through the sharing of evidence-based care in both hospital and community settings. Student learning is at the heart of this international model, and through practice learning, leadership, and reflective practice, student immersion in global health care and practice is immense. Moving forward, we are seeking new opportunities to explore learning partnerships to provide this collaborative cultural learning experience.

  1. Sensory evaluation of dairy supplements enriched with reduced iron, ferrous sulfate or ferrous fumarate

    Directory of Open Access Journals (Sweden)

    Josefina C Morales

    2015-01-01

    Full Text Available Objective. To determine the degree of liking of the Oportunidades programme dietary supplements (DS –purees and beverages– added with different iron salts (IS: reduced iron (RI, ferrous sulphate (FS or ferrous fumarate (FF during 24 weeks of storage. Materials and methods. The DS were evaluated through a hedonic scale for aroma, flavour and colour attributes; at time zero and every eight weeks, each panel member evaluated three DS with same flavour and presentation but different IS. Seventy women participated as panel members. Results. The chocolate and banana DS exhibited a change in preference by colour and flavour due to storage. DS with FS or RI showed the least preference by flavour and colour in the context of the three IS considered. The chocolate and neutral DS enriched with FS changed their colour and flavour. Conclusion. DS were, in general, well-liked; nonetheless, for purees enriched with FS and for beverages enriched with RI, the less-liked attributes were colour and flavour

  2. Embrittlement of austempered nodular irons: Grain boundary phosphorus enrichment resulting from precipitate decomposition

    Science.gov (United States)

    Klug, R. C.; Hintz, M. B.; Rundman, K. B.

    1985-05-01

    The microstructures, mechanical properties, and fracture behavior were characterized for a series of Mg treated nodular cast iron specimens austenitized at 1170, 1255, and 1340 K and subsequently austempered at 640 K. The ductility and toughness of the alloy decreased as austenitization temperatures were increased, which is contrary to the behavior anticipated from the observed micro-structural evolution. Fractographic and surface chemical analyses demonstrated that the mechanical property degradation was associated with embrittlement of the austenite grain boundaries by phosphorus. The primary mechanism of grain boundary phosphorus enrichment does not appear to be equilibrium segregation, and an alternative mechanism based on the decomposition of P rich precipitates is proposed and discussed.

  3. Effect of macronutrient enrichment on the size distribution, sorption, and bioconcentration factor of iron by coastal phytoplanktonic diatoms.

    Science.gov (United States)

    Li, Shun-Xing; Zheng, Feng-Ying

    2011-09-01

    The influences of macronutrient enrichment on iron absorption, adsorption, and the bioconcentration factor (BCF) of iron by coastal diatoms were examined. In addition, the distribution of different iron size fractions in seawater in relation to two diatom species exposed to nutrient enrichment over an extended period (6 days for Thalassiosira weissflogii, and 4 days for Skeletonema costatum), was investigated. Iron concentrations were measured of seven size fractions: particles (>0.4 μm), colloidal particles (0.4 μm-100, 100-50, 50-30, 30-10, 10-3 kDa), and soluble species (iron by the diatoms, and the iron species distribution in seawater were affected by the diatom species, as well as the nitrate (N) and phosphate (P) concentration. The addition of P could affect the iron internalization strategy. The content of soluble iron species was positively correlated with the amount of iron absorption by T. weissflogii, but it was not suitable for S. costatum.

  4. Maize Porridge Enriched with a Micronutrient Powder Containing Low-Dose Iron as NaFeEDTA but Not Amaranth Grain Flour Reduces Anemia and Iron Deficiency in Kenyan Preschool Children1-3

    National Research Council Canada - National Science Library

    Catherine W Macharia-Mutie; Diego Moretti; Natalie Van den Briel; Agnes M Omusundi; Alice M Mwangi; Frans J Kok; Michael B Zimmermann; Inge D Brouwer

    2012-01-01

    ...) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with amaranth grain or MNP to reduce IDA in Kenyan preschool children...

  5. Experiences and challenges in industrialized countries: control of iron deficiency in industrialized countries.

    Science.gov (United States)

    Ramakrishnan, Usha; Yip, Ray

    2002-04-01

    This paper provides a synopsis of the experience in combating iron deficiency in industrialized countries and identifies the reasons for the considerable success and future challenges. Significant progress has been made over the last century in reducing and even eliminating iron deficiency in many industrialized countries. Current estimates are that the prevalence of iron deficiency has declined to children, compared with 30 to 70% in many developing countries. The reasons for this success cannot be attributed solely to a single approach but rather to a range of factors that have occurred over time as a result of both economic development and the implementation of specific policies. Several factors have contributed to improving both iron intakes and reducing iron losses; these include fortification, supplementation, dietary diversification and public health measures. For example, the decline in anemia in infants can be attributed to the introduction of iron-fortified formula and complementary foods in the 1960s to 1970s. Similarly, the enrichment and fortification of cereals with iron that began during World War II in North America and Europe is a result of effective public-private partnerships. Despite these successes, iron deficiency remains a public health concern in industrialized countries for selected subgroups such as women of reproductive age with excess menstrual losses and pregnant women who cannot meet increased requirements from the diet alone. Constant vigilance and innovative approaches for screening and combating this problem are thus still required even in developed countries.

  6. Physico-chemical quality and homogeneity of folic acid and iron in enriched flour using principal component analysis.

    Science.gov (United States)

    Soeiro, Bruno T; Boen, Thaís R; Wagner, Roger; Lima-Pallone, Juliana A

    2009-01-01

    The aim of the present work was to determine parameters of the corn and wheat flour matrix, such as protein, lipid, moisture, ash and carbohydrates, folic acid and iron contents. Three principal components explained 91% of the total variance. Wheat flours were characterized by high protein and moisture content. On the other hand, the corn flours had the greater carbohydrates, lipids and folic acid levels. The concentrations of folic acid were lower than the issued value for wheat flours. Nevertheless, corn flours presented extremely high values. The iron concentration was higher than that recommended in Brazilian legislation. Poor homogenization of folic acid and iron was observed in enriched flours. This study could be useful to help the governmental authorities in the enriched food programs evaluation.

  7. Complexation Effect on Redox Potential of Iron(III)-Iron(II) Couple: A Simple Potentiometric Experiment

    Science.gov (United States)

    Rizvi, Masood Ahmad; Syed, Raashid Maqsood; Khan, Badruddin

    2011-01-01

    A titration curve with multiple inflection points results when a mixture of two or more reducing agents with sufficiently different reduction potentials are titrated. In this experiment iron(II) complexes are combined into a mixture of reducing agents and are oxidized to the corresponding iron(III) complexes. As all of the complexes involve the…

  8. Geochemistry and Microbial Communities in Iron- and Manganese-Enriched Cold Groundwater Biofiltration Units

    Science.gov (United States)

    Chang, W.; Dangeti, S.; Roshani, B.; McBeth, J. M.

    2015-12-01

    Exploring how to enhance the microbially mediated oxidization of iron (Fe) and manganese (Mn) in natural and engineered environments in cold climates requires an understanding of the interactive relationships between the geochemistry of cold groundwater and Fe- and Mn-oxidizing bacteria. This study precisely measured geochemical and microbial communities in a scaled-up biofiltration system using synchrotron-based X-ray Absorption Near-Edge Spectroscopy (XANES) analyses coupled with next-generation sequencing (Illumina Miseq). Two pilot-scale biofiltration columns for Fe (Filter 1) and Mn (Filter 2) were connected in series and installed at the Langham Water Treatment Plant in Saskatoon, Canada. The groundwater temperature ranged from 4 to 8 °C. The pilot-scale study showed that successful treatment (99% removal) of both Fe and Mn was achieved in the biofilters. However, the Mn removal was significantly retarded for four months, likely due to the slow growth of Mn-oxidizing bacteria (MnOB) in Filter 2. The removal of Mn was accelerated once the redox potential in Filter 2 exceeded +300 mV. At that point, the XANES analyses showed that the oxidization states of Mn in Filter 2 were mainly +3 and +4, confirming that Mn oxidization had occurred. Geochemical analyses (PHREEQCi) also indicated changed geochemical conditions that favoured the formation of Mn-oxides during biofiltration. Next-generation sequencing analyses indicated the enrichment of iron-oxidizing bacteria (FeOB), including Gallionella sp. and Sideroxydans sp., in Filter 1. There were high read numbers for MnOB relatives, including Pseudomonas sp., Hydrogenophaga sp., Bdellovibrio sp., and Leptothrix sp., in Filter 2. Furthermore, the addition of anthracite (coal-based filter media) positively affected the growth MnOB and enhanced Mn oxidization. The evidence obtained in this study provides insight into how Mn oxidization can be accelerated in cold groundwater treatment systems.

  9. Maize porridge enriched with a micronutrient powder containing low-dose iron as NaFeEDTA but not Amaranth grain flour reduces anemia and iron deficiency in Kenyan preschool children

    NARCIS (Netherlands)

    Macharia-Mutie, C.W.; Moretti, D.; Briel, van den N.; Omusundi, A.M.; Mwangi, A.M.; Kok, F.J.; Zimmerman, J.B.; Brouwer, I.D.

    2012-01-01

    Few studies have evaluated the impact of fortification with iron-rich foods such as amaranth grain and multi-micronutrient powder (MNP) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with amara

  10. Extreme iron enrichment and liquid immiscibility in mafic intrusions: Experimental evidence revisited

    Science.gov (United States)

    Veksler, Ilya V.

    2009-07-01

    This paper examines phase equilibria and mass balance constraints on Fe enrichment in tholeiitic liquids in plutonic environments. The peak of Fe enrichment is thought to roughly coincide with magma saturation in Fe-Ti oxides; and olivine starts to react with the liquid at about the same time. This crucial stage of crystallization is examined in detail using a compilation of chemical analyses of 64 experimental charges that comprise liquids (quenched glasses) equilibrated with the liquidus assemblage of olivine, plagioclase, high-Ca pyroxene, and low-Ca pyroxene. Some samples also contain Fe-Ti oxides. It is shown that the 4-phase liquidus assemblage does not constrain a narrow range of liquid compositions. The concentrations of SiO 2 in the selection of experimental glasses vary broadly from 42 to 66 wt.%. Silica content shows strong negative correlations with FeO and CaO/Al 2O 3, and strong positive correlation with alkalis. Extreme Fe enrichment above 22 wt.% FeO is observed only in alkali-free or alkali-poor liquids. Broad compositional variations for the multiply-saturated liquids are attributed to strong non-ideality and complex concentration-activity relationships in ferrobasaltic melts. Liquid immiscibility characteristic of Fe-rich silicate liquids is the ultimate consequence of non-ideality. Petrogenetic implications of phase equilibria and mass balance constraints are discussed for a classical example of the Skaergaard intrusion in East Greenland, where the trend of extreme Fe enrichment has been in contention. It is proposed that seemingly conflicting results of experiments on Skaergaard natural cumulate rocks and model melt compositions can be reconciled if it is assumed that silicate liquid immiscibility in Skaergaard started not at the very end of crystallization but earlier, soon after the start of ilmenite and magnetite crystallization.

  11. AGN feedback and iron enrichment in the powerful radio galaxy, 4C+55.16

    CERN Document Server

    Hlavacek-Larrondo, J; Sanders, J S; Taylor, G B

    2011-01-01

    We present a detailed X-ray analysis of 4C+55.16, an unusual and interesting radio galaxy, located at the centre of a cool core cluster of galaxies. 4C+55.16 is X-ray bright (~10^45 erg/s), radio powerful, and shows clear signs of interaction with the surrounding intracluster medium. By combining deep Chandra (100 ks) with 1.4 GHz VLA observations, we find evidence of multiple outbursts from the central AGN, providing enough energy to offset cooling of the ICM (P_bubbles=6.7x10^44 erg/s). Furthermore, 4C+55.16 has an unusual intracluster iron distribution showing a plume-like feature rich in Fe L emission that seems to run along one of the X-ray cavities. The excess of Fe associated with the plume is around 10^7M_sol. The metal abundances are consistent with being Solar-like, indicating that both SNIa and SNII contribute to the enrichment. The plume and southern cavity form a region of cool metal-rich gas. At the edge of this region, there is a clear discontinuity in temperature (from kT~2.5 keV to kT~5.0 keV...

  12. Iron stocks of buried Podzols: Endogenic iron deficits and potential exogenic enrichment in the Maashorst region, SE Netherlands

    NARCIS (Netherlands)

    J.M. van Mourik; S.J. de Vet

    2015-01-01

    Podzolation is the dominant soil forming process in chemical poor sandy soils. It iswell studied howiron concentrations of podzols are effected by translocation of active iron fromeluvial to illuvial horizons and leaching to the aquifer. Iron stocks of Podzols, in contrasts, have not been widely stu

  13. Middle Iron-Enriched Fructose Diet on Gestational Diabetes Risk and on Oxidative Stress in Offspring Rats.

    Science.gov (United States)

    Zein, Salam; Sitti, Farida; Osman, Mireille; Arnaud, Josiane; Batandier, Cécile; Gauchez, Anne-Sophie; Rachidi, Samar; Couturier, Karine; Hininger-Favier, Isabelle

    2017-02-01

    Gestational diabetes mellitus (GDM) is associated with increased insulin resistance and a heightened level of oxidative stress (OS). Additionally, high iron consumption could also increase insulin resistance and OS, which could aggravate GDM risk. The aim of this study is to evaluate a high fructose diet (F) as an alternative experimental model of GDM on rats. We also have evaluated the worst effect of a fructose iron-enriched diet (FI) on glucose tolerance and OS status during pregnancy. Anthropometric parameters, plasma glucose levels, insulin, and lipid profile were assessed after delivery in rats fed an F diet. The effects observed in mothers (hyperglycemia, and hyperlipidemia) and on pups (macrosomia and hypoglycemia) are similar to those observed in women with GDM. Therefore, the fructose diet could be proposed as an experimental model of GDM. In this way, we can compare the effect of an iron-enriched diet on the metabolic and redox status of mother rats and their pups. The mothers' glycemic was similar in the F and FI groups, whereas the glycemic was significantly different in the newborn. In rat pups born to mothers fed on an FI diet, the activities of the antioxidant enzyme glutathione peroxidase (GPx) and glutathione-S-transferase in livers and GPx in brains were altered and the gender analysis showed significant differences. Thus, alterations in the glycemic and redox status in newborns suggest that fetuses are more sensitive than their mothers to the effect of an iron-enriched diet in the case of GDM pregnancy. This study proposed a novel experimental model for GDM and provided insights on the effect of a moderate iron intake in adding to the risk of glucose disorder and oxidative damage on newborns.

  14. Chemical Forms of Heavy Metals in Carbonate—Derived Laterite and Enrichment of Its Iron Oxide Minerals

    Institute of Scientific and Technical Information of China (English)

    朱立军; 漆亮

    1997-01-01

    In this paper the seven-step continuous extracting method was employed in the study of chemical forms of the six heavy metals Co,Zn,Pb,Cu,Cr and Mn,The result shows that the etals in the laterite are present in the chemical form of crystalline iron oxides and residues,and they are transformed towared organic and exchangeable forms in the surface soil.Linear regression analysis indicates that the above heavy metals have a positive correlation with the crystalline iron oxide minerals.The crystalline iron oxide minerals have a very important role to play in the enrichment of heavy metals,especially the solid components in the laterite.

  15. Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

    Directory of Open Access Journals (Sweden)

    Jacek Rożnowski

    Full Text Available ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS. Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II and copper(II ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C were observed. Fortified native spelt starch with copper(II ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II ions in samples caused reduced its final viscosity by 170 (spelt starch and 103 mPa·s (monostarch phosphate. Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II ions and to 59.9% in case of iron(II ions.

  16. Analysis of Iron in Ferritin, the Iron-Storage Protein: A General Chemistry Experiment

    Science.gov (United States)

    Donlin, Maureen J.; Frey, Regina F.; Putnam, Christopher; Proctor, Jody; Bashkin, James K.

    1998-04-01

    The chemical properties of the iron-storage protein ferritin will be examined in this experiment by quantitating the average amount of iron in a ferritin sample, and observing the kinetics of iron release from the protein core under reducing conditions. Students learn and apply the principles of absorption spectroscopy, redox reactions, and metal chelation to study ferritin. The presentation of the basic concepts of protein and molecular structure is greatly enhanced through the use of a computer-based graphical tutorial which is available on the World Wide Web on the on the Washington University Department of Chemistry homepage. The computer-based tutorial serves as an introduction to three-dimensional structure and molecular structure-function relationships. The experiment is derived from a standard general-chemistry experiment in which the concentration of an iron unknown is determined spectroscopically using a chromophoric indicator. However, application of this technique to ferritin, which stores iron as an iron-oxide mineral core, helps to develop links between general chemistry and biology, and to use biological importance as a driving force for studying chemistry.

  17. Spectroelectrochemical Sensing of Aqueous Iron: An Experiment for Analytical Chemistry

    Science.gov (United States)

    Shtoyko, Tanya; Stuart, Dean; Gray, H. Neil

    2007-01-01

    We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical…

  18. Calcium-enriched goats' milk aids recovery of iron status better than calcium-enriched cows' milk, in rats with nutritional ferropenic anaemia.

    Science.gov (United States)

    Nestares, Teresa; Barrionuevo, Mercedes; Díaz-Castro, Javier; López-Aliaga, Inmaculada; Alférez, Ma José M; Campos, Margarita S

    2008-05-01

    Ca-Fe interactions are known, but no studies are available about the effects of Ca-enriched goat or cow milk on Fe status in nutritional ferropenic anaemia (NFA). To examine this matter, control and Fe-deficient rats were fed for 14 d with goat or cow milk diets containing either normal or high Ca content (5000 or 10,000 mg/kg diet), and different indices and parameters related to iron status were measured. The apparent digestibility coefficient (ADC) and the Fe retention/intake (R/I) ratio were higher in control and anaemic rats fed goat milk diet (G diet), despite high-Ca content. Ca enrichment decreased Fe stores in liver and sternum in anaemic rats fed cow milk diet (C diet), however G diet did not modify Fe content in the organs studied in control and anaemic rats. In anaemic rats, Ca-supplementation decreased haematocrit, but platelets and serum Fe were not affected, however, in control rats platelets increased except for Ca-enriched G diet, this fact reveals that Ca-Fe interaction is minimized with G diet. Serum ferritin was always higher in rats fed G vs. C diet, both in control and anaemic rats fed either normal or Ca-enriched diets. Ca-supplementation decreased ferritin levels in control and anaemic rats fed C diet and also, though to a lesser extent, in those given the G diet. This indicates that with this G diet there is a better recovery of body Fe stores in anaemic rats, despite Ca-supplementation. In this study it is noteworthy that despite high Ca content, a goat milk diet resulted in minimal Ca-Fe interactions and did not adversely affect Fe status in rats with NFA.

  19. Chemical fingerprint of iron oxides related to iron enrichment of banded iron formation from the Cauê Formation - Esperança Deposit, Quadrilátero Ferrífero, Brazil: a laser ablation ICP-MS study

    Directory of Open Access Journals (Sweden)

    Lucilia Aparecida Ramos de Oliveira

    Full Text Available Chemical signatures of iron oxides from dolomitic itabirite and high-grade iron ore from the Esperança deposit, located in the Quadrilátero Ferrífero, indicate that polycyclic processes involving changing of chemical and redox conditions are responsible for the iron enrichment on Cauê Formation from Minas Supergroup. Variations of Mn, Mg and Sr content in different generations of iron oxides from dolomitic itabirite, high-grade iron ore and syn-mineralization quartz-carbonate-hematite veins denote the close relationship between high-grade iron ore formation and carbonate alteration. This indicates that dolomitic itabirite is the main precursor of the iron ore in that deposit. Long-lasting percolation of hydrothermal fluids and shifts in the redox conditions have contributed to changes in the Y/Ho ratio, light/heavy rare earth elements ratio and Ce anomaly with successive iron oxide generations (martite-granular hematite, as well as lower abundance of trace elements including rare earth elements in the younger specularite generations.

  20. Synthesis of iron fertilization experiments : From the iron age in the age of enlightenment

    NARCIS (Netherlands)

    de Baar, HJW; Boyd, PW; Coale, KH; Landry, MR; Tsuda, A; Assmy, P; Bakker, DCE; Bozec, Y; Barber, RT; Brzezinski, MA; Buesseler, KO; Boye, M; Croot, PL; Gervais, F; Gorbunov, MY; Harrison, PJ; Hiscock, WT; Laan, P; Lancelot, C; Law, CS; Levasseur, M; Marchetti, A; Millero, FJ; Nishioka, J; Nojiri, Y; van Oijen, T; Riebesell, U; Rijkenberg, MJA; Saito, H; Takeda, S; Timmermans, KR; Veldhuis, MJW; Waite, AM

    2005-01-01

    [1] Comparison of eight iron experiments shows that maximum Chl a, the maximum DIC removal, and the overall DIC/ Fe efficiency all scale inversely with depth of the wind mixed layer (WML) defining the light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, and grazi

  1. Effects of Organic Enrichment on Sandy Beach Meiofauna:A Laboratory Microcosm Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Jianing; ZHOU Hong,; ZHANG Zhinan; CONG Bingqing; XU Shuhui

    2011-01-01

    Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach,China,were collected for field study,and subjected to organic enrichment in a laboratory microcosm experiment for 21 d.There were three different treatments including non-organic addition as the control,low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL).After 21 d,the meiofauna richness decreased in both organic enrichment treatments.Among the three treatments,total meiofauna abundance was significantly different,and the control groups had higher abundance than the other two treatment groups.However,the responses of the meiofauna abundance in the two organic enrichment treatments were non-significantly different.The relationship of meiofaunal abundance and nematode/copepod ratios to organic matter and oxygen level in the microcosm experiments were discussed.

  2. Iron and mixing affect biological carbon uptake in SOIREE and EisenEx, two Southern Ocean iron fertilisation experiments

    NARCIS (Netherlands)

    Bakker, Dorothee C.E.; Bozec, Yann; Nightingale, Philip D.; Goldson, Laura; Messias, Marie-José; Baar, Hein J.W. de; Liddicoat, Malcolm; Skjelvan, Ingunn; Strass, Volker; Watson, Andrew J.

    2005-01-01

    This study explores the changes in the surface water fugacity of carbon dioxide (fCO2) and biological carbon uptake in two Southern Ocean iron fertilisation experiments with different hydrographic regimes. The Southern Ocean Iron Release Experiment (SOIREE) experiment was carried out south of the An

  3. Scenes from a Science Classroom: An Enrichment Program Experience.

    Science.gov (United States)

    Brownstein, Erica M.; Destino, Thomas

    To increase the representation of African Americans in science fields, potential candidates must have positive personal science experiences. Even with recent reforms, most students in the United States have a limited exposure to science experiences, especially African American students. One approach to addressing this problem has been to offer…

  4. Cross-Pollination -- An Experiment in Language Enrichment

    Science.gov (United States)

    Breach, H. T.

    1975-01-01

    Describes an experiment with a second-year class of about 35 pupils in teaching English, French and Indonesian in an interconnected way, involving art and social studies as well as language and literature. Although the experiment is as yet unevaluated, the general effect was considered encouraging. (KM)

  5. Cross-Pollination -- An Experiment in Language Enrichment

    Science.gov (United States)

    Breach, H. T.

    1975-01-01

    Describes an experiment with a second-year class of about 35 pupils in teaching English, French and Indonesian in an interconnected way, involving art and social studies as well as language and literature. Although the experiment is as yet unevaluated, the general effect was considered encouraging. (KM)

  6. Maize porridge enriched with a micronutrient powder containing low-dose iron as NaFeEDTA but not amaranth grain flour reduces anemia and iron deficiency in Kenyan preschool children.

    Science.gov (United States)

    Macharia-Mutie, Catherine W; Moretti, Diego; Van den Briel, Natalie; Omusundi, Agnes M; Mwangi, Alice M; Kok, Frans J; Zimmermann, Michael B; Brouwer, Inge D

    2012-09-01

    Few studies have evaluated the impact of fortification with iron-rich foods such as amaranth grain and multi-micronutrient powder (MNP) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with amaranth grain or MNP to reduce IDA in Kenyan preschool children. In a 16-wk intervention trial, children (n = 279; 12-59 mo) were randomly assigned to: unrefined maize porridge (control; 4.1 mg of iron/meal; phytate:iron molar ratio 5:1); unrefined maize (30%) and amaranth grain (70%) porridge (amaranth group; 23 mg of iron/meal; phytate:iron molar ratio 3:1); or unrefined maize porridge with MNP (MNP group; 6.6 mg iron/meal; phytate:iron molar ratio 2.6:1; 2.5 mg iron as NaFeEDTA). Primary outcomes were anemia and iron status with treatment effects estimated relative to control. At baseline, 38% were anemic and 30% iron deficient. Consumption of MNP reduced the prevalence of anemia [-46% (95% CI: -67, -12)], iron deficiency [-70% (95% CI: -89, -16)], and IDA [-75% (95% CI: -92, -20)]. The soluble transferrin receptor [-10% (95% CI: -16, -4)] concentration was lower, whereas the hemoglobin (Hb) [2.7 g/L (95% CI: 0.4, 5.1)] and plasma ferritin [40% (95% CI: 10, 95)] concentrations increased in the MNP group. There was no significant change in Hb or iron status in the amaranth group. Consumption of maize porridge fortified with low-dose, highly bioavailable iron MNP can reduce the prevalence of IDA in preschool children. In contrast, fortification with amaranth grain did not improve iron status despite a large increase in iron intake, likely due to high ratio of phytic acid:iron in the meal.

  7. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    Science.gov (United States)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-06-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  8. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    Science.gov (United States)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-02-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  9. An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean

    Directory of Open Access Journals (Sweden)

    F. Chever

    2009-07-01

    Full Text Available Total dissolvable iron (TDFe was measured in the water column above and in the surrounding of the Kerguelen Plateau (Indian sector of the Southern Ocean during the KErguelen Ocean Plateau compared Study (KEOPS cruise. TDFe concentrations ranged from 0.90 to 65.6 nmol L−1 above the plateau and from 0.34 to 2.23 nmol L−1 offshore of the plateau. Station C1 located south of the plateau, near Heard Island, exhibited very high values (329–770 nmol L−1. Apparent particulate iron (Feapp, calculated as the difference between the TDFe and the dissolved iron measured on board (DFe represented 95±5% of the TDFe above the plateau, suggesting that particles and refractory colloids largely dominated the iron pool. This paper presents a budget of DFe and Feapp above the plateau. Lateral advection of water that had been in contact with the continental shelf of Heard Island seems to be the predominant source of Feapp and DFe above the plateau, with a supply of 9.7±2.3×106 and 8.3±6.7×103 mol d−1, respectively. The residence times of 1.7 and 48 days estimated for Feapp and DFe, respectively, indicate a rapid turnover in the surface water. A comparison between Feapp and total particulate iron (TPFe suggests that the total dissolved fraction is mainly constituted of small refractory colloids. This fraction does not seem to be a potential source of iron to the phytoplankton in our study. Finally, when taking into account the lateral supply of dissolved iron, the seasonal carbon sequestration efficiency was estimated at 154 000 mol C (mol Fe−1, which is 4-fold lower than the previously estimated value in this area but still 18-fold higher than the one estimated during the other study of a natural iron fertilisation experiment, CROZEX.

  10. An iron budget during the natural iron fertilisation experiment KEOPS (Kerguelen Islands, Southern Ocean

    Directory of Open Access Journals (Sweden)

    F. Chever

    2010-02-01

    Full Text Available Total dissolvable iron (TDFe was measured in the water column above and in the surrounding of the Kerguelen Plateau (Indian sector of the Southern Ocean during the KErguelen Ocean Plateau compared Study (KEOPS cruise. TDFe concentrations ranged from 0.90 to 65.6 nmol L−1 above the plateau and from 0.34 to 2.23 nmol L−1 offshore of the plateau. Station C1 located south of the plateau, near Heard Island, exhibited very high values (329–770 nmol L−1. Apparent particulate iron (Feapp, calculated as the difference between the TDFe and the dissolved iron measured on board (DFe represented 95±5% of the TDFe above the plateau, suggesting that particles and refractory colloids largely dominated the iron pool. This paper presents a budget of DFe and Feapp above the plateau. Lateral advection of water that had been in contact with the continental shelf of Heard Island seems to be the predominant source of Feapp and DFe above the plateau, with a supply of 9.7±3.6×106 and 8.3±11.6×103 mol d−1, respectively. The residence times of 1.7 and 48 days estimated for Feapp and DFe respectively, indicate a rapid turnover in the surface water. A comparison between Feapp and total particulate iron (TPFe suggests that the total dissolved fraction is mainly constituted of small refractory colloids. This fraction does not seem to be a potential source of iron to the phytoplankton in our study. Finally, when taking into account the lateral supply of dissolved iron, the seasonal carbon sequestration efficiency was estimated at 154 000 mol C (mol Fe−1, which is 4-fold lower than the previously estimated value in this area but still 18-fold higher than the one estimated during the other study of a natural iron fertilisation experiment, CROZEX.

  11. Enriching the Ensemble Experience for Students with Visual Impairments

    Science.gov (United States)

    Siligo, Wayne Roy

    2005-01-01

    This article will give music educators some practical tools and information for helping students with visual impairments enjoy the ensemble experience. The author has used these tools as music director at the California School for the Blind (CSB) and as a musician who is visually impaired. All observations and techniques mentioned here come out of…

  12. An improved cell recovery method for iron oxidizing bacterial (IOB) enrichments

    DEFF Research Database (Denmark)

    Yu, Ran; Graf, Joerg; Smets, Barth F.

    2008-01-01

    Two cell recovery methods for IOB enrichments were evaluated for DNA extraction and further PCR-based 16S rRNA gene clone library creation. One was a published method consisting of heating plus oxalic acid treatment and the other one was a new method based on enzymatic agarose digestion (using β......-agarase I). The results indicated that the enzymatic method was much gentler on IOB cells and yielded an approximately 5000-fold higher DNA mass than the published method. The 16S rRNA gene clone library developed from the β-agarase I treated IOB enrichments indicated a high IOB community diversity...

  13. Computational design of short pulse laser driven iron opacity experiments

    Science.gov (United States)

    Martin, M. E.; London, R. A.; Goluoglu, S.; Whitley, H. D.

    2017-02-01

    The resolution of current disagreements between solar parameters calculated from models and observations would benefit from the experimental validation of theoretical opacity models. Iron's complex ionic structure and large contribution to the opacity in the radiative zone of the sun make iron a good candidate for validation. Short pulse lasers can be used to heat buried layer targets to plasma conditions comparable to the radiative zone of the sun, and the frequency dependent opacity can be inferred from the target's measured x-ray emission. Target and laser parameters must be optimized to reach specific plasma conditions and meet x-ray emission requirements. The HYDRA radiation hydrodynamics code is used to investigate the effects of modifying laser irradiance and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of iron and iron-magnesium buried layer targets. It was determined that plasma conditions are dominantly controlled by the laser energy and the tamper thickness. The accuracy of the inferred opacity is sensitive to tamper emission and optical depth effects. Experiments at conditions relevant to the radiative zone of the sun would investigate the validity of opacity theories important to resolving disagreements between solar parameters calculated from models and observations.

  14. Arsenic enrichment in estuarine sediments-impact of iron and manganese mining

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, M.; Joseph, T.; Balachandran, K.K.; Nair, K.K.C.; Paimpillii, J.S.

    of Mandovi-Zuari catchments area has approximately 50.04 mu g/g of arsenic and partial dissolution of the mining rejects could enrich the dissolved arsenic in estuaries. The seasonal variability of arsenic in water column and in the sediments was investigated...

  15. Replicating the Z iron opacity experiments on the NIF

    Science.gov (United States)

    Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Ross, P. W.; Kline, J. L.; Flippo, K. A.; Sherrill, M. E.; Dodd, E. S.; DeVolder, B. G.; Cardenas, T.; Archuleta, T. N.; Craxton, R. S.; Zhang, R.; McKenty, P. W.; Garcia, E. M.; Huffman, E. J.; King, J. A.; Ahmed, M. F.; Emig, J. A.; Ayers, S. L.; Barrios, M. A.; May, M. J.; Schneider, M. B.; Liedahl, D. A.; Wilson, B. G.; Urbatsch, T. J.; Iglesias, C. A.; Bailey, J. E.; Rochau, G. A.

    2017-06-01

    X-ray opacity is a crucial factor of all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in the simulation codes. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment, casting doubt on the validity of the opacity models. Therefore, a new experimental opacity platform is being developed on the National Ignition Facility (NIF) not only to verify the Z-machine experimental results but also to extend the experiments to other temperatures and densities. The first experiments will be directed towards measuring the opacity of iron at a temperature of ∼160 eV and an electron density of ∼7 × 1021 cm-3. Preliminary experiments on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule and also a hohlraum that can heat the opacity sample to the desired conditions. The first of these iron opacity experiments is expected to be performed in 2017.

  16. Simulating Experiments on Enrichment of Gold by Bacteria and Their Geochemical Significance

    Institute of Scientific and Technical Information of China (English)

    张景荣; 陆建军; 等

    1997-01-01

    The experiments on the enrichment of gold by bacteria indicate that bacteria have a very intense capacity of enriching gold and act as an arrester of trace gold in sea water,Bacteria enrich gold in two forms:absorption and adsorption.Absorption means that gold finds its way into organisms and it is combined with the mercapto group of protein,whereas adsorption means that gold is adsorbed on organisma by amino acid secreted by cell walls,Bacteria are organisms with very high vitality and reproductive capacity and huge productivity in nature Bacteria,which are important geolgical agents for gold enrichment and can exert effects on geological environments by their metabolism,are of important geochemical significance for the formation of gold-bearing black rock series.

  17. [Formation and environmental implications of iron-enriched precipitates derived from natural neutralization of acid mine drainage].

    Science.gov (United States)

    Zhou, Yue-Fei; Xie, Yue; Zhou, Li-Xiang

    2010-06-01

    Acid mine drainage (AMD) and its natural neutralizing products in Wangjiatan iron mine were collected and analyzed by using spectroscopic and electron microanalytic methods. The results show that after natural neutralization of AMD by surface water of the stream, acidity and electric conductivity of AMD are both decreased. While for dissolved elements, no other element is obviously decreased except for Fe3+, SO4(2-), and Ca2+. For precipitates formed by natural neutralization, Fe is enriched and ferrihydrite is the main iron mineral, with little amount of goethite and fibroferrite contained in downstream precipitates. To ferrihydrite, 2-line and 6-line ferrihydrite are the main mineral type in upstream and downstream precipitates, respectively. Furthermore, for all precipitates, two layers are observed. In outer layer 2-line ferrihydrite is the main mineral, while in inner layer 6-line ferrihydrite and goethite are the main minerals. Ferrihydrite dominated precipitates are favorable in immobilizing toxic and hazardous elements. Furthermore, it is demonstrated that pH and the concentration of SO4(2-) are decisive factors for ferrihydrite formation. The ferrihydrite translocation and its attenuation for toxic elements are, to a great extent, affected by hydrodynamics in neutralization zone.

  18. On Iron Enrichment, Star Formation, and Type Ia Supernovae in Galaxy Clusters

    Science.gov (United States)

    Loewenstein, Michael

    2006-01-01

    The nature of star formation and Type Ia supernovae (SNIa) in galaxies in the field and in rich galaxy clusters are contrasted by juxtaposing the buildup of heavy metals in the universe inferred from observed star formation and supernovae rate histories with data on the evolution of Fe abundances in the intracluster medium (ICM). Models for the chemical evolution of Fe in these environments are constructed, subject to observational constraints, for this purpose. While models with a mean delay for SNIa of 3 Gyr and standard initial mass function (IMF) are fully consistent with observations in the field, cluster Fe enrichment immediately tracked a rapid, top-heavy phase of star formation - although transport of Fe into the ICM may have been more prolonged and star formation likely continued beyond redshift 1. The means of this prompt enrichment consisted of SNII yielding greater than or equal to 0.1 solar mass per explosion (if the SNIa rate normalization is scaled down from its value in the field according to the relative number of candidate progenitor stars in the 3 - 8 solar mass range) and/or SNIa with short delay times originating during the rapid star formation epoch. Star formation is greater than 3 times more efficient in rich clusters than in the field, mitigating the overcooling problem in numerical cluster simulations. Both the fraction of baryons cycled through stars, and the fraction of the total present-day stellar mass in the form of stellar remnants, are substantially greater in clusters than in the field.

  19. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  20. Iron

    Science.gov (United States)

    ... of iron stored in the body become low, iron deficiency anemia sets in. Red blood cells become smaller and ... from the lungs throughout the body. Symptoms of iron deficiency anemia include tiredness and lack of energy, GI upset, ...

  1. On Iron Enrichment, Star Formation, and Type Ia Supernovae in Galaxy Clusters

    CERN Document Server

    Loewenstein, M

    2006-01-01

    The nature of star formation and Type Ia supernovae (SNIa) in galaxies in the field and in rich galaxy clusters are contrasted by juxtaposing the build-up of heavy metals in the universe inferred from observed star formation and supernovae rate histories with data on the evolution of Fe abundances in the intracluster medium (ICM). Models for the chemical evolution of Fe in these environments are constructed, subject to observational constraints, for this purpose. While models with a mean delay for SNIa of 3 Gyr and standard initial mass function (IMF) are consistent with observations in the field, cluster Fe enrichment immediately tracks a rapid, top-heavy phase of star formation -- although transport of Fe into the ICM may be more prolonged and star formation likely continues to redshifts 3 times more efficient in rich clusters than in the field, mitigating the overcooling problem in numerical cluster simulations. Both the fraction of baryons cycled through stars, and the fraction of the total present-day st...

  2. Outstanding Lobelia dortmanna in iron armor

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Møller, Claus Lindskov; Raun, Ane-Marie Løvendahl

    2008-01-01

    .4%) of degradable organic matter. Coatings of oxidized iron on roots in organically enriched sediments reduce radial oxygen loss and, thereby, increase internal concentrations and supply of oxygen to root tips. Oxidized iron is also a redox buffers which may prevent the ingress of sulfides and other reduced toxic...... solutes during nights. Controlled experiments are under way to test if iron enrichment can help survival of rosette species threatened by lake pollution or whether removal of organic surface sediments is required....

  3. Synthesis of iron fertilization experiments: From the Iron Age in the Age of Enlightenment

    Science.gov (United States)

    de Baar, Hein J. W.; Boyd, Philip W.; Coale, Kenneth H.; Landry, Michael R.; Tsuda, Atsushi; Assmy, Philipp; Bakker, Dorothee C. E.; Bozec, Yann; Barber, Richard T.; Brzezinski, Mark A.; Buesseler, Ken O.; Boyé, Marie; Croot, Peter L.; Gervais, Frank; Gorbunov, Maxim Y.; Harrison, Paul J.; Hiscock, William T.; Laan, Patrick; Lancelot, Christiane; Law, Cliff S.; Levasseur, Maurice; Marchetti, Adrian; Millero, Frank J.; Nishioka, Jun; Nojiri, Yukihiro; van Oijen, Tim; Riebesell, Ulf; Rijkenberg, Micha J. A.; Saito, Hiroaki; Takeda, Shigenobu; Timmermans, Klaas R.; Veldhuis, Marcel J. W.; Waite, Anya M.; Wong, Chi-Shing

    2005-09-01

    Comparison of eight iron experiments shows that maximum Chl a, the maximum DIC removal, and the overall DIC/Fe efficiency all scale inversely with depth of the wind mixed layer (WML) defining the light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, and grazing play additional roles. The Southern Ocean experiments were most influenced by very deep WMLs. In contrast, light conditions were most favorable during SEEDS and SERIES as well as during IronEx-2. The two extreme experiments, EisenEx and SEEDS, can be linked via EisenEx bottle incubations with shallower simulated WML depth. Large diatoms always benefit the most from Fe addition, where a remarkably small group of thriving diatom species is dominated by universal response of Pseudo-nitzschia spp. Significant response of these moderate (10-30 μm), medium (30-60 μm), and large (>60 μm) diatoms is consistent with growth physiology determined for single species in natural seawater. The minimum level of "dissolved" Fe (filtrate < 0.2 μm) maintained during an experiment determines the dominant diatom size class. However, this is further complicated by continuous transfer of original truly dissolved reduced Fe(II) into the colloidal pool, which may constitute some 75% of the "dissolved" pool. Depth integration of carbon inventory changes partly compensates the adverse effects of a deep WML due to its greater integration depths, decreasing the differences in responses between the eight experiments. About half of depth-integrated overall primary productivity is reflected in a decrease of DIC. The overall C/Fe efficiency of DIC uptake is DIC/Fe ˜ 5600 for all eight experiments. The increase of particulate organic carbon is about a quarter of the primary production, suggesting food web losses for the other three quarters. Replenishment of DIC by air/sea exchange tends to be a minor few percent of primary CO2 fixation but will continue well after observations have stopped. Export of

  4. Improvement of electrochemical activity of LiMnPO4-based cathode by surface iron enrichment

    Science.gov (United States)

    Xu, Xiaoyue; Wang, Tao; Bi, Yujing; Liu, Meng; Yang, Wenchao; Peng, Zhe; Wang, Deyu

    2017-02-01

    LiMnPO4 has attracted massive interests due to its appropriate redox potential and the success of its iron comparative in the lithium ion batteries. The bulk substitution has been widely used to address the poor electrochemical activity of LiMnPO4, which is much lower than that of LiFePO4. In this work, we compare the performance of the core-shell structure and the homogeneous substitution with the same Mn/Fe molar ratio of LiMn0.8Fe0.2PO4. The core-shell phosphate material after carbon coating is composed of a core part of quasi-single LiMnPO4 phase, and a 3-4 nm shell layer of quasi-single LiFePO4-phase, separated by the phase boundary with 1-2 nm thickness. It is interesting to reveal that the core-shell samples exhibit capacities of 156.4, 144.5, 128.2 mAh g-1 under 0.1C, 1C and 5C respectively, which are 5-10% higher than that of the homogenous substituted LiMn0.8Fe0.2PO4 at the corresponding rates, while both of these samples present excellent cyclic stability, still retaining ∼95% of the initial capacities after 1000 cycles under 1C discharging rate. Our results demonstrate that the main reason for LiMnPO4's poor electrochemical activity should be emphasized on the surface polarization, whereas the tardiness on bulk transportation is not as serious as it was presumed.

  5. Improving iron-enriched basalt with additions of ZrO{sub 2} and TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, G.A.; Kong, P.C.

    1993-06-01

    The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified to IEB4 by adding sufficient ZrO{sub 2} and TiO{sub 2} to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi{sub 2}O{sub 7}) is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium have been found that have endured more than 2 billion years of natural processes. On this basis, zirconolite was considered to be an ideal host crystal for the actinides contained in transuranic (TRU)-contaminated wastes. Crystals of zirconolite were developed in laboratory melts of IEB4 that contained 5% each of ZrO{sub 2} and TiO{sub 2} and that were slow-cooled in the 1200--1000{degrees}C range. When actinide surrogates were added to IEB4, these oxides were incorporated into the crystals of zirconolite rather than precipitating in the residual glass phase. Zirconolite crystals developed in IEB4 should stabilize and immobilize the dilute TRUs in heterogeneous, buried low-level wastes as effectively as this same phase does in the various formulations of Synroc used for the more concentrated TRUs encountered in high-level wastes. Synroc requires hot-pressing equipment, while IEB4 precipitates zirconolite from a cooling basaltic melt.

  6. CdWO4 crystal scintillators from enriched isotopes for double beta decay experiments

    CERN Document Server

    Poda, D V; Belli, P; Bernabei, R; Boiko, R S; Brudanin, V B; Cappella, F; Caracciolo, V; Castellano, S; Cerulli, R; Chernyak, D M; Danevich, F A; d'Angelo, S; Degoda, V Ya; Di Vacri, M L; Dossovitskiy, A E; Galashov, E N; Incicchitti, A; Kobychev, V V; Konovalov, S I; Kovtun, G P; Laubenstein, M; Mikhlin, A L; Mokina, V M; Nikolaiko, A S; Nisi, S; Podviyanuk, R B; Polischuk, O G; Shcherban, A P; Shlegel, V N; Solopikhin, D A; Tretyak, V I; Umatov, V I; Vasiliev, Ya V; Virich, V D

    2013-01-01

    Cadmium tungstate crystal scintillators enriched in 106Cd and 116Cd were developed. The produced scintillators exhibit good optical and scintillation properties, and a low level of radioactive contamination. Experiments to search for double beta decay of 106Cd and 116Cd are in progress at the Gran Sasso National Laboratories of the INFN (Italy). Prospects to further improve the radiopurity of the detectors by recrystallization are discussed.

  7. A layered magnetic iron/iron oxide nanoscavenger for the analytical enrichment of ng-L(-1) concentration levels of heavy metals from water.

    Science.gov (United States)

    Karatapanis, Andreas E; Petrakis, Dimitrios E; Stalikas, Constantine D

    2012-05-13

    Magnetically driven separation techniques have received considerable attention in recent decade because of their great potential application. In this study, we investigate the application of an unmodified layered magnetic Fe/Fe(2)O(3) nanoscavenger for the analytical enrichment and determination of sub-parts per billion concentrations of Cd(II), Pb(II), Ni(II), Cr(VI) and As(V) from water samples. The synthesized nanoscavenger was characterized by BET, TGA, XRD and IR and the parameters influencing the extraction and recovery of the preconcentration process were assessed by atomic absorption spectrometry. The possible mechanism of the enrichment of heavy metals on Fe/Fe(2)O(3) was proposed, which involved the dominant adsorption and reduction. The nanoscale size offers large surface area and high reactivity of sorption and reduction reactions. The obtained limits of detection for the metals studied were in the range of 20-125 ng L(-1) and the applicability of the nanomaterial was verified using a real sample matrix. The method is environmentally friendly as only 15 mg of nanoscavenger are used, no organic solvent is required for the extraction and the experiment is performed without the need for filtration or preparation of packed preconcentration columns.

  8. Seasonal Nutrient Enrichment Experiment in Homa Lagoon (İzmir Bay, Aegean Sea

    Directory of Open Access Journals (Sweden)

    Banu Kutlu

    2014-05-01

    Full Text Available In order to determine the effects of nutrient (P, Si, NH4, NO3 enrichment on the growth of phytoplankton in Homa Lagoon (İzmir Bay, Aegean Sea, experiments of enrichment with discontinuous cultures have been executed seasonally in 2007. In our study, the elements limiting the growth of phytoplankton were NO3, P and Si in spring season, N and P in summer season, and NH4 in autumn and winter seasons. So, it has been determined that the addition of nitrogen (N and phosphor (P has led significant change in biomass and growth of phytoplankton. It has also been observed that diatom and dinoflagellate species have grown under various concentrations of, especially, Silicate (Si and nitrogen (N.

  9. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the β-cell is complex. Excess free iron is toxic......, but at the same time, iron is required for normal β-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to present...... and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...

  10. Identification of enzymes involved in anaerobic benzene degradation by a strictly anaerobic iron-reducing enrichment culture.

    Science.gov (United States)

    Abu Laban, Nidal; Selesi, Draženka; Rattei, Thomas; Tischler, Patrick; Meckenstock, Rainer U

    2010-10-01

    Anaerobic benzene degradation was studied with a highly enriched iron-reducing culture (BF) composed of mainly Peptococcaceae-related Gram-positive microorganisms. The proteomes of benzene-, phenol- and benzoate-grown cells of culture BF were compared by SDS-PAGE. A specific benzene-expressed protein band of 60 kDa, which could not be observed during growth on phenol or benzoate, was subjected to N-terminal sequence analysis. The first 31 amino acids revealed that the protein was encoded by ORF 138 in the shotgun sequenced metagenome of culture BF. ORF 138 showed 43% sequence identity to phenylphosphate carboxylase subunit PpcA of Aromatoleum aromaticum strain EbN1. A LC/ESI-MS/MS-based shotgun proteomic analysis revealed other specifically benzene-expressed proteins with encoding genes located adjacent to ORF 138 on the metagenome. The protein products of ORF 137, ORF 139 and ORF 140 showed sequence identities of 37% to phenylphosphate carboxylase PpcD of A. aromaticum strain EbN1, 56% to benzoate-CoA ligase (BamY) of Geobacter metallireducens and 67% to 3-octaprenyl-4-hydroxybenzoate carboxy-lyase (UbiD/UbiX) of A. aromaticum strain EbN1 respectively. These genes are proposed as constituents of a putative benzene degradation gene cluster (∼ 17 kb) composed of carboxylase-related genes. The identified gene sequences suggest that the initial activation reaction in anaerobic benzene degradation is probably a direct carboxylation of benzene to benzoate catalysed by putative anaerobic benzene carboxylase (Abc). The putative Abc probably consists of several subunits, two of which are encoded by ORFs 137 and 138, and belongs to a family of carboxylases including phenylphosphate carboxylase (Ppc) and 3-octaprenyl-4-hydroxybenzoate carboxy-lyase (UbiD/UbiX).

  11. Creating 13C- and 15N-enriched tree leaf litter for decomposition experiments

    Science.gov (United States)

    Szlavecz, K. A.; Pitz, S.; Chang, C.; Bernard, M.

    2013-12-01

    Labeling plant material with heavy isotopes of carbon and nitrogen can produce a traceable nutrient signal that can be followed into the different trophic levels and decomposer food web. We treated 60 tree saplings with 13C-enriched CO2 gas and 15N-enriched ammonium nitrate over a three-month period to create dually-labeled plant material for future decomposition experiments. The trees included both early (Red maple, Sweetgum, Tulip poplar) and late (American beech, White oak) successional deciduous tree species, and a conifer, White pine. We constructed a 2.4 m × 2.4 m × 2.4 m environmental chamber that was climate-controlled using an air conditioning system. An Arduino microcontroller interfaced with a Vaisala GMP343 CO2 probe maintained a CO2 concentration between 500-520 ppm by controlling a solenoid valve on the CO2 tank regulator. The trees were placed into the chamber in August 2012 and remained until senescence unless they were lost to death or disease. Ammonium nitrate was added twice, in September and October. Leaf samples were collected prior to the start of the experiment and after senescence, whereas root samples were collected only in December. Samples were dried, ground and analyzed using an isotope ratio mass spectrometer. American beech and White oak had 40% mortality, and 34% of tulip poplar trees were removed because of powdery mildew overgrowth or death. Most tulip poplar trees exhibited a second leaf out following senescence in late September. Nearly 1 kg of litter was produced with tulip poplar representing over half of the total mass. Levels of enrichment varied greatly by species. Beech (-14.2‰) and White oak (-4.8‰) had low levels of enrichment in comparison to early successional species such as Sweetgum (41.7‰) and Tulip poplar (30.7‰ [first leaf fall] and 238.0‰ [second leaf fall]). Leaf enrichment with 15N followed a similar pattern, though it was achieved at a higher level with δ15N values varying from 271.6‰ to 1354.2

  12. Mineralogical investigations of the interaction between iron corrosion products and bentonite from the NF-PRO Experiments (Phase 1)

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Cave, M.R.; Kemp, S.J.; Taylor, B.H.; Vickers, B.P.; Green, K.A.; Williams, C.L.; Shaw, R.A. (British Geological Survey (United Kingdom))

    2009-01-15

    This report summarises the findings of a programme of work under taken by the British Geological Survey (BGS) on behalf of SKB, to characterise the mineralogical alteration of compacted bentonite from experiments designed to study the interaction between iron corrosion and bentonite. The experiments were undertaken by Serco Assurance (Culham Laboratory, Oxfordshire, United Kingdom), and were co-funded by SKB within the EU Framework 6 NF-PRO Project. Reacted bentonite residues from three NF-PRO Experiments - NFC12, NFC16 and NFC17 were examined by BGS using; X-ray diffraction analysis (XRD); petrographical analysis with backscattered scanning electron microscopy (BSEM) and energy-dispersive X-ray microanalysis (EDXA) techniques, cation exchange capacity (CEC) and exchangeable cation analysis; and sequential chemical extraction. Bentonite immediately adjacent to corroding steel was found to have interacted with Fe released from the corroding metal. This resulted in the formation of narrow haloes of altered bentonite around the corroding steel wires, in which the clay matrix was significantly enriched in Fe. Detailed petrographical observation found no evidence for the formation of discrete iron oxide or iron oxyhydroxide phases within the clay matrix but appeared to show that the clay particles themselves had become enriched in Fe. XRD observations indicated a slight increase in d002/d003 peak ratio, which could possibly be accounted for by a small amount of substitution of Fe into the octahedral layers of the montmorillonite. If correct, then this alteration might represent the early stages of conversion of the dioctahedral montmorillonite to an iron-rich dioctahedral smectite such as nontronite. Alternatively, the same effect may have been produced as a result of the displacement of exchangeable interlayer cations by Fe and subsequent conversion to form additional Fe-rich octahedral layers. In either case, the XRD results are consistent with the petrographical

  13. [INFLUENCE OF THE REGULAR INTAKE OF FERMENTED MILK PRODUCTS ENRICHED BY MICRONUTRIENTS ON SOME INDICES OF IRON METABOLISM IN ADOLESCENTS INVOLVED IN SPORTS].

    Science.gov (United States)

    Turchaninov, D V; Bovarskaya, L A; Bogdashin, I V; Bagrova, L V; Gotwald, A R; Kozubenko, O V

    2015-01-01

    There was performed an experimental study of the influence of regular intake offermented milk enriched by products "Bifidin" and "Prolacta" on indices of iron metabolism in adolescents of 12-17 years, involved in sports (n = 94). In all study participants there was made double blood test (every 60 days), there were determined the levels of hemoglobin, serum iron, serum ferritin, C-reactive protein. The intervention in the main group (n = 68) was in daily intake offermented milk product in a volume of 200 ml (1 Cup) in addition to the normal diet within 2 months, including 35 cases who had used the bioproduct "Bifidin" and 33 persons- bioproduct "Prolacta". The control group was consisted of 26 persons from the adolescents engaged in the same sections, but not taking additional fermented milk drinks. The average values of all studied indices in adolescent athletes of the main and control groups before and after the intervention were consistent with reference values. Latent iron deficiency was detected in 23.4 ± 4.4% of adolescents involved in sports. At the second point of the research in two months of intake of enriched dairy products in the main group there was noticed the gain in levels of serum iron, ferritin, and the decline of the concentration of C-reactive protein. The results of the study allow us to consider enriched dairy products "Bifidin" and "Prolacta" as one of the components of complex measures of prophylaxis of hypovitaminosis and microelementoses in adolescents who are actively involved in sports.

  14. Ocean iron cycle

    Science.gov (United States)

    Boyd, Philip W.

    Interest in the biogeochemical cycle of iron has grown rapidly over the last two decades, due to the potential role of this element in modulating global climate in the geological past and ocean productivity in the present day. This trace metal has a disproportionately large effect (1 × 105 C:Fe) on photosynthetic carbon fixation by phytoplankton. In around one third of the open ocean, so-called high-nitrate low-chlorophyll (HNLC) regions, the resident phytoplankton have low growth rates despite an abundance of plant nutrients. This is due to the low supply of iron. Iron is present in the ocean in three phases, dissolved, colloidal, and particulate (biogenic and lithogenic). However, iron chemistry is complex with interactions between chemistry and biology such as the production of iron-binding siderophores by oceanic bacteria. This results in the interplay of inorganic chemistry, photochemistry, and organic complexation. Sources of new iron include dust deposition, upwelling of iron-rich deep waters, and the resuspension and lateral transport of sediments. Sinks for iron are mainly biological as evidenced by the vertical nutrient-like profile for dissolved iron in the ocean. Iron is rapidly recycled by the upper ocean biota within a so-called "ferrous wheel." The fe ratio [(new iron)/(new + regenerated iron)] provides an index of the relative supply of iron to the biota by new versus recycled iron. Over the last 15 years, interest in the potential role of iron in shaping climate in the geological past resulted in some of the most ambitious experiments in oceanography: large-scale (i.e., 50-1000 km2) iron enrichment of HNLC waters. They have provided valuable insights into how iron supply influences the biogeochemical cycles of elements such as carbon, sulfur, silicon, nitrogen, and phosphate.

  15. Measurement of Iron in Egg Yolk: An Instrumental Analysis Experiment Using Biochemical Principles

    Science.gov (United States)

    Maloney, Kevin M.; Quiazon, Emmanuel M.; Indralingam, Ramee

    2008-01-01

    The generally accepted method to determine iron content in food is by acid digestion or dry ashing and subsequent flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. We have developed an experiment that chemically extracts the iron from an egg yolk and quantifies it using UV-vis absorption…

  16. Measurement of Iron in Egg Yolk: An Instrumental Analysis Experiment Using Biochemical Principles

    Science.gov (United States)

    Maloney, Kevin M.; Quiazon, Emmanuel M.; Indralingam, Ramee

    2008-01-01

    The generally accepted method to determine iron content in food is by acid digestion or dry ashing and subsequent flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. We have developed an experiment that chemically extracts the iron from an egg yolk and quantifies it using UV-vis absorption…

  17. Sensorial evaluation of nutritional supplements (PROGRESA) enriched with 3 different forms of iron in a rural Mexican community.

    Science.gov (United States)

    Morales, J; Vargas, F; Cassís, L; Sánchez, E; Villalpando, S

    2008-01-01

    As part of the efforts to reduce iron deficiency anemia (IDA), the Mexican Federal program PROGRESA distributes complementary foods to toddlers and pregnant women living in extreme poverty. Complementary foods were originally fortified with hydrogen-reduced iron, which proved a limited efficacy. The supplement was reformulated to provide higher iron bioavailability. This investigation aims to assess the sensory changes and the acceptance of new versions of the complementary foods fortified with either reduced iron, ferrous fumarate, or ferrous sulfate, stored at room temperature for 2, 4, and 6 mo. Complementary foods were presented without flavor (plain) or flavored with either chocolate or vanilla. The complementary foods were evaluated in toddlers and their mothers using a hedonic scale. The percentage of overall acceptance for the baby foods was higher in toddlers (80% to 88%) than in their mothers (63% to 68%). The complementary foods with a better acceptance were those fortified with reduced iron (63% to 68%) and ferrous fumarate (61% to 80%) independently of the flavoring added. The acceptance of the beverage intended for women was better for those fortified with reduced iron (52% to 63%) or ferrous fumarate (44% to 63%) in their vanilla-flavored version. For women, the most accepted sources of iron were reduced iron (50% to 60%) and ferrous fumarate (50% to 58%).

  18. ForCent model development and testing using the Enriched Background Isotope Study experiment

    Energy Technology Data Exchange (ETDEWEB)

    Parton, W.J.; Hanson, P. J.; Swanston, C.; Torn, M.; Trumbore, S. E.; Riley, W.; Kelly, R.

    2010-10-01

    The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool {sup 14}C signature ({Delta} {sup 14}C) data from the Enriched Background Isotope Study {sup 14}C experiment (1999-2006) shows that the model correctly simulates the temporal dynamics of the {sup 14}C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass {Delta} {sup 14}C data, and with soil respiration {Delta} {sup 14}C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study {sup 14}C experimental treatments on soil respiration {Delta} {sup 14}C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.

  19. Benchmark critical experiments on low-enriched uranium oxide systems with H/U = 0. 77

    Energy Technology Data Exchange (ETDEWEB)

    Tuck, G; Oh, I

    1979-08-01

    Ten benchmark experiments were performed at the Critical Mass Laboratory at Rockwell International's Rocky Flats Plant, Golden, Colorado, for the US Nuclear Regulatory Commission. They provide accurate criticality data for low-enriched damp uranium oxide (U/sub 3/O/sub 8/) systems. The core studied consisted of 152 mm cubical aluminum cans containing an average of 15,129 g of low-enriched (4.46% /sup 235/U) uranium oxide compacted to a density of 4.68 g/cm/sup 3/ and with an H/U atomic ratio of 0.77. One hundred twenty five (125) of these cans were arranged in an approx. 770 mm cubical array. Since the oxide alone cannot be made critical in an array of this size, an enriched (approx. 93% /sup 235/U) metal or solution driver was used to achieve criticality. Measurements are reported for systems having the least practical reflection and for systems reflected by approx. 254-mm-thick concrete or plastic. Under the three reflection conditions, the mass of the uranium metal driver ranged from 29.87 kg to 33.54 kg for an oxide core of 1864.6 kg. For an oxide core of 1824.9 kg, the weight of the high concentration (351.2 kg U/m/sup 3/) solution driver varied from 14.07 kg to 16.14 kg, and the weight of the low concentration (86.4 kg U/m/sup 3/) solution driver from 12.4 kg to 14.0 kg.

  20. Do previous sports experiences influence the effect of an enrichment programme in basketball skills?

    Science.gov (United States)

    Santos, Sara; Mateus, Nuno; Sampaio, Jaime; Leite, Nuno

    2016-09-29

    The aim of this study was to examine the effect of an enrichment programme in motor, technical and tactical basketball skills, when accounting for the age of youth sport specialisation. Seventy-six college students (age: M = 20.4, SD = 1.9) were allocated according to three different paths: (i) non-structured (n = 14), (ii) early specialisation (n = 34), and (iii) late specialisation (n = 28), according to information previously provided by the participants about the quantity and type of sporting activities performed throughout their sporting careers. Then, the participants of each path were randomly distributed across control and experimental groups. Variables under study included agility, technical skills circuit, as well as tactical actions performed in a 4-on-4 full-court basketball game. The results indicated improvements in the early and late specialisation paths namely in the experimental training groups. However, the late specialisation path revealed larger benefits, in contrast with the non-structured path, which showed less sensitivity to the enrichment programme, mostly sustained in physical literacy and differential learning. Higher improvements were observed in agility, and also in reducing the number of unsuccessful actions performed during the game. Overall, this study provided evidence of how early sports experiences affect basketball skill acquisition and contribute to adapt to new contexts with motor and technical-tactical challenges. In addition, a path supported by late specialisation might present several advantages in sport performance achievement.

  1. CBD-enriched medical cannabis for intractable pediatric epilepsy: The current Israeli experience.

    Science.gov (United States)

    Tzadok, Michal; Uliel-Siboni, Shimrit; Linder, Ilan; Kramer, Uri; Epstein, Orna; Menascu, Shay; Nissenkorn, Andrea; Yosef, Omer Bar; Hyman, Eli; Granot, Dorit; Dor, Michael; Lerman-Sagie, Tali; Ben-Zeev, Bruria

    2016-02-01

    To describe the experience of five Israeli pediatric epilepsy clinics treating children and adolescents diagnosed as having intractable epilepsy with a regimen of medical cannabis oil. A retrospective study describing the effect of cannabidiol (CBD)-enriched medical cannabis on children with epilepsy. The cohort included 74 patients (age range 1-18 years) with intractable epilepsy resistant to >7 antiepileptic drugs. Forty-nine (66%) also failed a ketogenic diet, vagal nerve stimulator implantation, or both. They all started medical cannabis oil treatment between 2-11/2014 and were treated for at least 3 months (average 6 months). The selected formula contained CBD and tetrahydrocannabinol at a ratio of 20:1 dissolved in olive oil. The CBD dose ranged from 1 to 20mg/kg/d. Seizure frequency was assessed by parental report during clinical visits. CBD treatment yielded a significant positive effect on seizure load. Most of the children (66/74, 89%) reported reduction in seizure frequency: 13 (18%) reported 75-100% reduction, 25 (34%) reported 50-75% reduction, 9 (12%) reported 25-50% reduction, and 19 (26%) reported epilepsy in a population of children and adolescents are highly promising. Further prospective, well-designed clinical trials using enriched CBD medical cannabis are warranted. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  2. Nucleation and solidification of thin walled ductile iron - Experiments and numerical simulation

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2005-01-01

    Investigation of solidification of thin walled ductile cast iron has been performed based on experiments and numerical simulation. The experiments were based on temperature and microstructure examination. Results of the experiments have been compared with a 1-D numerical solidification model...

  3. Effects of elevated CO2 on grain yield and quality of wheat: results from a 3-year free-air CO2 enrichment experiment.

    Science.gov (United States)

    Högy, P; Wieser, H; Köhler, P; Schwadorf, K; Breuer, J; Franzaring, J; Muntifering, R; Fangmeier, A

    2009-11-01

    Spring wheat (Triticum aestivum L. cv. TRISO) was grown for three consecutive seasons in a free-air carbon dioxide (CO(2)) enrichment (FACE) field experiment in order to examine the effects on crop yield and grain quality. CO(2) enrichment promoted aboveground biomass (+11.8%) and grain yield (+10.4%). However, adverse effects were predominantly observed on wholegrain quality characteristics. Although the thousand-grain weight remained unchanged, size distribution was significantly shifted towards smaller grains, which may directly relate to lower market value. Total grain protein concentration decreased significantly by 7.4% under elevated CO(2), and protein and amino acid composition were altered. Corresponding to the decline in grain protein concentration, CO(2) enrichment resulted in an overall decrease in amino acid concentrations, with greater reductions in non-essential than essential amino acids. Minerals such as potassium, molybdenum and lead increased, while manganese, iron, cadmium and silicon decreased, suggesting that adjustments of agricultural practices may be required to retain current grain quality standards. The concentration of fructose and fructan, as well as amounts per area of total and individual non-structural carbohydrates, except for starch, significantly increased in the grain. The same holds true for the amount of lipids. With regard to mixing and rheological properties of the flour, a significant increase in gluten resistance under elevated CO(2) was observed. CO(2) enrichment obviously affected grain quality characteristics that are important for consumer nutrition and health, and for industrial processing and marketing, which have to date received little attention.

  4. Mineralogical investigations of the interaction between iron corrosion products and bentonite from the NF-PRO Experiments (Phase 2)

    Energy Technology Data Exchange (ETDEWEB)

    Milodowski, A.E.; Cave, M.R.; Kemp, S.J.; Taylor, B.H.; Green, K.A.; Williams, C.L.; Shaw, R.A.; Gowing, C.J.B.; Eatherington, N.D. (British Geological Survey (United Kingdom))

    2009-01-15

    This report describes the findings of a second programme of work (Phase 2) undertaken by the British Geological Survey (BGS) on behalf of SKB, to characterise the mineralogical alteration of samples of compacted bentonite from experiments that SKB have co-funded in a study by Serco Assurance (Culham Laboratory, UK) to investigate the interaction of iron and bentonite, within the EU Framework 6 NF-PRO Project. Reacted bentonite residues from four NF-PRO Experiments - NFC1, NFC4, NFC7 and NFC13 were examined by BGS using; X-ray diffraction analysis (XRD); petrographical analysis with backscattered scanning electron microscopy (BSEM) with energy-dispersive X-ray microanalysis (EDXA) techniques, cation exchange capacity (CEC) and exchangeable cation analysis; and sequential chemical extraction. In addition, background chemical analysis of altered and background bentonite were also obtained by X-ray fluorescence spectrometry (XRFS). Bentonite immediately adjacent to corroding steel wires was found to have interacted with Fe released from the corroding metal. This resulted in the formation of narrow haloes of altered bentonite around the corroding steel wires, in which the clay matrix was significantly enriched in Fe. Similar observations were observed in bentonite around corroded iron coupons (observed in experiments NFC4 and NFC7 only), although the alteration zones were not as well developed in comparison to those around corroded steel wires. Detailed petrographical observation found no evidence for the formation discrete iron oxide or iron oxyhydroxide phases within the clay matrix but appeared to show that the clay particles themselves had become enriched in Fe. However, data from sequential chemical extraction suggests that a significant proportion (26 to 68%) of the iron in the altered bentonite is present as amorphous iron oxide or crystalline iron oxides (15 to 33% of the total iron). Some of the crystalline iron is present as primary magnetite and ilmenite

  5. Program to enrich science and mathematics experiences of high school students through interactive museum internships

    Energy Technology Data Exchange (ETDEWEB)

    Reif, R.J. [State Univ. of New York, New Paltz, NY (United States); Lock, C.R. [Univ. of North Carolina, Charlotte, NC (United States)

    1998-11-01

    This project addressed the problem of female and minority representation in science and mathematics education and in related fields. It was designed to recruit high school students from under-represented groups into a program that provided significant, meaningful experiences to encourage those young people to pursue careers in science and science teaching. It provided role models for those students. It provided experiences outside of the normal school environment, experiences that put the participants in the position to serve as role models themselves for disadvantaged young people. It also provided encouragement to pursue careers in science and mathematics teaching and related careers. In these respects, it complemented other successful programs to encourage participation in science. And, it differed in that it provided incentives at a crucial time, when career decisions are being made during the high school years. Further, it encouraged the pursuit of careers in science teaching. The objectives of this project were to: (1) provide enrichment instruction in basic concepts in the life, earth, space, physical sciences and mathematics to selected high school students participating in the program; (2) provide instruction in teaching methods or processes, including verbal communication skills and the use of questioning; (3) provide opportunities for participants, as paid student interns, to transfer knowledge to other peers and adults; (4) encourage minority and female students with high academic potential to pursue careers in science teaching.

  6. Chemical fingerprint of iron oxides related to iron enrichment of banded iron formation from the Cauê Formation - Esperança Deposit, Quadrilátero Ferrífero, Brazil: a laser ablation ICP-MS study

    National Research Council Canada - National Science Library

    Oliveira, Lucilia Aparecida Ramos de; Rosière, Carlos Alberto; Rios, Francisco Javier; Andrade, Sandra; Moraes, Renato de

    2015-01-01

    ... Formation from Minas Supergroup. Variations of Mn, Mg and Sr content in different generations of iron oxides from dolomitic itabirite, high-grade iron ore and syn-mineralization quartz-carbonate-hematite veins denote the close...

  7. The role of dissolved molecular oxygen in abiotic pyrite oxidation under acid pH conditions - Experiments with {sup 18}O-enriched molecular oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Heidel, Claudia, E-mail: claudia.heidel@gmx.net [Institute of Mineralogy, TU Bergakademie Freiberg, Brennhausgasse 14, 09599 Freiberg (Germany); Tichomirowa, Marion [Institute of Mineralogy, TU Bergakademie Freiberg, Brennhausgasse 14, 09599 Freiberg (Germany)

    2010-11-15

    Research highlights: {yields} A small amount of molecular oxygen is permanently incorporated into sulfate during pyrite oxidation. {yields} Molecular oxygen may be incorporated into sulfate by sulfite oxidation and tetrathionate oxidation. {yields} Molecular oxygen is incorporated into water molecules during its cathodic reduction. {yields} Molecular oxygen mainly accepts electrons from pyrite and minor from dissolved and adsorbed ferrous iron. - Abstract: Several O isotope studies have shown that SO{sub 4}{sup 2-} produced from aqueous pyrite oxidation mainly contains water-derived O and minor atmospherically-derived O{sub 2}. However, the incorporation of O{sub 2} into SO{sub 4}{sup 2-} has been shown to decrease continuously during pyrite oxidation experiments. Hence, it remains uncertain if (and how) O{sub 2} is permanently incorporated into SO{sub 4}{sup 2-} during pyrite oxidation. Abiotic aerobic batch pyrite oxidation experiments in aqueous solutions were performed under acid pH conditions. After 151 days, {sup 18}O-enriched O{sub 2} was injected into the headspace of the reaction vessels. Increasing {delta}{sup 18}O{sub SO{sub 4}} values with increasing injection volume of {sup 18}O-enriched O{sub 2} indicated the permanent incorporation of about 9% O{sub 2} into the produced SO{sub 4}{sup 2-} during pyrite oxidation from 151 to 201 days. Molecular oxygen may be incorporated into SO{sub 4}{sup 2-} by oxidation of the S intermediate species sulfite (and maybe tetrathionate) into SO{sub 4}{sup 2-}. However, only 4% of the O{sub 2} consumed during the experiments was incorporated into SO{sub 4}{sup 2-}. Slightly increased {delta}{sup 18}O{sub H{sub 2}O} values from experiments with the largest injection of {sup 18}O-enriched O{sub 2} indicated the incorporation of O{sub 2} into water molecules which may proceed during the cathodic reduction of O{sub 2}. Thus, O{sub 2} was an important electron acceptor under aerobic acid conditions. The observed {epsilon

  8. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, R.E.

    1996-09-30

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.

  9. Laboratory experiments on the impact disruption of iron meteorites at temperature of near-Earth space

    Science.gov (United States)

    Katsura, Takekuni; Nakamura, Akiko M.; Takabe, Ayana; Okamoto, Takaya; Sangen, Kazuyoshi; Hasegawa, Sunao; Liu, Xun; Mashimo, Tsutomu

    2014-10-01

    Iron meteorites and some M-class asteroids are generally understood to be fragments that were originally part of cores of differentiated planetesimals or part of local melt pools on primitive bodies. The parent bodies of iron meteorites may have formed in the terrestrial planet region, from which they were then scattered into the main belt (Bottke, W.F., Nesvorný, D., Grimm, R.E., Morbidelli, A., O'Brien, D.P. [2006]. Nature 439, 821-824). Therefore, a wide range of collisional events at different mass scales, temperatures, and impact velocities would have occurred between the time when the iron was segregated and the impact that eventually exposed the iron meteorites to interplanetary space. In this study, we performed impact disruption experiments of iron meteorite specimens as projectiles or targets at room temperature to increase understanding of the disruption process of iron bodies in near-Earth space. Our iron specimens (as projectiles or targets) were almost all smaller in size than their counterparts (as targets or projectiles, respectively). Experiments of impacts of steel specimens were also conducted for comparison. The fragment mass distribution of the iron material was different from that of rocks. In the iron fragmentation, a higher percentage of the mass was concentrated in larger fragments, probably due to the ductile nature of the material at room temperature. The largest fragment mass fraction f was dependent not only on the energy density but also on the size d of the specimen. We assumed a power-law dependence of the largest fragment mass fraction to initial peak pressure P0 normalized by a dynamic strength, Y, which was defined to be dependent on the size of the iron material. A least squares fit to the data of iron meteorite specimens resulted in the following relationship: f∝∝d, indicating a large size dependence of f. Additionally, the deformation of the iron materials in high-velocity shots was found to be most significant when the

  10. Enriched TeO2 bolometers with active particle discrimination: Towards the CUPID experiment

    Science.gov (United States)

    Artusa, D. R.; Avignone, F. T.; Beeman, J. W.; Dafinei, I.; Dumoulin, L.; Ge, Z.; Giuliani, A.; Gotti, C.; de Marcillac, P.; Marnieros, S.; Nagorny, S.; Nisi, S.; Nones, C.; Norman, E. B.; Novati, V.; Olivieri, E.; Orlandi, D.; Pagnanini, L.; Pattavina, L.; Pessina, G.; Pirro, S.; Poda, D. V.; Rusconi, C.; Schäffner, K.; Scielzo, N. D.; Zhu, Y.

    2017-04-01

    We present the performances of two 92% enriched 130TeO2 crystals operated as thermal bolometers in view of a next generation experiment to search for neutrinoless double beta decay of 130Te. The crystals, 435 g each, show an energy resolution, evaluated at the 2615 keV γ-line of 208Tl, of 6.5 and 4.3 keV FWHM. The only observable internal radioactive contamination arises from 238U (15 and 8 μBq/kg, respectively). The internal activity of the most problematic nuclei for neutrinoless double beta decay, 226Ra and 228Th, are both evaluated as <3.1 μBq/kg for one crystal and <2.3 μBq/kg for the second. Thanks to the readout of the weak Cherenkov light emitted by β / γ particles by means of Neganov-Luke bolometric light detectors we were able to perform an event-by-event identification of β / γ events with a 95% acceptance level, while establishing a rejection factor of 98.21% and 99.99% for α particles.

  11. Enriched TeO 2 bolometers with active particle discrimination: Towards the CUPID experiment

    Energy Technology Data Exchange (ETDEWEB)

    Artusa, D. R.; Avignone, F. T.; Beeman, J. W.; Dafinei, I.; Dumoulin, L.; Ge, Z.; Giuliani, A.; Gotti, C.; de Marcillac, P.; Marnieros, S.; Nagorny, S.; Nisi, S.; Nones, C.; Norman, E. B.; Novati, V.; Olivieri, E.; Orlandi, D.; Pagnanini, L.; Pattavina, L.; Pessina, G.; Pirro, S.; Poda, D. V.; Rusconi, C.; Schäffner, K.; Scielzo, N. D.; Zhu, Y.

    2017-04-01

    We present the performances of two 92% enriched 130TeO2 crystals operated as thermal bolometers in view of a next generation experiment to search for neutrinoless double beta decay of 130Te. The crystals, 435 g each, show an energy resolution, evaluated at the 2615 keV γ-line of 208Tl, of 6.5 and 4.3 keV FWHM. The only observable internal radioactive contamination arises from 238U (15 and 8 μBq/kg, respectively). The internal activity of the most problematic nuclei for neutrinoless double beta decay, 226Ra and 228Th, are both evaluated as <3.1 μBq/kg for one crystal and <2.3 μBq/kg for the second. Thanks to the readout of the weak Cherenkov light emitted by β/γ particles by means of Neganov–Luke bolometric light detectors we were able to perform an event-by-event identification of β/γ events with a 95% acceptance level, while establishing a rejection factor of 98.21% and 99.99% for α particles.

  12. Enriched TeO$_2$ bolometers with active particle discrimination: towards the CUPID experiment

    CERN Document Server

    Artusa, D R; Beeman, J W; Dafinei, I; Dumoulin, L; Ge, Z; Giuliani, A; Gotti, C; de Marcillac, P; Marnieros, S; Nagorny, S; Nisi, S; Nones, C; Norman, E B; Novati, V; Olivieri, E; Orlandi, D; Pagnanini, L; Pattavina, L; Pessina, G; Pirro, S; Poda, D V; Rusconi, C; Schäffner, K; Scielzo, N D; Zhu, Y

    2016-01-01

    We present the performances of two 92% enriched $^{130}$TeO$_2$ crystals operated as thermal bolometers in view of a next generation experiment to search for neutrinoless double beta decay of $^{130}$Te. The crystals, 435 g each, show an energy resolution, evaluated at the 2615 keV $\\gamma$-line of $^{208}$Tl, of 6.5 and 4.3 keV FWHM. The only observable internal radioactive contamination arises from $^{238}$U (15 and 8 $\\mu$Bq/kg, respectively). The internal activity of the most problematic nuclei for neutrinoless double beta decay, $^{226}$Ra and $^{228}$Th, are both evaluated as $<$3.1 $\\mu$Bq/kg for one crystal and $<$2.3 $\\mu$Bq/kg for the second. Thanks to the readout of the weak Cherenkov light emitted by $\\beta/\\gamma$ particles by means of Neganov-Luke bolometric light detectors we were able to perform an event-by-event identification of $\\beta/\\gamma$ events with a 95% acceptance level, while establishing a rejection factor of 98.21% and 99.99% for $\\alpha$ particles.

  13. Allometric biomass partitioning under nitrogen enrichment: Evidence from manipulative experiments around the world

    Science.gov (United States)

    Peng, Yunfeng; Yang, Yuanhe

    2016-06-01

    Allometric and optimal hypotheses have been widely used to explain biomass partitioning in response to resource changes for individual plants; however, little evidence has been reported from measurements at the community level across a broad geographic scale. This study assessed the nitrogen (N) effect on community-level root to shoot (R/S) ratios and biomass partitioning functions by synthesizing global manipulative experiments. Results showed that, in aggregate, N addition decreased the R/S ratios in various biomes. However, the scaling slopes of the allometric equations were not significantly altered by the N enrichment, possibly indicating that N-induced reduction of the R/S ratio is a consequence of allometric allocation as a function of increasing plant size rather than an optimal partitioning model. To further illustrate this point, we developed power function models to explore the relationships between aboveground and belowground biomass for various biomes; then, we generated the predicted root biomass from the observed shoot biomass and predicted R/S ratios. The comparison of predicted and observed N-induced changes of the R/S ratio revealed no significant differences between each other, supporting the allometric allocation hypothesis. These results suggest that allometry, rather than optimal allocation, explains the N-induced reduction in the R/S ratio across global biomes.

  14. An Enriched Research Experience for Minority Undergraduates--A Step toward Increasing the Number of Minority Nurse Researchers.

    Science.gov (United States)

    Leeman, Jennifer; Goeppinger, Jean; Funk, Sandra; Roland, E. Joyce

    2003-01-01

    A partnership between a research university and a minority-serving institution created a research enrichment and apprenticeship program for minority nursing students. The program provides students an opportunity to experience nursing research with the goal of increasing the number of minority researchers in nursing. (Contains 11 references.) (JOW)

  15. Response of zooplankton to nutrient enrichment and fish in shallow lakes: a pan-European mesocosm experiment

    NARCIS (Netherlands)

    Vakkilainen, K.; Kairesalo, T.; Hietala, J.; Balayla, D.; Bécares, E.; van de Bund, W.; Van Donk, E.; Fernández-Aláez, M.; Gyllström, M.; Hansson, L-A.; Rosa Miracle, M.; Moss, B.; Romo, S.; Rueda, J.; Stephen, D.

    2004-01-01

    1. Responses of zooplankton to nutrient enrichment and fish predation were studied in 1998 and 1999 by carrying out parallel mesocosm experiments in six lakes across Europe. 2. Zooplankton community structure, biomass and responses to nutrient and fish manipulation showed geographical and year-to-ye

  16. Enrichment experiment changes microbial interactions in an ultra-oligotrophic environment.

    Science.gov (United States)

    Ponce-Soto, Gabriel Y; Aguirre-von-Wobeser, Eneas; Eguiarte, Luis E; Elser, James J; Lee, Zarraz M-P; Souza, Valeria

    2015-01-01

    The increase of nutrients in water bodies, in particular nitrogen (N) and phosphorus (P) due to the recent expansion of agricultural and other human activities is accelerating environmental degradation of these water bodies, elevating the risk of eutrophication and reducing biodiversity. To evaluate the ecological effects of the influx of nutrients in an oligotrophic and stoichiometrically imbalanced environment, we performed a replicated in situ mesocosm experiment. We analyzed the effects of a N- and P-enrichment on the bacterial interspecific interactions in an experiment conducted in the Cuatro Cienegas Basin (CCB) in Mexico. This is a desert ecosystem comprised of several aquatic systems with a large number of microbial endemic species. The abundance of key nutrients in this basin exhibits strong stoichiometric imbalance (high N:P ratios), suggesting that species diversity is maintained mostly by competition for resources. We focused on the biofilm formation and antibiotic resistance of 960 strains of cultivated bacteria in two habitats, water and sediment, before and after 3 weeks of fertilization. The water habitat was dominated by Pseudomonas, while Halomonas dominated the sediment. Strong antibiotic resistance was found among the isolates at time zero in the nutrient-poor bacterial communities, but resistance declined in the bacteria isolated in the nutrient-rich environments, suggesting that in the nutrient-poor original environment, negative inter-specific interactions were important, while in the nutrient-rich environments, competitive interactions are not so important. In water, a significant increase in the percentage of biofilm-forming strains was observed for all treatments involving nutrient addition.

  17. Enrichment experiment changes microbial interactions in an ultra-oligotrophic environment

    Directory of Open Access Journals (Sweden)

    Gabriel Yaxal Ponce-Soto

    2015-04-01

    Full Text Available The increase of nutrients in water bodies, in particular nitrogen (N and phosphorus (P due to the recent expansion of agricultural and other human activities is accelerating environmental degradation of these water bodies, elevating the risk of eutrophication and reducing biodiversity. To evaluate the ecological effects of the influx of nutrients in an oligotrophic and stoichiometrically imbalanced environment, we performed a replicated in situ mesocosm experiment. We analyzed the effects of a N- and P-enrichment on the bacterial interspecific interactions in an experiment conducted in the Cuatro Cienegas Basin (CCB in Mexico. This is a desert ecosystem comprised of several aquatic systems with a large number of microbial endemic species. The abundance of key nutrients in this basin exhibits strong stoichiometric imbalance (high N:P ratios, suggesting that species diversity is maintained mostly by competition for resources. We focused on the biofilm formation and antibiotic resistance of 960 strains of cultivated bacteria in two habitats, water and sediment, before and after three weeks of fertilization. The water habitat was dominated by Pseudomonas, while Halomonas dominated the sediment. Strong antibiotic resistance was found among the isolates at time zero in the nutrient-poor bacterial communities, but resistance declined in the bacteria isolated in the nutrient-rich environments, suggesting that in the nutrient-poor original environment, negative inter-specific interactions were important, while in the nutrient-rich environments, competitive interactions are not so important. In water, a significant increase in the percentage of biofilm-forming strains was observed for all treatments involving nutrient addition.

  18. Iron enrichment and photoreduction of iron under UV and PAR in the presence of hydroxycarboxylic acid: implications for phytoplankton growth in the Southern Ocean

    CSIR Research Space (South Africa)

    Ozturk, M

    2004-01-01

    Full Text Available will eventually turn back relatively quickly into the pool 2050 2100 2150 2200 0 2 4 6 8 10 12 14 Σ CO 2 (mmol m- 3 ) C-PAR Fe -PAR FeGA -PAR C- UV-PAR Fe-UV-PAR FeGA-UV-PAR Time (days) Fig. 11. Decreases... radicals) may play some role for observable Fe(II) but their mechanisms are not yet fully understood. These mechanisms may enhance the production of available iron and make Fe(II) available from a pool of Fe(III) which is already present. Apparently...

  19. Interactions between iron, phenolic compounds, emulsifiers, and pH in omega-3-enriched oil-in-water emulsions

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Haahr, Anne-Mette; Becker, E.M.

    2008-01-01

    in a 10% oil-in-water emulsion. The emulsifiers tested were Tween 80 and Citrem, and the phenolic compounds were naringenin, rutin, caffeic acid, and coumaric acid. Lipid oxidation was evaluated at all levels, that is, formation of radicals (ESR), hydroperoxides (PV), and secondary volatile oxidation......The behavior of antioxidants in emulsions is influenced by several factors such as pH and emulsifier type. This study aimed to evaluate the interaction between selected food emulsifiers, phenolic compounds, iron, and pH and their effect on the oxidative stability of n-3 polyunsaturated lipids...... significant effects, as caffeic acid was found to be prooxidative irrespective of pH, emulsifier type, and presence of iron, although the degrees of lipid oxidation were different at the different experimental conditions. The other evaluated phenols were prooxidative at pH 3 in Citrem-stabilized emulsions...

  20. Nutrient Limitation in Surface Waters of the Oligotrophic Eastern Mediterranean Sea: an Enrichment Microcosm Experiment

    KAUST Repository

    Tsiola, A.

    2015-12-01

    The growth rates of planktonic microbes in the pelagic zone of the Eastern Mediterranean Sea are nutrient limited, but the type of limitation is still uncertain. During this study, we investigated the occurrence of N and P limitation among different groups of the prokaryotic and eukaryotic (pico-, nano-, and micro-) plankton using a microcosm experiment during stratified water column conditions in the Cretan Sea (Eastern Mediterranean). Microcosms were enriched with N and P (either solely or simultaneously), and the PO4 turnover time, prokaryotic heterotrophic activity, primary production, and the abundance of the different microbial components were measured. Flow cytometric and molecular fingerprint analyses showed that different heterotrophic prokaryotic groups were limited by different nutrients; total heterotrophic prokaryotic growth was limited by P, but only when both N and P were added, changes in community structure and cell size were detected. Phytoplankton were N and P co-limited, with autotrophic pico-eukaryotes being the exception as they increased even when only P was added after a 2-day time lag. The populations of Synechococcus and Prochlorococcus were highly competitive with each other; Prochlorococcus abundance increased during the first 2 days of P addition but kept increasing only when both N and P were added, whereas Synechococcus exhibited higher pigment content and increased in abundance 3 days after simultaneous N and P additions. Dinoflagellates also showed opportunistic behavior at simultaneous N and P additions, in contrast to diatoms and coccolithophores, which diminished in all incubations. High DNA content viruses, selective grazing, and the exhaustion of N sources probably controlled the populations of diatoms and coccolithophores.

  1. NACOWA experiments on LMFBR cover gas aerosols, heat transfer, and fission product enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Minges, J.; Schuetz, W.

    1993-12-01

    Fifteen different NACOWA test series were carried out. The following items were investigated: sodium mass concentration in the cover gas, sodium aerosol particle size, radiative heat transfer across the cover gas, total heat transfer across the cover gas, sodium deposition on the cover plate, temperature profiles across the cover gas, phenomena if the argon cover gas is replaced by helium, enrichment of cesium, iodine, and zinc in the aerosol and in the deposits. The conditions were mainly related to the design parameters of the EFR. According to the first consistent design, a pool temperature of 545 C and a roof temperature of only 120 C were foreseen at a cover gas height of 85 cm. The experiments were carried out in a stainless steel test vessel of 0.6 m diameter and 1.14 m height. Pool temperature (up to 545 C), cover gas height (12.5 cm, 33 cm, and others), and roof temperature (from 110 C to 450 C) were the main parameters. (orig./HP) [Deutsch] Es wurden fuenfzehn verschiedene NACOWA-Versuchsreihen durchgefuehrt. Folgende Themen wurden behandelt: Natrium-Massenkonzentration im Schutzgas, Natriumaerosol-Partikelgroesse, Strahlungswaermeuebergang durch das Schutzgas, Gesamtwaermeuebergang durch das Schutzgas, Natriumablagerung am Deckel, Temperaturprofile im Schutzgas, Phaenomene beim Uebergang von Argon-Schutzgas auf Helium-Schutzgas, Anreicherung von Caesium, Jod und Zink im Aerosol und in den Ablagerungen. Die Versuchsbedingungen wurden hauptsaechlich durch die Auslegungsparameter des EFR bestimmt. Beim `first consistent design` war eine Pooltemperatur von 545 C und eine Dachtemperatur von nur 120 C bei 85 cm Argon-Schutzgashoehe vorgesehen. Die Experimente wurden in einem Edelstahlbehaelter von 0,6 m Durchmesser und 1,14 m Hoehe durchgefuehrt. Pooltemperatur (bis 545 C), Schutzgashoehe (12,5 cm, 33 cm und andere) sowie Deckeltemperatur (von 100 C bis 450 C) waren die wichtigsten experimentellen Parameter. (orig./HP)

  2. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    Science.gov (United States)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  3. The Shilu Iron Ore Deposit in Hainan Province, South China: A Structurally and Hydrothermally Reworked and Re-Enriched Lake-Superior-Type BIF Iron Deposit%The Shilu Iron Ore Deposit in Hainan Province,South China: A Structurally and Hydrothermally Reworked and Re-Enriched Lake-Superior-Type BIF Iron Deposit

    Institute of Scientific and Technical Information of China (English)

    XU De-ru; WANG Zhi-lin; XIAO Yong; Bakun-Czubarow Nonna; LIU Zhao-lu; WANG Li; FU Qi-ji; WU Jun; Kusiak Monika Agnieszka

    2009-01-01

    @@ The Shilu iron ore deposit, located in the western Hainan Province, South China, is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite- rich ores, but also for its potentially economic significance of associated metals of copper, cobalt, nickel, silver, lead and zinc, and of non-metals of dolomite, quartzite,barite,gypsum and sulfur.

  4. Bacterial mobilization and transport through manure enriched soils: Experiment and modeling.

    Science.gov (United States)

    Sepehrnia, N; Memarianfard, L; Moosavi, A A; Bachmann, J; Guggenberger, G; Rezanezhad, F

    2017-10-01

    A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R(2) = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the

  5. Nutrient enrichment modifies temperature-biodiversity relationships in large-scale field experiments

    Science.gov (United States)

    Wang, Jianjun; Pan, Feiyan; Soininen, Janne; Heino, Jani; Shen, Ji

    2016-12-01

    Climate effects and human impacts, that is, nutrient enrichment, simultaneously drive spatial biodiversity patterns. However, there is little consensus about their independent effects on biodiversity. Here we manipulate nutrient enrichment in aquatic microcosms in subtropical and subarctic regions (China and Norway, respectively) to show clear segregation of bacterial species along temperature gradients, and decreasing alpha and gamma diversity toward higher nutrients. The temperature dependence of species richness is greatest at extreme nutrient levels, whereas the nutrient dependence of species richness is strongest at intermediate temperatures. For species turnover rates, temperature effects are strongest at intermediate and two extreme ends of nutrient gradients in subtropical and subarctic regions, respectively. Species turnover rates caused by nutrients do not increase toward higher temperatures. These findings illustrate direct effects of temperature and nutrients on biodiversity, and indirect effects via primary productivity, thus providing insights into how nutrient enrichment could alter biodiversity under future climate scenarios.

  6. Property of compound protective agents on ferrous iron of heme-iron enriched polypeptide%亚铁血红素肽复合型保护剂的性能

    Institute of Scientific and Technical Information of China (English)

    庄红; 陈乐群; 张婷; 朱媛媛; 唐宁; 袁媛

    2012-01-01

    Heme-iron enriched polypeptide product was produced from bovine blood enzymolysis.Various kinds of protective agents were added to the enzymolysis substrates and the products to examine they protective effect on the products.Results show that the compound protective agents are superior to a single protective agent.Ferrous iron in enzymolysis substrates and in products are increased by 24.5% and 37.7% respectively after the addition of compound protective agents with mass ratio of antioxidant/reductant = 2∶1.%酶解牛血制取亚铁血红素肽,并于酶解底物及产物中分别添加不同种类亚铁保护剂,考察其对产物亚铁血红素肽的保护效果。结果表明,复合型保护剂的性能明显优于单一型。与空白组相比,酶解底物添加2∶1(抗氧化剂/还原剂质量比)的复合型保护剂可使亚铁含量提高24.5%;酶解产物中添加复合型保护剂后(2∶1),亚铁含量可提高37.7%。

  7. DMSP and DMS dynamics during a mesoscale iron fertilization experiment in the Northeast Pacific Part II: Biological cycling

    Science.gov (United States)

    Merzouk, Anissa; Levasseur, Maurice; Scarratt, Michael G.; Michaud, Sonia; Rivkin, Richard B.; Hale, Michelle S.; Kiene, Ronald P.; Price, Neil M.; Li, William K. W.

    2006-10-01

    Dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) biological cycling rates were determined during SERIES, a mesoscale iron-fertilization experiment conducted in the high-nutrient low-chlorophyll (HNLC) waters of the northeast subarctic Pacific. The iron fertilization resulted in the rapid development of a nanoplankton assemblage that persisted for 11 days before abruptly crashing. The nanoplankton bloom was followed by a diatom bloom, accompanied by an important increase in bacterial abundance and production. These iron-induced alterations of the plankton assemblage coincided with changes in the size and biological cycling of the DMSP and DMS pools. The initial nanoplankton bloom resulted in increases in particulate DMSP (DMSPp; 77-180 nmol L -1), dissolved DMSP (DMSPd; 1-24 nmol L -1), and biological gross (0.11-0.78 nmol L -1 h -1) and net (0.04-0.74 nmol L -1 h -1) DMS production rates. During the nanoplankton bloom, DMSPd consumption by bacteria exceeded their sulfur demand and the excess sulfur was probably released as DMS, consistent with the high gross DMS production rates observed during that period. The crash of the nanoplankton bloom was marked by the rapid decline of DMSPp, DMSPd, and gross DMS production to their initial values. Following the crash of the nanoplankton bloom, bacterial production and estimated sulfur demand reached transient maxima of 9.3 μg C L -1 d -1 and 14.2 nmol S L -1 d -1, respectively. During this period of high bacterial production, bacterial DMSPd consumption was also very high (6 nmol L -1 h -1), but none of the consumed DMSPd was converted into DMS and a net biological DMS consumption was measured. This transient period initiated a rapid decrease in DMS concentrations inside the iron-enriched patch, which persisted during the following diatom bloom due to low biological gross and net DMS production that prevented the replenishment of DMS. Our results show that the impact of Fe fertilization on DMS production in

  8. Constraints on the Parental Melts of Enriched Shergottites from Image Analysis and High Pressure Experiments

    Science.gov (United States)

    Collinet, M.; Medard, E.; Devouard, B.; Peslier, A.

    2012-01-01

    Martian basalts can be classified in at least two geochemically different families: enriched and depleted shergottites. Enriched shergottites are characterized by higher incompatible element concentrations and initial Sr-87/Sr-86 and lower initial Nd-143/Nd-144 and Hf-176/Hf-177 than depleted shergottites [e.g. 1, 2]. It is now generally admitted that shergottites result from the melting of at least two distinct mantle reservoirs [e.g. 2, 3]. Some of the olivine-phyric shergottites (either depleted or enriched), the most magnesian Martian basalts, could represent primitive melts, which are of considerable interest to constrain mantle sources. Two depleted olivine-phyric shergottites, Yamato (Y) 980459 and Northwest Africa (NWA) 5789, are in equilibrium with their most magnesian olivine (Fig. 1) and their bulk rock compositions are inferred to represent primitive melts [4, 5]. Larkman Nunatak (LAR) 06319 [3, 6, 7] and NWA 1068 [8], the most magnesian enriched basalts, have bulk Mg# that are too high to be in equilibrium with their olivine megacryst cores. Parental melt compositions have been estimated by subtracting the most magnesian olivine from the bulk rock composition, assuming that olivine megacrysts have partially accumulated [3, 9]. However, because this technique does not account for the actual petrography of these meteorites, we used image analysis to study these rocks history, reconstruct their parent magma and understand the nature of olivine megacrysts.

  9. Enriched experience and recovery from amblyopia in adult rats: impact of motor, social and sensory components.

    Science.gov (United States)

    Baroncelli, Laura; Bonaccorsi, Joyce; Milanese, Marco; Bonifacino, Tiziana; Giribaldi, Francesco; Manno, Ilaria; Cenni, Maria Cristina; Berardi, Nicoletta; Bonanno, Giambattista; Maffei, Lamberto; Sale, Alessandro

    2012-06-01

    Amblyopia is one of the most common forms of visual impairment, arising from an early functional imbalance between the two eyes. It is currently accepted that, due to a lack of neural plasticity,amblyopia is an untreatable pathology in adults. Environmental enrichment (EE) emerged as a strategy highly effective in restoring plasticity in adult animals, eliciting recovery from amblyopia through a reduction of intracortical inhibition. It is unknown whether single EE components are able to promote plasticity in the adult brain, crucial information for designing new protocols of environmental stimulation suitable for amblyopic human subjects. Here, we assessed the effects of enhanced physical exercise,increased social interaction, visual enrichment or perceptual learning on visual function recovery in adult amblyopic rats. We report a complete rescue of both visual acuity and ocular dominance in exercised rats, in animals exposed to visual enrichment and in animals engaged in perceptual learning.These effects were accompanied by a reduced inhibition/excitation balance in the visual cortex. In contrast, we did not detect any sign of recovery in socially enriched rats or in animals practicing a purely associative visual task. These findings could have a bearing in orienting clinical research in the field of amblyopia therapy.

  10. Nigella Sativa and Oriental Spices with Protective Role in Iron Intoxication: in vivo Experiments on Rabbits

    Directory of Open Access Journals (Sweden)

    Mirela Ahmadi

    2016-11-01

    Full Text Available Homeostasis of hematological parameters is essential for assuring a general health status for any living organism. Iron is one of the essential mineral, involved in many vital processes – mainly in blood cells production, but in the same way it can become toxic in very high concentration. Hemoglobin and red blood cells are directed related with the iron ion, due to the high quantity (70% of total iron from organism being part of the blood (hemoglobin and muscle (myoglobin cells. Ferrous ion is part of hemoglobin structure, and red blood cells. But, the administration of high doses of iron can negatively affect the general health status, because the iron alters the enzymatic system in the vital organs. The aim of our experimental study was to verify the hypothesis that in rabbit’s organism, after intraperitoneal administration of 15g Fe2+/body weight as ferrous-gluconate hydro solution, a special diet based on a complex, fresh, organic vegetables (roots and leaves protects the organism by iron intoxication and help the hematological homeostasis. The research experiment was conducted during 43 days in summer time, on German Lop Eared breed young rabbits, which were protected with a diet that consisted of administration of Nigella sativa, some oriental spices (Allium ampeloprasum, Allium tuberosum, Coriandrum sativum, Eruca sativa, Cucumis sativus, Raphanus sativus, Trigonella foenum-graecum and other vegetables (Trifolium, Petroselinum crispum, Dacus carrota subsp.sativus and Cucumis sativus. At the final of experiment we collected blood samples for hematological test and we evaluated the erythrocytes, leukocytes, platelets, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and red cell distribution width. The results were analytical evaluated and only for hemoglobin we obtained significant increase value in experimental rabbits compared to control group of rabbits.

  11. Photochemistry of iron(III)-carboxylato complexes in aqueous atmospheric particles - Laboratory experiments and modeling studies

    Science.gov (United States)

    Weller, C.; Tilgner, A.; Herrmann, H.

    2010-12-01

    Iron is always present in the atmosphere in concentrations from ~10-9 M (clouds, rain) up to ~10-3 M (fog, particles). Sources are mainly mineral dust emissions. Iron complexes are very good absorbers in the UV-VIS actinic region and therefore photo-chemically reactive. Iron complex photolysis leads to radical production and can initiate radical chain reactions, which is related to the oxidizing capacity of the atmosphere. These radical chain reactions are involved in the decomposition and transformation of a variety of chemical compounds in cloud droplets and deliquescent particles. Additionally, the photochemical reaction itself can be a degradation pathway for organic compounds with the ability to bind iron. Iron-complexes of atmospherically relevant coordination compounds like oxalate, malonate, succinate, glutarate, tartronate, gluconate, pyruvate and glyoxalate have been investigated in laboratory experiments. Iron speciation depends on the iron-ligand ratio and the pH. The most suitable experimental conditions were calculated with a speciation program (Visual Minteq). The solutions were prepared accordingly and transferred to a 1 cm quartz cuvette and flash-photolyzed with an excimer laser at wavelengths 308 or 351 nm. Photochemically produced Fe2+ has been measured by spectrometry at 510 nm as Fe(phenantroline)32+. Fe2+ overall effective quantum yields have been calculated with the concentration of photochemically produced Fe2+ and the measured energy of the excimer laser pulse. The laser pulse energy was measured with a pyroelectric sensor. For some iron-carboxylate systems the experimental parameters like the oxygen content of the solution, the initial Iron concentration and the incident laser energy were systematically altered to observe an effect on the overall quantum yield. The dependence of some quantum yields on these parameters allows in some cases an interpretation of the underlying photochemical reaction mechanism. Quantum yields of malonate

  12. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bellini, F.; Casali, N.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Sezione di Roma, Rome (Italy); Benetti, P. [Universita di Pavia, Dipartimento di Chimica, Pavia (Italy); INFN, Sezione di Pavia, Pavia (Italy); Cardani, L. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Princeton University, Physics Department, Princeton, NJ (United States); Chiesa, D.; Clemenza, M.; Gironi, L.; Maino, M. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Dafinei, I.; Orio, F.; Tomei, C.; Vignati, M. [INFN, Sezione di Roma, Rome (Italy); Di Domizio, S. [INFN, Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Giuliani, A. [Centre de Spectrometrie de Masse, Orsay (France); Gotti, C.; Pessina, G.; Previtali, E.; Rusconi, C. [INFN, Sezione di Milano Bicocca, Milan (Italy); Laubenstein, M.; Nisi, S.; Pattavina, L.; Pirro, S.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) (Italy); Nagorny, S.; Pagnanini, L. [Gran Sasso Science Institute, L' Aquila (Italy); Nones, C. [SPP Centre de Saclay, CEA, Irfu, Gif-sur-Yvette (France)

    2015-12-15

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3 % enriched {sup 82}Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4.10{sup 22}, 1.3.10{sup 22} and 1.0.10{sup 22} y, respectively, with a 90 % C.L. (orig.)

  13. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J. W. [Lawrence Berkeley National Laboratory, 94720, Berkeley, CA (United States); Bellini, F. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy); Benetti, P. [Dipartimento di Chimica, Università di Pavia, 27100, Pavia (Italy); INFN, Sezione di Pavia, 27100, Pavia (Italy); Cardani, L. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); Physics Department, Princeton University, 08544, Princeton, NJ (United States); Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy)

    2015-12-13

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3 % enriched {sup 82}Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4·10{sup 22}, 1.3·10{sup 22} and 1.0·10{sup 22} y, respectively, with a 90 % C.L.

  14. Stable Composition of the Nano- and Picoplankton Community during the Ocean Iron Fertilization Experiment LOHAFEX

    KAUST Repository

    Thiele, Stefan

    2014-11-17

    The iron fertilization experiment LOHAFEX was conducted in a cold-core eddy in the Southern Atlantic Ocean during austral summer. Within a few days after fertilization, a phytoplankton bloom developed dominated by nano- and picoplankton groups. Unlike previously reported for other iron fertilization experiments, a diatom bloom was prevented by iron and silicate co-limitation. We used 18S rRNA gene tag pyrosequencing to investigate the diversity of these morphologically similar cell types within the nano- and picoplankton and microscopically enumerated dominant clades after catalyzed reported deposition fluorescence in situ hybridization (CARD-FISH) with specific oligonucleotide probes. In addition to Phaeocystis, members of Syndiniales group II, clade 10–11, and the Micromonas clades ABC and E made up a major fraction of the tag sequences of the nano- and picoplankton community within the fertilized patch. However, the same clades were also dominant before the bloom and outside the fertilized patch. Furthermore, only little changes in diversity could be observed over the course of the experiment. These results were corroborated by CARD-FISH analysis which confirmed the presence of a stable nano- and picoplankton community dominated by Phaeocystis and Micromonas during the entire course of the experiment. Interestingly, although Syndiniales dominated the tag sequences, they could hardly be detected by CARD-FISH, possibly due to the intracellular parasitic life style of this clade. The remarkable stability of the nano- and picoplankton community points to a tight coupling of the different trophic levels within the microbial food web during LOHAFEX.

  15. Biomass gasification and in-bed contaminants removal: performance of iron enriched olivine and bauxite in a process of steam/O2 gasification.

    Science.gov (United States)

    Barisano, D; Freda, C; Nanna, F; Fanelli, E; Villone, A

    2012-08-01

    A modified Olivine, enriched in iron content (10% Fe/Olivine), and a natural bauxite, were tested in the in-bed reduction of tar and alkali halides (NaCl and KCl) released in a process of biomass steam/O(2) gasification. The tests were carried out at an ICBFB bench scale reactor under the operating conditions of: 855-890 °C, atmospheric pressure, 0.5 steam/biomass and 0.33 ER ratios. From the use of the two materials, a reduction in the contaminant contents of the fuel gas produced was found. For the alkali halides, a decrease up to 70%(wt) was observed for the potassium concentration, while for sodium, the reduction was found to be quite poor. For the organic content, compared to unmodified Olivine, the chromatographically determined total tar quantity showed a removal efficiency of 38%(wt). Moreover, regarding the particulate content a rough doubling in the fuel gas revealed a certain brittleness of the new bed material.

  16. A Course at the Master Level Demonstrating Quality Assurance by Spectrophotometric Determination of Iron in two experiments

    DEFF Research Database (Denmark)

    In two experiments, the first a batch determination of iron, and the second determination of iron by flow injection analysis, the students perform a number of repetitions. The measurements were repeated until it became possible to estimate which one of the two methods exhibited the better perform...

  17. Temperature measurement during solidification of thin wall ductile cast iron. Part 1: Theory and experiment

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2008-01-01

    Temperature measurement using thermocouples (TC’s) influence solidification of the casting, especially in thin wall castings. The problems regarding acquisition of detailed cooling curves from thin walled castings is discussed. Experiments were conducted where custom made TC’s were used to acquire...... cooing curves in thin wall ductile iron castings. The experiments show how TC’s of different design interact with the melt and how TC design and surface quality affect the results of the data acquisition. It is discussed which precautions should be taken to ensure reliable acquisition of cooling curves...

  18. Design, construction, and operation of an actively controlled deep-sea CO2 enrichment experiment using a cabled observatory system

    Science.gov (United States)

    Kirkwood, William J.; Walz, Peter M.; Peltzer, Edward T.; Barry, James P.; Herlien, Robert A.; Headley, Kent L.; Kecy, Chad; Matsumoto, George I.; Maughan, Thom; O'Reilly, Thomas C.; Salamy, Karen A.; Shane, Farley; Brewer, Peter G.

    2015-03-01

    We describe the design, testing, and performance of an actively controlled deep-sea Free Ocean CO2 Enrichment (dp-FOCE) system for the execution of seafloor experiments relating to the impacts of ocean acidification on natural ecosystems. We used the 880 m deep MARS (Monterey Accelerated Research System) cable site offshore Monterey Bay, California for this work, but the Free Ocean CO2 Enrichment (FOCE) system concept is designed to be scalable and can be modified to be used in a wide variety of ocean depths and locations. The main frame is based on a flume design with active thruster control of flow and a central experimental chamber. The unit was allowed to free fall to the seafloor and connected to the cable node by remotely operated vehicle (ROV) manipulation. For operation at depth we designed a liquid CO2 containment reservoir which provided the CO2 enriched working fluid as ambient seawater was drawn through the reservoir beneath the more buoyant liquid CO2. Our design allowed for the significant lag time associated with the hydration of the dissolved CO2 molecule, resulting in an e-folding time, τ, of 97 s between fluid injection and pH sensing at the mean local T=4.31±0.14 °C and pHT of 7.625±0.011. The system maintained a pH offset of ~0.4 pH units compared to the surrounding ocean for a period of ~1 month. The unit allows for the emplacement of deep-sea animals for testing. We describe the components and software used for system operation and show examples of each. The demonstrated ability for active control of experimental systems opens new possibilities for deep-sea biogeochemical perturbation experiments of several kinds and our developments in open source control systems software and hardware described here are applicable to this end.

  19. Search for double beta decay of $^{116}$Cd with enriched $^{116}$CdWO$_4$ crystal scintillators (Aurora experiment)

    CERN Document Server

    Danevich, F A; Belli, P; Bernabei, R; Cappella, F; Caracciolo, V; Cerulli, R; Chernyak, D M; d'Angelo, S; Incicchitti, A; Kobychev, V V; Konovalov, S I; Laubenstein, M; Mokina, V M; Poda, D V; Polischuk, O G; Shlegel, V N; Tretyak, V I; Umatov, V I

    2016-01-01

    The Aurora experiment to investigate double beta decay of $^{116}$Cd with the help of 1.162 kg cadmium tungstate crystal scintillators enriched in $^{116}$Cd to 82\\% is in progress at the Gran Sasso Underground Laboratory. The half-life of $^{116}$Cd relatively to the two neutrino double beta decay is measured with the highest up-to-date accuracy $T_{1/2}=(2.62\\pm0.14)\\times10^{19}$ yr. The sensitivity of the experiment to the neutrinoless double beta decay of $^{116}$Cd to the ground state of $^{116}$Sn is estimated as $T_{1/2} \\geq 1.9\\times10^{23}$ yr at 90\\% CL, which corresponds to the effective Majorana neutrino mass limit $\\langle m_{\

  20. Development of Self-TOF neutron detector and its application to concrete and iron shielding experiments

    CERN Document Server

    Sasaki, M; Nunomiya, T; Fukumura, A; Nakamura, T; Shibata, T

    2002-01-01

    A new type detector, called 'Self-TOF detector', has been developed for high energy neutron spectrometry behind a shield. The detector consists of a veto counter, a set of radiators with 20 thin detectors, a start counter and a stop counter of nine segments. The measurement of the detector response function for high energy neutrons and the concrete and iron shielding experiments were done at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS), Japan. By using the response functions, neutron spectra behind shield were obtained by unfolding and the results were compared with the LAHET Code System (LCS).

  1. BUGLE-96 validation with MORSE-SGC/S using water and iron experiments from SINBAD 97

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, A.

    1999-12-03

    This document summarizes the validation of MORSE-SGC/S with the BUGLE-96 cross section library. SINBAD Benchmark Experiment 2.004, Winfrith Water Benchmark Experiment and SBE 6.001, Karlsruhe Iron Sphere Benchmark Experiment were utilized for this validation. The MORESE-SGC/S code with the BUGLE-96 cross-section library was used to model the experimental configurations as given in SINDBAD 97. SINDBAD is a shielding integral benchmark archive and database developed at the Oak Ridge National Laboratory (ORNL). For means of comparison, the experimental models were also executed with MORSE-SGC/S using the BUGLE-80 cross-section library. BUGLE-96 cross section will be used for shielding applications only as recommended by ORNL.

  2. The removal of arsenate from water using iron-modified diatomite (D-Fe): isotherm and column experiments.

    Science.gov (United States)

    Pantoja, M L; Jones, H; Garelick, H; Mohamedbakr, H G; Burkitbayev, M

    2014-01-01

    Iron hydroxide supported onto porous diatomite (D-Fe) is a low-cost material with potential to remove arsenic from contaminated water due to its affinity for the arsenate ion. This affinity was tested under varying conditions of pH, contact time, iron content in D-Fe and the presence of competitive ions, silicate and phosphate. Batch and column experiments were conducted to derive adsorption isotherms and breakthrough behaviours (50 μg L(-1)) for an initial concentration of 1,000 μg L(-1). Maximum capacity at pH 4 and 17% iron was 18.12-40.82 mg of arsenic/g of D-Fe and at pH 4 and 10% iron was 18.48-29.07 mg of arsenic/g of D-Fe. Adsorption decreased in the presence of phosphate and silicate ions. The difference in column adsorption behaviour between 10% and 17% iron was very pronounced, outweighing the impact of all other measured parameters. There was insufficient evidence of a correlation between iron content and arsenic content in isotherm experiments, suggesting that ion exchange is a negligible process occurring in arsenate adsorption using D-Fe nor is there co-precipitation of arsenate by rising iron content of the solute above saturation.

  3. Using Goal-Setting Strategies To Enrich the Practicum and Internship Experiences of Beginning Counselors.

    Science.gov (United States)

    Curtis, Russell C.

    2000-01-01

    Goal setting can be an effective way to help beginning counselors focus on important developmental issues. This article argues that counselors and supervisors must consider issues related to goal-setting theory and understand the process by which goals are set so that optimal learning experiences are created. (Author/MKA)

  4. Model-data synthesis for the next generation of forest free-air CO2 enrichment (FACE) experiments.

    Science.gov (United States)

    Norby, Richard J; De Kauwe, Martin G; Domingues, Tomas F; Duursma, Remko A; Ellsworth, David S; Goll, Daniel S; Lapola, David M; Luus, Kristina A; MacKenzie, A Rob; Medlyn, Belinda E; Pavlick, Ryan; Rammig, Anja; Smith, Benjamin; Thomas, Rick; Thonicke, Kirsten; Walker, Anthony P; Yang, Xiaojuan; Zaehle, Sönke

    2016-01-01

    The first generation of forest free-air CO2 enrichment (FACE) experiments has successfully provided deeper understanding about how forests respond to an increasing CO2 concentration in the atmosphere. Located in aggrading stands in the temperate zone, they have provided a strong foundation for testing critical assumptions in terrestrial biosphere models that are being used to project future interactions between forest productivity and the atmosphere, despite the limited inference space of these experiments with regards to the range of global ecosystems. Now, a new generation of FACE experiments in mature forests in different biomes and over a wide range of climate space and biodiversity will significantly expand the inference space. These new experiments are: EucFACE in a mature Eucalyptus stand on highly weathered soil in subtropical Australia; AmazonFACE in a highly diverse, primary rainforest in Brazil; BIFoR-FACE in a 150-yr-old deciduous woodland stand in central England; and SwedFACE proposed in a hemiboreal, Pinus sylvestris stand in Sweden. We now have a unique opportunity to initiate a model-data interaction as an integral part of experimental design and to address a set of cross-site science questions on topics including responses of mature forests; interactions with temperature, water stress, and phosphorus limitation; and the influence of biodiversity. © UT-Battelle, LLC New Phytologist © 2015 New Phytologist Trust.

  5. Enriching the Research Experiences for Undergraduates in Geoscience Through Student Feedback

    Science.gov (United States)

    Sears, R. F.; Bank, C. G.

    2014-12-01

    Research Experiences for Undergraduates (REU) allow students to work alongside professionals while they conduct scientific research and offer excellent opportunities to expose students to the practical components of their university education. Indeed, anecdotal evidence shows that a well-planned REU builds teamwork skills, provides a deeper understanding of the science learned in the classroom, and allows students to experience the various stages of science and thus consider wider career options. However, such evidence is difficult to measure. In this presentation we will present preliminary results from a survey of 2nd and 3rd year students who have been engaged in separate interdisciplinary projects (a geophysical survey in South Africa to assist archaeologists, and a forensic study in collaboration with the provincial police). Our before and after surveys address criteria such as students' understanding of scientific methodology, familiarity with the topic and tools for the research, expectations of the study and of themselves, and logistics of doing science. It is our hope that the student voices we present will help REU program coordinators to address limitations and establish best practices to provide the richest possible learning experience.

  6. USING HIGH Mg-CONTENT CORED-WIRE TO SPHEROIDIZE AND DESULPHURIZE DUCTILE IRON MELT IN INDUSTRIAL EXPERIMENTS

    Institute of Scientific and Technical Information of China (English)

    R.Z. Wu; B.D. Sun; H.J. Ni; Y.B. Wu; H.S. Wu; J.G. Ge

    2004-01-01

    40% Mg-content cored-wire was used to desulphurize and spheroidize ductile iron melt in industrial experiments. The optimal feeding speed and suitable treatment temperature were determined in the experiments. And cored-wire method and pouring method were compared.Conclusions have been drawn that, under these conditions in the experiments, the optimal feeding speed is 15m/min, treatment temperature should be as low as possible, 1400-1450℃ generally; and cored-wire method can act more effective in ductile iron melt desulphurization and spheroid than pouring method.

  7. Challenging terrestrial biosphere models with data from the long-term multifactor Prairie Heating and CO2 Enrichment experiment.

    Science.gov (United States)

    De Kauwe, Martin G; Medlyn, Belinda E; Walker, Anthony P; Zaehle, Sönke; Asao, Shinichi; Guenet, Bertrand; Harper, Anna B; Hickler, Thomas; Jain, Atul K; Luo, Yiqi; Lu, Xingjie; Luus, Kristina; Parton, William J; Shu, Shijie; Wang, Ying-Ping; Werner, Christian; Xia, Jianyang; Pendall, Elise; Morgan, Jack A; Ryan, Edmund M; Carrillo, Yolima; Dijkstra, Feike A; Zelikova, Tamara J; Norby, Richard J

    2017-09-01

    Multifactor experiments are often advocated as important for advancing terrestrial biosphere models (TBMs), yet to date, such models have only been tested against single-factor experiments. We applied 10 TBMs to the multifactor Prairie Heating and CO2 Enrichment (PHACE) experiment in Wyoming, USA. Our goals were to investigate how multifactor experiments can be used to constrain models and to identify a road map for model improvement. We found models performed poorly in ambient conditions; there was a wide spread in simulated above-ground net primary productivity (range: 31-390 g C m(-2)  yr(-1) ). Comparison with data highlighted model failures particularly with respect to carbon allocation, phenology, and the impact of water stress on phenology. Performance against the observations from single-factors treatments was also relatively poor. In addition, similar responses were predicted for different reasons across models: there were large differences among models in sensitivity to water stress and, among the N cycle models, N availability during the experiment. Models were also unable to capture observed treatment effects on phenology: they overestimated the effect of warming on leaf onset and did not allow CO2 -induced water savings to extend the growing season length. Observed interactive (CO2  × warming) treatment effects were subtle and contingent on water stress, phenology, and species composition. As the models did not correctly represent these processes under ambient and single-factor conditions, little extra information was gained by comparing model predictions against interactive responses. We outline a series of key areas in which this and future experiments could be used to improve model predictions of grassland responses to global change. © 2017 John Wiley & Sons Ltd.

  8. Relation between contemplative exercises and an enriched psychology students' experience in a neuroscience course

    Science.gov (United States)

    Levit Binnun, Nava; Tarrasch, Ricardo

    2014-01-01

    This article examines the relation of contemplative exercises with enhancement of students' experience during neuroscience studies. Short contemplative exercises inspired by the Buddhist tradition of self-inquiry were introduced in an undergraduate neuroscience course for psychology students. At the start of the class, all students were asked to participate in short “personal brain investigations” relevant to the topic presented. These investigations were aimed at bringing stable awareness to a specific perceptual, emotional, attentional, or cognitive process and observing it in a non-judgmental, non-personal way. In addition, students could choose to participate, for bonus credit, in a longer exercise designed to expand upon the weekly class activity. In the exercise, students continued their “personal brain investigations” for 10 min a day, 4 days a week. They wrote “lab reports” on their daily observations, obtained feedback from the teacher, and at the end of the year reviewed their reports and reflected upon their experiences during the semester. Out of 265 students, 102 students completed the bonus track and their final reflections were analyzed using qualitative methodology. In addition, 91 of the students answered a survey at the end of the course, 43 students participated in a quiz 1 year after course graduation, and the final grades of all students were collected and analyzed. Overall, students reported satisfaction from the exercises and felt they contributed to their learning experience. In the 1-year follow-up, the bonus-track students were significantly more likely than their peers to remember class material. The qualitative analysis of bonus-track students' reports revealed that the bonus-track process elicited positive feelings, helped students connect with class material and provided them with personal insights. In addition, students acquired contemplative skills, such as increased awareness and attention, non-judgmental attitudes, and

  9. Effects of iron stress on chromatic adaptation by natural phytoplankton communities in the Southern Ocean

    NARCIS (Netherlands)

    van Leeuwe, M.A.; Timmermans, K.R.; Witte, H.J.; Kraay, G.W.; Veldhuis, M.J.W.; de Baar, H.J.W.

    1998-01-01

    Effects of iron stress on chromatic adaptation were studied in natural phytoplankton communities collected in the Pacific region of the Southern Ocean. Iron enrichment experiments (48 to 72 h) were performed, incubating plankton communities under white, green and blue light respectively, with and wi

  10. Enriched $^{76}$Ge the Heidelberg-Moscow double beta decay experiment

    CERN Document Server

    Zuber, K

    1995-01-01

    The recent results of the Heidelberg-Moscow double beta decay experiment are presented. After 8.6 kg\\cdoty of measuring time no signal is seen for the neutrinoless decay mode, therefore giving a half life limit of . This converts into a neutrino mass limit of < 0.7 eV (90\\% CL), showing that double beta decay entered the region below 1eV. For the 2 neutrino mode a half life of T_{1/2} = 1.53 \\cdot 10^{21} y is derived, meaning that more than 10000 double beta events are observed. This is the first high statistic observation. Limits on exotic decay modes and on dark matter particles are also presented.

  11. Iron, phytoplankton growth, and the carbon cycle.

    Science.gov (United States)

    Street, Joseph H; Paytan, Adina

    2005-01-01

    Iron is an essential nutrient for all living organisms. Iron is required for the synthesis of chlorophyll and of several photosynthetic electron transport proteins and for the reduction of CO2, SO4(2-), and NO3(-) during the photosynthetic production of organic compounds. Iron concentrations in vast areas of the ocean are very low (iron in oxic seawater. Low iron concentrations have been shown to limit primary production rates, biomass accumulation, and ecosystem structure in a variety of open-ocean environments, including the equatorial Pacific, the subarctic Pacific and the Southern Ocean and even in some coastal areas. Oceanic primary production, the transfer of carbon dioxide into organic carbon by photosynthetic plankton (phytoplankton), is one process by which atmospheric CO2 can be transferred to the deep ocean and sequestered for long periods of time. Accordingly, iron limitation of primary producers likely plays a major role in the global carbon cycle. It has been suggested that variations in oceanic primary productivity, spurred by changes in the deposition of iron in atmospheric dust, control atmospheric CO2 concentrations, and hence global climate, over glacial-interglacial timescales. A contemporary application of this "iron hypothesis" promotes the large-scale iron fertilization of ocean regions as a means of enhancing the ability of the ocean to store anthropogenic CO2 and mitigate 21st century climate change. Recent in situ iron enrichment experiments in the HNLC regions, however, cast doubt on the efficacy and advisability of iron fertilization schemes. The experiments have confirmed the role of iron in regulating primary productivity, but resulted in only small carbon export fluxes to the depths necessary for long-term sequestration. Above all, these experiments and other studies of iron biogeochemistry over the last two decades have begun to illustrate the great complexity of the ocean system. Attempts to engineer this system are likely to

  12. Assessing degradation rates of chlorinated ethylenes in column experiments with commercial iron materials used in permeable reactive barriers.

    Science.gov (United States)

    Ebert, Markus; Köber, Ralf; Parbs, Anika; Plagentz, Volkmar; Schäfer, Dirk; Dahmke, Andreas

    2006-03-15

    Multiple column experiments were performed using two commercial iron materials to evaluate the necessity and usefulness of preliminary investigations in permeable reactive barrier (PRB) design for chlorinated organics. Experiments were performed with contaminated groundwater and involved fresh iron granules or altered iron material excavated from PRBs. The determination of first-order rate coefficients by global nonlinear least-squares fittings indicated a variability in rate coefficients on 1 or 2 orders of magnitude. Geometric mean values of surface area normalized rate coefficients (in 10(-5) L m(-2) h(-1)) for fresh gray cast iron and iron sponge, respectively, are: tetrachloroethene (4.5, 2.6), trichloroethene (8.1, 3.3), cis-1,2-dichloroethene (3.1, 2.9), trans-1,2-dichloroethene (9.5, 5.3), 1,1-dichloroethene (4.0, 4.4), and vinyl chloride (1.6, 6.1). The increasing rate coefficients with decreasing grade of chlorination, which characterize degradation at iron sponge are linearly related to diffusion coefficients in water, suggesting diffusion limitation in the degradation process for this particular material, possibly due to a high inner surface. The variability in rate coefficients seems to be too high to use mean rate coefficients from published studies in the design procedure of PRBs, and variabilities cannot be related to groundwater characteristics, waterflow through the reactive cells, or secondary corrosion reactions.

  13. RAYLEIGH-TAYLOR STRENGTH EXPERIMENTS OF THE PRESSURE-INDUCED alpha->epsilon->alpha' PHASE TRANSITION IN IRON

    Energy Technology Data Exchange (ETDEWEB)

    Belof, J L; Cavallo, R M; Olson, R T; King, R S; Gray, G T; Holtkamp, D B; Chen, S R; Rudd, R E; Barton, N R; Arsenlis, A; Remington, B A; Park, H; Prisbrey, S T; Vitello, P A; Bazan, G; Mikaelian, K O; Comley, A J; Maddox, B R; May, M J

    2011-08-10

    We present here the first dynamic Rayleigh-Taylor (RT) strength measurement of a material undergoing solid-solid phase transition. Iron is quasi-isentropically driven across the pressure-induced bcc ({alpha}-Fe) {yields} hcp ({var_epsilon}-Fe) phase transition and the dynamic strength of the {alpha}, {var_epsilon} and reverted {alpha}{prime} phases have been determined via proton radiography of the resulting Rayleigh-Taylor unstable interface between the iron target and high-explosive products. Simultaneous velocimetry measurements of the iron free surface yield the phase transition dynamics and, in conjunction with detailed hydrodynamic simulations, allow for determination of the strength of the distinct phases of iron. Forward analysis of the experiment via hydrodynamic simulations reveals significant strength enhancement of the dynamically-generated {var_epsilon}-Fe and reverted {alpha}{prime}-Fe, comparable in magnitude to the strength of austenitic stainless steels.

  14. Assumption Centred Modelling of Ecosystem Responses to CO2 at Six US Atmospheric CO2 Enrichment Experiments.

    Science.gov (United States)

    Walker, A. P.; De Kauwe, M. G.; Medlyn, B. E.; Zaehle, S.; Luus, K. A.; Ryan, E.; Xia, J.; Norby, R. J.

    2015-12-01

    Plant photosynthetic rates increase and stomatal apertures decrease in response to elevated atmospheric CO[2] (eCO2), increasing both plant carbon (C) availability and water use efficiency. These physiological responses to eCO2 are well characterised and understood, however the ecological effects of these responses as they cascade through a suite of plant and ecosystem processes are complex and subject to multiple interactions and feedbacks. Therefore the response of the terrestrial carbon sink to increasing atmospheric CO[2] remains the largest uncertainty in global C cycle modelling to date, and is a huge contributor to uncertainty in climate change projections. Phase 2 of the FACE Model-Data Synthesis (FACE-MDS) project synthesises ecosystem observations from five long-term Free-Air CO[2] Enrichment (FACE) experiments and one open top chamber (OTC) experiment to evaluate the assumptions of a suite of terrestrial ecosystem models. The experiments are: The evergreen needleleaf Duke Forest FACE (NC), the deciduous broadleaf Oak Ridge FACE (TN), the prairie heating and FACE (WY), and the Nevada desert FACE, and the evergreen scrub oak OTC (FL). An assumption centered approach is being used to analyse: the interaction between eCO2 and water limitation on plant productivity; the interaction between eCO2 and temperature on plant productivity; whether increased rates of soil decomposition observed in many eCO2 experiments can account for model deficiencies in N uptake shown during Phase 1 of the FACE-MDS; and tracing carbon through the ecosystem to identify the exact cause of changes in ecosystem C storage.

  15. Enriched and Deprived Sensory Experience Induces Structural Changes and Rewires Connectivity during the Postnatal Development of the Brain

    Science.gov (United States)

    Bengoetxea, Harkaitz; Ortuzar, Naiara; Bulnes, Susana; Rico-Barrio, Irantzu; Lafuente, José Vicente; Argandoña, Enrike G.

    2012-01-01

    During postnatal development, sensory experience modulates cortical development, inducing numerous changes in all of the components of the cortex. Most of the cortical changes thus induced occur during the critical period, when the functional and structural properties of cortical neurons are particularly susceptible to alterations. Although the time course for experience-mediated sensory development is specific for each system, postnatal development acts as a whole, and if one cortical area is deprived of its normal sensory inputs during early stages, it will be reorganized by the nondeprived senses in a process of cross-modal plasticity that not only increases performance in the remaining senses when one is deprived, but also rewires the brain allowing the deprived cortex to process inputs from other senses and cortices, maintaining the modular configuration. This paper summarizes our current understanding of sensory systems development, focused specially in the visual system. It delineates sensory enhancement and sensory deprivation effects at both physiological and anatomical levels and describes the use of enriched environment as a tool to rewire loss of brain areas to enhance other active senses. Finally, strategies to apply restorative features in human-deprived senses are studied, discussing the beneficial and detrimental effects of cross-modal plasticity in prostheses and sensory substitution devices implantation. PMID:22848849

  16. Enriched and Deprived Sensory Experience Induces Structural Changes and Rewires Connectivity during the Postnatal Development of the Brain

    Directory of Open Access Journals (Sweden)

    Harkaitz Bengoetxea

    2012-01-01

    Full Text Available During postnatal development, sensory experience modulates cortical development, inducing numerous changes in all of the components of the cortex. Most of the cortical changes thus induced occur during the critical period, when the functional and structural properties of cortical neurons are particularly susceptible to alterations. Although the time course for experience-mediated sensory development is specific for each system, postnatal development acts as a whole, and if one cortical area is deprived of its normal sensory inputs during early stages, it will be reorganized by the nondeprived senses in a process of cross-modal plasticity that not only increases performance in the remaining senses when one is deprived, but also rewires the brain allowing the deprived cortex to process inputs from other senses and cortices, maintaining the modular configuration. This paper summarizes our current understanding of sensory systems development, focused specially in the visual system. It delineates sensory enhancement and sensory deprivation effects at both physiological and anatomical levels and describes the use of enriched environment as a tool to rewire loss of brain areas to enhance other active senses. Finally, strategies to apply restorative features in human-deprived senses are studied, discussing the beneficial and detrimental effects of cross-modal plasticity in prostheses and sensory substitution devices implantation.

  17. Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

    Institute of Scientific and Technical Information of China (English)

    WANG Xian; CAI Qing-Sheng

    2006-01-01

    The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1)of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

  18. Tight coupling between enrichment of iron and manganese in North Sea suspended matter and sedimentary redox processes: evidence for seasonal variability

    OpenAIRE

    Dehairs, F.A.; Baeyens, W.F.J.; Van Gansbeke, D.

    1989-01-01

    Suspended matter and sediments from the North Sea were analysed for Al, Fe and Mn. A seasonal variation of Mn and Fe over Al ratios is observed. For most of the year suspended matter is enriched in Mn and Fe relative to average soil composition. No enrichment, and even depletion, occurs during a short period of the year (April-May) coinciding with the occurrence of the spring phytoplankton bloom. Surface sediments from the Southern Bight show the inverse image, with Mn and Fe enrichment occur...

  19. Effect of ascorbic acid on iron release from the emulsifier interface and on the oxidative flavor deterioration in fish oil enriched mayonnaise.

    Science.gov (United States)

    Jacobsen, C; Adler-Nissen, J; Meyer, A S

    1999-12-01

    This research examines the effect of ascorbic acid (0-800 ppm) on the sensory perception of mayonnaises containing 16% fish oil and on the levels of iron and copper in the aqueous phase. Ascorbic acid increased the formation of fishy off-flavors in fresh mayonnaise. Simultaneously, the iron concentration increased from below the detection limit (1.8 microM) to 34 microM in the aqueous phase of mayonnaises. Model mayonnaises with various concentrations of egg yolk (1-7% w/w) and ascorbic acid (0-8000 ppm) were prepared. Iron concentrations in the aqueous phase increased with increasing ascorbic acid levels, whereas iron concentrations in the assumed interfacial layer decreased. It is proposed that ascorbic acid is able to complex and reduce Fe(3+) to Fe(2+) from phosvitin in the egg yolk, whereby iron is released from the interface. The ascorbic acid-iron complex subsequently reacts with lipid hydroperoxides, resulting in increased lipid oxidation and in the immediate formation of rancid and fishy off-flavors.

  20. The Dynamics of Visual Art Dialogues: Experiences to Be Used in Hospital Settings with Visual Art Enrichment

    Directory of Open Access Journals (Sweden)

    Britt-Maj Wikström

    2011-01-01

    Full Text Available Objectives. Given that hospitals have environmental enrichment with paintings and visual art arrangement, it would be meaningful to develop and document how hospital art could be used by health professionals. Methods. The study was undertaken at an art site in Sweden. During 1-hour sessions, participants (=20 get together in an art gallery every second week five times. Results. According to the participants a new value was perceived. From qualitative analyses, three themes appear: raise association, mentally present, and door-opener. In addition 72% of the participants reported makes me happy and gives energy and inspiration, and 52% reported that dialogues increase inspiration, make you involved, and stimulate curiosity. Conclusion. The present study supported the view that visual art dialogue could be used by health care professionals in a structured manner and that meaningful art stimulation, related to a person’s experiences, could be of importance for the patients. Implementing art dialogues in hospital settings could be a fruitful working tool for nurses, a complementary manner of patient communication.

  1. Constraining the process-based land surface model ORCHIDEE by nutrient enrichment and forest management experiments in Sweden

    Science.gov (United States)

    Sofie Lansø, Anne; Resovsky, Alex; Guenet, Bertrand; Peylin, Philippe; Vuichard, Nicolas; Messina, Palmira; Smith, Benjamin; Ryder, James; Naudts, Kim; Chen, Yiying; Otto, Juliane; McGrath, Matthew; Valade, Aude; Luyssaert, Sebastiaan

    2017-04-01

    Understanding the coupling between carbon (C) and nitrogen (N) cycling in terrestrial ecosystems is key to predicting global change. While numerous experimental studies have demonstrated the positive response of stand-level photosynthesis and net primary production (NPP) to atmospheric CO2 enrichment, N availability has been shown to exert an important control on the timing and magnitude of such responses. Forest management is also a key driver of C storage in such ecosystems but interactions between forest management and the N cycle as a C storage driver are not well known. In this study, we use data from N-fertilization experiments at two long-term forest manipulation sites in Sweden to inform and improve the representation of C and N interaction in the ORCHIDEE land surface model. Our version of the model represents the union of two ORCHIDEE branches; 1) ORCHIDEE-CN, which resolves processes related to terrestrial C and N cycling, and 2) ORCHIDEE-CAN, which integrates a multi-layer canopy structure and includes representation of forest management practices. Using this new model branch, referred to as ORCHIDEE-CN-CAN, we simulate the growth patterns of managed forests both with and without N limitations. Combining our simulated results with measurements of various ecosystem parameters (such as soil N) will aid in ecosystem model development, reducing structural uncertainty and optimizing parameter settings in global change simulations.

  2. Effect of macrofauna, oxygen exchange and particle reworking on iron and manganese sediment gogeochemistry: a laboratory experiment

    NARCIS (Netherlands)

    Ferro, I.; Van Nugteren, P.; Middelburg, J.J.; Herman, P.M.J.; Heip, C.H.R.

    2003-01-01

    The impact of bioturbation on iron and manganese cycling in rine sediments was studied in laboratory experiments in which faunal effects which combine in the field (particle mixing and oxygen exchange) were studied separately. Particle mixing and sediment aeration both enhance metal oxide reduction

  3. Effect of macrofauna, oxygen exchange and particle reworking on iron and manganese sediment gogeochemistry: a laboratory experiment

    NARCIS (Netherlands)

    Ferro, I.; Van Nugteren, P.; Middelburg, J.J.; Herman, P.M.J.; Heip, C.H.R.

    2003-01-01

    The impact of bioturbation on iron and manganese cycling in rine sediments was studied in laboratory experiments in which faunal effects which combine in the field (particle mixing and oxygen exchange) were studied separately. Particle mixing and sediment aeration both enhance metal oxide reduction

  4. Underestimation of the coexistence of iron deficiencies and thalassemia minors: a single institution experience in Taiwan.

    Science.gov (United States)

    Lin, Chung-King; Chen, Ling-Ping; Chang, Hsiu-Lin; Sung, Yung-Chuan

    2014-08-01

    Some physicians neglect the possible coexistence of an iron deficiency with a thalassemia minor and do not treat the iron deficiency accordingly. This motivated us to conduct this study. We retrospectively reviewed the records of 3892 patients who visited our clinics and had hemoglobin (Hb) electrophoreses performed in our hematologic laboratory from August 1, 2007 to December 31, 2012. The thalassemia minors were identified by characteristic complete blood count (CBC) parameters obtained from an autoanalyzer and Hb electrophoresis, and some cases were confirmed with molecular tests. Then, we checked iron studies [ferritin and/or serum iron with total iron-binding capacity (TIBC)] to determine the coexistence of an iron deficiency with a thalassemia minor and a response to iron, if such treatments were given. We found 792 cases with thalassemia minors, and excluded those without iron studies, with 661 cases as our sample. A total of 202/661 cases (31%) also had iron deficiencies. They had lower red blood cell (RBC) counts, Hb, and ferritin levels as compared to those thalassemia minor cases without coexistence of iron deficiencies. We concluded that the thalassemia minor patients did not have iron overload complications in our population. On the contrary, iron deficiencies commonly coexist in the clinical visits. We propose that if Hb thalassemia minor, one should screen for iron deficiency simultaneously. The sensitivity is 79.8% and the specificity is 82.6%. Therefore, physicians should be aware of this coexisting condition, and know how to recognize and treat it accordingly. Copyright © 2014. Published by Elsevier B.V.

  5. 富铁面包酵母的筛选及富集条件研究%Isolation and Accumulation Conditions of Iron-enrich Baker ’s Yeast

    Institute of Scientific and Technical Information of China (English)

    李静; 谭海刚; 王滢雪

    2014-01-01

    本文探索获得富铁面包酵母的富集条件。筛选获得一株富铁能力较强的面包酵母菌株QN006。通过单因素实验确定该菌株富铁工艺条件为:铁盐种类为硫酸亚铁,亚铁离子浓度为900μg/mL,添加时间为0h,温度为28℃, pH为5.0。在此条件测得面包酵母QN006的铁富集量为13.92mg/g干菌体,不加糖面团发酵力达到623mL/h。%To explore the accumulation conditions of baker’s yeast which is able to enrich iron. The baker’s yeast strain QN006 with strong iron-rich ability was obtained. By the single factor test, the accumulation conditions of iron-rich were as follows: the inorganic ferrite was FeSO4, the content of Fe2+ was 900μg/mL, the adding time was 0h, the accumulation temperature was 28℃, and the accumulation pH was 5.0. Under these conditions, the iron content and the CO2 production in lean dough of QN006 reached 13.92mg/g (cell dry weight) and 623mL/h, re-spectively.

  6. Microclimatic performance of a free-air warming and CO2 enrichment experiment in windy Wyoming, USA.

    Directory of Open Access Journals (Sweden)

    Daniel LeCain

    Full Text Available In order to plan for global changing climate experiments are being conducted in many countries, but few have monitored the effects of the climate change treatments (warming, elevated CO2 on the experimental plot microclimate. During three years of an eight year study with year-round feedback-controlled infra-red heater warming (1.5/3.0°C day/night and growing season free-air CO2 enrichment (600 ppm in the mixed-grass prairie of Wyoming, USA, we monitored soil, leaf, canopy-air, above-canopy-air temperatures and relative humidity of control and treated experimental plots and evaluated ecologically important temperature differentials. Leaves were warmed somewhat less than the target settings (1.1 & 1.5°C day/night but soil was warmed more creating an average that matched the target settings extremely well both during the day and night plus the summer and winter. The site typically has about 50% bare or litter covered soil, therefore soil heat transfer is more critical than in dense canopy ecosystems. The Wyoming site commonly has strong winds (5 ms(-1 average and significant daily and seasonal temperature fluctuations (as much as 30°C daily but the warming system was nearly always able to maintain the set temperatures regardless of abiotic variation. The within canopy-air was only slightly warmed and above canopy-air was not warmed by the system, therefore convective warming was minor. Elevated CO2 had no direct effect nor interaction with the warming treatment on microclimate. Relative humidity within the plant canopy was only slightly reduced by warming. Soil water content was reduced by warming but increased by elevated CO2. This study demonstrates the importance of monitoring the microclimate in manipulative field global change experiments so that critical physiological and ecological conclusions can be determined. Highly variable energy demand fluctuations showed that passive IR heater warming systems will not maintain desired warming for

  7. Microclimatic performance of a free-air warming and CO2 enrichment experiment in windy Wyoming, USA.

    Science.gov (United States)

    LeCain, Daniel; Smith, David; Morgan, Jack; Kimball, Bruce A; Pendall, Elise; Miglietta, Franco

    2015-01-01

    In order to plan for global changing climate experiments are being conducted in many countries, but few have monitored the effects of the climate change treatments (warming, elevated CO2) on the experimental plot microclimate. During three years of an eight year study with year-round feedback-controlled infra-red heater warming (1.5/3.0°C day/night) and growing season free-air CO2 enrichment (600 ppm) in the mixed-grass prairie of Wyoming, USA, we monitored soil, leaf, canopy-air, above-canopy-air temperatures and relative humidity of control and treated experimental plots and evaluated ecologically important temperature differentials. Leaves were warmed somewhat less than the target settings (1.1 & 1.5°C day/night) but soil was warmed more creating an average that matched the target settings extremely well both during the day and night plus the summer and winter. The site typically has about 50% bare or litter covered soil, therefore soil heat transfer is more critical than in dense canopy ecosystems. The Wyoming site commonly has strong winds (5 ms(-1) average) and significant daily and seasonal temperature fluctuations (as much as 30°C daily) but the warming system was nearly always able to maintain the set temperatures regardless of abiotic variation. The within canopy-air was only slightly warmed and above canopy-air was not warmed by the system, therefore convective warming was minor. Elevated CO2 had no direct effect nor interaction with the warming treatment on microclimate. Relative humidity within the plant canopy was only slightly reduced by warming. Soil water content was reduced by warming but increased by elevated CO2. This study demonstrates the importance of monitoring the microclimate in manipulative field global change experiments so that critical physiological and ecological conclusions can be determined. Highly variable energy demand fluctuations showed that passive IR heater warming systems will not maintain desired warming for much of the

  8. Biogeochemical fluxes and fate of diazotroph-derived nitrogen in the food web after a phosphate enrichment: modeling of the VAHINE mesocosms experiment

    Science.gov (United States)

    Gimenez, Audrey; Baklouti, Melika; Bonnet, Sophie; Moutin, Thierry

    2016-09-01

    The VAHINE mesocosm experiment in the oligotrophic waters of the Nouméa lagoon (New Caledonia), where high N2 fixation rates and abundant diazotroph organisms were observed, aimed to assess the role of the nitrogen input through N2 fixation in carbon production and export and to study the fate of diazotroph-derived nitrogen (DDN) throughout the planktonic food web. A 1-D vertical biogeochemical mechanistic model was used in addition to the in situ experiment to enrich our understanding of the dynamics of the planktonic ecosystem and the main biogeochemical carbon (C), nitrogen (N) and phosphate (P) fluxes. The mesocosms were intentionally enriched with ˜ 0.8 µmol L-1 of inorganic P to trigger the development of diazotrophs and amplify biogeochemical fluxes. Two simulations were run, one with and the other without the phosphate enrichment. In the P-enriched simulation, N2 fixation, primary production (PP) and C export increased by 201, 208 and 87 %, respectively, consistent with the trends observed in the mesocosms (+124, +141 and +261 % for N2 fixation, PP and C export, respectively). In total, 5-10 days were necessary to obtain an increase in primary and export productions after the dissolved inorganic phosphate (DIP) enrichment, thereby suggesting that classical methods (short-term microcosms experiments) used to quantify nutrient limitations of primary production may not be relevant. The model enabled us to monitor the fate of fixed N2 by providing the proportion of DDN in each compartment (inorganic and organic) of the model over time. At the end of the simulation (25 days), 43 % of the DDN was found in the non-diazotroph organisms, 33 % in diazotrophs, 16 % in the dissolved organic nitrogen pool, 3 % in the particulate detrital organic pool and 5 % in traps, indicating that N2 fixation was of benefit to non-diazotrophic organisms and contributed to C export.

  9. Comprehensive ecosystem model-experiment synthesis using multiple datasets at two temperate forest free-air CO2 enrichment experiments: model performance and compensating biases

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Anthony P [ORNL; Hanson, Paul J [ORNL; DeKauwe, Martin G [Macquarie University; Medlyn, Belinda [Macquarie University; Zaehle, S [Max Planck Institute for Biogeochemistry; Asao, Shinichi [Colorado State University, Fort Collins; Dietze, Michael [University of Illinois, Urbana-Champaign; Hickler, Thomas [Goethe University, Frankfurt, Germany; Huntinford, Chris [Centre for Ecology and Hydrology, Wallingford, United Kingdom; Iversen, Colleen M [ORNL; Jain, Atul [University of Illinois, Urbana-Champaign; Lomas, Mark [University of Sheffield; Luo, Yiqi [University of Oklahoma; McCarthy, Heather R [Duke University; Parton, William [Colorado State University, Fort Collins; Prentice, I. Collin [Macquarie University; Thornton, Peter E [ORNL; Wang, Shusen [Canada Centre for Remote Sensing (CCRS); Wang, Yingping [CSIRO Marine and Atmospheric Research; Warlind, David [Lund University, Sweden; Weng, Ensheng [University of Oklahoma, Norman; Warren, Jeffrey [ORNL; Woodward, F. Ian [University of Sheffield; Oren, Ram [Duke University; Norby, Richard J [ORNL

    2014-01-01

    Free Air CO2 Enrichment (FACE) experiments provide a remarkable wealth of data to test the sensitivities of terrestrial ecosystem models (TEMs). In this study, a broad set of 11 TEMs were compared to 22 years of data from two contrasting FACE experiments in temperate forests of the south eastern US the evergreen Duke Forest and the deciduous Oak Ridge forest. We evaluated the models' ability to reproduce observed net primary productivity (NPP), transpiration and Leaf Area index (LAI) in ambient CO2 treatments. Encouragingly, many models simulated annual NPP and transpiration within observed uncertainty. Daily transpiration model errors were often related to errors in leaf area phenology and peak LAI. Our analysis demonstrates that the simulation of LAI often drives the simulation of transpiration and hence there is a need to adopt the most appropriate of hypothesis driven methods to simulate and predict LAI. Of the three competing hypotheses determining peak LAI (1) optimisation to maximise carbon export, (2) increasing SLA with canopy depth and (3) the pipe model the pipe model produced LAI closest to the observations. Modelled phenology was either prescribed or based on broader empirical calibrations to climate. In some cases, simulation accuracy was achieved through compensating biases in component variables. For example, NPP accuracy was sometimes achieved with counter-balancing biases in nitrogen use efficiency and nitrogen uptake. Combined analysis of parallel measurements aides the identification of offsetting biases; without which over-confidence in model abilities to predict ecosystem function may emerge, potentially leading to erroneous predictions of change under future climates.

  10. Role of iron content on serpentinite dehydration depth in subduction zones: Experiments and thermodynamic modeling

    Science.gov (United States)

    Merkulova, Margarita; Muñoz, Manuel; Vidal, Olivier; Brunet, Fabrice

    2016-11-01

    A series of dehydration experiments in the piston-cylinder apparatus was carried out at 2 GPa and 550-850 °C on a natural antigorite sample mixed with 5 wt.% of magnetite. Chemical analyses of experimental products show a progressive decrease of the Mg# in antigorite and clinopyroxene between 550 and 675 °C, whereas the Mg# of olivine increases. The observed behavior of Mg# signifies Fe-Mg exchange between coexisting minerals. At higher temperatures, between 700 and 850 °C, compositions remain stable for all minerals in experimental assemblages. Thermodynamic parameters of the ferrous antigorite end-member were refined with the use of Holland and Powell (1998) data set and added to the antigorite solid solution. Good agreement between theoretical calculations performed for the studied bulk composition and experimental results confirms extrapolated thermodynamic data for Fe-antigorite. Constrained parameters allowed to calculate phase relationships for various serpentinite compositions. First, we assessed the effect of bulk iron content, from 0 to 10 wt.% FeO, on the stability field of antigorite. The results show significant decrease of the antigorite thermal stability with increasing bulk Fe content. Second, we demonstrated the influence of bulk iron content on dehydration reactions in subduction zones along typical thermal gradients. Dehydration observed in pure MSH (MgO-SiO2-H2O) systems comprised of antigorite appears as a univariant reaction, which happens at 710 °C/3.7 GPa and 640 °C/6 GPa in "hot" and "cold" subduction, respectively. In contrast, more complex in composition Fe-bearing serpentinites show spread dehydration profiles through divariant reactions from ~ 300 °C/0.8 GPa to 700 °C/3.6 GPa and from 450 °C/4 GPa to 650 °C/7.4 GPa for "hot" and "cold" thermal gradients respectively. A comparison between depths of "water-release events" and "earthquake occurrence" in the South Chile slab ("hot" subduction) highlights a clear correlation between

  11. Research on Enrichment of Iron in Pyrite Cinder%硫酸渣中铁的富集试验研究

    Institute of Scientific and Technical Information of China (English)

    李国旺; 王家伟; 赵平源; 吴霜

    2014-01-01

    研究了从硫酸渣中富集铁,考察了物料细度、物料配比、焙烧温度、焙烧时间对铁品位的影响。结果表明:在物料配比0.20、700℃下焙烧1.5 h ,再用试剂WJ‐2浸出,可将硫酸渣中铁质量分数从49%提高到59.24%。%Enrichmentof iron in pyrite cinder was studied .The effects of pyrite cinder fineness, material proportion, roasting temperature, roasting time on iron grade were examined .The results show that at the conditions of roasting temperature of 700 ℃, the materials proportion of 0 .20, roasting time of 1 .5 h, and leaching using WJ‐2 reagent, the mass fraction of iron in the leaching residue can increase from 49% to 59 .24% .

  12. Zero-valent iron/iron oxide-oxyhydroxide/graphene as a magnetic sorbent for the enrichment of polychlorinated biphenyls, polyaromatic hydrocarbons and phthalates prior to gas chromatography-mass spectrometry.

    Science.gov (United States)

    Karamani, Anna A; Douvalis, Alexios P; Stalikas, Constantine D

    2013-01-04

    A composite magnetic material consisting of zero-valent iron, iron oxide-oxyhydroxide and graphene was synthesized and used successfully as a sorbent for the micro solid-phase extraction of PAHs, PCBs and phthalic acid esters. The components endow the composite with multiple characteristics such as adsorption capability and facile removal due to its magnetic properties. Due to the π-π electrostatic stacking property of graphene, the high specific surface area and the adsorption capability of both components, the resulting black flaky Fe(0)/iron oxide-oxyhydroxide/graphene composite showed high extraction efficiency for the target analytes from water samples. Compared with the neat graphene, the composite material has improved properties in terms of microextraction capabilities as both the hydrophobic graphene and zero-valent iron participate in the adsorption of the hydrophobic molecules. The precision from the extraction of all three groups of compounds was lower than 7% and the recoveries were from 90 to 93% from a spiked lake water sample. The high recoveries in relation to the low final volume of the desorption solvent ensure high preconcentration efficiency and a promising sorbent for analytical applications.

  13. Science Teaching Experiences in Informal Settings: One Way to Enrich the Preparation Program for Preservice Science Teachers

    Science.gov (United States)

    Hsu, Pei-Ling

    2016-01-01

    The high attrition rate of new science teachers demonstrates the urgent need to incorporate effective practices in teacher preparation programs to better equip preservice science teachers. The purpose of the study is to demonstrate a way to enrich preservice science teachers' preparation by incorporating informal science teaching practice into…

  14. Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; Ambus, Per; Michelsen, Anders

    2011-01-01

    Carbon dioxide (CO2) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO2 concentration from c. 380 μmol...

  15. Industry experience in promoting weekly iron-folic acid supplementation in the Philippines.

    Science.gov (United States)

    Garcia, Josel; Datol-Barrett, Eva; Dizon, Maynilad

    2005-12-01

    After participating in a pilot project under a government-industry partnership to promote the adoption of weekly iron-folic acid supplementation among women of reproductive age in the Philippines in 1998, United Laboratories (UNILAB), the Philippines' largest private pharmaceutical company, decided in April 2002 to launch a weekly iron-folic acid supplement for pregnant and non-pregnant women under the brand name Femina. The business objective set for the Femina brand was to build the category of preventive iron-folic acid supplements in line with the Philippine Department of Health's advocacy on weekly supplementation as an alternate to daily dosing to reduce the prevalence of anemia in the country. The brand was supported with an integrated mix of traditional advertising media with complementary direct-to-consumer educational programs that aimed to create awareness of iron-deficiency anemia, its causes and effects, and the role of weekly intake of iron-folic acid in preventing the condition. Aggressive marketing support for 1 year was successful in creating awareness among the target women. Significant lessons derived from consumers identified opportunity areas that can be further addressed in developing advocacy programs on weekly iron supplementation implemented on a nationwide scale in the future.

  16. Did the First Iron Blacksmiths Learn to Carburize Iron? Part II: Experiments Showing That it is Very Likely That They Did

    Science.gov (United States)

    Verhoeven, J. D.; Pendray, A. H.; Dauksch, W. E.

    2016-08-01

    Results of short-time carburizing of wrought iron in a charcoal-fired furnace present strong evidence that our earliest blacksmith ancestors probably discovered how to carburize their bloomery iron and produced cutting and scraping tools superior to bronze tools shortly after they had learned to make this iron in the 1200-900 BC time period. Their bloomery iron needed to be forged to make useful tools and it seems likely that at least some of them heated the iron to the forging temperature in charcoal burning in their bloomery furnaces, the same arrangement as used here.

  17. Role of soft-iron impellers on the mode selection in the von kármán-sodium dynamo experiment.

    Science.gov (United States)

    Giesecke, André; Stefani, Frank; Gerbeth, Gunter

    2010-01-29

    A crucial point for the understanding of the von Kármán-sodium (VKS) dynamo experiment is the influence of soft-iron impellers. We present numerical simulations of a VKS-like dynamo with a localized permeability distribution that resembles the shape of the flow driving impellers. It is shown that the presence of soft-iron material essentially determines the dynamo process in the VKS experiment. An axisymmetric magnetic field mode can be explained by the combined action of the soft-iron disk and a rather small alpha effect parametrizing the induction effects of unresolved small scale flow fluctuations.

  18. The nanophase iron mineral(s) in Mars soil

    Science.gov (United States)

    Banin, A.; Ben-Shlomo, T.; Margulies, L.; Blake, D. F.; Mancinelli, R. L.; Gehring, A. U.

    1993-01-01

    A series of surface-modified clays containing nanophase (np) iron oxide/oxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these "Mars-soil analogs" were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging, specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The clay acted as an effective matrix, both chemically and sterically, preventing the major part of the synthesized iron oxides from ripening, i.e., growing and developing larger crystals. The precipitated iron oxides appear as isodiametric or slightly elongated particles in the size range 1-10 nm, having large specific surface area. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (gamma-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxy mineral such as "green rust," or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable maghemite (gamma-Fe2O3) by mild heat treatment and then to nanophase hematite (alpha-Fe2O3) by extensive heat treatment. After mild heating, the iron-enriched clay became slightly magnetic, to the extent that it adheres to a hand-held magnet, as was observed with Mars soil. The chemical reactivity of the iron-enriched clays strongly resembles, and offers a plausible mechanism

  19. Iron-fortified milk can improve iron status in young women with low iron stores

    NARCIS (Netherlands)

    Scholz-Ahrens, K.E.; Schaafsma, G.; Kip, P.; Elbers, F.; Boeing, H.; Schrezenmeir, J.

    2004-01-01

    A considerable proportion of the populations of developing and industrialised nations does not meet the recommended daily allowance for iron and are thus at risk of chronic iron-deficiency anaemia. In a placebo-controlled, double-blind study we investigated whether supplementation with iron-enriched

  20. Iron-fortified milk can improve iron status in young women with low iron stores

    NARCIS (Netherlands)

    Scholz-Ahrens, K.E.; Schaafsma, G.; Kip, P.; Elbers, F.; Boeing, H.; Schrezenmeir, J.

    2004-01-01

    A considerable proportion of the populations of developing and industrialised nations does not meet the recommended daily allowance for iron and are thus at risk of chronic iron-deficiency anaemia. In a placebo-controlled, double-blind study we investigated whether supplementation with iron-enriched

  1. Experiments and computer simulations of iron profiles in p/p + silicon: segregation and the position of the iron donor level

    Science.gov (United States)

    Hieslmair, H.; Istratov, A. A.; Flink, C.; McHugo, S. A.; Weber, E. R.

    1999-12-01

    The position of the iron donor trap level in the silicon band gap at processing temperatures determines numerous important properties of iron such as its solubility and effective diffusivity. Thus this position influences the time and efficiency of the widely used p/p+ segregation gettering, i.e. the removal of iron from an epitaxial p-type silicon layer (the device region) by a heavily p+-doped silicon substrate. In this work, the iron concentration profiles within a 70 μm p-type epitaxial layer on a p+-type substrate were quantitatively measured using deep level transient spectroscopy in order to determine the position of the iron donor level. The samples are first intentionally contaminated with iron at 920°C and then annealed at 472°C for various times. The measured iron profiles are fitted with computer simulations in order to determine the iron trap level and the segregation coefficient at 472°C. The results indicate that the iron trap level is at Ev +0.32 eV at 472°C. The results of this study and of previous studies indicate that the iron donor level decreases in proportion to the band-gap narrowing.

  2. Research on Experimental and Application for the High Efficient Enrichment of the Low-grade Precious Metal Materials

    Institute of Scientific and Technical Information of China (English)

    FAN Xingxiang; FU Guangqiang; DONG Haigang; WU Yuedong; LIU Yang; ZHAO Jiachun; WU Xiaofeng; LI Bojie; TONG Weifeng

    2012-01-01

    On the basis of reviewing the progress in the high efficient enrichment from secondary resources of low-grade precious metals at home and abroad,a process route of the high efficient enrichment precious metals from secondary resources of low-grade metals by adding iron oxide as the trapping agent,reducing agent,additive,mixing uniformly and grinding,pelletizing,reduction,grinding and separation,and selectively acid leaching iron has been put forward in this paper.The experiments of reduction,grinding and separation,and selectively acid leaching iron were carried out mainly.Under the decided experiment parameters and conditions,iron generated during the reduction can trap precious metals during reduction,high active alloy powders were obtained from the reduced products by grinding and separation,the concentration of precious metals was obtained by acid leaching high active alloy powders.The better enrichment effect was obtained by adopting the technical route of processing.Other low grade noble metal materials and enrichment ratio of precious metals from the materials to acid products was high through acid leaching.This process has the advantages of simple process,environmental-friendly,strong adaptability of raw materials,high concentration ratio,which was regarded as a kind of the general efficient enrichment technology of low grade precious metal materials.

  3. Methane enrichment digestion experiments at the anaerobic experimental test unit at Walt Disney World. Final report, March 1989-August 1990

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.J.; Hill, A.H.

    1993-06-01

    The goal of the project was to determine the technical feasibility of utilizing a novel concept in anaerobic digestion, in-situ methane enrichment digestion or MED for producing utility-grade gas from a pilot-scale anaerobic digester. MED tests conducted during this program consistently achieved digester product gas with a methane (CH4) content of greater than 90% (on a dry-, nitrogen-free basis). The MED concept, because it requires relatively simple equipment and modest energy input, has the potential to simplify gas cleanup requirements and substantially reduce the cost of converting wastes and biomass to pipeline quality gas.

  4. The Oxidation of Iron: Experiment, Simulation, and Analysis in Introductory Chemistry

    Science.gov (United States)

    Schubert, Frederic E.

    2015-01-01

    In this exercise, an actual chemical reaction, oxidation of iron in air, is studied along with a related analogue simulation of that reaction. The rusting of steel wool is carried out as a class effort. The parallel simulation is performed by students working in small groups. The analogue for the reacting gas is a countable set of discrete marble…

  5. The Oxidation of Iron: Experiment, Simulation, and Analysis in Introductory Chemistry

    Science.gov (United States)

    Schubert, Frederic E.

    2015-01-01

    In this exercise, an actual chemical reaction, oxidation of iron in air, is studied along with a related analogue simulation of that reaction. The rusting of steel wool is carried out as a class effort. The parallel simulation is performed by students working in small groups. The analogue for the reacting gas is a countable set of discrete marble…

  6. Mercury: its iron and sulfur enrichment has roots in mechanical concentration of dense particles in the inner part of rotating primordial gas-dust cloud

    Science.gov (United States)

    Kochemasov, G. G.

    2013-09-01

    After MESSENGER explorations one could crystallize an idea of nature of this innermost planet of the Solar system. It has on the whole dull low albedo surface with small variations in compositions of Mg-rich Fe-poor large tectonic units. Only widespread small hollows and their groups with darker and brighter haloes brighten this dull landscape. The relief variations are small (maximum 10 km, but normally within 3-5 km), much less than on other rocky planets. The large iron core making the planet's density high leaves a modest place for mantle. Atmosphere is practically absent notwithstanding strong degassing, and this is due to strong cleaning by the solar wind. All mentioned peculiarities could be explained by the Mercury's position in the innermost zone. This was done even before the first orbital explorations just on a basis of the wave planetology connecting planets' properties with their orbital characteristics [ 1, 2]. Surprising many planetologists the high sulfur presence in Mercury, not justified by its position in the hot inner zone was, however, practically predicted by a new model of primordial matter differentiation in a rotating gas-dust cloud [ 3, 4]. This cloud consisting of gas and mixture of solids with various densities under rotation produces concentration of heavy particles in the inner zone. This process is well known for prospectors making heavy concentrations (schlich) with use of a spiral separator. There separation of heavies is made by descending and rotating in a spiral water-sand mixture. This model for differentiation of a planetary system was presented at LPSC [3, 4]. At that time nobody could imagine volatile sulfur in the inner hot zone. In [1] is written "It is suggested that primary accretion minerals in some meteorites and probably also in the larger bodies of the Solar system are united by nearness of their densities rather than by temperatures of their condensation out of the protoplanet gas (for example, common association of

  7. Enriched Zn{sup 100}MoO{sub 4} scintillating bolometers to search for 0ν2β decay of {sup 100}Mo with the LUMINEU experiment

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A.S. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Chernyak, D.M.; Poda, D.V. [Institute for Nuclear Research, MSP, Kiev (Ukraine); Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Danevich, F.A. [Institute for Nuclear Research, MSP, Kiev (Ukraine); Giuliani, A. [Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Dipartimento di Scienza e Alta Tecnologia dell' Universita dell' Insubria, Como (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Ivanov, I.M.; Makarov, E.P.; Nasonov, S.G.; Shlegel, V.N.; Vasiliev, Ya.V. [Nikolaev Institute of Inorganic Chemistry, Novosibirsk (Russian Federation); Mancuso, M. [Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Dipartimento di Scienza e Alta Tecnologia dell' Universita dell' Insubria, Como (Italy); Marnieros, S.; Olivieri, E.; Tenconi, M. [Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Nones, C. [CEA-Saclay, Service de Physique des Particules, Gif-sur-Yvette (France); Pessina, G. [INFN, Sezione di Milano Bicocca, Milan (Italy); Tretyak, V.I. [Institute for Nuclear Research, MSP, Kiev (Ukraine); INFN, Sezione di Roma ' ' La Sapienza' ' , Rome (Italy); Velazquez, M. [CNRS, Universite de Bordeaux, ICMCB, Pessac (France); Zhdankov, V.N. [CML Ltd., Novosibirsk (Russian Federation)

    2014-10-15

    The LUMINEU project is a demonstrator experiment that will search for the neutrinoless double beta decay of the isotope {sup 100}Mo embedded in zinc molybdate (ZnMoO{sub 4}) scintillating bolometers. In this context, a zinc molybdate crystal boule enriched in {sup 100}Mo to 99.5 % with a mass of 171 g was grown for the first time by the low-thermalgradient Czochralski technique. The production cycle provided a high yield (the crystal boule mass was 84 % of the initial charge) and an acceptable level - around 4 % - of irrecoverable losses of the costly enriched material. Two crystals of 59 and 63 g, obtained from the enriched boule, were tested above ground at millikelvin temperatures as scintillating bolometers. They showed a good detection performance, equivalent to that of previously developed natural ZnMoO{sub 4} detectors. These results pave the way to future sensitive searches based on the LUMINEU technology, capable of approaching and exploring the inverted hierarchy region of the neutrino mass pattern. (orig.)

  8. The response of amphibian larvae to exposure to a glyphosate-based herbicide (Roundup WeatherMax) and nutrient enrichment in an ecosystem experiment.

    Science.gov (United States)

    Edge, Christopher; Thompson, Dean; Hao, Chunyan; Houlahan, Jeff

    2014-11-01

    Herbicides and fertilizers are widely used throughout the world and pose a threat to aquatic ecosystems. Using a replicated, whole ecosystem experiment in which 24 small wetlands were split in half with an impermeable barrier we tested whether exposure to a glyphosate-based herbicide, Roundup WeatherMax™, alone or in combination with nutrient enrichment has an effect on the survival, growth or development of amphibians. The herbicide was applied at one of two concentrations (low=210 μg a.e./L, high=2880 μg a.e./L) alone and in combination with nutrient enrichment to one side of wetlands and the other was left as an untreated control. Each treatment was replicated with six wetlands, and the experiment was repeated over two years. In the high glyphosate and nutrient enrichment treatment the survival of wood frog (Lithobates sylvaticus) larvae was lower in enclosures placed in situ on the treated sides than the control sides of wetlands. However, these results were not replicated in the second year of study and they were not observed in free swimming wood frog larvae in the wetlands. In all treatments, wood frog larvae on the treated sides of wetlands were slightly larger (<10%) than those on the control side, but no effect on development was observed. The most dramatic finding was that the abundance of green frog larvae (Lithobates clamitans) was higher on the treated sides than the control sides of wetlands in the herbicide and nutrient treatments during the second year of the study. The results observed in this field study indicate that caution is necessary when extrapolating results from artificial systems to predict effects in natural systems. In this experiment, the lack of toxicity to amphibian larvae was probably due to the fact the pH of the wetlands was relatively low and the presence of sediments and organic surfaces which would have mitigated the exposure duration. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Experiments and Simulations of the Use of Time-Correlated Thermal Neutron Counting to Determine the Multiplication of an Assembly of Highly Enriched Uranium

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester; Mathew T. Kinlaw; Scott M. Watson; Jeffrey M. Kalter; Eric C. Miller; William A. Noonan

    2014-11-01

    A series of experiments and numerical simulations using thermal-neutron time-correlated measurements has been performed to determine the neutron multiplication, M, of assemblies of highly enriched uranium available at Idaho National Laboratory. The experiments used up to 14.4 kg of highly-enriched uranium, including bare assemblies and assemblies reflected with high-density polyethylene, carbon steel, and tungsten. A small 252Cf source was used to initiate fission chains within the assembly. Both the experiments and the simulations used 6-channel and 8-channel detector systems, each consisting of 3He proportional counters moderated with polyethylene; data was recorded in list mode for analysis. 'True' multiplication values for each assembly were empirically derived using basic neutron production and loss values determined through simulation. A total of one-hundred and sixteen separate measurements were performed using fifty-seven unique measurement scenarios, the multiplication varied from 1.75 to 10.90. This paper presents the results of these comparisons and discusses differences among the various cases.

  10. Experiments and Simulations of the Use of Time-Correlated Thermal Neutron Counting to Determine the Multiplication of an Assembly of Highly Enriched Uranium

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester; Mathew T. Kinlaw; Scott M. Watson; Jeffrey M. Kalter; Eric C. Miller; William A. Noonan

    2014-11-01

    A series of experiments and numerical simulations using thermal-neutron time-correlated measurements has been performed to determine the neutron multiplication, M, of assemblies of highly enriched uranium available at Idaho National Laboratory. The experiments used up to 14.4 kg of highly-enriched uranium, including bare assemblies and assemblies reflected with high-density polyethylene, carbon steel, and tungsten. A small 252Cf source was used to initiate fission chains within the assembly. Both the experiments and the simulations used 6-channel and 8-channel detector systems, each consisting of 3He proportional counters moderated with polyethylene; data was recorded in list mode for analysis. 'True' multiplication values for each assembly were empirically derived using basic neutron production and loss values determined through simulation. A total of one-hundred and sixteen separate measurements were performed using fifty-seven unique measurement scenarios, the multiplication varied from 1.75 to 10.90. This paper presents the results of these comparisons and discusses differences among the various cases.

  11. Investigation of the fire at the Uranium Enrichment Laboratory. Analysis of samples and pressurization experiment/analysis of container

    Energy Technology Data Exchange (ETDEWEB)

    Akabori, Mitsuo; Minato, Kazuo; Watanabe, Kazuo [eds.] [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-05-01

    To investigate the cause of the fire at the Uranium Enrichment Laboratory of the Tokai Research Establishment on November 20, 1997, samples of uranium metal waste and scattered residues were analyzed. At the same time the container lid that had been blown off was closely inspected, and the pressurization effects of the container were tested and analyzed. It was found that 1) the uranium metal waste mainly consisted of uranium metal, carbides and oxides, whose relative amounts were dependent on the particle size, 2) the uranium metal waste hydrolyzed to produce combustible gases such as methane and hydrogen, and 3) the lid of the outer container could be blown off by an explosive rise of the inner pressure caused by combustion of inflammable gas mixture. (author)

  12. Parallax diagnostics of radiation source geometric dilution for iron opacity experiments

    CERN Document Server

    Nagayama, T; Loisel, G; Rochau, G A; Falcon, R E

    2014-01-01

    Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J.E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150 - 200 eV electron temperatures and 7e21 - 4e22 e/cc electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along +/- 9 degree with respect to the z-pinch axis to infer the sample iron opacity. Here we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from +/-9 degree. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

  13. High P-T experiments and first principles calculations of the diffusion of Si, O, Cr in liquid iron

    Science.gov (United States)

    Posner, Esther; Rubie, David C.; Frost, Daniel J.; Vlček, Vojtěch; Steinle-Neumann, Gerd

    2016-04-01

    Diffusion transport properties of molten iron and iron alloys at high pressures and temperatures are important for understanding large-scale geodynamic processes and thermochemical evolution of planetary interiors, such as the time and length scales of metal-silicate equilibration during core formation and chemical exchange across core-mantle boundaries during cooling. The density of the Earth's outer core is ˜10% too low to be composed of pure Fe-Ni and is assumed to contain significant concentrations of light elements, such as Si, S, O, and/or C, in addition to siderophile transition metals (V, Cr, Mn, W) which are depleted in the Earth's mantle relative to chondrites. The chemical diffusivity of light and siderophile elements in liquid iron under P -T conditions of the Earth's core and its formation are therefore required to constrain the composition and potential chemical stratification of planetary cores, in addition to the kinetics of chemical buoyancy from inner core crystallization that partially drives the geodynamo. In order to better understand the effects of pressure and temperature on Si, O, and Cr diffusion in liquid iron, we have conducted (1) chemical diffusion-couple experiments combined with numerical modeling of diffusion profiles to account for non-isothermal annealing, and (2) first principles molecular dynamic (FP-MD) calculations from ambient pressure to 135 GPa and 2200-5500 K. Experimental diffusion couples comprised of highly polished cylindrical disks of 99.97% Fe and metallic Fe alloy were contained within an MgO capsule and annealed within the P -T range 1873-2653 K and 1-18 GPa using a multi-anvil apparatus. A series of experiments are conducted at each pressure using variable heating rates, final quench temperatures (Tf), and time duration at Tf. Recovered capsules were cut and polished parallel to the axis of the cylindrical sample and measured using EMPA 10 μm-step line scans. To extend our dataset to P -T conditions of the Earth

  14. Ocean acidification affects iron speciation in seawater

    Directory of Open Access Journals (Sweden)

    E. Breitbarth

    2009-07-01

    Full Text Available Rising atmospheric CO2 is acidifying the surface ocean, a process which is expected to greatly influence the chemistry and biology of the future ocean. Following the development of iron-replete phytoplankton blooms in a coastal mesocosm experiment at 350, 700, and 1050 μatm pCO2, we observed significant increases in dissolved iron concentrations, Fe(II concentrations, and Fe(II half-life times during and after the peak of blooms in response to CO2 enrichment, suggesting increased iron bioavailability. If applicable to the open ocean this may provide a negative feedback mechanism to the rising atmospheric CO2 by stimulating marine primary production.

  15. New results in the ITEP/YePI double beta-decay experiment with enriched germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vasenko, A.A.; Kirpichnikov, I.V.; Kuznetsov, V.A.; Starostin, A.S. (Institute for Theoretical and Experimental Physics, Bolshaya Cheremushkinskaya 25, Moscow 117259 (SU)); Djanyan, A.G.; Pogosov, V.S.; Shachysisyan, S.P.; Tamanyan, A.G. (Yerevan Physical Institute, Markaryan 2, Yerevan 375036 (SU))

    1990-07-20

    This paper reports the search for double beta-decay of {sup 76}Ge carried out with a detector fabricated of enriched material (85% abundance of {sup 76}Ge compared with 7.8% natural abundance). Measurements have been performed by the ITEP/YePI team in the Avan salt mine, 245 meters underground, situated in Yerevan, Armenia. Evidence for two-neutrino double beta-decay of {sub 76}Ge with half-life of T{sub 1/2}(2v) = (9 {plus minus} 1 {center dot} 10{sup 20})y was obtained. New limits for neutrinoless double beta-decay, T{sub 1/2}(Ov) {gt} 1.3 {times} 10{sup 24}y, and double beta-decay with majoron emission T{sub 1/2}(Ov,B) {gt} 1 {times} 10{sup 22}y were obtained at 68% CL from mean background fluctuations. Limit for Ov-decay derived by the maximum likelihood method was T{sub 1/2} {gt} 2.0 {times} 10{sup 24}y.

  16. Graphite Nucleation in Cast Iron Melts Based on Solidification Experiments and Microstructure Simulation

    Institute of Scientific and Technical Information of China (English)

    Andreia Sommerfeld; Bernd B(o)ttger; Babette Tonn

    2008-01-01

    Microstructure strongly influences the mechanical properties of cast iron. By inoculating the melt with proper inoculants, foreign substrates are brought into the melt and eventually the graphite can crystallize on them. The elements and substrates that really play a role for nucleation are yet unknown. Until now there is very little knowledge about the fundamentals of nucleation, such as composition and morphology of nuclei[1,2]. In this work we utilized EN-GJL-200 as a base material and examined several produced specimens. The specimens were cast with and without inoculants and quenched at different solidification states. Specimens were also examined with a high and low oxygen concentration, but the results showed that different oxygen contents have no influence on the nucleation in cast iron melts. Our research was focused on the microscopic examination and phase-field simulations. For studying the samples we applied different analytical methods, where SEM-EDS, -WDS were proved to be most effective. The simulations were conducted by using the software MICRESS(R)[3], which is based on a multiphase-field model and has been coupled directly to the TCFE3 thermodynamic database from TCAB. On the basis of the experimental investigations a nucleation mechanism is proposed, which claims MnS precipitates as the preferred site for graphite nucleation. This theory is supported by the results of the phase-field simulations.

  17. Experiment Study of Treatment Waste Water of Higher Iron Manganese and Ammonia Nitrogen by Scrap Iron + Fly Ash%铁屑+粉煤灰处理含高浓度铁锰氨氮废水试验研究

    Institute of Scientific and Technical Information of China (English)

    狄军贞; 马龙; 李爱华; 牛晓丽

    2012-01-01

    通过单因素及多因素正交实验研究铁屑与粉煤灰处理含高浓度铁锰氨氮废水的有效性.结果表明,铁屑+粉煤灰去除铁锰及氨氮效率均高于单独作用,铁屑+粉煤灰最佳除锰条件为:铁屑与粉煤炭配比3:3,振荡频率150次/min,投加量6g/100mL,反应时间60min,pH值6.此条件下铁、锰、氨氮去除率分别为99.8%、86%和11.2%.%Wastewater that contain higher iron, manganese and ammonia nitrogen is researched using scrap iron and fly ash by the single factor experiment and orthogonal experiment of multiple factors. Single factor experiment shows that the removal efficiency of scrap iron and fly ash is better than independent action for iron, manganese and ammonia nitrogen. The optimum condition of scrap iron and fly ash removing manganese is: ratio of scrap iron and fly ash 3 : 3, oscillation frequency 150 times per minutes for 60 min, dosing quantity 6 g/100mL,pH value 6. The removal rate of Fe2+, Mn2+, NH3-N are 99.8%, 86% and 11.2% respectively under the optimum condition.

  18. Robotic surgical telepathology between the Iron Mountain and Milwaukee Department of Veterans Affairs Medical Centers: a 12-year experience.

    Science.gov (United States)

    Dunn, Bruce E; Choi, Hongyung; Recla, Daniel L; Kerr, Sarah E; Wagenman, Benjamin L

    2009-08-01

    Since mid-1996, we have operated a diagnostic robotic telepathology (TP) system at the Iron Mountain, MI, Department of Veterans Affairs Medical Center (VAMC) from the Milwaukee, WI, VAMC, located some 220 miles away. No on-site pathologist is present in Iron Mountain. Instead, an experienced, well-trained pathologist assistant, under direction of pathologists located in Milwaukee, is responsible for tissue grossing and sectioning. The pathologist assistant places slides onto the stage of the robotic microscope, which is then controlled by pathologists in Milwaukee. Each case read by TP is subsequently read by light microscopy (LM) by the same pathologist. Three distinct phases of TP have been recognized. Our experience during phase I (mid-1996 to early 1999) has been published previously. During phase II (early 1999 to mid-2004), 1 of the 2 senior telepathologists in phase I retired, and 3 junior pathologists were hired. During phase III (mid-2004 to June 2008), 2 new junior pathologists were hired, and ASAP Imaging (Apollo Telemedicine, Inc., Falls Church, VA) was implemented. The number of TP case opportunities in phases I, II, and III was 2200, 5841, and 3512, respectively, resulting in a total of 11 553. A total of 1834 cases were deferred to LM for a variety of reasons. The number of TP diagnoses rendered in phases I, II, and III was 2144, 4636, and 2939, respectively, resulting in a total of 9719. The major discordance rates in phases I, II, and III were 0.33%, 0.45%, and 0.20%, respectively, with an overall rate of 0.35%. Pathologist-specific discordance rates were not significantly different and ranged from a low of 0.12% to a high of 0.77%, whereas case deferral rates were significantly different (P Iron Mountain clinicians have expressed great satisfaction with the services provided by their off-site pathologist colleagues.

  19. Robotic surgical telepathology between the Iron Mountain and Milwaukee Department of Veterans Affairs Medical Centers: a twelve year experience.

    Science.gov (United States)

    Dunn, Bruce E; Choi, Hongyung; Recla, Daniel L; Kerr, Sarah E; Wagenman, Benjamin L

    2009-11-01

    Since mid-1996 we have operated a diagnostic robotic telepathology (TP) system at the Iron Mountain, Michigan, Department of Veterans Affairs Medical Center (VAMC) from the Milwaukee, Wisconsin VAMC, located some 220 miles away. No on-site pathologist is present in Iron Mountain. Instead, an experienced, well-trained pathologist assistant, under direction of pathologists located in Milwaukee, is responsible for tissue grossing and sectioning. The pathologist assistant places slides onto the stage of the robotic microscope, which is then controlled by pathologists in Milwaukee. Each case read by TP is subsequently read by light microscopy (LM) by the same pathologist. Three distinct phases of TP have been recognized. Our experience during Phase I (mid-1996 through early 1999) has been published previously. During Phase II (early 1999 through mid-2004), one of the two senior telepathologists in Phase I retired and three junior pathologists were hired. During Phase III (mid-2004 though June 2008), two new junior pathologists were hired and ASAP Imaging (Apollo Telemedicine, Inc., Falls Church, VA) was implemented. The number of TP case opportunities in Phases I, II and III was 2,200; 5,841 and 3,512; respectively resulting in a total of 11,553. A total of 1,834 cases were deferred to LM for a variety of reasons. The number of TP diagnoses rendered in Phases I, II and III was 2,144; 4,636 and 2,939; respectively, for a total of 9,719. The major discordance rates in Phases I, II and III were 0.33%, 0.45% and 0.20%, respectively with an overall rate of 0.35%. Pathologist-specific discordance rates were not significantly different and ranged from a low of 0.12% to a high of 0.77%, while case deferral rates were significantly different (P Iron Mountain clinicians have expressed great satisfaction with the services provided by their off-site pathologist colleagues.

  20. Effects of Q&P Processing Conditions on Austenite Carbon Enrichment Studied by In Situ High-Energy X-ray Diffraction Experiments

    Directory of Open Access Journals (Sweden)

    Sébastien Yves Pierre Allain

    2017-06-01

    Full Text Available We report the first ultra-fast time-resolved quantitative information on the quenching and partitioning process of conventional high-strength steel by an in situ high-energy X-ray diffraction (HEXRD experiment. The time and temperature evolutions of phase fractions, their carbon content, and internal stresses were determined and discussed for different process parameters. It is shown that the austenite-to-martensite transformation below the martensite start temperature Ms is followed by a stage of fast carbon enrichment in austenite during isothermal holding at both 400 and 450 °C. The analysis proposed supports the concurrent bainite transformation and carbon diffusion from martensite to austenite as the main mechanisms of this enrichment. Furthermore, we give evidence that high hydrostatic tensile stresses in austenite are produced during the final quenching, and must be taken into account for the estimation of the carbon content in austenite. Finally, a large amount of carbon is shown to be trapped in the microstructure.

  1. Influence of invasive earthworm activity on carbon dynamics in soils from the Aspen Free Air CO2 Enrichment Experiment

    Science.gov (United States)

    Filley, T. R.; Top, S. M.; Hopkins, F. M.

    2010-12-01

    The influence of CO2-driven increase in net primary productivity on soil organic carbon accrual has received considerable emphasis in ecological literature with conclusions varying from positive, to neutral, to negative. What has been understudied is the coupled role of soil fauna, such as earthworms, in controlling the ultimate fate of new above and below ground plant carbon under elevated CO2. Such considerations are particularly relevant considering that in most northern North American forests earthworms are an exotic organism known to cause significant changes to forest floor chemistry and soil structure, possibly increasing nutrient loss from both soil and leaf litter and mixing litter and humus deep into the mineral soil. The impact of these exotic earthworms on overall soil carbon stabilization is largely unknown but likely a function of both species composition and edaphic soil properties. In this paper we present the initial results of a carbon isotope study (13C, 14C) conducted at the Aspen free air CO2 enrichment (FACE) site, Rhinelander, WI, USA to track allocation and redistribution within the soil of plant litter and root carbon (bulk and biopolymer). Along with litter and soil to 25 cm depth, earthworm populations were quantified, and their gut contents collected for isotopic and plant biopolymer chemistry analysis. Contributions of root vs. leaf input to soil and earthworm fecal matter were derived from differences in the chemical and isotope composition of alkaline CuO-derived lignin and substituted fatty acids (SFA) from cutin and suberin. Our investigation demonstrates the presence of invasive European earthworms, of both litter and surface soil dwelling (epigeic) and deep soil dwelling (endogeic) varieties, whose abundance increases under elevated CO2 conditions. Additionally, the different species show selective vertical movement of new and pre-FACE plant biopolymers indicating dynamics in root and leaf decomposition and burial (down to 30 cm

  2. Mean-field model of the von Kármán sodium dynamo experiment using soft iron impellers.

    Science.gov (United States)

    Nore, C; Léorat, J; Guermond, J-L; Giesecke, A

    2015-01-01

    It has been observed that dynamo action occurs in the von-Kármán-Sodium (VKS) experiment only when the rotating disks and the blades are made of soft iron. The purpose of this paper is to numerically investigate the role of soft iron in the VKS dynamo scenario. This is done by using a mean-field model based on an axisymmetric mean flow, a localized permeability distribution, and a localized α effect modeling the action of the small velocity scales between the blades. The action of the rotating blades is modeled by an axisymmetric effective permeability field. Key properties of the flow giving to the numerical magnetic field a geometric structure similar to that observed experimentally are identified. Depending on the permeability of the disks and the effective permeability of the blades, the dynamo that is obtained is either oscillatory or stationary. Our numerical results confirm the leading role played by the ferromagnetic impellers. A scenario for the VKS dynamo is proposed.

  3. Neutrinoless double-β decay of76Ge: First results from the International Germanium Experiment (IGEX) with six isotopically enriched detectors

    Science.gov (United States)

    Aalseth, C. E.; Avignone, F. T.; Brodzinski, R. L.; Collar, J. I.; Garcia, E.; González, D.; Hasenbalg, F.; Hensley, W. K.; Kirpichnikov, I. V.; Klimenko, A. A.; Miley, H. S.; Morales, A.; Morales, J.; Ortiz de Solórzano, A.; Osetrov, S. B.; Pogosov, V. S.; Puimedón, J.; Reeves, J. H.; Salinas, A.; Sarsa, M. L.; Smolnikov, A. A.; Starostin, A. S.; Tamanyan, A. G.; Vasenko, A. A.; Vasiliev, S. I.; Villar, J. A.

    1999-04-01

    The International Germanium Experiment (IGEX) has six HPGe detectors, isotopically enriched to 86% in 76Ge, containing approximately 90 active moles of 76Ge. Three detectors of 2 kg each operate in the Canfranc Underground Laboratory (Spain) with pulse-shape analysis electronics. One detector (~0.7 kg active volume) has been operating in the Baksan Low-Background Laboratory for several years, and two additional similar detectors will operate in Baksan. A maximum likelihood analysis of 74.84 active mole years of data yields a lower bound T0ν1/2>=0.8×1025 yr (90% C.L.), corresponding to <(0.5-1.5) eV, depending on the theoretical nuclear matrix elements used to extract the neutrino mass parameter.

  4. Neutrinoless double-{beta} decay of {sup 76}Ge: First results from the International Germanium Experiment (IGEX) with six isotopically enriched detectors

    Energy Technology Data Exchange (ETDEWEB)

    Aalseth, C.E.; Avignone, F.T. III; Collar, J.I.; Hasenbalg, F. [University of South Carolina, Columbia, South Carolina 29208 (United States); Brodzinski, R.L.; Hensley, W.K.; Miley, H.S.; Reeves, J.H. [Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Garcia, E.; Gonzalez, D.; Morales, A.; Morales, J.; Ortiz de Solorzano, A.; Puimedon, J.; Salinas, A.; Sarsa, M.L.; Villar, J.A. [University of Zaragoza, 50009 Zaragoza (Spain); Kirpichnikov, I.V.; Starostin, A.S.; Vasenko, A.A. [Institute for Theoretical and Experimental Physics, 117259 Moscow (Russia); Klimenko, A.A.; Osetrov, S.B.; Smolnikov, A.A.; Vasiliev, S.I. [Institute for Nuclear Research, Baksan Neutrino Observatory, 361609 Neutrino (Russia); Pogosov, V.S.; Tamanyan, A.G. [Yerevan Physical Institute, 375 036 Yerevan (Armenia)

    1999-04-01

    The International Germanium Experiment (IGEX) has six HPGe detectors, isotopically enriched to 86{percent} in {sup 76}Ge, containing approximately 90 active moles of {sup 76}Ge. Three detectors of 2 kg each operate in the Canfranc Underground Laboratory (Spain) with pulse-shape analysis electronics. One detector ({approximately}0.7 kg active volume) has been operating in the Baksan Low-Background Laboratory for several years, and two additional similar detectors will operate in Baksan. A maximum likelihood analysis of 74.84 active mole years of data yields a lower bound T{sub 1/2}{sup 0{nu}}{ge}0.8{times}10{sup 25}yr (90{percent} C.L.), corresponding to {l_angle}m{sub {nu}}{r_angle}{lt}(0.5{endash}1.5)eV, depending on the theoretical nuclear matrix elements used to extract the neutrino mass parameter. {copyright} {ital 1999} {ital The American Physical Society}

  5. Increased Litter Build Up and Soil Organic Matter Stabilization in a Poplar Plantation After 6 Years of atmospheric CO2 Enrichment (FACE): Final Results of POP-EuroFace Compared to Other Forest FACE Experiments

    NARCIS (Netherlands)

    Hoosbeek, M.R.; Scarascia-Mugnozza, G.

    2009-01-01

    Free air CO2 enrichment (FACE) experiments in aggrading temperate forests and plantations have been initiated to test whether temperate forest ecosystems act as sinks for anthropogenic emissions of CO2. These FACE experiments have demonstrated increases in net primary production and carbon (C)

  6. A Cerenkov - Delta E/Delta X experiment for measuring cosmic-ray isotopes from neon through iron

    Science.gov (United States)

    Buffington, A.; Lau, K.; Schindler, S. M.; Stone, E. C.; Laursen, S.; Rasmussen, I. L.

    1983-01-01

    Cosmic-ray isotope masses are measured in a balloon-borne cosmic-ray experiment. Two Cerenkov counters and an NaI scintillator stack are used to determine changes in energy and in the Lorentz factor for a traversing or stopping particle. The mass is defined at the ratio of the change in energy to the change in the Lorentz factor. For incident elements from neon through iron, mass resolution better than 0.3 a.m.u. is expected, with incident Lorentz gammas ranging from 2.4 to 3.1, depending on the element. The mass resolution is approximately 0.2 a.m.u., measured for Mn-55 ions having an incident Lorentz factor of 2.75.

  7. Heavy metal incorporation in foraminiferal calcite: results from multi-element enrichment culture experiments with Ammonia tepida

    Directory of Open Access Journals (Sweden)

    G.-J. Reichart

    2010-08-01

    Full Text Available The incorporation of heavy metals into carbonate tests of the shallow water benthic foraminifer Ammonia tepida was investigated under controlled laboratory conditions. Temperature, salinity, and pH of the culture solutions were kept constant throughout the duration of this experiment, while trace metal concentrations were varied. Concentrations of Ni, Cu, and Mn were set 5-, 10-, and 20 times higher than levels found in natural North Sea water; for reference, a control experiment with pure filtered natural North Sea water was also analysed. The concentrations of Cu and Ni from newly grown chambers were determined by means of both μ-synchrotron XRF and Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS. The results of both independent analytical techniques agreed within the analytical uncertainty. In general, the concentration of the analysed elements in the tests increased in line with their concentration in the culture solutions. Potential toxic and/or chemical competition effects might have resulted in the decreased incorporation of Ni and Cu into the calcite of the specimens exposed to the highest elemental concentrations. Mn incorporation exhibited large variability in the experiment with the 20-fold increased element concentrations, potentially due to antagonistic effects with Cu. The partition coefficients of Cu and Ni were calculated to be 0.14 ± 0.02 and 1.0 ± 0.5, respectively, whereas the partition coefficient of Mn was estimated to be least 2.4. These partition coefficients now open the way for reconstructing past concentrations for these elements in sea water.

  8. Mobility of Nanoscale and Microscale iron for groundwater remediation: experiments and modelling

    Science.gov (United States)

    Tosco, T.; Gastone, F.; Sethi, R.

    2012-12-01

    Colloidal suspensions of zerovalent iron micro- and nanoparticles (MZVI and NZVI) have been studied in recent years for in-situ groundwater remediation. Thanks to their small size, MZVI and NZVI can be dispersed in aqueous suspensions and directly injected into the subsurface, for a targeted treatment of contamination plumes and even sources. However, colloidal dispersions of such particles are not stable in pure water, due to fast aggregation (for NZVI) and gravitational sedimentation (for MZVI). Viscous, environmentally friendly fluids (guar gum and xanthan gum solutions), which exhibit shear thinning rheological properties, were found to be effective in improving colloidal stability, thus greatly improving handling and injectability (1-3). The present work reports laboratory tests and numerical modelling concerning the mobility of MZVI and NZVI viscous suspensions in porous media. The efficacy of xanthan and guar gum was investigated in column transport tests, performed injecting highly concentrated iron suspensions (20 g/L), dispersed in xanthan gum (3g/L) and guar gum (3-6 g/l) solutions. Particle breakthrough curves and concentration profiles were monitored by magnetic susceptibility measurements. Pressure drop at column ends was also continuously monitored. The tests proved that green polymers can greatly improve both colloidal stability and mobility of the particles. Their use is fundamental in particular for MZVI, which cannot be transported nor even dispersed in pure water. A numerical model for NZVI and NZVI transport in porous media was then developed (E-MNM1D, Enhanced Micro-and Nanoparticle transport Model in porous media in 1D geometry) (4). Due to the high concentration of the particles and to the non-Newtonian rheology of the carrier fluid, hydrodynamic parameters, fluid properties and concentration of deposed and suspended particles are mutually influenced. The rheological properties of the suspensions are accounted for through a variable

  9. The studies of nodular graphite cast iron early stages austempering

    OpenAIRE

    A. Krzyńska; M. Kaczorowski

    2008-01-01

    The results of early stage of ductile cast iron austempering are presented. The aim of the investigations was to look closer into the structure – mechanical properties relationships of this very attractive cast material. The experiment was carried out with enriched with Cu EN-GJS-500-7 grade ductile iron. The specimens were first solution heat treated 1 hour in 910oC and then isothermally quenched for different time in molten tin at the temperature 275oC. The mechanical properties of as cast ...

  10. Electronic and magnetic properties of iron doped zirconia: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Debernardi, A., E-mail: alberto.debernardi@mdm.imm.cnr.it; Sangalli, D.; Lamperti, A.; Cianci, E. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (MB) (Italy); Lupo, P.; Casoli, F.; Albertini, F.; Nasi, L. [CNR-IMEM, Parco Area delle Scienze 37/A, 43124 Parma (Italy); Ciprian, R.; Torelli, P. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy)

    2014-05-07

    We systematically investigated, both theoretically and experimentally, Zr{sub 1−x}Fe{sub x}O{sub 2−y} ranging from diluted (x ≈ 0.05) up to large (x ≈ 0.25) Fe concentration. By atomic layer deposition, we grew thin films of high-κ zirconia in cubic phase with Fe uniformly distributed in the film, as proven by time of flight secondary ion mass spectrometry and transmission electron microscopy measurements. Iron is in Fe{sup 3+} oxidation state suggesting the formation of oxygen vacancies with y concentration close to x/2. By ab-initio simulations, we studied the phase diagram relating the stability of monoclinic vs. tetragonal phase as a function of Fe doping and film thickness: the critical thickness at which the pure zirconia is stabilized in the tetragonal phase is estimated ranging from 2 to 6 nm according to film morphology. Preliminary results by X-ray magnetic circular dichroism and alternating gradient force magnetometry are discussed in comparison to ab initio data enlightening the role of oxygen vacancies in the magnetic properties of the system.

  11. The next generation of iron fertilization experiments in the southern Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Smetacek, V.; Naqvi, S.W.A.

    additional data from properly designed experiments are urgently needed for realistic parametrization. OEF is likely to boost zooplankton stocks, including krill, which could have a positive effect on recovery of the great whale populations. Negative effects...

  12. Does leaf photosynthesis adapt to CO2-enriched environments? An experiment on plants originating from three natural CO2 springs.

    Science.gov (United States)

    Onoda, Yusuke; Hirose, Tadaki; Hikosaka, Kouki

    2009-01-01

    Atmospheric CO2 elevation may act as a selective agent, which consequently may alter plant traits in the future. We investigated the adaptation to high CO2 using transplant experiments with plants originating from natural CO2 springs and from respective control sites. We tested three hypotheses for adaptation to high-CO2 conditions: a higher photosynthetic nitrogen use efficiency (PNUE); a higher photosynthetic water use efficiency (WUE); and a higher capacity for carbohydrate transport from leaves. Although elevated growth CO2 enhanced both PNUE and WUE, there was no genotypic improvement in PNUE. However, some spring plants had a higher WUE, as a result of a significant reduction in stomatal conductance, and also a lower starch concentration. Higher natural variation (assessed by the coefficient of variation) within populations in WUE and starch concentration, compared with PNUE, might be responsible for the observed population differentiation. These results support the concept that atmospheric CO2 elevation can act as a selective agent on some plant traits in natural plant communities. Reduced stomatal conductance and reduced starch accumulation are highlighted for possible adaptation to high CO2.

  13. A non-diatom plankton bloom controlled by copepod grazing and amphipod predation: Preliminary results from the LOHAFEX iron-fertilisation experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Mazzocchi, M.G.; Gonzalez, H.E.; Vandromme, P.; Borrione, I.; deAlcala, M.R.; Gauns, M.; Assmy, P.; Fuchs, B.; Klaas, C.; Martin, P.; Montresor, M.; Ramaiah, N.; Naqvi, S.W.A.; Smetacek, V.

    The most memorable LOHAFEX cruise came to an end on 17 March 2009 when RV Polarstern docked in the harbour of Punta Arenas (southern Chile) after successfully carrying out the longest iron fertilisation experiment so far (39 days). The two and a...

  14. Tactile stimulation partially prevents neurodevelopmental changes in visual tract caused by early iron deficiency.

    Science.gov (United States)

    Horiquini-Barbosa, Everton; Gibb, Robbin; Kolb, Bryan; Bray, Douglas; Lachat, Joao-Jose

    2017-02-15

    Iron deficiency has a critical impact on maturational mechanisms of the brain and the damage related to neuroanatomical parameters is not satisfactorily reversed after iron replacement. However, emerging evidence suggest that enriched early experience may offer great therapeutic efficacy in cases of nutritional disorders postnatally, since the brain is remarkably responsive to its interaction with the environment. Given the fact that tactile stimulation (TS) treatment has been previously shown to be an effective therapeutic approach and with potential application to humans, here we ask whether exposure to TS treatment, from postnatal day (P) 1 to P32 for 3min/day, could also be employed to prevent neuroanatomical changes in the optic nerve of rats maintained on an iron-deficient diet during brain development. We found that iron deficiency changed astrocyte, oligodendrocyte, damaged fiber, and myelinated fiber density, however, TS reversed the iron-deficiency-induced alteration in oligodendrocyte, damaged fiber and myelinated fiber density, but failed to reverse astrocyte density. Our results suggest that early iron deficiency may act by disrupting the timing of key steps in visual system development thereby modifying the normal progression of optic nerve maturation. However, optic nerve development is sensitive to enriching experiences, and in the current study we show that this sensitivity can be used to prevent damage from postnatal iron deficiency during the critical period. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Major element composition of an Early Enriched Reservoir: constraints from 142Nd/144Nd isotope systematics in the early Earth and high-pressure melting experiments of a primitive peridotite

    Science.gov (United States)

    Kondo, Nozomi; Yoshino, Takashi; Matsukage, Kyoko N.; Kogiso, Tetsu

    2016-12-01

    The Accessible Silicate Earth (ASE) has a higher 142Nd/144Nd ratio than most chondrites. Thus, if the Earth is assumed to have formed from these chondrites, a complement low-142Nd/144Nd reservoir is needed. Such a low-142Nd/144Nd reservoir is believed to have been derived from a melt in the early Earth and is called the Early Enriched Reservoir (EER). Although the major element composition of the EER is crucial for estimating its chemical and physical properties (e.g., density) and is also essential for understanding the origin and fate of the EER, which are both major factors that determine the present composition of the Earth, it has not yet been robustly established. In order to determine the major element composition of the EER, we estimated the age and pressure-temperature conditions to form the EER that would best explain its Nd isotopic characteristics, based on Sm-Nd partitioning and its dependence on pressure, temperature, and melting phase relations. Our estimate indicates that the EER formed within 33.5 Myr of Solar System formation and at near-solidus temperatures and shallow upper-mantle pressures. We then performed high-pressure melting experiments on primitive peridotite to determine the major element composition of the EER at estimated temperature at 7 GPa and calculated the density of the EER. The result of our experiments indicates that the near-solidus melt is iron-rich komatiite. The estimated density of the near-solidus melt is lower than that of the primitive peridotite, suggesting that the EER melt would have ascended in the mantle to form an early crust. Given that high mantle potential temperatures are assumed to have existed in the Hadean, it follows that the EER melt was generated at high pressure and, therefore, its composition would have been picritic to komatiitic. As the formation age of the EER estimated in our study precedes the last giant, lunar-forming impact, the picritic to komatiitic crust (EER) would most likely have been

  16. Analysis of the Intrinsic Uncertainties in the Laser-Driven Iron Hugoniot Experiment Based on the Measurement of Velocities

    Institute of Scientific and Technical Information of China (English)

    Huan Zhang; Xiao-Xi Duan; Chen Zhang; Hao Liu; Hui-Ge Zhang; Quan-Xi Xue; Qing Ye

    2016-01-01

    One of the most challenging tasks in the laser-driven Hugoniot experiment is how to increase the reproducibility and precision of the experimental data to meet the stringent requirement in validating equation of state models.In such cases,the contribution of intrinsic uncertainty becomes important and cannot be ignored.A detailed analysis of the intrinsic uncertainty of the aluminum-iron impedance-match experiment based on the measurement of velocities is presented.The influence of mirror-reflection approximation on the shocked pressure of Fe and intrinsic uncertainties from the equation of state uncertainty of standard material are quantified.Furthermore,the comparison of intrinsic uncertainties of four different experimental approaches is presented.It is shown that,compared with other approaches including the most widely used approach which relies on the measurements of the shock velocities of Al and Fe,the approach which relies on the measurement of the particle velocity of Al and the shock velocity of Fe has the smallest intrinsic uncertainty,which would promote such work to significantly improve the diagnostics precision in such an approach.

  17. Precipitation of iron in windopane oyster shells by marine shell-boring cyanobacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Rao, V.P.; Iyer, S.D.

    electron microscopy, suggested the presence of iron as iron oxides. The cyanobacteria from such black shells were cultured in enriched seawater medium. In this medium also they precipitated iron as confirmed by Prussian blue reaction. They were identified...

  18. Effect of ammonium input over the distribution of iron in the seawater and the phytoplankton in a mesocosm experiment in a North Patagonian fjord

    Directory of Open Access Journals (Sweden)

    N. Sanchez

    2014-09-01

    Full Text Available The distribution and concentration of iron in seawater and plankton were studied under different ammonium concentrations along a 22 day mesocosm experiment in order to assess possible effects of aquaculture over the phytoplankton and the biogeochemistry in fjords of Chile. Brackish and marine water were used in two different setups, each one with 1 control and 4 different NH4+ concentrations. Total Chelex labile (TFeCh, dissolved Chelex labile (DFeCh and DGT labile (FeDGT iron measurements were performed in seawater, wheile the particulate iron content was determined as total (PFe and fractionated (PFeSF for the plankton community. Average concentration per treatment showed higher concentrations for both TFeCh and DFeCh in the marine system compared to the brackish. TFeCh showed general increasing trend in time and with increasing ammonium concentration, exhibiting positive correlation to the chlorophyll and particulate organic carbon content, whereas DFeCh presented an inverse pattern as expected. FeDGT showed an average lower concentration compare to DFeCh with final concentrations significantly lower in treatments with artificial ammonium addition. PFe showed an increasing trend in time and with increasing ammonium in both systems. Yet, when normalized to Chlorophyll a or particulate organic carbon the trend inverted, showing that at higher ammonium loading the iron per Chlorophyll a or particulate organic carbon decreases. PFeSF major changes occurred in the marine system in the ratio between the 20–140 μm and the 2–20 μm fractions, suggesting possible community structure shift. Overall, ammonium input indicated an effect over iron in the seawater and the particulate matter, depending on the iron form and the microbial assemblage. The further changes over the microbial composition due to ammonium addition may affect the cycling of iron, having possible negative or positive feedbacks over major biogeochemical cycles.

  19. The next generation of iron fertilization experiments in the Southern Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Smetacek, V.; Naqvi, S.W.A.

    and marine phytoplankton, respectively (Falkowski et al.1998; Haberl et al. 2007)—the remainder exchanged with the oceans by seasonal cooling and warming combined with replacement of surface water by upwelling and downwelling (the physical solubility pump... are estimated to account for one-quarter to one-third of the total (natural C anthropogenic) N 2 O inputs to the carbon pump (BCP; Lampitt et al. 2008). If, in a thought experiment, the BCP were shut down but ventilation of the deep ocean by thermohaline...

  20. Investigating the Multiple Food Sources and N Chemistry of Invasive Earthworms at the Rhinelander, WI, Free Air CO2 Enrichment (FACE) Experiment

    Science.gov (United States)

    Top, S. M.; Filley, T. R.

    2013-12-01

    Rising levels of atmospheric CO2 can directly and indirectly alter biogeochemical cycling in forest ecosystems through changes to plant productivity, tissue chemistry, and associated feedbacks to microbial and faunal communities. At the Rhinelander free air CO2 enrichment site (FACE), Rhinelander WI, we examined the consumption and movement of plant tissue and soil by invasive earthworm species using a multi-proxy stable isotope and amino acid chemistry analysis of plant and soil, as well as fecal matter extracted from invasive earthworms present at the site. Using an isotopic mixing model that exploits the 13C-depleted CO2 source and a previous 15N labeling in the FACE experiment, we determined potential sources to the earthworm fecal matter and the movement of amino compounds. For epigeic, surface dwelling earthworms, the stable isotope modeling showed the largest contribution to the C and N in fecal matter was from leaf litter (up to 80%) which was depleted in amino acid C under elevated CO2 conditions. Fecal matter from the endogeic, mineral soil dwelling earthworms was primarily derived from 0-5 cm soil (up to 56%) and fine root tissue (up to 70%). Additionally, amino acid C in this group of earthworms had a proportionately greater relative concentration compared to the epigeic species and the 0-5cm soil. Here we demonstrate that earthworms are incorporating multiple sources (leaf litter, root, and soil) into their fecal matter, which then get deposited throughout the soil profile, where nutrients could become available for plant use.

  1. Enrichment Experiences in Engineering (E[superscript 3]) for Teachers Summer Research Program: An Examination of Mixed-Method Evaluation Findings on High School Teacher Implementation of Engineering Content in High School STEM Classrooms

    Science.gov (United States)

    Page, Cheryl A.; Lewis, Chance W.; Autenrieth, Robin L.; Butler-Purry, Karen L.

    2013-01-01

    Ongoing efforts across the U.S. to encourage K-12 students to consider science, technology, engineering and mathematics (STEM) careers have been motivated by concerns that the STEM pipeline is shrinking because of declining student enrollment and increasing rates of retirement in industry. The Enrichment Experiences in Engineering (E[superscript…

  2. γ-Determination of 235U Enrichment in Inspection Techniques

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The uranium enrichment analysis method was studied and established for the thick shielding uranium samples. The analysis errors are less than 5% at the conditions of 1-3 cm iron shielding for 235U

  3. pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef.

    Science.gov (United States)

    Georgiou, Lucy; Falter, James; Trotter, Julie; Kline, David I; Holcomb, Michael; Dove, Sophie G; Hoegh-Guldberg, Ove; McCulloch, Malcolm

    2015-10-27

    Geochemical analyses (δ(11)B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼-0.05 to -0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ(11)B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ(11)B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4-8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges.

  4. Interactive Effects of Experimental Warming and Elevated CO2 on Belowground Allocation and Soil Organic Matter Decomposition at the Prairie Heating and CO2 Enrichment Experiment

    Science.gov (United States)

    Pendall, E.; Blumenthal, D. M.; Carrillo, Y.; Dijkstra, F. A.; Mueller, K. E.; Nelson, L.; Nie, M.; Ogle, K.; Ryan, E.; Samuels-Crow, K. E.; Williams, D. G.; Zelikova, T. J.

    2016-12-01

    Climate change has direct and indirect effects on plant growth and carbon cycling. For instance, elevated CO2 (eCO2) stimulates photosynthesis and enhances soil moisture, while warming increases decomposition and dries soil. Grassland species' belowground carbon allocation responses to climate change will depend on ecological strategies such as rooting depth and nutrient acquisition. Rhizosphere priming of soil organic matter (SOM) decomposition occurs when C-rich substrates fuel ("prime") the activity of microbes to mineralize N from long-lived soil pools. Our work seeks to reveal how interactions of these biotic and abiotic processes influence the stability of SOM in the context of climate change. We conducted 8 years of experimental climate manipulation in native Wyoming grassland, with canopy warming (+1.5C/+3C day/night), free-air CO2 enrichment (ambient + 200 ppm) and supplemental precipitation. We measured SOM decomposition in plant-free plots, and also with a continuous 13CO2 label in the eCO2 treatments (at ambient and warmed temperatures). Experimental duration and soil moisture mediated many of the ecosystem responses we observed. C3 grasses and sedges were favoured in future climate (warming plus eCO2), and this effect became much stronger as the experiment progressed. Root biomass was consistently stimulated by future climate, while aboveground biomass was stimulated primarily in dry years. Aboveground plant activity (greenness) and soil moisture combined to increase ecosystem respiration, especially in future climate conditions. SOM decomposition rates, as measured by root exclusion, were stimulated by eCO2, but relatively unaffected by warming. SOM decomposition, calculated from isotope partitioning on undisturbed plots, increased with warming. Our field results are supported by growth chamber experiments demonstrating the importance of growing plants and mycorrhizae in decomposition. Our combined results contribute an ecosystem perspective on

  5. Modeling Polymer Stabilized Nano-scale Zero Valent Iron Transport Experiments in Porous Media to Understand the Transport Behavior

    Science.gov (United States)

    Mondal, P.; Krol, M.; Sleep, B. E.

    2015-12-01

    A wide variety of groundwater contaminants can be treated with nano-scale zero valent iron (nZVI). However, delivery of nZVI in the subsurface to the treatment zones is challenging as the bare nZVI particles have a higher tendency to agglomerate. The subsurface mobility of nZVI can be enhanced by stabilizing nZVI with polymer, such as carboxymethyl cellulose (CMC). In this study, numerical simulations were conducted to evaluate CMC stabilized nZVI transport behavior in porous media. The numerical simulations were based on a set of laboratory-scale transport experiments that were conducted in a two-dimensional water-saturated glass-walled sandbox (length - 55 cm; height - 45 cm; width - 1.4 cm), uniformly packed with silica sand. In the transport experiments: CMC stabilized nZVI and a non-reactive dye tracer Lissamine Green B (LGB) were used; water specific discharge and CMC concentration were varied; movements of LGB, and CMC-nZVI in the sandbox were tracked using a camera, a light source and a dark box. The concentrations of LGB, CMC, and CMC-nZVI at the sandbox outlet were analyzed. A 2D multiphase flow and transport model was applied to simulate experimental results. The images from LGB dye transport experiments were used to determine the pore water velocities and media permeabilities in various layers in the sand box. These permeability values were used in the subsequent simulations of CMC-nZVI transport. The 2D compositional simulator, modified to include colloid filtration theory (CFT), treated CMC as a solute and nZVI as a colloid. The simulator included composition dependent viscosity to account for CMC injection and mixing, and attachment efficiency as a fitting parameter for nZVI transport modeling. In the experiments, LGB and CMC recoveries were greater than 95%; however, CMC residence time was significantly higher than the LGB residence time and the higher CMC concentration caused higher pressure drops in the sandbox. The nZVI recovery was lower than 40

  6. 21 CFR 137.165 - Enriched flour.

    Science.gov (United States)

    2010-04-01

    ... riboflavin, 24 milligrams of niacin, 0.7 milligrams of folic acid, and 20 milligrams of iron. (b) It may... calcium or wheat germ is excluded in calculating ash content. (f) All ingredients from which the food is... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched flour. 137.165 Section 137.165 Food...

  7. Iron fertilisation and century-scale effects of open ocean dissolution of olivine in a simulated CO2 removal experiment

    Science.gov (United States)

    Hauck, Judith; Köhler, Peter; Wolf-Gladrow, Dieter; Völker, Christoph

    2016-02-01

    Carbon dioxide removal (CDR) approaches are efforts to reduce the atmospheric CO2 concentration. Here we use a marine carbon cycle model to investigate the effects of one CDR technique: the open ocean dissolution of the iron-containing mineral olivine. We analyse the maximum CDR potential of an annual dissolution of 3 Pg olivine during the 21st century and focus on the role of the micro-nutrient iron for the biological carbon pump. Distributing the products of olivine dissolution (bicarbonate, silicic acid, iron) uniformly in the global surface ocean has a maximum CDR potential of 0.57 gC/g-olivine mainly due to the alkalinisation of the ocean, with a significant contribution from the fertilisation of phytoplankton with silicic acid and iron. The part of the CDR caused by ocean fertilisation is not permanent, while the CO2 sequestered by alkalinisation would be stored in the ocean as long as alkalinity is not removed from the system. For high CO2 emission scenarios the CDR potential due to the alkalinity input becomes more efficient over time with increasing ocean acidification. The alkalinity-induced CDR potential scales linearly with the amount of olivine, while the iron-induced CDR saturates at 113 PgC per century (on average ˜ 1.1 PgC yr-1) for an iron input rate of 2.3 Tg Fe yr-1 (1% of the iron contained in 3 Pg olivine). The additional iron-related CO2 uptake occurs in the Southern Ocean and in the iron-limited regions of the Pacific. Effects of this approach on surface ocean pH are small (\\lt 0.01).

  8. Jendl-3.1 iron validation on the PCA-REPLICA (H{sub 2}O/Fe) shielding benchmark experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pescarini, M.; Borgia, M. G. [ENEA, Centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Energia

    1997-03-01

    The PCA-REPLICA (H{sub 2}O/Fe) neutron shielding benchmarks experiment is analysed using the SN 2-D DOT 3.5-E code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is designed to test the accuracy of the calculation of the in-vessel neutron exposure parameters. This accuracy is strongly dependent on the quality of the iron neutron cross sections used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the JENDL-3.1 iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA-Bologna validation of the ENDF/B VI iron cross sections. The integral result comparison indicates that, for all the threshold detectors considered (Rh-103 (n, n`) Rh-103m, In-115 (n, n`) In-115m and S-32 (n, p) P-32), the JENDL-3.1 natural iron data produce satisfactory results similar to those obtained with the ENDF/B VI iron data. On the contrary, when the JENDL/3.1 Fe-56 data file is used, strongly underestimated results are obtained for the lower energy threshold detectors, Rh-103 and In-115. This fact, in particular, becomes more evident with increasing the neutron penetration depth in the RPV simulator.

  9. BIFoR FACE: A ten-year Free-Air Carbon Dioxide Enrichment (FACE) Experiment in Old Growth Deciduous English Woodland

    Science.gov (United States)

    Thomas, R. M.; MacKenzie, A. R.; Ellsworth, D.; Hemming, D.; Crous, K.; Pope, F.; Blaen, P.; Poynter, A.; Hamilton, L.; Blenkhorn, D.; Jarvis-Rouse, F.

    2015-12-01

    The Birmingham Institute of Forest research (BIFoR) will perform fundamental physical, biological, ecological, social and cultural research of direct relevance to forested landscapes worldwide. A core platform for BIFoR to study the ten-year response of a mature temperate deciduous forest ecosystem to against a large step-change in atmospheric [CO2] is the BIFoR Free-Air Carbon Dioxide Enrichment (FACE) experiment. BIFoR FACE is being established in Mill Haft, a mature (~150 year-old) oak (Quercus robur) and hazel (Corylus avellana) coppice-with-standards woodland in central England. The facility will enable elevated CO2 (eCO2) treatments to be introduced in 30 m diameter rings (3 treatment and 6 control plots), commencing in spring 2016. Under eCO2 conditions primary research questions will investigate carbon uptake and storage, corresponding nutrient limitations, and biodiversity and ecosystem responses. As well as describing the facility and experimental design, we present baseline data collected throughout 2015, prior to fumigation. These data include: biophysical tree properties; atmospheric CO2/H2O fluxes; airborne and ground laser scatterometry; leaf area index; geophysical survey data; phenology camera derivatives; soil and water chemical and physical properties; and invertebrate surveys. Data from an intensive campaign conducted during august 2015 are also shown, including in- and above- canopy characterisation of biogenic VOCs using a Proton Transfer Reaction Mass Spectrometer, aerosol loading including bioaerosols, and enhanced atmospheric chemistry. Further campaign results are presented from leaf level photosynthetic carbon-dioxide response curve (A/Ci) performed at different canopy heights on oak trees, and on the dominant understory species - hazel and sycamore (Acer pseudoplatinus) across the site. BIFoR FACE is an exciting new international facility for forest science - ideas for collaborations are encouraged. Please see http

  10. Plasma current start-up experiments without a central solenoid in the iron core STOR-M tokamak

    Science.gov (United States)

    Mitarai, O.; Tomney, G.; Rohollohi, A.; Lewis, E.; McColl, D.; Xiao, C.; Hirose, A.

    2015-06-01

    Reproducible plasma current start-up without a central solenoid (CS) has been demonstrated using the outer ohmic heating (OH) coils in the iron core STOR-M tokamak (Mitarai et al 2014 Fusion Eng. Des. 89 2467-71). Although the outer OH coil current saturates the iron core eventually, it has been demonstrated that the plasma current can be maintained during the iron core saturation phase. In this work, further studies have been conducted to investigate the effects of the turn number of the outer OH coils (N = 4 or N = 6) in the CS-less discharges and to evaluate the plasma stability with respect to the n-decay index of the vertical magnetic field. For the loose coupling of the iron core with N = 4 turns, the plasma current can be sustained after the additional third capacitor bank is applied near the iron core saturation phase, showing the slow transition from the unsaturated to the partially saturated phase. For the case of stronger coupling of N = 6 turns, the plasma current is increased at the same fast bank voltage, but the main discharge is shortened from 35 to 20 ms. As the magnetizing current is smaller due to stronger coupling between the OH coils and the plasma current, the transition from the unsaturated to the saturated phase is slightly difficult at present. The present experimental results suggest a feasible operation scenario in a future spherical tokamak (ST) at least using loose iron core coupling for smoother transition from the unsaturated to the saturated iron core phase. Thus, a reliable plasma current start-up by the outer OH coils and the current ramp-up to a steady state by additional heating power and vertical field coils could be considered as an operation scenario for future ST reactors with an iron core transformer.

  11. Iron Test

    Science.gov (United States)

    ... as: Serum Iron; Serum Fe Formal name: Iron, serum Related tests: Ferritin ; TIBC, UIBC and Transferrin ; Hemoglobin ; Hematocrit ; Complete Blood Count ; Reticulocyte Count ; Zinc Protoporphyrin ; Iron Tests ; Soluble Transferrin Receptor ... I should know? How is it used? Serum iron, total iron-binding capacity (TIBC) , and/or ...

  12. Comparison of Global Model Results from the Carbon-Land Model Intercomparison Project (C-LAMP) with Free-Air Carbon Dioxide Enrichment (FACE) Manipulation Experiments

    Science.gov (United States)

    Hoffman, F. M.; Randerson, J. T.; Fung, I.; Thornton, P.; Covey, C.; Bonan, G.; Running, S.; Norby, R.

    2008-12-01

    Free-Air CO2 Enrichment (FACE) manipulation experiments have been carried out at a handful of sites to gauge the response of the biosphere to significant increases in atmospheric [CO2]. Early synthesis results from four temperate forest sites suggest that the response of net primary productivity (NPP) is conserved across a broad range of productivity with a stimulation at the median of 23±2% when the surrounding air [CO2] was raised to 550~ppm. As a part of the Carbon-Land Model Intercomparison Project (C-LAMP), a community-based model-data comparison activity, the authors have performed a global FACE modeling experiment using two terrestrial biogeochemistry modules, CLM3-CASA' and CLM3-CN, coupled to the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). The two models were forced with an improved NCEP/NCAR reanalysis data set and reconstructed atmospheric [CO2] and N deposition data through 1997. At the beginning of 1997 in the transient simulations, global atmospheric [CO2] was abruptly raised to 550~ppm, the target value used at the FACE sites. In the control runs, [CO2] continued to rise following observations until 2004, after which it was held constant out to year 2100. In both simulations, the last 25 years of reanalysis forcing and a constant N deposition were applied after year 2004. Across all forest biomes, the NPP responses from both models are weaker than those reported for the four FACE sites. Moreover, model responses vary widely geographically with a decreasing trend of NPP increases from 40°N to 70°N. For CLM3- CASA', the largest responses occur in arid regions of western North America and central Asia, suggesting that responses are most strongly influenced by increased water use efficiency for this model. CLM3-CN exhibits consistently weaker responses than CLM3-CASA' with the strongest responses in central Asia, but significantly constrained by N limitation. C-LAMP is a sub-project of the Computational

  13. Socioeconomic status, child enrichment factors, and cognitive performance among preschool-age children: Results from the Follow-Up of Growth and Development Experiences study☆

    Science.gov (United States)

    Christensen, Deborah L.; Schieve, Laura A.; Devine, Owen; Drews-Botsch, Carolyn

    2015-01-01

    Lower cognitive performance is associated with poorer health and functioning throughout the lifespan and disproportionately affects children from lower socioeconomic status (SES) populations. Previous studies reporting positive associations between child home enrichment and cognitive performance generally had a limited distribution of SES. We evaluated the associations of SES and child enrichment with cognitive performance in a population with a wide range of SES, particularly whether enrichment attenuates associations with SES. Children were sampled from a case–control study of small-for-gestational-age (SGA) conducted in a public hospital serving a low SES population (final n = 198) and a private hospital serving a middle-to-high SES population (final n = 253). SES (maternal education and income) and perinatal factors (SGA, maternal smoking and drinking) were obtained from maternal birth interview. Five child home enrichment factors (e.g. books in home) and preschool attendance were obtained from follow-up interview at age 4.5 years. Cognitive performance was assessed with the Differential Ability Scales (DAS), a standardized psychometric test administered at follow-up. SES and enrichment scores were created by combining individual factors. Analyses were adjusted for perinatal factors. Children from the public birth hospital had a significantly lower mean DAS general cognitive ability (GCA) score than children born at the private birth hospital (adjusted mean difference −21.4, 95% CI: −24.0, −18.7); this was substantially attenuated by adjustment for individual SES, child enrichment factors, and preschool attendance (adjusted mean difference −5.1, 95% CI: −9.5, −0.7). Individual-level SES score was associated with DAS score, beyond the general SES effect associated with hospital of birth. Adjustment for preschool attendance and home enrichment score attenuated the association between individual SES score and adjusted mean DAS-GCA among children born

  14. Socioeconomic status, child enrichment factors, and cognitive performance among preschool-age children: results from the Follow-Up of Growth and Development Experiences study.

    Science.gov (United States)

    Christensen, Deborah L; Schieve, Laura A; Devine, Owen; Drews-Botsch, Carolyn

    2014-07-01

    Lower cognitive performance is associated with poorer health and functioning throughout the lifespan and disproportionately affects children from lower socioeconomic status (SES) populations. Previous studies reporting positive associations between child home enrichment and cognitive performance generally had a limited distribution of SES. We evaluated the associations of SES and child enrichment with cognitive performance in a population with a wide range of SES, particularly whether enrichment attenuates associations with SES. Children were sampled from a case-control study of small-for-gestational-age (SGA) conducted in a public hospital serving a low SES population (final n=198) and a private hospital serving a middle-to-high SES population (final n=253). SES (maternal education and income) and perinatal factors (SGA, maternal smoking and drinking) were obtained from maternal birth interview. Five child home enrichment factors (e.g. books in home) and preschool attendance were obtained from follow-up interview at age 4.5 years. Cognitive performance was assessed with the Differential Ability Scales (DAS), a standardized psychometric test administered at follow-up. SES and enrichment scores were created by combining individual factors. Analyses were adjusted for perinatal factors. Children from the public birth hospital had a significantly lower mean DAS general cognitive ability (GCA) score than children born at the private birth hospital (adjusted mean difference -21.4, 95% CI: -24.0, -18.7); this was substantially attenuated by adjustment for individual SES, child enrichment factors, and preschool attendance (adjusted mean difference -5.1, 95% CI: -9.5, -0.7). Individual-level SES score was associated with DAS score, beyond the general SES effect associated with hospital of birth. Adjustment for preschool attendance and home enrichment score attenuated the association between individual SES score and adjusted mean DAS-GCA among children born at both of the

  15. Surface ocean iron fertilization: The role of airborne volcanic ash and iron-flux into the Pacific Ocean

    Science.gov (United States)

    Olgun, N.; Duggen, S.; Croot, P.; Dietze, H.

    2009-04-01

    Iron is a limiting micro-nutrient for marine primary production (MPP) in vast areas in the surface ocean. Hence, atmospheric supply of iron to the surface ocean can affect marine biogeochemical cycles, associated ocean-atmosphere exchange of CO2 and eventually climate development. Airborne volcanic ash from volcanic eruptions can be an important atmospheric iron-source in the surface ocean by releasing bio-available iron while settling through in the surface ocean. Here we present new data from time-dependent geochemical experiments with pristine (unhydrated) volcanic ash samples and natural seawater by means of Cathodic Stripping Voltammetry. Our results demonstrate that volcanic ash mobilizes significant amounts of soluble Fe within 60 minutes of contact with natural seawater. Depending on the amount of volcanic ash deposited offshore during major volcanic eruptions and the amount of iron that ash can release on contact with seawater, the calculated increase in the surface ocean Fe levels range from several nanomolar up to several hundred nanomolar (nM). Only 2 nM increase in iron concentrations can stimulate massive diatom blooms in the oceanic regions in which MPP is limited by the availability of iron (the iron-limited oceanic areas) (Wells, 2003). Therefore volcanic ash should be able to significantly affect marine phytoplankton growth in an ash fall area, acting as an iron fertilizer. Based on our new iron-release data and marine sediment core data we provide the first estimate of the flux of Fe from volcanic ash into the Pacific Ocean that covers more than 60 percent of the iron-limited oceanic regions. Our calculations show that the flux of Fe from volcanic ash is comparable to the order of magnitude of the flux of Fe from aeolian dust. Our study shows that volcanic ash is a major and so far underestimated atmospheric iron-source for the oceans and therefore an important component in marine biogeochemical iron cycles. Wells, M.L.: The level of iron

  16. Formulating an caramel flavoured drink with milk-based and enriched with iron and folic acid aimed to pregnant women FORMULACIÓN DE UNA BEBIDA LÁCTEA CON SABOR A AREQUIPE ENRIQUECIDA CON HIERRO Y ÁCIDO FÓLICO, DIRIGIDA A MUJERES GESTANTES

    Directory of Open Access Journals (Sweden)

    Bejarano-Roncancio Jhon Jairo

    2011-06-01

    Full Text Available Background. Colombia is one of the world's countries having a moderate prevalence of anaemic expectant women (20%-40%; it has been shown that mothers' serum folate and iron levels are relevant biochemical factors for babies' formation. Such statements have justified formulating an iron- and folic acid-enriched food product which has been specifically designed for expectant mothers and which contributes towards improving their nutritional conditions. Objective. Developing an organoleptically acceptable, caramel (arequipe-flavoured, sweetened iron- and folic acid-enriched milk-based drink. Materials and methods. The enriched drink was formulated in two stages (i.e. the standard and the product. The initial product was enriched with iron and folic acid and its final organoleptic acceptance was then determined. Results. The arequipe-flavoured Mamá vitae milk-based drink formulation had 86% acceptance. It included 10 mg aminochelated iron and 230 μg pteroylmonoglutamate per 200 mL milk portion and supplied 17% of the recommended iron and 33% folic acid intake for pregnant women. Conclusion. The product's characteristics favoured better nutritional conditions for pregnant women and fertile females who want to plan a viable pregnancy. This type of product is epidemiologically necessary for vulnerable populations such as expectant and breast-feeding mothers.Antecedentes. Colombia se encuentra dentro de los países con prevalencia moderada de anemia en mujeres gestantes (20-40%; está comprobado que los niveles séricos de folato y hierro en la madre son factores bioquímicos relevantes para la formación del bebé. Dichas aseveraciones, justifican la formulación de un producto alimenticio enriquecido con hierro y ácido fólico, específico para mujeres gestantes y que contribuya a mejorar sus condiciones nutricionales. Objetivo. Desarrollar una bebida láctea enriquecida con hierro y ácido fólico, endulzada y con sabor a arequipe, organol

  17. Iron chelation with deferasirox for the treatment of secondary hemosiderosis in pediatric oncology patients: a single-center experience.

    Science.gov (United States)

    Ktena, Yiouli P; Athanasiadou, Anastasia; Lambrou, George; Adamaki, Maria; Moschovi, Maria

    2013-08-01

    Pediatric oncology patients are often iron overloaded, due to the multiple blood transfusions necessary during the course of chemotherapy. Our aim is to report the efficacy and safety of deferasirox, an oral iron chelator, in this patient group. Deferasirox was administered to 13 children with malignancies in remission and iron overload. Ferritin, blood urea nitrogen, creatinine, transaminases, and bilirubin were recorded at 4- to 8-week intervals, and hepatic and cardiac iron overload were assessed with magnetic resonance imaging before initiation of treatment. Deferasirox was administered for an average of 6 months (SD=4.5; range, 0.3 to 18.2). Two children presented with skin rash, 1 with gastrointestinal disturbances, and 1 with fully reversible acute renal failure. The mean monthly rate of change in ferritin levels was -10.8 μg/L before initiation of treatment (95% confidence interval [CI], -19.8 to -1.8; P=0.02) and -93.6 μg/L during deferasirox treatment (95% CI, -118.1 to -69.1; PDeferasirox was effective in reducing the iron burden. The adverse effects were easily monitored and managed. Further studies are warranted to investigate the effect of deferasirox on mortality and morbidity in this population.

  18. Interactions of the metal tolerant heterotrophic microorganisms and iron oxidizing autotrophic bacteria from sulphidic mine environment during bioleaching experiments.

    Science.gov (United States)

    Jeremic, Sanja; Beškoski, Vladimir P; Djokic, Lidija; Vasiljevic, Branka; Vrvić, Miroslav M; Avdalović, Jelena; Gojgić Cvijović, Gordana; Beškoski, Latinka Slavković; Nikodinovic-Runic, Jasmina

    2016-05-01

    Iron and sulfur oxidizing chemolithoautotrophic acidophilic bacteria, such as Acidithiobacillus species, hold the dominant role in mine environments characterized by low pH values and high concentrations of reduced sulfur and iron compounds, such as ores, rocks and acid drainage waters from mines. On the other hand, heterotrophic microorganisms, especially their biofilms, from these specific niches are receiving increased attention, but their potential eco-physiological roles have not been fully understood. Biofilms are considered a threat to human health, but biofilms also have beneficial properties as they are deployed in waste recycling and bioremediation systems. We have analyzed interactions of the metal tolerant heterotrophic microorganisms in biofilms with iron oxidizing autotrophic bacteria both from the sulphidic mine environment (copper mine Bor, Serbia). High tolerance to Cu(2+), Cd(2+) and Cr(6+) and the presence of genetic determinants for the respective metal tolerance and biofilm-forming ability was shown for indigenous heterotrophic bacteria that included strains of Staphylococcus and Rhodococcus. Two well characterized bacteria- Pseudomonas aeruginosa PAO1 (known biofilm former) and Cupriavidus metallidurans CH34 (known metal resistant representative) were also included in the study. The interaction and survivability of autotrophic iron oxidizing Acidithiobacillus bacteria and biofilms of heterotrophic bacteria during co-cultivation was revealed. Finally, the effect of heterotrophic biofilms on bioleaching process with indigenous iron oxidizing Acidithiobacillus species was shown not to be inhibitory under in vitro conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Laboratory Shock Experiments on Basalt - Iron Sulfate Mixes at Approximately 40-50 GPa and Their Relevance to the Martian Regolith Component Present in Shergottites

    Science.gov (United States)

    Rao, M. N.; Nyquist, L. E.; Ross, D. K.; Asimow, P. D.; See, T.; Sutton, S.; Cardernas, F.; Montes, R.; Cintala, M.

    2012-01-01

    Basaltic shergottites such as Shergotty, Zagami and EET79001 contain impact melt glass pockets that are rich in Martian atmospheric gases [1] and are known as gas-rich impact-melt (GRIM) glasses. These glasses show evidence for the presence of a Martian regolith component based on Sm and Kr isotopic studies [2]. The GRIM glasses are sometimes embedded with clusters of innumerable micron-sized iron-sulfide blebs associated with minor amounts of iron sulfate particles [3, 4]. These sulfide blebs are secondary in origin and are not related to the primary igneous sulfides occurring in Martian meteorites. The material comprising these glasses arises from the highly oxidizing Martian surface and sulfur is unlikely to occur as sulfide in the Martian regoilith. Instead, sulfur is shown to occur as sulfate based on APXS and Mossbauer results obtained by the Opportunity and Spirit rovers at Meridiani and Gusev [5]. We have earlier suggested that the micron-sized iron sulfide globules in GRIM glasses were likely produced by shock-reduction of iron sulfate occurring in the regolith at the time when the GRIM glasses were produced by the meteoroid impact that launched the Martian meteorites into space [6]. As a result of high energy deposition by shock (approx. 40-60 GPa), the iron sulfate bearing phases are likely to melt along with other regolith components and will get reduced to immiscible sulfide fluid under reducing conditions. On quenching, this generates a dispersion of micron-scale sulfide blebs. The reducing agents in our case are likely to be H2 and CO which were shock-implanted from the Martian atmosphere into these glasses along with the noble gases. We conducted lab simulation experiments in the Lindhurst Laboratory of Experimental Geophysics at Caltech and the Experimental Impact Laboratory at JSC to test whether iron sulfide globules can be produced by impact-driven reduction of iron sulfate by subjecting Columbia River Basalt (CRB) and ferric sulfate mixtures to

  20. 活性炭富集电感耦合等离子体原子发射光谱测定铋系超导粉中痕量铁%Enrichment of Trace Iron with Activated Carbon in Bi-Based Superconductor Powder and Determination by Inductively Coupled Plasma Atomic Emission Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    黄文杰; 李建强; 范慧俐; 范丽新; 包蕊; 张霞; 王杰; 陆青

    2012-01-01

    建立了电感耦合等离子体原子发射光谱(ICP-AES)测定超导粉中痕量铁的新方法.优化了仪器工作参数,对痕量铁测定时的基体干扰及消除干扰的方法进行了系统研究,结果表明:大量存在的基体元素产生一定基体效应,并使重现性变差,且由于铁含量甚微,仪器灵敏度不能满足测定的要求,需采用分离富集方法以提高测定结果的准确度和精密度.以三乙醇胺掩蔽基体元素铋和铜,在适宜的酸度条件下,铁与邻二氮菲生成配合物,以活性炭定量吸附,用1∶1硝酸解吸,并对分离富集条件进行了优化.对模拟标准样品进行测定,分析结果与理论值一致,相对标准偏差为2.4%,方法检出限为0.033μg·g-1.该方法已用于超导前驱粉样品中痕量铁的分析,结果令人满意,并进行了回收实验,回收率为95.6%~98.0%.%A new method for determination of trace iron in superconductor powder by ICP-AES was proposed. The instrument parameters were optimized, and the matrix effects as well as the method of eliminating interferences were also studied systemical-ly. The results showed that matrix interference was serious when the amount of matrix increased, and the repeatability was poor, so it was necessary that separation and preconcentration were used to improve the accuracy and precision. In the experiment , complex was formed with Fe and phenanthroline after the matrix elements Bi and Cu were masked by triethanolamine in an appropriate acidity condition. Then the complex was quantitatively adsorbed by activated carbon, and desorbed by 1 : 1 HNO3.The enrichment conditions were investigated in detail. Under the optimal condition, an artificial sample was analysed, and the result was identical with reference values, with the RSD and detection limit being 2. 42% and 0. 033μg ? G-1, respectively. The method was applied for the determination of trace iron in Bi-based superconductor powder samples with satisfactory

  1. Use of rare earth oxides and iron oxides as soil erosion tracers in water erosion experiments at hillslope scale

    Science.gov (United States)

    Guzmán, G.; Cañasveras, J. C.; Barrón, V.; Boulal, H.; Gómez, H.; Conde, E.; Fernández, M.; Gómez, J. A.

    2010-05-01

    The characteristics of the ideal soil erosion have been defined by several authors, for example by Zhang et al. (2001). Despite intensive research on erosion tracers in the last decades there is not a single tracer fulfilling all these characteristics. That is why research on different soil erosion tracers remains as an active field. Two desirable characteristics in erosion tracers are that they should be relatively inexpensive (to purchase and analyze) and that they should be determined with high accuracy in soil or sediment. The availability of multiple tracers is another of the key requirements. In this communication we present our preliminary results on the use of two different sets of erosion tracers. One set are iron oxides with different magnetic and optical properties (Fe3O4, α-Fe2O3 and FeOOH) analyzed by NIRS and magnetic susceptibility measurements. The other set consists of five rare earth oxides (La2O3, Pr6O11, Nd2O3, Sm2O3 and Gd2O3) analyzed using inductively coupled plasma mass spectrometry (ICP-MS). These two groups were studied under controlled and natural conditions, through several water erosion experiments, in field plots with different soil management, crops and scale. In one experiment these tracers were used to determine the source of sediment within sprinkle irrigated fields planted with cotton on shoulders. For this purpose, rainfall simulations were performed under controlled conditions at two scales, one with a portable rainfall simulator at small scale (0.81m2) and with the sprinkler irrigation system in the whole cotton field (2450 m2). Furrows were tagged with both groups of tracers, keeping shoulders untagged (where cotton was planted). Soil samples before and after the rainfall simulations were collected as well as sediment samples. In another experiment four olive orchard plots (330 m2) with different soil managements (cover crop and conventional tillage) were also tagged with the two groups of tracers. Soil samples were taken at

  2. Assessing the utility of trace and rare earth elements as biosignatures in microbial iron oxyhydroxides

    Directory of Open Access Journals (Sweden)

    Christine eHeim

    2015-02-01

    Full Text Available Microbial iron oxyhydroxides are common deposits in natural waters, recent sediments and mine drainage systems and often contain significant accumulations of trace and rare earth elements (TREE. TREE patterns are widely used to characterize minerals and rocks, and to elucidate their evolution and origin. Whether and which characteristic TREE signatures distinguish between a biological and an abiological origin of iron minerals is still not well understood. Long-term flow reactor studies were performed in the Äspö Hard Rock Laboratory to investigate the development of microbial mats dominated by iron-oxidizing bacteria, namely Mariprofundus sp. and Gallionella sp. The experiments investigated the accumulation and fractionation of TREE under controlled conditions and enabled us to assess potential biosignatures evolving within the microbial iron oxyhydroxides. Concentrations of Be, Y, Zn, Zr, Hf, W, Th, Pb, and U in the microbial mats were 1e3- to 1e5-fold higher than in the feeder fluids whereas the rare earth elements and Y (REE+Y contents were 1e4 and 1e6 fold enriched. Except for a hydrothermally induced Eu anomaly, the normalized REE+Y patterns of the microbial iron oxyhydroxides were very similar to published REE+Y distributions of Archaean Banded Iron Formations. The microbial iron oxyhydroxides from the flow reactors were compared to iron oxyhydroxides that were artificially precipitated from the same feeder fluid. These abiotic and inorganic iron oxyhydroxides show the same REE+Y distribution patterns. Our results indicate that the REE+Y mirror quite exactly the water chemistry, but they do not allow to distinguish microbially mediated from inorganic iron precipitates. All TREE studied showed an overall similar fractionation behavior in biogenic, abiotic and inorganic iron oxyhydroxides. Exceptions are Ni and Tl, which were only accumulated in the microbial iron oxyhydroxides and may point to a potential usage of these elements as

  3. HTGR Generic Technology Program. Materials technology reactor operating experience medium-enriched-uranium fuel development. Quarterly progress report for the period ending April 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Kaae, J. L.; Lai, G. Y.; Thompson, L. D.; Sheehan, J. E.; Rosenwasser, S. N.; Johnson, W. R.; Li, C. C.; Pieren, W. R.; Smith, A. B.; Holko, K. H.; Baenteli, G. J.; Cheung, K. C.; Orr, J. D.; Potter, R. C.; Baxter, A.; Bell, W.; Lane, R.; Wunderlich, R. G.; Neylan, A. J.

    1978-05-01

    The work reported includes the development of the materials properties data base for noncore components, plant surveillance and testing performed at Fort St. Vrain, and work to demonstrate the feasibility of using medium-enriched fuel in Fort St. Vrain. Studies and analyses plus experimental procedures and results are discussed and data are presented.

  4. HTGR Generic Technology Program: materials technology reactor; operating experience; medium-enriched-uranium fuel development. Quarterly progress report for the period ending July 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    The work reported includes the development of the materials properties data base for noncore components, plant surveillance and testing performed at Fort St. Vrain, and work to demonstrate the feasibility of using medium-enriched fuel in Fort St. Vrain. Studies and analyses plus experimental procedures and results are discussed and data are presented.

  5. Non-chondritic iron isotope ratios in planetary mantles as a result of core formation

    Science.gov (United States)

    Elardo, Stephen M.; Shahar, Anat

    2017-02-01

    Information about the materials and conditions involved in planetary formation and differentiation in the early Solar System is recorded in iron isotope ratios. Samples from Earth, the Moon, Mars and the asteroid Vesta reveal significant variations in iron isotope ratios, but the sources of these variations remain uncertain. Here we present experiments that demonstrate that under the conditions of planetary core formation expected for the Moon, Mars and Vesta, iron isotopes fractionate between metal and silicate due to the presence of nickel, and enrich the bodies' mantles in isotopically light iron. However, the effect of nickel diminishes at higher temperatures: under conditions expected for Earth's core formation, we infer little fractionation of iron isotopes. From our experimental results and existing conceptual models of magma ocean crystallization and mantle partial melting, we find that nickel-induced fractionation can explain iron isotope variability found in planetary samples without invoking nebular or accretionary processes. We suggest that near-chondritic iron isotope ratios of basalts from Mars and Vesta, as well as the most primitive lunar basalts, were achieved by melting of isotopically light mantles, whereas the heavy iron isotope ratios of terrestrial ocean floor basalts are the result of melting of near-chondritic Earth mantle.

  6. Iron deficiency.

    Science.gov (United States)

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world.

  7. Clinical Observation on Infantile Iron-deficiency Anemia Treated with Therapy of Invigorating the Spleen and Enriching the Blood%健脾补血法治疗幼儿缺铁性贫血的临床观察

    Institute of Scientific and Technical Information of China (English)

    黄坚明

    2000-01-01

    @@ 缺血性贫血(Iron Deficiency Anemia)是小儿常见病,采用铁剂治疗或可缓解,但往往因出现胃肠不适的副作用而终止治疗.笔者采用中医健脾补血法,治疗缺铁性贫血患儿196例,疗效满意.现报道如下:

  8. Inevitable iron loss by human adolescents, with calculations of the requirement for absorbed iron.

    Science.gov (United States)

    Fomon, Samuel J; Drulis, Jean M; Nelson, Steven E; Serfass, Robert E; Woodhead, Jerold C; Ziegler, Ekhard E

    2003-01-01

    In growing individuals, the requirement for absorbed iron consists of iron needed for growth and iron needed to replace inevitable iron loss. We were able to estimate inevitable iron loss by adolescents because total body iron of the adolescents had been enriched with the stable isotope, (58)Fe, as the result of earlier studies of iron absorption. During an interval beginning at least 1.56 y after isotope administration (a time sufficient for complete mixing of the isotope with total body iron) and extending for no less than 3.29 y, we determined the isotopic enrichment of circulating iron. On the basis of several assumptions, we calculated total body (58)Fe and total body iron at the beginning and end of the interval. Because of complete mixing of the isotope with total body iron, fractional total (58)Fe loss was the same as fractional loss of total iron. In males, the fractional loss of iron was 9.70%/y and the quantitative loss was 256 mg/y or 0.70 mg/d. In females, the fractional loss of iron was 14.60%/y and the quantitative loss was 306 mg/y or 0.84 mg/d. Using several assumptions, we then calculated that the iron requirement for growth during this interval was 0.76 mg/d for males and 0.31 mg/d for females. Adding the iron loss to the iron requirement for growth, the requirement for absorbed iron was estimated to be 1.46 mg/d for males and 1.15 mg/d for females.

  9. Second series of electric double locomotives for the North Scandinavian iron ore railway. Pt. 2. Field experience and project second series; Zweite Doppellokomotiv-Serie fuer die nordskandinavische Erzbahn. T. 2. Betriebserfahrung und Projektabwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Zambo, Gabor [Bombardier Transportation Schweiz, Zuerich (Switzerland); Olovsson, Jan [LKAB, Kiruna (Sweden); Buchholz, Karl-Heinz [Bombardier Transportation, Kassel (Germany)

    2010-08-15

    Nine newly designed twelve axle electrical locomotives for hauling of 8.160 t iron ore trains have been delivered under a fi rst contract in a period till August 2004 to Kiruna, Sweden. After gaining experience on fi eld with subarctic conditions and as the further demand on iron ore in a world market raised in 2007 LKAB decided to call for tenders for further four double locomotives and optional up to three additional locomotives. (orig.)

  10. Light element controlled iron isotope fractionation in planetary cores

    Science.gov (United States)

    Shahar, A.; Hillgren, V. J.; Horan, M. F.; Duke, L.; Mock, T. D.

    2013-12-01

    Using iron isotope fractionations measured in planetary and meteorite samples to trace planetary differentiation or formation has yielded contradictory results. Iron from high-Ti lunar basalts is more enriched in 57Fe/54Fe than mantle-derived terrestrial samples, in contrast to the isotopic similarity for almost every other element between the Earth and Moon. SNC (Shergottite, Nakhlite, Chassigny) and HED (Howardite, Eucrite, Diogenite) meteorites, which are thought to be derived from the mantles of Mars and Vesta, respectively, show no isotopic fractionation relative to chondrites. While the Bulk Silicate Earth (BSE) value is debated, recent work has shown effectively that basalts (mid-ocean ridge basalts, terrestrial basalts, and ocean island basalts) are enriched in 57Fe/54Fe relative to chondrites, but the causes of that fractionation are unclear (Craddock et al. 2013). Angrites, basaltic achondrite meteorites, also show enrichment in δ57Fe (Wang et al. 2012). Possible mechanisms include high-pressure core formation, oxidation during perovskite disproportionation, evaporation during the giant impact, and mantle melting. It is important to reconcile why the Earth's basalts are enriched in 57Fe/54Fe but the meteorites from Mars and Vesta are not. One possible explanation is that Mars and Vesta are smaller and the lower pressure attenuated the potential Fe fractionation during core formation. A second possibility is that the intrinsic oxidation states of the planets are causing the differences. However, another option is that the light elements (e.g. S, C, O, H, Si) in the cores of differentiated bodies control the iron isotope fractionation during differentiation. We have conducted experiments at 1 GPa and 1650-1800°C in a piston cylinder apparatus to address how sulfur, carbon and silicon alloyed with iron affect the iron isotopic fractionation between metallic alloy and silicate melt. We find that sulfur has the greatest effect on the iron isotopic

  11. Aluminum Deoxidation Equilibria in Liquid Iron: Part III—Experiments and Thermodynamic Modeling of the Fe-Mn-Al-O System

    Science.gov (United States)

    Paek, Min-Kyu; Do, Kyung-Hyo; Kang, Youn-Bae; Jung, In-Ho; Pak, Jong-Jin

    2016-10-01

    Deoxidation equilibria in high-Mn- and high-Al-alloyed liquid steels were studied over the entire Fe-Mn-Al composition range by both experiments and thermodynamic modeling. Effect of Mn on the Al deoxidation equilibria in liquid iron was measured by the different experimental techniques depending on the Al content. In order to confirm the reproducibility of the experimental results, the deoxidation experiments were carried out reversibly from high oxygen state by addition of Al as a deoxidizer, and from low oxygen state by addition of Fe2O3 or MnO as an oxygen source. For the Al-rich side, CaO flux was added on top of liquid iron in order to remove suspended Al2O3 inclusions in the melt. Based on the present experimental result and available critically evaluated literature data, the Al deoxidation equilibria in Fe-Mn-Al-O liquid alloy were thermodynamically modeled. The Modified Quasichemical Model was used in order to take into account a strong short-range ordering of atoms in molten state. Deoxidation equilibria and inclusion stability diagram for entire Fe-Mn-Al melt were successfully reproduced by the present model.

  12. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    Science.gov (United States)

    Stephens, D. L.; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71 st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R 2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R 2 respectively.

  13. Hematological improvement during iron-chelation therapy in myelodysplastic syndromes: the experience of the "Rete Ematologica Lombarda".

    Science.gov (United States)

    Molteni, Alfredo; Riva, Marta; Pellizzari, Annamaria; Borin, Lorenza; Freyrie, Alessandra; Freyre, Alessandra; Greco, Rosa; Ubezio, Marta; Bernardi, Massimo; Fariciotti, Alessio; Nador, Guido; Nichelatti, Michele; Ravano, Emanuele; Morra, Enrica

    2013-10-01

    To analyze the unpredicted event of hematological improvement (HI) during iron-chelation therapy (ICT), we reviewed a series of 53 myelodysplastic patients with transfusion dependency in a retrospective study involving 8 centers afferent to the "Rete Ematologica Lombarda". According to the IWG response criteria published in the year 2000, we observed erythroid responses in 19 patients (35.1%), 5 major (9.2%) and 14 minor (25.9%). In the assessable patients, platelet response was 8/13 (61%) and neutrophil response was 13/17 (76.4%). Only in patients with erythroid improvement, multilineage responses were observed. Apparently, patients with greater erythropoiesis dysfunction may take more advantage.

  14. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    Science.gov (United States)

    Török, B.; Thiele, A.

    2013-12-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well.

  15. Native iron

    DEFF Research Database (Denmark)

    Brooks, Charles Kent

    2015-01-01

    , a situation unique in the Solar System. In such a world, iron metal is unstable and, as we all know, oxidizes to the ferric iron compounds we call 'rust'. If we require iron metal it must be produced at high temperatures by reacting iron ore, usually a mixture of ferrous (Fe2+) and ferric (Fe3+) oxides (Fe2O3......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost...... unique examples of iron metal, otherwise called 'native iron' or 'telluric iron', occur naturally....

  16. The liver in regulation of iron homeostasis.

    Science.gov (United States)

    Rishi, Gautam; Subramaniam, V Nathan

    2017-09-01

    The liver is one of the largest and most functionally diverse organs in the human body. In addition to roles in detoxification of xenobiotics, digestion, synthesis of important plasma proteins, gluconeogenesis, lipid metabolism, and storage, the liver also plays a significant role in iron homeostasis. Apart from being the storage site for excess body iron, it also plays a vital role in regulating the amount of iron released into the blood by enterocytes and macrophages. Since iron is essential for many important physiological and molecular processes, it increases the importance of liver in the proper functioning of the body's metabolism. This hepatic iron-regulatory function can be attributed to the expression of many liver-specific or liver-enriched proteins, all of which play an important role in the regulation of iron homeostasis. This review focuses on these proteins and their known roles in the regulation of body iron metabolism. Copyright © 2017 the American Physiological Society.

  17. Iron Homeostasis and Nutritional Iron Deficiency123

    OpenAIRE

    2011-01-01

    Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins enc...

  18. [To-day exposure to occupational carcinogens and their effects. The experience of the rubber industry, iron metallurgy, asphalt work and aviculture].

    Science.gov (United States)

    Barbieri, Pietro Gino

    2009-01-01

    While the progressive improvement of hygiene situations in the workplaces has taken to a reduction of chemical carcinogens exposure, in recent years in Italy the number of compensated occupational cancer resulting from carcinogens exposures of distant decades, has been increasing. Nevertheless, several experiences suggest that the proportion of occupational cancers unrecognised and not notified, as required by law, still remains important. This contribution concerns some experiences, performed between 2004-2008 by the Local Occupational Health Service (SPSAL) located in a highly industrialised province, on the working sector of rubber, iron and steel industry, the asphalt working and the poultry stock-breeders. This work concerns the following issues: - the evaluation of carcinogens exposure; - technical preventive measures and personal protection; - the level of workers' information and formation and the registration of exposed workers; - the characterization of work-related cancer. The results of the 5 years of activity allow us to underline that, in the most of 49 plants involved in the study, the carcinogens exposure evaluation and the prevention and protection measures were lacking. Information of workers was largely deficient and the registration of exposed workers was absent. A major attention to detect and to evaluate the work-related cancer has allowed us to recognize 50 new cases in the iron-steel industries and 21 new cases in a rubber industry. Although this experience concerns only few occupational fields, it provides the basis to call for a greater commitment of SPSAL addressed to companies and general practitioners to both, the promotion and surveillance of the correct procedures of carcinogens exposure evaluation and his prevention, and the active detection of occupational cancer, still missing.

  19. Analyses of iron and concrete shielding experiments at JAEA/TIARA with JENDL/HE-2007, ENDF/B-VII.1 and FENDL-3.0

    Energy Technology Data Exchange (ETDEWEB)

    Konno, Chikara, E-mail: konno.chikara@jaea.go.jp; Ochiai, Kentaro; Sato, Satoshi; Ohta, Masayuki

    2015-10-15

    IAEA released a new Fusion Evaluated Nuclear Data Library, FENDL-3.0, in 2012. FENDL-3.0 extends the neutron energy range from 20 MeV to greater than 60 MeV. Now there is increasing interest in nuclear data above 20 MeV. Thus we have analyzed the iron and concrete shielding experiments with the 40 and 65 MeV neutron sources at TIARA in Japan Atomic Energy Agency with the latest high-energy nuclear data libraries, JENDL/HE-2007, ENDF/B-VII.1 and FENDL-3.0. The Monte Carlo code MCNP-5 and ACE files of JENDL/HE-2007, ENDF/B-VII.1 and FENDL-3.0, which are supplied from JAEA, LANL and IAEA, respectively, were used for this analysis. The collimated neutron beam and test shields were modeled in the analysis. The measured source neutron data were adopted in the analysis. The followings are found out from the results; (1) Iron experiments: The calculation result with FENDL-3.0 agrees with the measured one best. That with JENDL/HE-2007 fairly agrees with the measured one. On the contrary that with ENDF/B-VII.1 drastically overestimates the measured one. It is confirmed that this overestimation is due to the smaller non-elastic scattering data of {sup 56}Fe in ENDF/B-VII.1. (2) Concrete experiments: The calculation result with ENDL/HE-2007 agrees with the measured one best, while those with FENDL-3.0 and ENDF/B-VII.1 drastically overestimate the measured one. It is confirmed that this overestimation is due to both the larger elastic and smaller non-elastic scattering data of {sup 16}O in FENDL-3.0 and ENDF/B-VII.1.

  20. Iron and oxygen isotope fractionation during iron UV photo-oxidation: Implications for early Earth and Mars

    Science.gov (United States)

    Nie, Nicole X.; Dauphas, Nicolas; Greenwood, Richard C.

    2017-01-01

    Banded iron formations (BIFs) contain appreciable amounts of ferric iron (Fe3+). The mechanism by which ferrous iron (Fe2+) was oxidized into Fe3+ in an atmosphere that was globally anoxic is highly debated. Of the three scenarios that have been proposed to explain BIF formation, photo-oxidation by UV photons is the only one that does not involve life (the other two are oxidation by O2 produced by photosynthesis, and anoxygenic photosynthesis whereby Fe2+ is directly used as electron donor in place of water). We experimentally investigated iron and oxygen isotope fractionation imparted by iron photo-oxidation at a pH of 7.3. The iron isotope fractionation between precipitated Fe3+-bearing lepidocrocite and dissolved Fe2+ follows a Rayleigh distillation with an instantaneous 56Fe/54Fe fractionation factor of + 1.2 ‰. Such enrichment in the heavy isotopes of iron is consistent with the values measured in BIFs. We also investigated the nature of the mass-fractionation law that governs iron isotope fractionation in the photo-oxidation experiments (i.e., the slope of the δ56Fe-δ57Fe relationship). The experimental run products follow a mass-dependent law corresponding to the high-T equilibrium limit. The fact that a ∼3.8 Gyr old BIF sample (IF-G) from Isua (Greenland) falls on the same fractionation line confirms that iron photo-oxidation in the surface layers of the oceans was a viable pathway to BIF formation in the Archean, when the atmosphere was largely transparent to UV photons. Our experiments allow us to estimate the quantum yield of the photo-oxidation process (∼0.07 iron atom oxidized per photon absorbed). This yield is used to model iron oxidation on early Mars. As the photo-oxidation proceeds, the aqueous medium becomes more acidic, which slows down the reaction by changing the speciation of iron to species that are less efficient at absorbing UV-photons. Iron photo-oxidation in centimeter to meter-deep water ponds would take months to years to

  1. Iron-Tolerant Cyanobacteria: Ecophysiology and Fingerprinting

    Science.gov (United States)

    Brown, I. I.; Mummey, D.; Lindsey, J.; McKay, D. S.

    2006-01-01

    Although the iron-dependent physiology of marine and freshwater cyanobacterial strains has been the focus of extensive study, very few studies dedicated to the physiology and diversity of cyanobacteria inhabiting iron-depositing hot springs have been conducted. One of the few studies that have been conducted [B. Pierson, 1999] found that cyanobacterial members of iron depositing bacterial mat communities might increase the rate of iron oxidation in situ and that ferrous iron concentrations up to 1 mM significantly stimulated light dependent consumption of bicarbonate, suggesting a specific role for elevated iron in photosynthesis of cyanobacteria inhabiting iron-depositing hot springs. Our recent studies pertaining to the diversity and physiology of cyanobacteria populating iron-depositing hot springs in Great Yellowstone area (Western USA) indicated a number of different isolates exhibiting elevated tolerance to Fe(3+) (up to 1 mM). Moreover, stimulation of growth was observed with increased Fe(3+) (0.02-0.4 mM). Molecular fingerprinting of unialgal isolates revealed a new cyanobacterial genus and species Chroogloeocystis siderophila, an unicellular cyanobacterium with significant EPS sheath harboring colloidal Fe(3+) from iron enriched media. Our preliminary data suggest that some filamentous species of iron-tolerant cyanobacteria are capable of exocytosis of iron precipitated in cytoplasm. Prior to 2.4 Ga global oceans were likely significantly enriched in soluble iron [Lindsay et al, 2003], conditions which are not conducive to growth of most contemporary oxygenic cyanobacteria. Thus, iron-tolerant CB may have played important physiological and evolutionary roles in Earths history.

  2. Construction, detection and microarray analysis on Shigella dysenteriae A1 IroN, ShuA single, double mutants

    Institute of Scientific and Technical Information of China (English)

    BIN; Wen; LIU; Moqing; PENG; Junping; SUN; Lilian; XU; Xingye; ZHANG; Jinghai; JIN; Qi

    2006-01-01

    In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was performed at the level of culture medium and cell experiment. The gene expression profiles of the mutants and the wild-type strains under iron- enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. The results showed that all the mutants grew obviously less well than the wild-type strains in L broth appending iron chelator DIP. The addition of iron to the cultures can stimulate the growth of mutants back to wild-type levels. In either the experiments on the ability of intracellular multiplication or the cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obvious change in virulence compared with the parental strain SD51197. However when DIP was added to the cultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reduced about 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limited condition showed that the mutants were more sensitive for the changes of iron deficiency than the wild-type strains, many genes have been altered. Up-regulated genes mainly involved genes of transcription, coenzyme metabolism, amino acid transport and metabolism, and unknown functional genes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism and unknown function genes; the expression levels of known iron-transport associated genes generally showed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA were likely to have some effects on the virulence and growth of S. dysenteriae.

  3. Influence of High-Current-Density Impulses on the Compression Behavior: Experiments with Iron and a Nickel-Based Alloy

    Science.gov (United States)

    Demler, E.; Gerstein, G.; Dalinger, A.; Epishin, A.; Rodman, D.; Nürnberger, F.

    2017-01-01

    Difficulties of processing of high strength and/or brittle materials by plastic deformation, e.g., by forging, require to develop new industrial technologies. In particular, the feasible deformation rates are limited for low-ductile metallic materials. For this reason, processes were investigated to improve the deformability in which electrical impulses are to be applied to lower the yield strength. However, owing to the impulse duration and low current densities, concomitant effects always occur, e.g., as a result of Joule heating. Current developments in power electronics allow now to transmit high currents as short pulses. By reducing the impulse duration and increasing the current density, the plasticity of metallic materials can be correspondingly increased. Using the examples of polycrystalline iron and a single-crystal, nickel-based alloy (PWA 1480), current advances in the development of methods for forming materials by means of high-current-density impulses are demonstrated. For this purpose, appropriate specimens were loaded in compression and, using novel testing equipment, subjected to a current strength of 10 kA with an impulse duration of 2 ms. For a pre-defined strain, the test results show a significant decrease in the compressive stress during the compression test and a significant change in the dislocation distribution following the current impulse treatment.

  4. Influence of High-Current-Density Impulses on the Compression Behavior: Experiments with Iron and a Nickel-Based Alloy

    Science.gov (United States)

    Demler, E.; Gerstein, G.; Dalinger, A.; Epishin, A.; Rodman, D.; Nürnberger, F.

    2016-12-01

    Difficulties of processing of high strength and/or brittle materials by plastic deformation, e.g., by forging, require to develop new industrial technologies. In particular, the feasible deformation rates are limited for low-ductile metallic materials. For this reason, processes were investigated to improve the deformability in which electrical impulses are to be applied to lower the yield strength. However, owing to the impulse duration and low current densities, concomitant effects always occur, e.g., as a result of Joule heating. Current developments in power electronics allow now to transmit high currents as short pulses. By reducing the impulse duration and increasing the current density, the plasticity of metallic materials can be correspondingly increased. Using the examples of polycrystalline iron and a single-crystal, nickel-based alloy (PWA 1480), current advances in the development of methods for forming materials by means of high-current-density impulses are demonstrated. For this purpose, appropriate specimens were loaded in compression and, using novel testing equipment, subjected to a current strength of 10 kA with an impulse duration of 2 ms. For a pre-defined strain, the test results show a significant decrease in the compressive stress during the compression test and a significant change in the dislocation distribution following the current impulse treatment.

  5. Iron in the Fire: Searching for Fire's Magnetic Fingerprint using Controlled Heating Experiments, High-Resolution FORCs, IRM Coercivity Spectra, and Low-Temperature Remanence Experiments

    Science.gov (United States)

    Lippert, P. C.; Reiners, P. W.

    2014-12-01

    Evidence for recent climate-wildfire linkages underscores the need for better understanding of relationships between wildfire and major climate shifts in Earth history, which in turn offers the potential for prognoses for wildfire and human adaptations to it. In particular, what are the links between seasonality and wildfire frequency and severity, and what are the feedbacks between wildfire, landscape evolution, and biogeochemical cycles, particularly the carbon and iron cycles? A key first step in addressing these questions is recovering well-described wildfire records from a variety of paleolandscapes and paleoclimate regimes. Although charcoal and organic biomarkers are commonly used indicators of fire, taphonomic processes and time-consuming analytical preparations often preclude their routine use in some environments and in high-stratigraphic resolution paleowildfire surveying. The phenomenological relationship between fire and magnetic susceptibility can make it a useful surveying tool, but increased magnetic susceptibility in sediments is not unique to fire, and thus limits its diagnostic power. Here we utilize component-specific rock magnetic methods and analytical techniques to identify the rock magnetic fingerprint of wildfire. We use a custom-designed air furnace, a series of iron-free laboratory soils, natural saprolites and soils, and fuels from Arizona Ponderosa pine forests and grasslands to simulate wildfire in a controlled and monitored environment. Soil-ash residues and soil and fuel controls were then characterized using First Order Reversal Curve (FORC) patterns, DC backfield IRM coercivity spectra, low-temperature SIRM demagnetization behavior, and low-temperature cycling of room-temperature SIRM behavior. We will complement these magnetic analyses with high-resolution TEM of magnetic extracts. Here we summarize the systematic changes to sediment magnetism as pyrolitized organic matter is incorporated into artificial and natural soils. These

  6. Experiment Research of Extracting Iron from Bayer Red Mud by Magnetic Separation Equipment%永磁法赤泥选铁的试验研究

    Institute of Scientific and Technical Information of China (English)

    邓琦; 张冬梅

    2012-01-01

    Red mud is the residue in alumina production process. With the rapid development of alumina industry, its emissions are growing rapidly. At present, both at home and abroad, red mud is wet stored in most alumina plant. More yard construction and maintenance fees are cost and its strong alkalis make the soil more alkaline. As the surface and underground water are polluted and the ecological environment is harmed directly or indirectly, the comprehensive utilization of iron from red mud has become a worldwide problem. In order to reduce the waste of red mud and thoroughly recycle the iron minerals in it, the extraction of iron from red mud by magnetic separation equipment was tested through experiments. According to the characteristics of the minerals in red mud, high-gradient magnetic separation equipment with a permanent magnet was chosen for extracting iron from red mud. The operation mode of the equipment, the working frequency of the magnetic roller, the opening scale of the magnetic equipment, the flushing area, and other influencing factors were studied. Continuous small-scale industrial test under optimal conditions was done. And the results of the test show that: the iron separation efficiency of high magnetic material Fe2O3 is 69.28%, and the recovery rates of red mud and Fe2O3 are 24.96% and 58.12%, respectively.%赤泥是氧化铝生产过程中铝土矿经强碱浸出后所产生的废渣.随着氧化铝工业的高速发展,其排放量增长很快.目前国内外氧化铝厂大都将赤泥筑坝湿法堆存,耗费较多的堆场建设和维护费用,而且其强碱性、高盐度造成土壤严重碱化,污染地表及地下水源,对生态环境造成直接或间接的危害,其综合利用已成为世界性的难题.为了减少赤泥的外排量,综合回收赤泥中的铁矿物,本研究对拜耳法赤泥进行了永磁法选铁的工艺试验研究.针对赤泥矿物成分的特点,选用了高梯度永磁体磁选设备进行赤泥选铁,研究

  7. Iron load

    Directory of Open Access Journals (Sweden)

    Filippo Cassarà

    2013-03-01

    Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.

  8. Experiments Using a Ground-Based Electrostatic Levitator and Numerical Modeling of Melt Convection for the Iron-Cobalt System in Support of Space Experiments

    Science.gov (United States)

    Lee, Jonghyun; SanSoucie, Michael P.

    2017-08-01

    Materials research is being conducted using an electromagnetic levitator installed in the International Space Station. Various metallic alloys were tested to elucidate unknown links among the structures, processes, and properties. To accomplish the mission of these space experiments, several ground-based activities have been carried out. This article presents some of our ground-based supporting experiments and numerical modeling efforts. Mass evaporation of Fe50Co50, one of flight compositions, was predicted numerically and validated by the tests using an electrostatic levitator (ESL). The density of various compositions within the Fe-Co system was measured with ESL. These results are being served as reference data for the space experiments. The convection inside a electromagnetically-levitated droplet was also modeled to predict the flow status, shear rate, and convection velocity under various process parameters, which is essential information for designing and analyzing the space experiments of some flight compositions influenced by convection.

  9. Iron status in Danish women, 1984-1994: a cohort comparison of changes in iron stores and the prevalence of iron deficiency and iron overload

    DEFF Research Database (Denmark)

    Milman, N.; Byg, K.E.; Ovesen, Lars;

    2003-01-01

    Background and objectives: From 1954 to 1986, flour in Denmark was fortified with 30 mg carbonyl iron per kilogram. This mandatory enrichment of cereal products was abolished in 1987. The aim was to evaluate iron status in the Danish female population before and after abolishment of iron...... fortification. Methods: Iron status, serum ferritin and haemoglobin, was assessed in population surveys in 1983-1984 comprising 1221 Caucasian women (1089 non-blood-donors, 130 donors) and in 1993-1994 comprising 1261 women (1155 non-blood-donors, 104 donors) equally distributed in age cohorts of 40, 50, 60......, postmenopausal women had median ferritin of 75 mug/L and in 1994 of 93 mug/L (P iron stores (ferritin iron stores (ferritin less...

  10. Black reefs: iron-induced phase shifts on coral reefs.

    Science.gov (United States)

    Kelly, Linda Wegley; Barott, Katie L; Dinsdale, Elizabeth; Friedlander, Alan M; Nosrat, Bahador; Obura, David; Sala, Enric; Sandin, Stuart A; Smith, Jennifer E; Vermeij, Mark J A; Williams, Gareth J; Willner, Dana; Rohwer, Forest

    2012-03-01

    The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km(2)). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.

  11. Iron refractory iron deficiency anemia

    OpenAIRE

    De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole

    2013-01-01

    Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in ad...

  12. Nutrient-enrichment effect on plankton composition:

    OpenAIRE

    Malej, Alenka; Mozetič, Patricija; Turk, Valentina

    1998-01-01

    Three enrichment experiments were conduced in order to analyze the development of plankton biomass and species composition as a response to different nutrient regimes. The additions of all nutrients had the most profound effect on phytoplankton biomass increase, whereas picoplankton abundance decreased continuously in all treatments. Initially dominating phytoplanktonic groups and species expanded significantly towards the end of experiments...

  13. Characterizing the production and retention of dissolved iron as Fe(II) across a natural gradient in chlorophyll concentrations in the Southern Drake Passage - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Katherine Barbeau

    2007-04-10

    Recent mesoscale iron fertilization studies in the Southern Ocean (e.g. SOIREE, EisenEx, SOFeX) have demonstrated the importance of iron as a limiting factor for phytoplankton growth in these high nutrient, low-chlorophyll (HNLC) waters. Results of these experiments have demonstrated that factors which influence the biological availability of the iron supplied to phytoplankton are crucial in bloom development, longevity, and generation of carbon export flux. These findings have important implications for the future development of iron fertilization protocols to enhance carbon sequestration in high-latitude oceans. In particular, processes which lead to the mobilization and retention of iron in dissolved form in the upper ocean are important in promoting continued biological availability of iron. Such processes can include photochemical redox cycling, which leads to the formation of soluble reduced iron, Fe(II), within iron-enriched waters. Creation of effective fertilization schemes will thus require more information about Fe(II) photoproduction in Southern Ocean waters as a means to retain new iron within the euphotic zone. To contribute to our knowledge base in this area, this project was funded by DOE with a goal of characterizing the production and retention of dissolved Fe as Fe(II) in an area of the southern Drake Passage near the Shackleton Transverse Ridge, a region with a strong recurrent chlorophyll gradient which is believed to be a site of natural iron enrichment in the Southern Ocean. This area was the focus of a multidisciplinary NSF/OPP-funded investigation in February 2004 (OPP02-30443, lead PI Greg Mitchell, SIO/UCSD) to determine the influence of mesoscale circulation and iron transport with regard to the observed patterns in sea surface chlorophyll in the region near the Shackleton Transverse Ridge. A number of parameters were assessed across this gradient in order to reveal interactions between plankton community structure and iron distributions

  14. Reduction of Mn-oxides by ferrous iron in a flow system: column experiment and reactive transport modeling

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Appelo, C. A. J.

    2000-01-01

    The reduction of Mn-oxide by Fe21 was studied in column experiments, using a column filled with natural Mn-oxide coated sand. Analysis of the Mn-oxide indicated the presence of both Mn(III) and Mn(IV) in the Mn-oxide. The initial exchange capacity of the column was determined by displacement of a...

  15. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  16. Intravenous iron supplementation in children on hemodialysis.

    NARCIS (Netherlands)

    Leijn, E.; Monnens, L.A.H.; Cornelissen, E.A.M.

    2004-01-01

    BACKGROUND: Children with end-stage renal disease (ESRD) on hemodialysis (HD) are often absolute or functional iron deficient. There is little experience in treating these children with intravenous (i.v.) iron-sucrose. In this prospective study, different i.v. iron-sucrose doses were tested in child

  17. Intravenous iron supplementation in children on hemodialysis.

    NARCIS (Netherlands)

    Leijn, E.; Monnens, L.A.H.; Cornelissen, E.A.M.

    2004-01-01

    BACKGROUND: Children with end-stage renal disease (ESRD) on hemodialysis (HD) are often absolute or functional iron deficient. There is little experience in treating these children with intravenous (i.v.) iron-sucrose. In this prospective study, different i.v. iron-sucrose doses were tested in

  18. XRF元素检测技术在三江地区某铁矿异常查证中的应用%The Application of the XRF Technology to Validate Iron Ore Enrichment in a Ceratin Place of SanJiang Area

    Institute of Scientific and Technical Information of China (English)

    喻东; 赖万昌; 程锋; 孙雪; 王广西; 张林

    2009-01-01

    介绍新一代手持式元素检测仪在三江地区某铁矿异常验证中的勘查应用,对应用中存在的基体效应和矿化不均匀效应进行了校正.现场测试结果表明,IED2000S型手持式元素检测仪在地质勘查应用中起到了快速、经济、有效的作用[1].%It presents the application of new-generation X-ray fluorescence analysis instrument to validate iron ore enrichment in a certain place of SanJiang area. Some methods were used to correct the base ma-trix effect and asymmetry effect. The result proved that the new-generation X-ray fluorescence analysis instrument can be a speedy, economical and effective way in such aspects as irrsitu soil and rock analysis and anomaly follow-up and verification.

  19. Neutrophilic iron oxidizers adapted to highly oxic environments

    DEFF Research Database (Denmark)

    Gülay, Arda; Musovic, Sanin; Albrechtsen, Hans-Jørgen;

    of iron oxidizing bacterial in the highly oxic environments found in typical rapid sand filters. The neutrophilic FeOB were enriched by the Fe2+/O2 opposing gradient technique and quantified by MPN methodology. Diversity fingerprints of the enrichment cultures were obtained with a 16S rRNA targeted DGGE...... oxidation of iron would be retarded. For that reason, no attempts have been documented to describe the density and diversity of iron oxidizing bacteria (FeOB) in oxic neutrophilic environments. Under low temperatures (5 to 10°C) conditions, as typically found in groundwater, extremely low rates of chemical...... technique, and dominant bands were isolated and sequenced for identification of dominant enrichment members. Enrichment were microscopically examined via CSLM in combination with FeOB specific or generic cytostains to verify enrichments, check cell morphologies and quantify cell densities. Our results...

  20. Iron status and the female athlete.

    Science.gov (United States)

    McClung, James P

    2012-06-01

    Iron deficiency (ID) is the most prevalent micronutrient deficiency disorder in the world. In the developed world, the greatest prevalence of ID and iron deficiency anemia (IDA) occurs in premenopausal women. Premenopausal women experience ID and IDA due to inadequate consumption of dietary iron coupled with iron losses through physiologic processes such as menstruation. Further, female athletes may experience an elevated risk of ID and IDA, as hepcidin, a peptide hormone that inhibits iron absorption and sequesters iron in the macrophage, may rise in response to physical activity. Declines in physical and cognitive performance have been demonstrated in female athletes with ID and IDA. Performance decrements are attenuated as iron status improves. This review will focus on iron status in female athletes, and will include a review of nutritional countermeasures to prevent ID and IDA.

  1. Productive Experiment and Investigation on Vermicularizers Used for Low Sulphur Iron Melt%低硫铁液用蠕化剂及其生产性试验研究

    Institute of Scientific and Technical Information of China (English)

    子澍; 严启光; 杨大平; 周尔范; 刘觉

    2012-01-01

    介绍了供感应电炉熔炼低硫铁液生产蠕墨铸铁用的三种REMgTiSiFe合金蠕化剂的化学成分,并用其中的#1、#2和#3号蠕化剂进行了蠕墨铸铁的生产性试验.分析了铁液的蠕化衰退问题和铸造性能问题.指出:这种类型蠕化剂的蠕化效果随时间的衰退不明显;用该合金蠕化剂生产蠕墨铸铁,其铁液的铸造性能和线收缩率与HT200的线收缩基本相同,而体收缩率比HT200的要大一些.%An introduction was given to three different chemical compositions of REMgTiSiFE alloys used for production of vermicular iron with induction fumace-inelted low sulphur iron melt. The experiments to produce vermicular iron were carried out by using #1 ,#2 and #3 alloys of them. The prohlems with the vermicularizing effect fading and cast-ability were analyzed. It was pointed out that the vermirularizing effect fading tendency with holding time of the vermiculasr iron treated with this type of vermiculizing alloys was not obvious. The cast-ability and linear contraction rate of the vermicular iron produced with this type of alloys were similar lo that of the HT200 grade gray iron, however its volumetric contraction rate was some higher than that of HT200 gray iron.

  2. 纳米铁-真养产碱杆菌柱实验去除硝酸盐%Denitration by nanoscale iron-alcaligenes eutrophus in column experiment

    Institute of Scientific and Technical Information of China (English)

    赵倩倩; 王成斌; 安毅; 金朝晖; 李铁龙

    2012-01-01

    In this study,experimental column equipment was established to explore the nitrate removal efficiency and the products under the conditions of different media,initial nitrate concentrations and flow rates.The results show that the complex obtained by mixed culture of nanoscale iron and alcaligenes eutrophus for 5 days prior to the experiment,achieves removal rate of 75% and the yield of ammonia is just 2.99 mg/L.This is the best removal effects among the 4 media,the rest of which were nanoscale iron,alcaligenes eutrophus,simplely mixed culture of fresh nanoscale iron and alcaligenes eutrophus.The degradation of the NO-3-N by the nanoscale iron-alcaligenes eutrophus achieved the best effect when initial concentration of nitrate was 32mg / L.The removal rate can achieve 78.9%,and the amounts of ammonia and nitrite generation were 2.34 mg/L and 2.89 mg/L,respectively,which was lower than that when initial concentrations of nitrate were 65 mg/L or 95 mg/L;the nitrate removal rate reached to 77% at the flow rate of 6.0 cm/h,and when the flow rate was controlled at 2.4 cm/h,the nitrite generation would lower to 0.34 mg/L.%建立柱实验装置,探讨了反应柱中填加介质、硝酸盐的初始浓度及不同过水流速时硝酸盐的去除效果及产物的生成情况。4种不同材料,纳米铁、真养产碱杆菌、纳米铁与真养产碱杆菌简单混合体、纳米铁与真养产碱杆菌驯化培养5 d的复合体,分别与初始浓度为65 mg/L硝酸盐溶液反应。结果表明,经培养5 d的纳米铁-真养产碱杆菌复合体对硝酸盐的去除效果最佳,去除率可达到75%,且氨氮的生成量仅为2.99 mg/L;硝酸盐初始浓度分别为32、65和95 mg/L时,32mg/L的体系中硝酸盐的降解效果最好,去除率达78.9%且亚硝酸盐及氨氮的生成量分别为2.34 mg/L和2.89 mg/L,均低于另外2组;溶液流速为6.0 cm/h时,经驯化培养的纳米铁-真养产碱杆菌对硝酸盐的去除率达77%,当控制流速降至2.4cm/h

  3. Absorption and loss of iron in toddlers are highly correlated.

    Science.gov (United States)

    Fomon, Samuel J; Nelson, Steven E; Serfass, Robert E; Ziegler, Ekhard E

    2005-04-01

    For estimating the requirements for dietary iron, it is important to know the amount of iron that is lost from the body. Inevitable losses of iron have been determined in adult humans but not in infants or children. We administered (58)Fe, the least abundant stable isotope of iron, to free-living infants at 168 d of age (5.6 mo) and followed them to age 26 mo. There was no dietary restriction after isotope administration. Blood was obtained at regular intervals for determination of isotopic enrichment and indices of iron status. We estimated the quantity of circulating iron, noncirculating active iron, and storage iron at each age. The administered isotope equilibrated with total body iron by 13 mo of age. From 13 to 26 mo of age, we estimated inevitable loss and absorption of iron from the change in tracer abundance in circulating iron. The rate of decrease of tracer abundance was proportional to addition of tracee, i.e., absorption of iron. Conversely, the rate of decrease in quantity of tracer was proportional to removal of tracee, i.e., loss of iron. From 13 to 26 mo of age, iron absorption was (mean +/- SD) 0.49 +/- 0.13 mg/d and inevitable iron loss was 0.25 +/- 0.12 mg/d. Intersubject variability of iron loss and iron absorption was high, and iron loss and absorption were highly correlated (r = 0.789, P absorption from the diet was inadequate to maintain or increase iron nutritional status. The data suggest that, in this cohort, which may be representative, the intake of bioavailable iron from 13 to 26 mo of age was insufficient to maintain iron nutritional status.

  4. Experiences in the development of solar stills light tire irons; Experiencias en el desarrollo de destiladores solares livianos desmontables

    Energy Technology Data Exchange (ETDEWEB)

    Fasulo, A.; Odicino, L.; Follari, J.; Perello, D.; Nieto, M.

    2008-07-01

    Experiences on solar stills developed in the Solar Energy Laboratory of San Luis University are shown in this work. The study is centred on the problems that arose from the transformation of laboratory prototypes into a desalinisation plant designed to provide continuous service. Many solar stills were operated for long term to cover the demand of the Chemical and Biochemical laboratories of the University. The results obtained for each design and arrangement adopted are presented by means of plots and tables. These results show a production of 16,000 litres per year and a conductance of the stilled water less than one microsiemens. (Author)

  5. Determining Iron Content in Foods by Spectrophotometry.

    Science.gov (United States)

    Adams, Paul E.

    1995-01-01

    Describes a laboratory experiment for secondary school chemistry students utilizing the classic reaction between the iron(III) ion and the thiocyanate ion. The experiment also works very well in other chemistry courses as an experience in spectrophotometric analysis. (PVD)

  6. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  7. On the Lower Limit of Chondrule Cooling Rates: The Significance of Iron Loss in Dynamic Crystallization Experiments

    Science.gov (United States)

    Paque, Julie M.; Connolly, Harold C., Jr.; Lofgren, Gary E.

    1998-01-01

    It is unlikely that the presence of chondrules, and thus their formation, within the protoplanetary nebula would be predicted if it were not for their ubiquitous presence in most chondritic meteorites. The study of these enigmatic, igneous objects has a direct influence on how meteoritic and solar system researchers model the processes operating and the materials present within our protoplanetary nebula. Key to understanding chondrule formation is a determination of constraints on their thermal histories. The three important variables in this history are their peak melting temperatures, the duration of their melting at peak temperatures, and the rate at which these object cool. Although these three variables are interdependent, it is cooling rate that provides the most powerful constraint. Cooling rate has a direct affect on the development of both crystal morphology and the elemental distributions within these grains. To date, experiments have indicated that chondrule cooling rates are in the range of 10's to 100's of degrees per hour for porphyritic chondrules (the most abundant type). The cooling rate for radial and barred chondrules is thought to be more rapid. To generate these cooling rates (rapid relative to the cooling of the nebula as a whole, but slow compared to simple black body radiation) the environment of chondrule formation must have been localized, and the abundance of solid materials must have been greatly enhanced above a gas of solar composition. Thus accurate determinations of chondrule cooling rates is critical in understanding both their formation and the nebular environment in which they formed. In a quest to more accurately determine the lower limit on cooling rates and to determine in more detail the effects of Fe loss from a molten sample to Pt wire loops, Weinbruch et al. have explored this issue experimentally and reevaluated the findings of Radomsky and Hewins in light of their new results. The basic conclusions of their paper are an

  8. Accelerated dissolution of iron oxides in ice

    Directory of Open Access Journals (Sweden)

    D. Jeong

    2012-08-01

    Full Text Available Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a~new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4, the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the type of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid-like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 °C to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

  9. Accelerated dissolution of iron oxides in ice

    Directory of Open Access Journals (Sweden)

    D. Jeong

    2012-11-01

    Full Text Available Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4, the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the surface area of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

  10. METABOLISM OF IRON STORES

    OpenAIRE

    Saito, Hiroshi

    2014-01-01

    ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since th...

  11. Ferronickel enrichment by fine particle reduction and magnetic separation from nickel laterite ore

    Institute of Scientific and Technical Information of China (English)

    Xiao-hui Tang; Run-zao Liu; Li Yao; Zhi-jun Ji; Yan-ting Zhang; Shi-qi Li

    2014-01-01

    Ferronickel enrichment and extraction from nickel laterite ore were studied through reduction and magnetic separation. Reduction experiments were performed using hydrogen and carbon monoxide as reductants at different temperatures (700-1000°C). Magnetic separa-tion of the reduced products was conducted using a SLon-100 cycle pulsating magnetic separator (1.2 T). Composition analysis indicates that the nickel laterite ore contains a total iron content of 22.50wt%and a total nickel content of 1.91wt%. Its mineral composition mainly con-sists of serpentine, hortonolite, and goethite. During the reduction process, the grade of nickel and iron in the products increases with in-creasing reduction temperature. Although a higher temperature is more favorable for reduction, the temperature exceeding 1000°C results in sintering of the products, preventing magnetic separation. After magnetic separation, the maximum total nickel and iron concentrations are 5.43wt%and 56.86wt%, and the corresponding recovery rates are 84.38%and 53.76%, respectively.

  12. Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bernard Jones; J. Blair Briggs; Leland Monteirth

    2007-05-01

    A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In addition to the idealizations made by the experimenters (removal of the platen and diaphragm), two simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. First of all, since impurities in core and reflector materials are only estimated, they are not included in the benchmark models. Secondly, the room, support structure, and other possible surrounding equipment were not included in the model. Bias values that result from these two simplifications were determined and associated

  13. Structural iron (II of basaltic glass as an energy source for Zetaproteobacteria in an abyssal plain environment, off the Mid Atlantic Ridge

    Directory of Open Access Journals (Sweden)

    Pauline Audrey Henri

    2016-01-01

    Full Text Available To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W. In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped in a palagonite-like structure with thicknesses up to 150 µm. The relative abundance of the associated microbial community was dominated (39% of all reads by a single operational taxonomic unit (OTU that shared 92% identity with the iron-oxidizer Mariprofundus ferrooxydans PV-1. Conversely, the oxidized basaltic glass showed the absence of iron-oxides enriched surface deposits and correspondingly there was a lack of known iron-oxidizing bacteria in the inventoried diversity. In vitro, a similar reduced basaltic glass was incubated in artificial seawater with a pure culture of the iron-oxidizing M. ferrooxydans DIS-1 for 2 weeks, without any additional nutrients or minerals. Confocal Laser Scanning Microscopy revealed that the glass surface was covered by twisted stalks characteristic of this iron-oxidizing Zetaproteobacteria. This result supported findings of the in situ experiments indicating that the Fe(II present in the basalt was the energy source for the growth of representatives of Zetaproteobacteria in both the abyssal plain and the in vitro experiment. In accordance, the surface alteration rind observed on the reduced basaltic glass incubated in situ could at least partly result from

  14. Design and operation of Taiyuan Iron & Steel' s sulphuric acid plant based on SO_2 from desulphurization and enrichment of sintering off-gas%太钢烧结烟气脱硫富集SO_2烟气制酸装置的设计与运行

    Institute of Scientific and Technical Information of China (English)

    涂瑞; 李强; 葛帅华

    2012-01-01

    太原钢铁(集团)有限公司炼铁厂2台烧结机烟气采用活性炭吸附法脱硫工艺。针对脱硫富集SO2烟气流量小、温度高、SO2浓度高、尘含量高并含有氟、氯、氨、汞等有害杂质的特点,烟气制酸设计采用喷淋塔—一级泡沫柱洗涤器—气体冷却塔—二级泡沫柱洗涤器—2级电除雾器稀酸洗净化、"3+1"ⅢⅠ-ⅣⅡ二转二吸工艺流程。2套制酸装置投产近1年时间,装置运行稳定,各项工艺指标均达到设计值,硫酸产量分别达到26,38 t/d,制酸尾气ρ(SO2)均小于或等于450 mg/m3,工业硫酸品质达到国家优等品标准。%The off-gas from two sintering machines was treated for desulphurization by activated carbon adsorption process in Iron Plant of Taiyuan Iron Steel.For the characteristics of low flow,high temperature,high SO2 and dust contents and existence of ammonia,fluorine,chlorine,mercury and other harmful impurities in desulphurization enriched off-gas,the plant adopted a cleaning section consisting of spray tower,1st stage froth column scrubber,gas cooling tower,2nd stage froth column scrubber and two-stage wet electrostatic precipitatores,and a "3+1" Ⅲ Ⅰ-Ⅳ Ⅱ double absorption process.The two plants have been operating for more than one year and every index reached design value,with tail gas SO2 concentration of both lower than 450 mg/m3,sulphuric acid production of 26 t/d and 38 t/d,respectively,and sulphuric acid quality up to the national premium grade requirement.

  15. Enriching the Catalog

    Science.gov (United States)

    Tennant, Roy

    2004-01-01

    After decades of costly and time-consuming effort, nearly all libraries have completed the retrospective conversion of their card catalogs to electronic form. However, bibliographic systems still are really not much more than card catalogs on wheels. Enriched content that Amazon.com takes for granted--such as digitized tables of contents, cover…

  16. GOMA: functional enrichment analysis tool based on GO modules

    Institute of Scientific and Technical Information of China (English)

    Qiang Huang; Ling-Yun Wu; Yong Wang; Xiang-Sun Zhang

    2013-01-01

    Analyzing the function of gene sets is a critical step in interpreting the results of high-throughput experiments in systems biology.A variety of enrichment analysis tools have been developed in recent years,but most output a long list of significantly enriched terms that are often redundant,making it difficult to extract the most meaningful functions.In this paper,we present GOMA,a novel enrichment analysis method based on the new concept of enriched functional Gene Ontology (GO) modules.With this method,we systematically revealed functional GO modules,i.e.,groups of functionally similar GO terms,via an optimization model and then ranked them by enrichment scores.Our new method simplifies enrichment analysis results by reducing redundancy,thereby preventing inconsistent enrichment results among functionally similar terms and providing more biologically meaningful results.

  17. GOMA: functional enrichment analysis tool based on GO modules

    Science.gov (United States)

    Huang, Qiang; Wu, Ling-Yun; Wang, Yong; Zhang, Xiang-Sun

    2013-01-01

    Analyzing the function of gene sets is a critical step in interpreting the results of high-throughput experiments in systems biology. A variety of enrichment analysis tools have been developed in recent years, but most output a long list of significantly enriched terms that are often redundant, making it difficult to extract the most meaningful functions. In this paper, we present GOMA, a novel enrichment analysis method based on the new concept of enriched functional Gene Ontology (GO) modules. With this method, we systematically revealed functional GO modules, i.e., groups of functionally similar GO terms, via an optimization model and then ranked them by enrichment scores. Our new method simplifies enrichment analysis results by reducing redundancy, thereby preventing inconsistent enrichment results among functionally similar terms and providing more biologically meaningful results. PMID:23237213

  18. Iron Dextran Injection

    Science.gov (United States)

    ... allergic to iron dextran injection; any other iron injections such as ferric carboxymaltose (Injectafer), ferumoxytol (Feraheme), iron sucrose (Venofer), or sodium ferric gluconate (Ferrlecit);any other ...

  19. Thermomagnetic evidence of native iron in sediments

    Science.gov (United States)

    Pechersky, D. M.; Sharonova, Z. V.

    2012-04-01

    The paper summarizes the results of thermomagnetic analysis concerning the distribution of metallic iron in the sediments ranging in age from Miocene to Early Cretaceous sampled from the following sections: Gams (Austria); Verkhorech'e and Sel'bukhra (the Crimea); Kvirinaki and Tetritskaro (Georgia); Aimaki, Dzhengutai, Madzhalis, and Gergebil (Ciscaucasia, Russia); Klyuchi and Teplovka (Volga region, Russia); Koshak (Kazakhstan); and Khalats and Kara-Kala (Turkmenia). Small amounts of native iron (from 10-5% to 0.05%) are identified in 521 samples of 921 studied; i.e., iron particles are almost pervasive. This fact traces the origin of these particles to cosmic dust. Some established features point to the heterogeneous character of the cosmic dust: (a) the samples clearly fall into two groups. One group comprises the rocks that contain iron particles; the rocks of the other group are iron-free. In the first group, four intervals are distinguished where the sediments are globally enriched with iron with constant nickel content (5-6%); (b) in terms of composition, the iron particles are divided into three groups. The first group contains pure iron; the particles pertaining to the second group contain iron with a minor amount of nickel typical for kamacite; and the third group comprises the particles of Fe-Ni alloy with more than 20% nickel. The first and the second groups are ubiquitous; the particles of the third group are spread locally. They bear no relation to cosmic dust and are probably associated with the meteoritic impacts.

  20. Sedimentary particulate iron: the missing micronutrients ?

    Science.gov (United States)

    Beghoura, Houda; Gorgues, Thomas; Aumont, Olivier; Planquette, Hélène

    2017-04-01

    Iron is known to regulate the marine primary production and to impact the structure of ecosystems. Indeed, iron is the limiting nutrient for the phytoplankton growth over about 30% of the global ocean. However, the nature of the external sources of iron to the ocean and their quantification remain uncertain. Among these external sources, the sediment sources have been recently shown to be underestimated. Besides, since the operationally defined dissolved iron (which is the sum of truly dissolved and colloidal iron) was traditionally assumed to be the only form available to phytoplankton and bacteria, most studies have focused on the supply of dissolved iron to the ocean, the role of the particulate fraction of iron being largely ignored. This traditional view has been recently challenged, noticeably, by observational evidences. Indeed, in situ observations have shown that large amounts of particulate iron are being resuspended from continental margins to the open ocean thanks to fine grained particles' transport over long distances. A fraction of this particulate iron may dissolve and thereby fuel the phytoplankton growth. The magnitude of the sedimentary sources of particulate iron and the releasing processes affecting this iron phase are not yet well constrained or quantified. As a consequence, the role of sedimentary particulate iron in the biogeochemical cycles is still unclear despite its potentially major widespread importance. Here, we propose a modeling exercise to assess the first order impacts of this newly considered particulate sedimentary iron on global ocean biogeochemistry. We designed global experiments with a coupled dynamical-biogeochemical model (NEMO-PISCES). First, a control simulation that includes only a sediment source of iron in the dissolved phase has been run. Then, this control simulation is being compared with simulations, in which we include a sediment source of iron in both phases (dissolved as well as particulate). Those latter

  1. Nanosized Iron Oxide Colloids Strongly Enhance Microbial Iron Reduction▿ †

    Science.gov (United States)

    Bosch, Julian; Heister, Katja; Hofmann, Thilo; Meckenstock, Rainer U.

    2010-01-01

    Microbial iron reduction is considered to be a significant subsurface process. The rate-limiting bioavailability of the insoluble iron oxyhydroxides, however, is a topic for debate. Surface area and mineral structure are recognized as crucial parameters for microbial reduction rates of bulk, macroaggregate iron minerals. However, a significant fraction of iron oxide minerals in the subsurface is supposed to be present as nanosized colloids. We therefore studied the role of colloidal iron oxides in microbial iron reduction. In batch growth experiments with Geobacter sulfurreducens, colloids of ferrihydrite (hydrodynamic diameter, 336 nm), hematite (123 nm), goethite (157 nm), and akaganeite (64 nm) were added as electron acceptors. The colloidal iron oxides were reduced up to 2 orders of magnitude more rapidly (up to 1,255 pmol h−1 cell−1) than bulk macroaggregates of the same iron phases (6 to 70 pmol h−1 cell−1). The increased reactivity was not only due to the large surface areas of the colloidal aggregates but also was due to a higher reactivity per unit surface. We hypothesize that this can be attributed to the high bioavailability of the nanosized aggregates and their colloidal suspension. Furthermore, a strong enhancement of reduction rates of bulk ferrihydrite was observed when nanosized ferrihydrite aggregates were added. PMID:19915036

  2. Microbial acquisition of iron from ferric iron bearing minerals

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, L.E. [Los Alamos National Lab., NM (United States); Sposito, G. [Univ. of California, Berkeley, CA (United States)

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Iron is a universal requirement for all life forms. Although the fourth most abundant element in the geosphere, iron is virtually insoluble at physiological pH in oxidizing environments, existing mainly as very insoluble oxides and hydroxides. Currently it is not understood how iron is solubilized and made available for biological use. This research project addressed this topic by conducting a series of experiments that utilized techniques from both soil microbiology and mineral surface geochemistry. Microbiological analysis consisted of the examination of metabolic and physiological responses to mineral iron supplements. At the same time mineral surfaces were examined for structural changes brought about by microbially mediated dissolution. The results of these experiments demonstrated that (1) bacterial siderophores were able to promote the dissolution of iron oxides, (2) that strict aerobic microorganisms may use anaerobic processes to promote iron oxide dissolution, and (3) that it is possible to image the surface of iron oxides undergoing microbial dissolution.

  3. Implementing the Schoolwide Enrichment Model in Brazil

    Science.gov (United States)

    de Souza Fleith, Denise; Soriano de Alencar, Eunice M. L.

    2010-01-01

    The Schoolwide Enrichment Model (SEM) has been one of the most widely used models in the education of the gifted in Brazil. It has inspired the political and pedagogical project of the Centers of Activities of High Abilities/Giftedness recently implemented in 27 Brazilian states by the Ministry of Education. In this article, our experience in…

  4. The studies of nodular graphite cast iron early stages austempering

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2008-12-01

    Full Text Available The results of early stage of ductile cast iron austempering are presented. The aim of the investigations was to look closer into the structure – mechanical properties relationships of this very attractive cast material. The experiment was carried out with enriched with Cu EN-GJS-500-7 grade ductile iron. The specimens were first solution heat treated 1 hour in 910oC and then isothermally quenched for different time in molten tin at the temperature 275oC. The mechanical properties of as cast and heat treated specimens were tested to evaluate tensile Rm and yield strength R p, 0.2 and elongation A5. Additionally hardness measurements were carried out using Brinell-Rockwell method. Structure of the specimens both as cast and after austempering was studied using conventional light microscopy. Moreover, scanning electron microscopy (SEM was applied for fracture surface observations. It was concluded that short time low temperature austempering lead to formation martensitic microstructure characterized by very high hardness with almost zero ductility. The lack of ductility make the material very sensitive to any structure defects which work as a stress concentrators which strongly influence the strength of heat treated ductile iron specimens.

  5. An interdisciplinary tillage erosion experiment: establishing a new field in grassland with reconstructed ard plough of the Bronze Age - Iron Age

    Science.gov (United States)

    Pavelka, Jan; Smetanová, Anna; Rejman, Jerzy; Kováčik, Peter

    2017-04-01

    Despite recognising the role of tillage erosion in landforms evolution, little research has documented its effects in prehistoric times. Herein, an interdisciplinary archaeological-geomorphological experiment with reconstructed tillage tools and management was conducted in order to measure tillage erosion when a new field in grasslands was established in the Bronze Age-Iron Age. Three wooden ards were reconstructed based on archaeological findings. They were tested in a cross-tillage experiment, consisting of a tillage pass perpendicular to the primary slope (6.5-9.7%), and a second tillage pass parallel to the primary slope of a convex-convex ridge with mowed grass (0.2 m high, vegetation cover >90%). The standard sole ard proved to be the most effective, with a mean tillage depth of 0.12 m, a mean tillage speed of 3.8 km h-1, and a mean distance between furrows of 0.20-0.25 m. Only 13% of the 264 tracers placed on 6 transects were displaced, and the mean tracers displacement parallel to the primary slope was 0.04 ± 0.17 m. Contour tillage perpendicular to primary slope created V or U shaped furrows with a mean depth of 0.1-0.12 m, a mean width of 0.05-0.1 m, and incision under the main root zone. Only soil in direct contact with the ard was displaced, with a mean translocation distance of 0.06 ± 0.2 m parallel and 0.06 ± 0.3 m perpendicular to the primary slope. During tillage parallel to slope, soil clods of 0.20 x 0.25 x 0.10 m were created and slightly disturbed or turned over one another. The tracers moved within the furrows and with the soil clods. Loose soil, resembling a seedbed, was not covered by soil clods. Mean displacement during the second pass was 0.03 ± 0.19 m parallel and 0.00 ± 0.15 m perpendicular to primary slope. The displacement from cross-tillage with a wooden ard in permanent grasslands was lower than many previously measured values of traditional animal-powered metal ploughs in permanent fields. No relationship between mean soil

  6. Iron Sucrose Injection

    Science.gov (United States)

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... enough iron, your body starts using the iron it has stored. Soon, the stored iron gets used ... fewer red blood cells. The red blood cells it does make have less hemoglobin than normal. Iron- ...

  8. Prevalence of iron deficiency anemia and iron deficiency in a pediatric population with inflammatory bowel disease

    OpenAIRE

    Carvalho, FS; de Medeiros, IA; Antunes, H.

    2017-01-01

    Iron deficiency is the most common cause of anemia in children with inflammatory bowel disease, although the real prevalence is unknown. Intravenous iron is suggested as the first line treatment. This study aims to determine the prevalence of iron deficiency anemia in children with inflammatory bowel disease followed in a Pediatric Gastroenterology Unit of a tertiary center and to evaluate this unit's experience with intravenous iron. info:eu-repo/semantics/publishedVersion

  9. Characterization of tetraethylene glycol passivated iron nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Eloiza da Silva; Viali, Wesley Renato [Laboratório de Materiais Magnéticos e Coloides, Departamento de Físico-química, Instituto de Química, Universidade Estadual Paulista, Araraquara, SP 14801-970 (Brazil); Silva, Sebastião William da; Coaquira, José Antonio Huamaní; Garg, Vijayendra Kumar; Oliveira, Aderbal Carlos de [Instituto de Física, Núcleo de Física Aplicada, Universidade de Brasília, Brasília, DF 70910-900 (Brazil); Morais, Paulo César [Instituto de Física, Núcleo de Física Aplicada, Universidade de Brasília, Brasília, DF 70910-900 (Brazil); School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China); Jafelicci Júnior, Miguel, E-mail: jafeli@iq.unesp.br [Laboratório de Materiais Magnéticos e Coloides, Departamento de Físico-química, Instituto de Química, Universidade Estadual Paulista, Araraquara, SP 14801-970 (Brazil)

    2014-10-01

    Graphical abstract: - Highlights: • Metallic iron nanoparticles were passivated in tetraethylene glycol media. • Passivated nanoparticles presented pomegranate-like core@shell structure. • Passivation of metallic iron correlates with the tetraethylene glycol degradation. • Boron enriched metallic iron phase was more susceptible to oxidation. • The iron oxide shell was identified as Fe{sub 3}O{sub 4} with a mass fraction of 43:53 related to αFe. - Abstract: The present study describes the synthesis and characterization of iron@iron oxide nanoparticles produced by passivation of metallic iron in tetraethylene glycol media. Structural and chemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Mössbauer spectroscopy. Pomegranate-like core@shell nanoparticulate material in the size range of 90–120 nm was obtained. According to quantitative phase analysis using Rietveld structure refinement the synthesized iron oxide was identified as magnetite (Fe{sub 3}O{sub 4}) whereas the iron to magnetite mass fractions was found to be 47:53. These findings are in good agreement with the data obtained from Mössbauer and thermal gravimetric analysis (TGA). The XPS data revealed the presence of a surface organic layer with higher hydrocarbon content, possibly due to the tetraethylene glycol thermal degradation correlated with iron oxidation. The room-temperature (300 K) saturation magnetization measured for the as-synthesized iron and for the iron–iron oxide were 145 emu g{sup −1} and 131 emu g{sup −1}, respectively. The measured saturation magnetizations are in good agreement with data obtained from TEM, XRD and Mössbauer spectroscopy.

  10. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

  11. Membrane preconcentration of iron in seawater samples and on-site determination in spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    PENG Yuanzhen; YUAN Dongxing; HUANG Yongming; JIANG Tao; LIU Baomin

    2012-01-01

    A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection.Fe(Ⅱ)-ferrozine complex was reacted with cetyltrimethylammonium bromide (CTAB) to form a Fe(Ⅱ)-ferrozine-CTAB paired compound,which was collected on a membrane by filtration under vacuum.The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis.Various factors affecting the iron collection and determination were investigated.With different sample preconcentration volumes,the range of determination was broadened to 0.5-120 μg/L.The detection limit of this method reached 0.19 μg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45.The relative standard deviation (n =7) was 1.9% for samples containing 10 μg/L Fe.Twelve seawater samples were analyzed on-site using the proposed method,and two were also analyzed in inductively coupled plasma mass spectrometry.No significant difference was shown between the two methods by the Student's t-test.The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple,accurate and inexpensive.

  12. Development of a clothing iron safety device.

    Science.gov (United States)

    Beers, Ryan; Anthamatten, Mitchell; Reid, Dixie; Kahn, Steven A; Lentz, Christopher W

    2009-01-01

    Contact burns from clothing irons are a common injury seen in children. These injuries occur when an unattended iron is within reach of toddlers in its upright position. In a previous study, the authors have shown that the surface of an iron takes 90 minutes to cool below the epidermal injury threshold of 49 degrees C. The authors have constructed an "iron shoe" to shield the iron surface from young hands during cooling. The device is intended to set the cooling iron in its down position providing additional protection. The device will insulate the iron surface to avoid the fire hazard when positioned in this manner. A silicone polymer was used to create an "iron shoe." This polymer is stable at temperatures up to 370 degrees C. The device included sidewalls to shield the edges from contact. Thermal analysis of the device was conducted using an inexpensive and expensive iron. Thermocouples were placed on the iron surface and below the iron shoe. The irons were heated to its maximum temperature, placed in the shoe and then unplugged. Temperature cooling curves were obtained from the thermocouples. The experiment was repeated by measuring the temperature difference between the iron edge and the shoe sidewalls. The surface of both expensive and inexpensive irons reached a maximum of 205 degrees C. The temperature below the iron shoe reached a maximum of 49 degrees C (inexpensive) and 60 degrees C (expensive). The iron edge temperature reached a maximum of 188 degrees C (inexpensive) and 154 degrees C (expensive). The shoe sidewall temperature achieved a maximum of 52 degrees C (inexpensive) and 49 degrees C (expensive). Both expensive and inexpensive irons reach temperatures over 200 degrees C. The silicone "iron shoe" effectively shielded the surface and edge of both irons and approached the epidermal injury threshold of 49 degrees C. The temperature beneath the expensive iron did exceed 49 degrees C, but because the intention of the device is to place the iron in

  13. Incorporation of iron and organic matter into young Antarctic sea ice during its initial growth stages

    Directory of Open Access Journals (Sweden)

    Julie Janssens

    2016-08-01

    Full Text Available Abstract This study reports concentrations of iron (Fe and organic matter in young Antarctic pack ice and during its initial growth stages in situ. Although the importance of sea ice as an Fe reservoir for oceanic waters of the Southern Ocean has been clearly established, the processes leading to the enrichment of Fe in sea ice have yet to be investigated and quantified. We conducted two in situ sea-ice growth experiments during a winter cruise in the Weddell Sea. Our aim was to improve the understanding of the processes responsible for the accumulation of dissolved Fe (DFe and particulate Fe (PFe in sea ice, and of particulate organic carbon and nitrogen, dissolved organic carbon, extracellular polymeric substances, inorganic macro-nutrients (silicic acid, nitrate and nitrite, phosphate and ammonium, chlorophyll a and bacteria. Enrichment indices, calculated for natural young ice and ice newly formed in situ, indicate that during Antarctic winter all of the measured forms of particulate matter were enriched in sea ice compared to underlying seawater, and that enrichment started from the initial stages of sea-ice formation. Some dissolved material (DFe and ammonium was also enriched in the ice but at lower enrichment indices than the particulate phase, suggesting that size is a key factor for the incorporation of impurities in sea ice. Low chlorophyll a concentrations and the fit of the macro-nutrients (with the exception of ammonium with their theoretical dilution lines indicated low biological activity in the ice. From these and additional results we conclude that physical processes are the dominant mechanisms leading to the enrichment of DFe, PFe, organic matter and bacteria in young sea ice, and that PFe and DFe are decoupled during sea-ice formation. Our study thus provides unique quantitative insight into the initial incorporation of impurities, in particular DFe and PFe, into Antarctic sea ice.

  14. Lagrangian Analysis of Kerguelen's Naturally Iron-fertilised Phytoplankton Bloom

    Science.gov (United States)

    Della Penna, A.; Trull, T. W.; Grenier, M.; Wotherspoon, S.; Johnson, C.; De Monte, S.; d'Ovidio, F.

    2015-12-01

    The role of iron as a limiting micro-nutrient for primary production in High Nutrient Low Chlorophyll regions has been highlighted by paleoceanography, artificial fertilisation experiments and observed naturally fertilised systems. Examples of natural fertilisation have suggested that (sub-)mesoscale (1-100 km, days-months) horizontal transport modulates and structures the spatial and temporal extent of iron enrichment, phytoplankton production and biogeography. Here we combine different satellite products (altimetry, ocean color, PHYSAT), in-situ sampling, drifting floats and autonomous profilers to analyse the naturally iron-fertilised phytoplankton bloom of the Kerguelen region (Southern Ocean). Considering the Kerguelen Plateau as the main local source of iron, we compute two Lagrangian diagnostics: the "age" - how long before a water parcel has touched the plateau- and the "origin" - the latitude where a water parcel has left the plateau. First, we verify that these altimetry-defined diagnostics' spatial patterns -computed using geostrophic and Ekman corrected velocity fields- are coherent with the ones structuring the trajectories of more than 100 drifters and that trends in surface Chlorophyll (Chl) present an overall agreement with total column content (yet with ~2-3x differences in dynamic ranges likely due to the varying presence of Chl below the mixed layer). Second, assuming a first-order removal, we fit "age" with iron measurements and we estimate removal rates for bloom and abiotic conditions of respectively 0.058 and 0.041 1/d. Then, we relate "age" and "origin" with locations of high Chl concentrations and diatom-dominance. We find out that locations of high Chl concentration correspond to water parcels that have recently left the plateau. Furthermore, general additive models reveal that recently enriched waters are more likely to present a diatom dominance. However, the expected exponential fit varies within the geographic domain suggesting that

  15. Experimental constraints on gold and silver solubility in iron sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Pal' yanova, Galina [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Mikhlin, Yuri [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036 (Russian Federation); Kokh, Konstantin, E-mail: k.a.kokh@gmail.com [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Siberian Physical–Technical Institute of Tomsk State University, 1, Novosobornaya, Tomsk, 634050 (Russian Federation); Karmanov, Nick [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Seryotkin, Yurii [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation)

    2015-11-15

    Experiments were performed to determine crystallization of Fe,S-melts (pyriti≿ and troilitic with molar ratio S/Fe ratios of 2 and 1, respectively) containing traces of gold and silver at (Ag/Au){sub wt} ratios varying from 10 to 0.1. The solid products were studied by optical microscopy, scanning electron microscopy, X-ray powder diffraction (XRD), microprobe analysis, and X-ray photoelectron spectroscopy (XPS) in order to reveal the concentration limits of “invisible” gold and silver in magmatic iron sulfides, and to determine the influence of sulfur on forms of precious metals in the Fe–S system with different Ag/Au ratios. Au–Ag phases do not form inclusions but instead concentrate on the grain boundaries in the synthetic pyrrhotite and troilite, while pyrite comprises micro- (1–5 μm) and macroinclusions of Au–Ag alloys and Au–Ag sulfides. In “pyriti≿” systems, the fineness of alloys increases from 650 to 970‰ and the composition of sulfides changes from acanthite (Ag{sub 2}S) to uytenbogaardtite (Ag{sub 3}AuS{sub 2}) and petrovskaite (AgAuS) as the Ag/Au ratio decreases. The concentrations of “invisible” precious metals revealed in troilite were 0.040 ± 0.013 wt.% Au and 0.079 ± 0.016 wt.% Ag. Measured concentrations in pyrite and pyrrhotite were <0.024 wt.% Au and <0.030 wt.% Ag. The surface layers of iron sulfides probed with XPS were enriched in the precious metals, and in silver relative to gold, especially in the systems with Fe/S = 1, probably, due to depletion of the metallic alloy surfaces with gold. Au- and Ag-bearing iron sulfides crystallized primarily from melts may be the source of redeposited phases in hydrothermal and hypergene processes. - Highlights: • The samples of Fe–S–Au–Ag system were synthesized. • Coupled solubility of gold and silver in iron sulfides was specified. • Ag–Au inclusions on surfaces of iron sulfides are likely to be enriched in silver. • Au–Ag sulfides can exist along with

  16. GLANET: genomic loci annotation and enrichment tool.

    Science.gov (United States)

    Otlu, Burçak; Firtina, Can; Keles, Sündüz; Tastan, Oznur

    2017-09-15

    Genomic studies identify genomic loci representing genetic variations, transcription factor (TF) occupancy, or histone modification through next generation sequencing (NGS) technologies. Interpreting these loci requires evaluating them with known genomic and epigenomic annotations. We present GLANET as a comprehensive annotation and enrichment analysis tool which implements a sampling-based enrichment test that accounts for GC content and/or mappability biases, jointly or separately. GLANET annotates and performs enrichment analysis on these loci with a rich library. We introduce and perform novel data-driven computational experiments for assessing the power and Type-I error of its enrichment procedure which show that GLANET has attained high statistical power and well-controlled Type-I error rate. As a key feature, users can easily extend its library with new gene sets and genomic intervals. Other key features include assessment of impact of single nucleotide variants (SNPs) on TF binding sites and regulation based pathway enrichment analysis. GLANET can be run using its GUI or on command line. GLANET's source code is available at https://github.com/burcakotlu/GLANET . Tutorials are provided at https://glanet.readthedocs.org . burcak@ceng.metu.edu.tr or oznur.tastan@cs.bilkent.edu.tr. Supplementary data are available at Bioinformatics online.

  17. Phylogenetic diversity of dissimilatory ferric iron reducers in paddy soil of Hunan, South China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xin-Jun [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Graduate Univ., Chinese Academy of Sciences, BJ (China); Yang Jing; Chen Xue-Ping; Sun Guo-Xin [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Zhu Yong-Guan [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Key Lab. of Urban Environment and Health, Inst. of Urban Environment, Chinese Academy of Sciences, Xiamen (China)

    2009-12-15

    Purpose: Dissimilatory iron-reducing bacteria have been described by both culture-dependent and -independent methods in various environments, including freshwater, marine sediments, natural wetlands, and contaminated aquifers. However, little is known about iron-reducing microbial communities in paddy soils. The goal of this study was to characterize iron-reducing microbial communities in paddy soil. Moreover, the effect of dissolved and solid-phase iron (III) species on the iron-reducing microbial communities was also investigated by enrichment cultures. Methods: Ferric citrate and ferrihydrite were used respectively to set up enrichment cultures of dissimilatory ironreducing microorganisms using 1% inoculum of soil samples, and the iron reduction was measured. Moreover, bacterial DNA was extracted and 16S rRNA genes were PCR-amplified, and subsequently analyzed by the clone library and terminal restriction fragment length polymorphism (T-RFLP). Results: Phylogenetic analysis of 16S rRNA gene sequences extracted from the enrichment cultures revealed that Bradyrhizobium, Bacteroides, Clostridium and Ralstonia species were the dominant bacteria in the ferric citrate enrichment. However, members of the genera Clostridium, Bacteroides, and Geobacter were the dominant micro-organisms in the ferrihydrite enrichment. Analysis of enrichment cultures by T-RFLP strongly supported the cloning and sequencing results. Conclusions: The present study demonstrated that dissimilatory iron-reducing consortia in As-contaminated paddy soil are phylogenetically diverse. Moreover, iron (III) sources as a key factor have a strong effect on the iron (III)-reducing microbial community structure and relative abundance in the enrichments. In addition, Geobacter species are selectively enriched by ferrihydrite enrichment cultures. (orig.)

  18. 高炉炉底铁水流动模拟试验研究%Research on Simulation Experiment of Moving Iron Water of Blast Furnace Bottom

    Institute of Scientific and Technical Information of China (English)

    王延平

    2014-01-01

    根据相似原理建立了炉缸炉底铁水流动模拟试验装置,在不同条件下进行排放过程炉缸内的铁水流速测定试验,研究了死铁层深度、铁口直径和死焦堆空隙度等参数对铁水流动的影响。%In this paper,based on the similarity principle,the hearth and bottom of metal flow simulation testing device was established.The process of hearth velocity of hot emissions under different conditions was tested.Effects of dead iron layer depth,iron mouth diameter,die coke pile porosity and other parameters on the flow of molten iron were researched.

  19. Impacto do uso de cereal adicionado de ferro sobre os níveis de hemoglobina e a antropometria de pré-escolares Effect of the use of iron-enriched cereal on the serum hemoglobin levels and anthropometric values of preschool children

    Directory of Open Access Journals (Sweden)

    Márcia Regina Vítolo

    1998-12-01

    Full Text Available A anemia na infância tem sido considerada um dos grandes desafios nutricionais nos países em desenvolvimento, seguida da desnutrição energética. Têm-se discutido muito a eficácia dos alimentos enriquecidos no combate a esse problema. O objetivo desse trabalho foi avaliar a aceitação diária de cereal adicionado de ferro e o seu impacto nos parâmetros antropométricos e nos níveis de hemoglobina de crianças de 1 a 4 anos de idade. Foram estudadas 54 crianças de uma creche municipal, de duas salas, sendo o grupo I constituído de 24 crianças com média de idade 2 anos e 2 meses e o grupo II constituído de 30 crianças de 3 anos e 6 meses. Essas crianças foram avaliadas, no início e no final da intervenção, quanto à ingestão alimentar, peso, estatura e níveis de hemoglobina sérica. Durante o período de dois meses, o café da manhã e o lanche da tarde, que eram constituídos de leite e pão, foram substituídos pelo cereal adicionado de ferro na forma de mingau, o que proporcionou aumento de 2 a 3mg de ferro por dia. Os resultados mostraram que houve aumento significante na adequação do índice P/E das crianças com desnutrição atual. Quanto aos níveis de hemoglobina sérica, o grupo I, cujo valor médio inicial foi de 9,9 ± 2,0g/dl, apresentou valor médio significantemente mais alto ao final do estudo, 11,4 ± 1,0g/dl (pAnemia and energetic malnutrition are considered to be the major nutritional challenges in developing countries. The efficacy of the various programs implemented to solve these problems has been assessed by studies with enriched food products. The objective of the present study was to evaluate the daily acceptance of an iron-enriched cereal, as well as its effect on the anthropometric parameters and hemoglobin levels of children aged 1 to 4 years old. Fifty-four children enrolled at a public day care unit participated in the study. They were divided into two groups: Group I with 24 children (median

  20. A Summary of Actinide Enrichment Technologies and Capability Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Bradley D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robinson, Sharon M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-01

    The evaluation performed in this study indicates that a new program is needed to efficiently provide a national actinide radioisotope enrichment capability to produce milligram-to-gram quantities of unique materials for user communities as summarized in Table 1. This program xiv should leverage past actinide enrichment, the recent advances in stable isotope enrichment, and assessments of the future requirements to cost effectively develop this capability while establishing an experience base for a new generation of researchers in this vital area. Preliminary evaluations indicate that an EMIS device would have the capability to meet the future needs of the user community for enriched actinides. The EMIS technology could be potentially coupled with other enrichment technologies, such as irradiation, as pre-enrichment and/or post-enrichment systems to increase the throughput, reduce losses of material, and/or reduce operational costs of the base EMIS system. Past actinide enrichment experience and advances in the EMIS technology applied in stable isotope separations should be leveraged with this new evaluation information to assist in the establishment of a domestic actinide radioisotope enrichment capability.

  1. The gamification and the enrichment of innovation practices in the firm: an analysis of experiences The gamification and the enrichment of innovation practices in the firm: an analysis of experiences La gamificación y el enriquecimiento de las prácticas de innovación en la empresa: un análisis de experiencias

    Directory of Open Access Journals (Sweden)

    Carmen de Pablos Heredero

    2013-09-01

    Full Text Available Purpose: Description of gamification practices in the company and the analysis of its influence on firm’s results by comparing experiences. Design/methodology: Analysis of experiences from different firm’s experiences. Findings: To show through real examples that the gamification leads to the achievement of better results in the organizations. Research limitations/implications: Access to the information of the few cases that we can find in our context. It is a quite new a yet unusual practice for most organizations. Practical implications: Reformulation of business communication strategies from best practices, where the gaming industry is an interesting precedent, which proofs that these practices improve business results. Social implications: Socialization of the innovation process at firms Originality/value: Provide an overview of the gamification as a practice that helps to pursue the strategy of collaboration with the client to improve results.Purpose: Description of gamification practices in the company and the analysis of its influence on firm’s results by comparing experiences. Design/methodology: Analysis of experiences from different firm’s experiences. Findings: To show through real examples that the gamification leads to the achievement of better results in the organizations. Research limitations/implications: Access to the information of the few cases that we can find in our context. It is a quite new a yet unusual practice for most organizations. Practical implications: Reformulation of business communication strategies from best practices, where the gaming industry is an interesting precedent, which proofs that these practices improve business results. Social implications: Socialization of the innovation process at firms Originality/value: Provide an overview of the gamification as a practice that helps to pursue the strategy of collaboration with the client to improve results.Objeto: Descripción de las prácticas de

  2. Iron Bioavailability of Meat:Bread Mixtures and Meat Loaves Fed to Anemic and Healthy Rats

    OpenAIRE

    Thannoun, Abdullah M.

    1987-01-01

    To study the effect of meat (beef) on dietary iron bioavailability from enriched white bread (EWB) or whole wheat bread (WWB), diets were prepared in which the ratios of beef iron to bread iron were 100:0, 75:25, 50:50, 25:75 or 0:100. Hemoglobin regeneration efficiency (HRE), apparent iron absorption, and dry matter absorption were determined using weanling anemic and healthy male rats. Meat iron was more available than EWB or WWB. Fortification iron in EWB was less available than the iro...

  3. Neutrophilic iron-oxidizing "zetaproteobacteria" and mild steel corrosion in nearshore marine environments.

    Science.gov (United States)

    McBeth, Joyce M; Little, Brenda J; Ray, Richard I; Farrar, Katherine M; Emerson, David

    2011-02-01

    Microbiologically influenced corrosion (MIC) of mild steel in seawater is an expensive and enduring problem. Little attention has been paid to the role of neutrophilic, lithotrophic, iron-oxidizing bacteria (FeOB) in MIC. The goal of this study was to determine if marine FeOB related to Mariprofundus are involved in this process. To examine this, field incubations and laboratory microcosm experiments were conducted. Mild steel samples incubated in nearshore environments were colonized by marine FeOB, as evidenced by the presence of helical iron-encrusted stalks diagnostic of the FeOB Mariprofundus ferrooxydans, a member of the candidate class "Zetaproteobacteria." Furthermore, Mariprofundus-like cells were enriched from MIC biofilms. The presence of Zetaproteobacteria was confirmed using a Zetaproteobacteria-specific small-subunit (SSU) rRNA gene primer set to amplify sequences related to M. ferrooxydans from both enrichments and in situ samples of MIC biofilms. Temporal in situ incubation studies showed a qualitative increase in stalk distribution on mild steel, suggesting progressive colonization by stalk-forming FeOB. We also isolated a novel FeOB, designated Mariprofundus sp. strain GSB2, from an iron oxide mat in a salt marsh. Strain GSB2 enhanced uniform corrosion from mild steel in laboratory microcosm experiments conducted over 4 days. Iron concentrations (including precipitates) in the medium were used as a measure of corrosion. The corrosion in biotic samples (7.4 ± 0.1 mM) was significantly higher than that in abiotic controls (5.0 ± 0.1 mM). These results have important implications for the role of FeOB in corrosion of steel in nearshore and estuarine environments. In addition, this work shows that the global distribution of Zetaproteobacteria is far greater than previously thought.

  4. Iron Regulatory Proteins Mediate Host Resistance to Salmonella Infection.

    Science.gov (United States)

    Nairz, Manfred; Ferring-Appel, Dunja; Casarrubea, Daniela; Sonnweber, Thomas; Viatte, Lydie; Schroll, Andrea; Haschka, David; Fang, Ferric C; Hentze, Matthias W; Weiss, Guenter; Galy, Bruno

    2015-08-12

    Macrophages are essential for systemic iron recycling, and also control iron availability to pathogens. Iron metabolism in mammalian cells is orchestrated posttranscriptionally by iron-regulatory proteins (IRP)-1 and -2. Here, we generated mice with selective and combined ablation of both IRPs in macrophages to investigate the role of IRPs in controlling iron availability. These animals are hyperferritinemic but otherwise display normal clinical iron parameters. However, mutant mice rapidly succumb to systemic infection with Salmonella Typhimurium, a pathogenic bacterium that multiplies within macrophages, with increased bacterial burdens in liver and spleen. Ex vivo infection experiments indicate that IRP function restricts bacterial access to iron via the EntC and Feo bacterial iron-acquisition systems. Further, IRPs contain Salmonella by promoting the induction of lipocalin 2, a host antimicrobial factor that inhibits bacterial uptake of iron-laden siderophores, and by suppressing the ferritin iron pool. This work reveals the importance of the IRPs in innate immunity.

  5. Iron bioavailability from commercially available iron supplements

    OpenAIRE

    2015-01-01

    Purpose Iron deficiency anaemia (IDA) is a global public health problem. Treatment with the standard of care ferrous iron salts may be poorly tolerated, leading to non-compliance and ineffective correction of IDA. Employing supplements with higher bioavailability might permit lower doses of iron to be used with fewer side effects, thus improving treatment efficacy. Here, we compared the iron bioavailability of ferrous sulphate tablets with alternative commercial iron products, including th...

  6. Enrichment and characterization of ferritin for nanomaterial applications.

    Science.gov (United States)

    Ghirlando, Rodolfo; Mutskova, Radina; Schwartz, Chad

    2016-01-29

    Ferritin is a ubiquitous iron storage protein utilized as a nanomaterial for labeling biomolecules and nanoparticle construction. Commercially available preparations of horse spleen ferritin, widely used as a starting material, contain a distribution of ferritins with different iron loads. We describe a detailed approach to the enrichment of differentially loaded ferritin molecules by common biophysical techniques such as size exclusion chromatography and preparative ultracentrifugation, and characterize these preparations by dynamic light scattering, and analytical ultracentrifugation. We demonstrate a combination of methods to standardize an approach for determining the chemical load of nearly any particle, including nanoparticles and metal colloids. Purification and characterization of iron content in monodisperse ferritin species is particularly critical for several applications in nanomaterial science.

  7. Enrichment and characterization of ferritin for nanomaterial applications

    Science.gov (United States)

    Ghirlando, Rodolfo; Mutskova, Radina; Schwartz, Chad

    2016-01-01

    Ferritin is a ubiquitous iron storage protein utilized as a nanomaterial for labeling biomolecules and nanoparticle construction. Commercially available preparations of horse spleen ferritin, widely used as a starting material, contain a distribution of ferritins with different iron loads. We describe a detailed approach to the enrichment of differentially loaded ferritin molecules by common biophysical techniques such as size exclusion chromatography and preparative ultracentrifugation, and characterize these preparations by dynamic light scattering, and analytical ultracentrifugation. We demonstrate a combination of methods to standardize an approach for determining the chemical load of nearly any particle, including nanoparticles and metal colloids. Purification and characterization of iron content in monodisperse ferritin species is particularly critical for several applications in nanomaterial science.

  8. Chemical forms and extractability of iron in sediments of three contrasting lakes of China and UK

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qi-xing; Gibson C.E.; Stewart B.M.

    2003-01-01

    Iron is a limiting factor for the eutrophication of lakes, especially those lakes that are enriched with phosphorus. Extractability of iron in sediments of West Lake and Taihu Lake in China and Lower Lough Erne in Northern Ireland of UK was comparatively investigated on the basis of analysing chemical forms of iron using different extractants. It was shown that extractable iron in sediments of the lakes was greatly different using various extractants. Reactive iron or easily released iron such as "active" iron oxides, total free iron oxide and water-soluble iron was not high, only accounting for 0.01%-0.15% of total iron. The efficiency of the extractants for exchangeable iron was decreased in the sequence 0.1 mol/L HCl> DTPA + TEA mixed solution > 1 mol/L NH4OAc > 0.5 mol/L MgCl2 = 0.5 mol/L CaCl2. It seems that the complexion of iron by organic matter was not strong because the concentration of organically bound iron was significantly lower than the concentration it was forecasted. Extractable iron is not entirely consistent with or dependent on total iron in lake sediments. To a certain extent,phosphate can inhibit the release of iron in sediments of the lakes. The selection of extractants is thus the first key step to evaluate bioavailability of iron in lake sediments.

  9. Pressure-dependent compatibility of iron in garnet: Insights into the origin of ferropicritic melt

    Science.gov (United States)

    Zhang, JunBo; Liu, YongSheng; Ling, WenLi; Gao, Shan

    2017-01-01

    Iron-rich silicate melts in the Earth's deep mantle have been seismologically and geochemically inferred in recent years. The origin of local enrichments in iron and low-velocity seismic anomalies that have been detected in dense mantle domains are critical to understanding the mantle's evolution, which has been canonically explained by long-term chemical reactions between the Earth's silicate mantle and its liquid iron outer core. However, the Pleistocene alkaline ferropicrites (∼0.73 Ma) from Wudi, North China, show chemical and Sr-Nd-Os isotopic features that suggest derivation from the preferential melting of silica-deficient eclogite, a lithology of delaminated mafic lower continental crust that had stagnated at mid-upper mantle depths during the Mesozoic decratonization of the North China block. These rocks are characterized by substantial enrichment in iron (14.9-15.2 wt% Fe2O3), relative depletion in silica (40-41 wt% SiO2) and decoupled Y and heavy rare earth element (HREE) compositions. These ferropicrites have particularly higher Y/Yb ratios than the other Cenozoic basalts from North China. The pressure-dependent compatibility of Fe, Y and Yb in eclogitic garnet can adequately explain the Fe-enrichment and Y-HREE decoupling of the Wudi ferropicrites and indicates that the eclogites were melted at pressures of 5-8 GPa, as also constrained by previous high-P-T experiments. This melting depth ties together a seismically imaged high-velocity anomaly that extends from 150 km to 350 km in depth under the study area, which has been commonly interpreted as evidence for the stagnation of the missing, delaminated continental lithosphere. Our findings provide an alternative mechanism to produce an extremely iron-rich mantle reservoir in addition to core-mantle interaction. Iron-rich silicate melts that form by this process are likely to be denser than the ambient mantle peridotite (and therefore drive flow downward) and may play a more significant role in the

  10. Transdermal iron replenishment therapy.

    Science.gov (United States)

    Modepalli, Naresh; Shivakumar, H N; Kanni, K L Paranjothy; Murthy, S Narasimha

    2015-01-01

    Iron deficiency anemia is one of the major nutritional deficiency disorders. Iron deficiency anemia occurs due to decreased absorption of iron from diet, chronic blood loss and other associated diseases. The importance of iron and deleterious effects of iron deficiency anemia are discussed briefly in this review followed by the transdermal approaches to deliver iron. Transdermal delivery of iron would be able to overcome the side effects associated with conventional oral and parenteral iron therapy and improves the patient compliance. During preliminary investigations, ferric pyrophosphate and iron dextran were selected as iron sources for transdermal delivery. Different biophysical techniques were explored to assess their efficiency in delivering iron across the skin, and in vivo studies were carried out using anemic rat model. Transdermal iron delivery is a promising approach that could make a huge positive impact on patients suffering with iron deficiency.

  11. Duodenal Absorption and Tissue Utilization of Dietary Heme and Nonheme Iron Differ in Rats123

    Science.gov (United States)

    Cao, Chang; Thomas, Carrie E.; Insogna, Karl L.; O'Brien, Kimberly O.

    2014-01-01

    Background: Dietary heme contributes to iron intake, yet regulation of heme absorption and tissue utilization of absorbed heme remains undefined. Objectives: In a rat model of iron overload, we used stable iron isotopes to examine heme- and nonheme-iron absorption in relation to liver hepcidin and to compare relative utilization of absorbed heme and nonheme iron by erythroid (RBC) and iron storage tissues (liver and spleen). Methods: Twelve male Sprague-Dawley rats were randomly assigned to groups for injections of either saline or iron dextran (16 or 48 mg Fe over 2 wk). After iron loading, rats were administered oral stable iron in the forms of 57Fe-ferrous sulfate and 58Fe-labeled hemoglobin. Expression of liver hepcidin and duodenal iron transporters and tissue stable iron enrichment was determined 10 d postdosing. Results: High iron loading increased hepatic hepcidin by 3-fold and reduced duodenal expression of divalent metal transporter 1 (DMT1) by 76%. Nonheme-iron absorption was 2.5 times higher than heme-iron absorption (P = 0.0008). Absorption of both forms of iron was inversely correlated with hepatic hepcidin expression (heme-iron absorption: r = −0.77, P = 0.003; nonheme-iron absorption: r = −0.80, P = 0.002), but hepcidin had a stronger impact on nonheme-iron absorption (P = 0.04). Significantly more 57Fe was recovered in RBCs (P = 0.02), and more 58Fe was recovered in the spleen (P = 0.01). Conclusions: Elevated hepcidin significantly decreased heme- and nonheme-iron absorption but had a greater impact on nonheme-iron absorption. Differential tissue utilization of heme vs. nonheme iron was evident between erythroid and iron storage tissues, suggesting that some heme may be exported into the circulation in a form different from that of nonheme iron. PMID:25332470

  12. Iron and iron derived radicals

    Energy Technology Data Exchange (ETDEWEB)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  13. Thermal breeder fuel enrichment zoning

    Science.gov (United States)

    Capossela, Harry J.; Dwyer, Joseph R.; Luce, Robert G.; McCoy, Daniel F.; Merriman, Floyd C.

    1992-01-01

    A method and apparatus for improving the performance of a thermal breeder reactor having regions of higher than average moderator concentration are disclosed. The fuel modules of the reactor core contain at least two different types of fuel elements, a high enrichment fuel element and a low enrichment fuel element. The two types of fuel elements are arranged in the fuel module with the low enrichment fuel elements located between the high moderator regions and the high enrichment fuel elements. Preferably, shim rods made of a fertile material are provided in selective regions for controlling the reactivity of the reactor by movement of the shim rods into and out of the reactor core. The moderation of neutrons adjacent the high enrichment fuel elements is preferably minimized as by reducing the spacing of the high enrichment fuel elements and/or using a moderator having a reduced moderating effect.

  14. NCOA4 Deficiency Impairs Systemic Iron Homeostasis

    Directory of Open Access Journals (Sweden)

    Roberto Bellelli

    2016-01-01

    Full Text Available The cargo receptor NCOA4 mediates autophagic ferritin degradation. Here we show that NCOA4 deficiency in a knockout mouse model causes iron accumulation in the liver and spleen, increased levels of transferrin saturation, serum ferritin, and liver hepcidin, and decreased levels of duodenal ferroportin. Despite signs of iron overload, NCOA4-null mice had mild microcytic hypochromic anemia. Under an iron-deprived diet (2–3 mg/kg, mice failed to release iron from ferritin storage and developed severe microcytic hypochromic anemia and ineffective erythropoiesis associated with increased erythropoietin levels. When fed an iron-enriched diet (2 g/kg, mice died prematurely and showed signs of liver damage. Ferritin accumulated in primary embryonic fibroblasts from NCOA4-null mice consequent to impaired autophagic targeting. Adoptive expression of the NCOA4 COOH terminus (aa 239–614 restored this function. In conclusion, NCOA4 prevents iron accumulation and ensures efficient erythropoiesis, playing a central role in balancing iron levels in vivo.

  15. Isolation of microorganisms involved in reduction of crystalline iron(III oxides in natural environments

    Directory of Open Access Journals (Sweden)

    Tomoyuki eHori

    2015-05-01

    Full Text Available Reduction of crystalline Fe(III oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet a limited number of isolates makes it difficult to understand physiology and ecological impact of the microorganisms involved. Here, two-staged cultivation was implemented to selectively enrich and isolate crystalline iron(III reducers in soils and sediments. Firstly, iron reducers were enriched and other untargeted eutrophs were depleted by two-year successive culture on a crystalline ferric iron oxide (i.e., goethite, lepidocrocite, hematite, or magnetite as electron acceptor. Fifty-eight out of 136 incubation conditions allowed the continued existence of microorganisms as confirmed by PCR amplification. High-throughput Illumina sequencing based on 16S rRNA genes revealed that the enrichment cultures on each of the ferric iron oxides contained bacteria belonging to the Deltaproteobacteria (mainly Geobacteraceae, followed by Firmicutes and Chloroflexi, which also comprised most of the operational taxonomic units (OTUs identified. The Venn diagrams indicated that the core OTUs enriched with all of the iron oxides were dominant in the Geobacteraceae. Secondly, 38 enrichment cultures including novel microorganisms were transferred to soluble-iron(III media in order to stimulate proliferation of the enriched iron reducers. Through extinction dilution-culture and single colony isolation, six strains within the Deltaproteobacteria were finally obtained; five strains belonged to the genus Geobacter and one strain to Pelobacter. These isolates had 94.8–98.1% sequence similarities of 16S rRNA genes to cultured relatives. All the isolates were able to grow on acetate and ferric iron but their physiological characteristics differed considerably in terms of growth rate. The results demonstrate the successful enrichment and isolation of novel iron(III reducers that were able to thrive by reducing highly

  16. High protein and iron-folate crackers supplementation on the iron status of pregnant women

    Directory of Open Access Journals (Sweden)

    Faisal Anwar

    2003-12-01

    Full Text Available Previous studies have revealed that several factors influenced the relatively low success of iron supplementation for pregnant women. The factors included poor distribution, low coverage and compliance, as well as low absorption. The aim of this study is to measure the iron status of pregnant women after consuming crackers containing fish powder and iron-folate. This study was carried out in the Purworejo district (Central Java from February through October 2002. Using a randomized controlled trial (RCT design, 70 pregnant women in their second-third month of pregnancy were recruited, and divided into two groups. Ten women dropped out during the study. The first group consisted of 28 women were given protein – iron enriched crackers (PIEC group, while the second group of 32 women were given iron–enriched crackers (IEC group for a total of 12 weeks. The results showed that the hemoglobin (Hb levels and serum transferrin receptors (sTfR of both groups were increased. Serum ferritins (SF of both groups were decreased. At the end of the study, the increase in Hb and sTfR levels between the two groups were significantly different, while the decrease in SF was not significantly different. Animal protein from fish powder tended to improve absorption of non-heme iron among pregnant women, resulting in improved Hb and sTfR levels. (Med J Indones 2003; 12: 243-6Keywords: pregnant women, anemia, iron deficiency, high protein crackers

  17. Developing a test-bed for robust research governance of geoengineering: the contribution of ocean iron biogeochemistry

    Science.gov (United States)

    Boyd, Philip W.; Bressac, Matthieu

    2016-11-01

    Geoengineering to mitigate climate change has long been proposed, but remains nebulous. Exploration of the feasibility of geoengineering first requires the development of research governance to move beyond the conceptual towards scientifically designed pilot studies. Fortuitously, 12 mesoscale (approx. 1000 km2) iron enrichments, funded to investigate how ocean iron biogeochemistry altered Earth's carbon cycle in the geological past, provide proxies to better understand the benefits and drawbacks of geoengineering. The utility of these iron enrichments in the geoengineering debate is enhanced by the GEOTRACES global survey. Here, we outline how GEOTRACES surveys and process studies can provide invaluable insights into geoengineering. Surveys inform key unknowns including the regional influence and magnitude of modes of iron supply, and stimulate iron biogeochemical modelling. These advances will enable quantification of interannual variability of iron supply to assess whether any future purposeful multi-year iron-fertilization meets the principle of `additionality' (sensu Kyoto protocol). Process studies address issues including upscaling of geoengineering, and how differing iron-enrichment strategies could stimulate wide-ranging biogeochemical outcomes. In summary, the availability of databases on both mesoscale iron-enrichment studies and the GEOTRACES survey, along with modelling, policy initiatives and legislation have positioned the iron-enrichment approach as a robust multifaceted test-bed to assess proposed research into climate intervention. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  18. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

    2014-01-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...

  19. An experiment to measure the spectra of primary proton, helium and iron nuclei at the 'knee' region at a high altitude

    CERN Document Server

    Xu, X W; Ding, L K; Zhang, C S; Ohnishi, M

    2003-01-01

    The possibility of measuring the energy spectra of some single elements (proton, helium and iron) in primary cosmic rays at the 'knee' energies, by setting up an air shower (AS) core detector in the AS gamma array (4300 m a.s.l., Tibet, China) is investigated. Taking into account the sensitivity and the acceptance needed for this measurement, the feasibility of construction and operation of the apparatus at a high altitude, and the cost, it is shown that this aim can be achieved by a simple AS core detector that mainly measures the high-energy electromagnetic components in AS cores. In this paper, such a detector is described. With a three-year exposure, proton, helium and iron spectra at the 'knee' energy region can be obtained with three event samples selected by an artificial neural network (ANN).

  20. Experiments on iron shield transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons via the {sup 7}Li(p,n) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tanaka, Shun-ichi; Nakao, Noriaki [and others

    1996-03-01

    In order to provide benchmark data of neutrons transmitted through iron shields in the intermediate-energy region, spatial distributions of neutron energy spectra and reaction rates behind and inside the iron shields of thickness up to 130 cm were measured for 43- and 68-MeVp-{sup 7}Li neutrons using a quasi-monoenergetic neutron beam source at the 90-MV AVF cyclotron facility of the TLARA facility in JAERI. The measured data by five kinds of detectors: the BC501A detector, the Bonner ball counter, {sup 238}U and {sup 232}Th fission counters, {sup 7}LiF and {sup nat}LiF TLDs and solid state nuclear track detector, are numerically provided in this report in the energy region between 10{sup -4} eV and the energy of peak neutrons generated by the {sup 7}Li(p,n) reaction. (author).

  1. Cheese bread enriched with biofortified cowpea flour

    Directory of Open Access Journals (Sweden)

    Rodrigo Barbosa Monteiro Cavalcante

    2016-02-01

    Full Text Available ABSTRACT The development and enrichment of food are of great importance not only for the industry but also to improve the population's nutrition, where you can create new products or optimize existing ones. The consumption of fortified products in the diet is an option for the control of deficiency diseases. This study aimed to develop enriched cheese bread with whole biofortified cowpea flour and evaluate their acceptance and chemical composition. Two formulations, F1 and F2, were prepared containing 5.6 and 8% of cowpea flour as a substitute for starch, respectively. To check acceptance, three sensory tests were used (Hedonic Scale, Purchase Intent, and Paired Comparison, F1 being sensory viable according to assessors, being chemically analyzed. Minerals were determined by atomic emission spectrometry with inductively coupled plasma source. The moisture was determined by drying at 105 °C, ash by calcination in muffle at 550 °C, proteins by the macro-Kjeldahl method, and lipids by hot extraction in a Soxhlet extractor. Carbohydrates were obtained by difference and the calories were calculated. The addition of cowpea increased the amounts of copper, iron, phosphorus, magnesium, manganese, and zinc, as well as protein and carbohydrate values. On the other hand, there was a reduction of the moisture concerning lipids and the total caloric value compared to the standard formulation. It was concluded , therefore, that the cowpea, a regional raw material in market expansion is presented as an option for the enrichment of baked foods that do not contain gluten, such as cheese bread.

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... or an inability to absorb enough iron from food. Overview Iron-deficiency anemia is a common type ... of the condition. Treatments may include dietary changes, medicines, and surgery. Severe iron-deficiency anemia may require ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... or an inability to absorb enough iron from food. Overview Iron-deficiency anemia is a common type ... condition. Treatments may include dietary changes, medicines, and surgery. Severe iron-deficiency anemia may require treatment in ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... at highest risk for iron-deficiency anemia. Outlook Doctors usually can successfully treat iron-deficiency anemia. Treatment ... poor skin tone, dizziness, and depression. After her doctor diagnosed her with iron-deficiency anemia, Susan got ...

  5. Iron and Your Child

    Science.gov (United States)

    ... extra iron in their diets. People following a vegetarian diet might also need additional iron. What's Iron ... as Whole Milk? About Anemia Minerals What's a Vegetarian? Word! Anemia Anemia Food Labels Vitamins and Minerals ...

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & Clinical ... iron-deficiency anemia may require treatment in a hospital, blood transfusions , iron injections, or intravenous iron therapy. ...

  7. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  8. Preparation of iron bound succinylated milk protein concentrate and evaluation of its stability.

    Science.gov (United States)

    Shilpashree, B G; Arora, Sumit; Sharma, Vivek; Bajaj, Rajesh Kumar; Tomar, S K

    2016-04-01

    Major problems associated with the fortification of soluble iron salts include chemical reactivity and incompatibility with other components. Milk protein concentrate (MPC) are able to bind significant amount of iron due to the presence of both casein and whey protein. MPC in its native state possess very poor solubility, therefore, succinylated derivatives of MPC (succ. MPC) were also used for the preparation of protein-iron complex. Preparation of the complex involved centrifugation (to remove insoluble iron), ultrafiltration (to remove unbound iron) and lyophilisation (to attain in dry form). Iron binding ability of MPC enhanced significantly (Piron from both varieties of complexes was monitored under different conditions encountered during processing. Higher stability (Piron was observed in succ. MPC-iron complex than native protein complex. This method could be adopted for the production of stable iron enriched protein, an organic iron source.

  9. Study on capillary electrophoresis enrichment and separation system based on field magnified injection-electric counter balance purge-trap and its application in iron ore detection%基于场放大进样-电动反平衡扫集的毛细管电泳富集分离系统的研究及其在铁矿石检测中的应用

    Institute of Scientific and Technical Information of China (English)

    张效伟

    2013-01-01

    Combining with field magnified injection technology,the determination of six heavy metal elements (manganese,chromium,lead,copper,nickel and cobalt) in iron ore by on-line dual-enrichment capillary electrophoresis enrichment and separation system based on field magnified injection-electric counter balance purge-trap was established using EDTA as trap carrier.The metal ions were firstly accumulated on the interface between water plug and high-conductivity buffer solution via field magnified injection,and then trapped by oncoming negative charged EDTA.The sample region was further compressed,realizing the dual amplification of signal.By controlling the electro-osmotic flow,the metal-EDTA chelate was under quasi-static condition.Thus,the large volume injection and significant amplification of detection signal were realized.After dual-enrichment at 15 kV for 50 min,the sensitivity increased by 1.2 × 104-8.5 × 104 times than that of conventional capillary electrophoresis.The detection limits of six heavy metal ions in iron ore were 0.06-0.32 μg/L.The proposed method was applied to the determination of manganese,chromium,lead,copper,nickel and cobalt in iron ore.The relative error between determination results of proposed method and those of ICP-MS was between 5.3 %-11.5 %.%利用EDTA作为捕获载体,结合场放大进样技术,建立了一种基于场放大进样-电动反平衡扫集在线双重富集的毛细管电泳富集分离新体系并用于铁矿石中锰、铬、铅、铜、镍和钴6种重金属元素的检测.金属离子首先通过场放大进样堆积在水塞与高电导缓冲溶液的界面上,然后被迎面而来的带负电荷的EDTA捕获,样品区带被进一步压缩,实现信号的双重放大.通过控制电渗流使金属-EDTA螯合物处于准静止状态,实现大体积进样及检测信号的高度放大.通过15 kV电动进样50 min双重富集后,灵敏度比常规毛细管电泳提高了1.2×104~8.5×104倍,铁矿石中6种重

  10. Genetics Home Reference: iron-refractory iron deficiency anemia

    Science.gov (United States)

    ... refractory iron deficiency anemia iron-refractory iron deficiency anemia Enable Javascript to view the expand/collapse boxes. ... All Close All Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

  11. ENRICHMENT OF OBO ONTOLOGIES

    Science.gov (United States)

    Bada, Michael; Hunter, Lawrence

    2006-01-01

    This paper describes a frame-based integration of the three GO subontologies, the Chemicals of Biological Interest ontology (ChEBI), and the Cell Type Ontology (CTO) in which relationships between elements of the ontologies are modeled in a way that better captures the relational semantics between biological concepts represented by the terms, rather than between the terms themselves, than previous frame-based efforts. We also describe a methodology for creating suggested enriching assertions of the form (subject, relationship, object) by identifying patterns in GO terms, mapping these patterns and subpatterns to relationships, matching concepts to these patterns and subpatterns, and integrating these assertions into the ontologies. Using this methodology, a large number of reliable assertions linking previously unlinked OBO terms using a wide variety of specific, hierarchically arranged relationships were created: A predicted assertion was made for 62% of GO terms that matched one of 31 patterns, and 97% of these predicted assertions were assessed to be valid; a further 429 assertions (corresponding to 6% of the matching terms) were manually created, resulting in an initial set of 4,497 assertions. Furthermore, this methodology programmatically integrates assertions into a base ontology such that each assertion is fully consistent with respect to higher (i.e., more general) relevant class and slot levels. Such an integration is absent from previous compositional efforts, and we argue its necessity for the creation of coherent biological ontologies when linking previously unlinked terms. PMID:17011833

  12. Earthquake forecast enrichment scores

    Directory of Open Access Journals (Sweden)

    Christine Smyth

    2012-03-01

    Full Text Available The Collaboratory for the Study of Earthquake Predictability (CSEP is a global project aimed at testing earthquake forecast models in a fair environment. Various metrics are currently used to evaluate the submitted forecasts. However, the CSEP still lacks easily understandable metrics with which to rank the universal performance of the forecast models. In this research, we modify a well-known and respected metric from another statistical field, bioinformatics, to make it suitable for evaluating earthquake forecasts, such as those submitted to the CSEP initiative. The metric, originally called a gene-set enrichment score, is based on a Kolmogorov-Smirnov statistic. Our modified metric assesses if, over a certain time period, the forecast values at locations where earthquakes have occurred are significantly increased compared to the values for all locations where earthquakes did not occur. Permutation testing allows for a significance value to be placed upon the score. Unlike the metrics currently employed by the CSEP, the score places no assumption on the distribution of earthquake occurrence nor requires an arbitrary reference forecast. In this research, we apply the modified metric to simulated data and real forecast data to show it is a powerful and robust technique, capable of ranking competing earthquake forecasts.

  13. City model enrichment

    Science.gov (United States)

    Smart, Philip D.; Quinn, Jonathan A.; Jones, Christopher B.

    The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods.

  14. Materials processing threshold report: 2. Use of low gravity for cast iron process development

    Science.gov (United States)

    Frankhouser, W. L.

    1980-01-01

    Potential applications of a low gravity environment of interest to the commercial producers of cast iron were assessed to determine whether low gravity conditions offer potential opportunities to producers for improving cast iron properties and expanding the use of cast irons. The assessment is limited to the gray and nodular types of iron, however, the findings are applicable to all cast irons. The potential advantages accrued through low gravity experiments with cast irons are described.

  15. [Is iron important in heart failure?].

    Science.gov (United States)

    Murín, Ján; Pernický, Miroslav

    2015-12-01

    Iron deficiency is a frequent comorbidity in a patient with chronic heart failure, and it associates with a worse prognosis of that patient. Mainly worse quality of life and more rehospitalizations are in these iron deficient patients. Iron metabolism is rather complex and there is some new information concerning this complexity in heart failure. We distinquish an absolute and a functional iron deficiency in heart failure. It is this deficit which is important and not as much is anemia important here. Prevalence of anaemia in heart failure is about 30-50%, higher it is in patients suffering more frequently heart failure decompensations. Treatment of iron deficiency is important and it improves prognosis of these patients. Most experiences there are with i.v. iron treatment (FERRIC HF, FAIR HF and CONFIRM HF studies), less so with per oral treatment. There are no clinical trials which analysed mortality influences.

  16. Method development for the redox speciation analysis of iron by ion chromatography-inductively coupled plasma mass spectrometry and carryover assessment using isotopically labeled analyte analogues.

    Science.gov (United States)

    Wolle, Mesay Mulugeta; Fahrenholz, Timothy; Rahman, G M Mizanur; Pamuku, Matt; Kingston, H M 'Skip'; Browne, Damien

    2014-06-20

    An ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS) method was developed for the redox speciation analysis of iron (Fe) based on in-column complexation of Fe(2+) and Fe(3+) by dipicolinic acid (DPA). The effects of column type, mobile phase composition and molecular ion interference were studied in the method optimization. The carryover of the target species in the IC-ICP-MS method was uniquely and effectively evaluated using isotopically enriched analogues of the analytes ((54)Fe(2+) and (57)Fe(3+)). Standard solutions of the enriched standards were injected into the system following analysis of a sample, and the ratios of the isotopes of iron in the enriched standards were calculated based on the chromatographic peak areas. The concentrations of the analytes carried over from the sample to the enriched standards were determined using the quantitative relationship in isotope dilution mass spectrometry (IDMS). In contrast to the routine way of evaluating carryover effect by injecting a blank solution after sample analysis, the use of isotopically enriched standards identified significant analyte carryover in the present method. Extensive experiments were carried out to systematically identify the source of the carryover and to eliminate the problem; the separation column was found to be the exclusive source. More than 95% of the analyte carryover was eliminated by reducing the length of the column. The detection limit of the IC-ICP-MS method (MDL) for the iron species was 2ngg(-1). The method was used to determine Fe(2+) and Fe(3+) in synthetic aqueous standard solutions and a beverage sample.

  17. Effect of microbial mediated iron plaque reduction on arsenic mobility in paddy soil

    Institute of Scientific and Technical Information of China (English)

    WANG Xinjun; CHEN Xueping; YANG Jing; WANG Zhaosu; SUN Guoxin

    2009-01-01

    The potential of microbial mediated iron plaque reduction,and associated arsenic (As) mobility were examined by iron reducing bacteria enriched from As contaminated paddy soil.To our knowledge,this is the first time to report the impact of microbial iron plaque reduction on As mobility.Iron reduction occurred during the inoculation of iron reducing enrichment culture in the treatments with iron plaque and ferrihydrite as the electron acceptors,respectively.The Fe(Ⅱ) concentration with the treatment of anthraquinone-2,6-disulfonic acid (AQDS) and iron reducing bacteria increased much faster than the control.Arsenic released from iron plaque with the iron reduction,and a significant correlation between Fe(Ⅱ) and total As in culture was observed.However,compared with control,the increasing rate of As was inhibited by iron reducing bacteria especially in the presence of AQDS.In addition,the concentrations of As(Ⅲ) and As(V) in abiotic treatments were higher than those in the biotic treatments at day 30.These results indicated that both microbial and chemical reductions of iron plaque caused As release from iron plaque to aqueous phase,however,microbial iron reduction induced the formation of more crystalline iron minerals,leading to As sequestration.In addition,the presence of AQDS in solution can accelerate the iron reduction,the As release from iron plaque and subsequently the As retention in the crystalline iron mineral.Thus,our results suggested that it is possible to remediate As contaminated soils by utilizing iron reducing bacteria and AQDS.

  18. Biosynthesis, isolation and characterization of {sup 57}Fe-enriched Phaseolus vulgaris ferritin after heterologous expression in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Hoppler, Matthias [ETH Zurich, Laboratory of Human Nutrition, Zurich (Switzerland); Meile, Leo [ETH Zurich, Laboratory of Food Biotechnology, Zurich (Switzerland); Walczyk, Thomas [National University of Singapore, Department of Chemistry and Department of Biochemistry, Singapore (Singapore)

    2008-01-15

    Ferritin is the major iron storage protein in the biosphere. Iron stores of an organism are commonly assessed by measuring the concentration of the protein shell of the molecule in fluids and tissues. The amount of ferritin-bound iron, the more desirable information, still remains inaccessible owing to the lack of suitable techniques. Iron saturation of ferritin is highly variable, with a maximum capacity of 4,500 iron atoms per molecule. This study describes the direct isotopic labeling of a complex metalloprotein in vivo by biosynthesis, in order to measure ferritin-bound iron by isotope dilution mass spectrometry. [{sup 57}Fe]ferritin was produced by cloning and overexpressing the Phaseolus vulgaris ferritin gene pfe in Escherichia coli in the presence of {sup 57}FeCl{sub 2}. Recombinant ferritin was purified in a fully assembled form and contained approximately 1,000 iron atoms per molecule at an isotopic enrichment of more than 95% {sup 57}Fe. We did not find any evidence of species conversion of the isotopic label for at least 5 months of storage at -20 C. Transfer efficiency of enriched iron into [{sup 57}Fe]ferritin of 20% was sufficient to be economically feasible. Negligible amounts of non-ferritin-bound iron in the purified [{sup 57}Fe]ferritin solution allows for use of this spike for quantification of ferritin-bound iron by isotope dilution mass spectrometry. (orig.)

  19. Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.

    Science.gov (United States)

    Anderson, James L.; And Others

    1980-01-01

    Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

  20. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  1. Iron-refractory iron deficiency anemia.

    Science.gov (United States)

    Yılmaz Keskin, Ebru; Yenicesu, İdil

    2015-03-05

    Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the "atypical" microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field.

  2. Iron-Refractory Iron Deficiency Anemia

    Science.gov (United States)

    Yılmaz Keskin, Ebru; Yenicesu, İdil

    2015-01-01

    Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the “atypical” microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field. PMID:25805669

  3. Liver iron transport

    Institute of Scientific and Technical Information of China (English)

    Ross M Graham; Anita CG Chua; Carly E Herbison; John K Olynyk; Debbie Trinder

    2007-01-01

    The liver plays a central role in iron metabolism. It is the major storage site for iron and also expresses a complex range of molecules which are involved in iron transport and regulation of iron homeostasis. An increasing number of genes associated with hepatic iron transport or regulation have been identified. These include transferrin receptors (TFR1 and 2), a ferrireductase (STEAP3), the transporters divalent metal transporter-1 (DMT1) and ferroportin (FPN) as well as the haemochromatosis protein, HFE and haemojuvelin (HJV),which are signalling molecules. Many of these genes also participate in iron regulatory pathways which focus on the hepatic peptide hepcidin. However, we are still only beginning to understand the complex interactions between liver iron transport and iron homeostasis. This review outlines our current knowledge of molecules of iron metabolism and their roles in iron transport and regulation of iron homeostasis.

  4. Hydrogen-enriched fuels

    Energy Technology Data Exchange (ETDEWEB)

    Roser, R. [NRG Technologies, Inc., Reno, NV (United States)

    1998-08-01

    NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventional fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.

  5. CLEAN: CLustering Enrichment ANalysis

    Directory of Open Access Journals (Sweden)

    Medvedovic Mario

    2009-07-01

    Full Text Available Abstract Background Integration of biological knowledge encoded in various lists of functionally related genes has become one of the most important aspects of analyzing genome-wide functional genomics data. In the context of cluster analysis, functional coherence of clusters established through such analyses have been used to identify biologically meaningful clusters, compare clustering algorithms and identify biological pathways associated with the biological process under investigation. Results We developed a computational framework for analytically and visually integrating knowledge-based functional categories with the cluster analysis of genomics data. The framework is based on the simple, conceptually appealing, and biologically interpretable gene-specific functional coherence score (CLEAN score. The score is derived by correlating the clustering structure as a whole with functional categories of interest. We directly demonstrate that integrating biological knowledge in this way improves the reproducibility of conclusions derived from cluster analysis. The CLEAN score differentiates between the levels of functional coherence for genes within the same cluster based on their membership in enriched functional categories. We show that this aspect results in higher reproducibility across independent datasets and produces more informative genes for distinguishing different sample types than the scores based on the traditional cluster-wide analysis. We also demonstrate the utility of the CLEAN framework in comparing clusterings produced by different algorithms. CLEAN was implemented as an add-on R package and can be downloaded at http://Clusteranalysis.org. The package integrates routines for calculating gene specific functional coherence scores and the open source interactive Java-based viewer Functional TreeView (FTreeView. Conclusion Our results indicate that using the gene-specific functional coherence score improves the reproducibility of the

  6. Graphite Formation in Cast Iron

    Science.gov (United States)

    Stefanescu, D. M.

    1985-01-01

    In the first phase of the project it was proven that by changing the ratio between the thermal gradient and the growth rate for commercial cast iron samples solidifying in a Bridgman type furnace, it is possible to produce all types of graphite structures, from flake to spheroidal, and all types of matrices, from ferritic to white at a certain given level of cerium. KC-135 flight experiments have shown that in a low-gravity environment, no flotation occurs even in spheroidal graphite cast irons with carbon equivalent as high as 5%, while extensive graphite flotation occurred in both flake and spheroidal graphite cast irons, in high carbon samples solidified in a high gravity environment. This opens the way for production of iron-carbon composite materials, with high carbon content (e.g., 10%) in a low gravity environment. By using KC-135 flights, the influence of some basic elements on the solidification of cast iron will be studied. The mechanism of flake to spheroidal graphite transition will be studied, by using quenching experiments at both low and one gravity for different G/R ratios.

  7. The schoolwide enrichment model: a comprehensive plan for the development of talents and giftedness

    Directory of Open Access Journals (Sweden)

    Joseph Renzulli

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1984686X14285The Schoolwide Enrichment Model (SEM is widely implemented as an enrichment program used with academically gifted and talented students and a general enrichment approach for all schools interested in developing the strengths and talents of all learners. The major goal of the SEM is the application of gifted education pedagogy to total school enrichment and joyful learning. The SEM provides enriched learning experiences and higher learning standards for all children through three goals: developing talents in all children, providing a broad range of enrichment experiences for all students, and providing advanced level follow-up opportunities for young people based on their strengths and interests. The SEM focuses on enrichment for all students through high levels of engagement and the use of enjoyable and challenging learning experiences that are constructed around students' interests, learning styles, and preferred modes of expression. 

  8. Enriching Earthdata by Improving Content Curation

    Science.gov (United States)

    Bagwell, R.; Wong, M. M.; Murphy, K. J.

    2014-12-01

    Since the launch of Earthdata in the later part of 2011, there has been an emphasis on improving the user experience and providing more enriched content to the user, ultimately with the focus to bring the "pixels to the people" or to ensure that a user clicks the fewest amount of times to get to the data, tools, or information which they seek. Earthdata was founded to be a single source of information for Earth Observing System Data and Information System (EOSDIS) components and services as a conglomeration between over 15 different websites. With an increased focus on access to Earth science data, the recognition is now on transforming Earthdata from a static website to one that is a dynamic, data-driven site full of enriched content.In the near future, Earthdata will have a number of components that will drive the access to the data, such as Earthdata Search, the Common Metadata Repository (CMR), and a redesign of the Earthdata website. The focus on content curation will be to leverage the use of these components to provide an enriched content environment and a better overall user experience, with an emphasis on Earthdata being "powered by EOSDIS" components and services.

  9. Iron isotopes in an Archean ocean analogue

    Science.gov (United States)

    Busigny, Vincent; Planavsky, Noah J.; Jézéquel, Didier; Crowe, Sean; Louvat, Pascale; Moureau, Julien; Viollier, Eric; Lyons, Timothy W.

    2014-05-01

    Iron isotopes have been extensively used to trace the history of microbial metabolisms and the redox evolution of the oceans. Archean sedimentary rocks display greater variability in iron isotope ratios and more markedly negative values than those deposited in the Proterozoic and Phanerozoic. This increased variability has been linked to changes in either water column iron cycling or the extent of benthic microbial iron reduction through time. We tested these contrasting scenarios through a detailed study of anoxic and ferruginous Lac Pavin (France), which can serve as a modern analogue of the Archean ocean. A depth-profile in the water column of Lac Pavin shows a remarkable increase in dissolved Fe concentration (0.1-1200 μM) and δ56Fe values (-2.14‰ to +0.31‰) across the oxic-anoxic boundary to the lake bottom. The largest Fe isotope variability is found at the redox boundary and is related to partial oxidation of dissolved ferrous iron, leaving the residual Fe enriched in light isotopes. The analysis of four sediment cores collected along a lateral profile (one in the oxic layer, one at the redox boundary, one in the anoxic zone, and one at the bottom of the lake) indicates that bulk sediments, porewaters, and reactive Fe mostly have δ56Fe values near 0.0 ± 0.2‰, similar to detrital iron. In contrast, pyrite δ56Fe values in sub-chemocline cores (60, 65, and 92 m) are highly variable and show significant deviations from the detrital iron isotope composition (δ56Fepyrite between -1.51‰ and +0.09‰; average -0.93‰). Importantly, the pyrite δ56Fe values mirror the δ56Fe of dissolved iron at the redox boundary—where near quantitative sulfate and sulfide drawdown occurs—suggesting limited iron isotope fractionation during iron sulfide formation. This finding has important implications for the Archean environment. Specifically, this work suggests that in a ferruginous system, most of the Fe isotope variability observed in sedimentary pyrites can

  10. Phytoplankton community structure is influenced by seabird guano enrichment in the Southern Ocean

    Science.gov (United States)

    Shatova, O. A.; Wing, S. R.; Hoffmann, L. J.; Wing, L. C.; Gault-Ringold, M.

    2017-05-01

    Phytoplankton biomass, productivity and community structure are strongly influenced by differences in nutrient concentrations among oceanographic water masses. Changes in community composition, particularly in the distribution of cell sizes, can result in dramatic changes in the energetics of pelagic food webs and ecosystem function in terms of biogeochemical cycling and carbon sequestration. Here we examine responses of natural phytoplankton communities from four major water masses in the Southern Ocean to enrichment from seabird guano, a concentrated source of bioactive metals (Mn, Fe, Co, Ni, Cu, Zn) and macronutrients (N, P), in a series of incubation experiments. Phytoplankton communities from sub-tropical water, modified sub-tropical water from the Snares Island wake, sub-Antarctic water and Antarctic water from the Ross Sea, each showed dramatic changes in community structure following additions of seabird guano. We observed particularly high growth of prymnesiophytes in response to the guano-derived nutrients within sub-Antarctic and sub-tropical frontal zones, resulting in communities dominated by larger cell sizes than in control incubations. Community changes within treatments enriched with guano were distinct, and in most cases more extensive, than those observed for treatments with additions of macronutrients (N, P) or iron (Fe) alone. These results provide the first empirical evidence that seabird guano enrichment can drive significant changes in the structure and composition of natural phytoplankton communities. Our findings have important implications for understanding the consequences of accumulation of bioactive metals and macronutrients within food webs and the role of seabirds as nutrient vectors within the Southern Ocean ecosystem.

  11. Maternal pregnancy weight gain and cord blood iron status are associated with eosinophilia in infancy.

    Science.gov (United States)

    Weigert, R; Dosch, N C; Bacsik-Campbell, M E; Guilbert, T W; Coe, C L; Kling, P J

    2015-08-01

    Allergic disease is multifactorial in origin. Because iron nutrition affects immune responses and maternal pregnancy weight gain impairs fetal iron delivery while increasing fetal demands for growth, the study examined maternal pregnancy weight gain, newborn iron status and an index of atopic disease, infant eosinophilia. Within a larger prospective study of healthy newborns at risk for developing iron deficiency anemia, umbilical cord iron indicators were compared to infant eosinophil counts. Infants who developed eosinophilia exhibited higher cord reticulocyte-enriched zinc protoporphyrin/heme ratio, Peosinophilia was 90%. High maternal pregnancy weight gain predicted infant eosinophil counts, Peosinophilia, Peosinophilia.

  12. Dietary iron concentration may influence aging process by altering oxidative stress in tissues of adult rats.

    Directory of Open Access Journals (Sweden)

    Lorena Fernandes Arruda

    Full Text Available Iron is an essential element. However, in its free form, iron participates in redox-reactions, leading to the production of free radicals that increase oxidative stress and the risk of damaging processes. Living organisms have an efficient mechanism that regulates iron absorption according to their iron content to protect against oxidative damage. The effects of restricted and enriched-iron diets on oxidative stress and aging biomarkers were investigated. Adult Wistar rats were fed diets containing 10, 35 or 350 mg/kg iron (adult restricted-iron, adult control-iron and adult enriched-iron groups, respectively for 78 days. Rats aged two months were included as a young control group. Young control group showed higher hemoglobin and hematocrit values, lower levels of iron and lower levels of MDA or carbonyl in the major studied tissues than the adult control group. Restricted-iron diet reduced iron concentrations in skeletal muscle and oxidative damage in the majority of tissues and also increased weight loss. Enriched-iron diet increased hematocrit values, serum iron, gamma-glutamyl transferase, iron concentrations and oxidative stress in the majority of tissues. As expected, young rats showed higher mRNA levels of heart and hepatic L-Ferritin (Ftl and kidneys SMP30 as well as lower mRNA levels of hepatic Hamp and interleukin-1 beta (Il1b and also lower levels of liver protein ferritin. Restricted-iron adult rats showed an increase in heart Ftl mRNA and the enriched-iron adult rats showed an increase in liver nuclear factor erythroid derived 2 like 2 (Nfe2l2 and Il1b mRNAs and in gut divalent metal transporter-1 mRNA (Slc11a2 relative to the control adult group. These results suggest that iron supplementation in adult rats may accelerate aging process by increasing oxidative stress while iron restriction may retards it. However, iron restriction may also impair other physiological processes that are not associated with aging.

  13. [Iron-refractory iron deficiency anemia].

    Science.gov (United States)

    Kawabata, Hiroshi

    2016-02-01

    The major causes of iron deficiency anemia (IDA) include iron loss due to bleeding, increased iron requirements, and decreased iron absorption by the intestine. The most common cause of IDA in Japanese women is iron loss during menstruation. Autoimmune atrophic gastritis and Helicobacter pylori infection can also cause IDA by reducing intestinal iron absorption. In addition to these common etiologies, germline mutations of TMPRSS6 can cause iron-refractory IDA (IRIDA). TMPRSS6 encodes matriptase-2, a membrane-bound serine protease primarily expressed in the liver. Functional loss of matriptase-2 due to homozygous mutations results in an increase in the expression of hepcidin, which is the key regulator of systemic iron homeostasis. The serum hepcidin increase in turn leads to a decrease in iron supply from the intestine and macrophages to erythropoietic cells. IRIDA is microcytic and hypochromic, but decreased serum ferritin is not observed as in IDA. IRIDA is refractory to oral iron supplementation, but does respond to intravenous iron supplementation to some extent. Because genetic testing is required for the diagnoses of IRIDA, a considerable number of cases may go undiagnosed and may thus be overlooked.

  14. Nutritional iron deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.; Hurrell, R.F.

    2007-01-01

    Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming

  15. Iron deficiency anemia

    Science.gov (United States)

    Anemia - iron deficiency ... iron from old red blood cells. Iron deficiency anemia develops when your body's iron stores run low. ... You may have no symptoms if the anemia is mild. Most of the time, ... slowly. Symptoms may include: Feeling weak or tired more often ...

  16. Nutritional iron deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.; Hurrell, R.F.

    2007-01-01

    Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming

  17. Serum iron test

    Science.gov (United States)

    Fe+2; Ferric ion; Fe++; Ferrous ion; Iron - serum; Anemia - serum iron; Hemochromatosis - serum iron ... A blood sample is needed. Iron levels are highest in the morning. Your health care provider will likely have you do this test in the morning.

  18. Iron stress in plants.

    Science.gov (United States)

    Connolly, Erin L; Guerinot, Mary

    2002-07-30

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches

  19. Iron stress in plants

    OpenAIRE

    Connolly, Erin L.; Guerinot, Mary Lou

    2002-01-01

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches.

  20. Assessment and management of iron overload in β-thalassaemia major patients during the 21st century: a real-life experience from the Italian WEBTHAL project.

    Science.gov (United States)

    Piga, Antonio; Longo, Filomena; Musallam, Khaled M; Cappellini, Maria Domenica; Forni, Gian Luca; Quarta, Giovanni; Chiavilli, Francesco; Commendatore, Francesca; Mulas, Sergio; Caruso, Vincenzo; Galanello, Renzo

    2013-06-01

    We conducted a cross-sectional study on 924 β-thalassaemia major patients (mean age 30·1 years) treated at nine Italian centres using the WEBTHAL software, to evaluate real-life application of iron overload assessment and management standards. Serum ferritin 2 years. Patients who never had a cardiac MRI (CMR) T2* measurement were 2 years. Deferoxamine (22·8%) was more commonly used in patients with Hepatitis C Virus or high serum creatinine. Deferiprone (20·6%) was less commonly prescribed in patients with elevated alanine aminotransferase; while a deferoxamine + deferiprone combination (17·9%) was more commonly used in patients with serum ferritin >2500 ng/ml or CMR T2* <20 ms. Deferasirox (38·3%) was more commonly prescribed in patients <18 years, but less commonly used in those with heart disease or high iron intake. These observations largely echoed guidelines at the time, although some practices are expected to change in light of evolving evidence.

  1. Urinary iron excretion test in iron deficiency anemia.

    Directory of Open Access Journals (Sweden)

    Kimura,Ikuro

    1980-02-01

    Full Text Available A urinary iron excretion test was carried out in 22 patients with iron deficiency anemia. The iron excretion index was significantly higher in patients with intractable iron deficiency anemia compared with normal subjects and anemic patients who were responsive to iron therapy. The findings suggest that iron excretion may be a factor that modulates the response of patients to iron therapy.

  2. Effects of environmental enrichment on gene expression in the brain

    OpenAIRE

    Rampon, Claire; Jiang, Cecilia H.; Dong, Helin; Tang, Ya-Ping; Lockhart, David J; Schultz, Peter G.; Joe Z Tsien; Hu, Yinghe

    2000-01-01

    An enriched environment is known to promote structural changes in the brain and to enhance learning and memory performance in rodents [Hebb, D. O. (1947) Am. Psychol. 2, 306–307]. To better understand the molecular mechanisms underlying these experience-dependent cognitive changes, we have used high-density oligonucleotide microarrays to analyze gene expression in the brain. Expression of a large number of genes changes in response to enrichment training, many of w...

  3. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  4. Recovery of Iron from Copper Tailings by Direct Reduction

    Science.gov (United States)

    Gu, Jing; Xia, De-Hong; Gu, Jing; Liu, Kai-Qi; Zhang, Feng; Wang, Shou-Zeng; Qi, Zhao-Dong; Ao, Wen-Qing

    2016-05-01

    Direct reduction of copper tailings were performed to recover iron efficiently by carbon-containing pellets, and the metallization rate was gained by chemical analysis method. The results showed that the metallization rate of copper tailings was up to 85.32% and the best reduction parameters are also found. Content of precious metals, such as, gold, silver in copper tailings can be enriched by 1.8~1.9 times through removing iron. The apparent activation energy of direct reduction of iron oxide in copper tailings is calculated to be 125.4 kJ/mol and the restrictive factor of reduction process is solid diffusion.

  5. Carbon content of austenite in austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Chang, L.C. [Kuang Wu Inst. of Tech. and Commerce, Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

    1998-06-05

    The development of austempered ductile iron (ADI) is a major achievement in cast iron technology. The austempering heat treatment enables the ductile cast iron containing mainly strong bainitic ferrite and ductile carbon-enriched austenite, with some martensite transforms from austenite during cooling down to room temperature. A key factor controlling the stability of the retained austenite can be evaluated soundly using the thermodynamics principles. It is the purpose here to demonstrate that the data of ADI from numerous sources have a similar trend.

  6. Evidence for the biogenic origin of manganese-enriched layers in Lake Superior sediments.

    Science.gov (United States)

    Palermo, Christine; Dittrich, Maria

    2016-04-01

    Manganese (Mn) and iron (Fe)-enriched sediment layers were discovered in Lake Superior within, above and below the oxic-anoxic interface. While the role of bacteria in redox reactions with Mn is known to be significant, little information exists about indigenous microbial communities in many freshwater environments. This study examined the bacterial communities of Mn-enriched layers in Lake Superior to identify the potential Mn(II) oxidizers responsible for the formation of Mn oxides. Anaerobic Mn(II) oxidation occurring in the Mn-enriched layers at the oxic-anoxic interface was investigated using Mn(II)-enriched cultures. High-resolution microscopic and spectroscopic investigations provided evidence of the biogenic formation of Mn oxides on cell surfaces. Spectroscopic mapping confirmed high levels of Mn in structures resembling biogenic Mn oxides. These structures were observed in enrichment cultures and in Mn-enriched layer sediment samples, indicating the significance of biogenic Mn oxidation occurring in situ. 16S ribosomal DNA pyrosequencing was used to identify the bacteria potentially responsible for Mnoxide formation in the enrichment cultures and Mn-enriched layers, revealing that the Mn-enriched layer contains classes with known Mn(II)-oxidizing members. Pyrosequencing of bacterial cultures suggested that these bacteria may be Bacillus strains, and that anaerobic microbial-mediated Mn(II) oxidation contributes to the formation of the layers.

  7. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1, respectiv

  8. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1, respectiv

  9. Experiment on the combined extraction of iron and alumina from red mud%从赤泥中联合提取铁和氧化铝试验

    Institute of Scientific and Technical Information of China (English)

    高建军; 齐渊洪; 居殿春; 程相利; 郭玉华

    2015-01-01

    赤泥是从铝土矿中浸出氧化铝后产生的固态废渣,含有一定量的铁、氧化铝以及其他有价金属元素。为了综合回收赤泥中铁和氧化铝,开发了赤泥配碳制备成含碳球团,含碳球团直接还原-熔分生产金属铁,熔渣自粉化浸出氧化铝的方法。试验研究了不同工艺参数对赤泥中铁和氧化铝提取结果的影响,得到的最佳工艺条件为:碳氧比为1.8,还原温度为1250℃,还原时间为60 min,熔分温度为1500℃,熔分时间为20 min,熔渣冷却速度小于20℃/min,钙铝比为1.6。在最佳工艺参数下,得到的生铁磷、硫质量分数分别为0.047%和0.017%,熔渣中w(FeO)为1.26%,熔渣自粉化完全,自粉化渣中Al2O3浸出率可以达到86.65%。%Red mud is the solid waste residue generated during alumina production from bauxite,which contains consid-erable amount of alumina,ferric oxide and other valuable metals. In order to recovery alumina and iron from red mud, the process of pig iron produced by direct reduction-smelting of carbon-containing red mud pellets,and alumina leaching from self-disintegrating slag was developed. The effects of different process parameters on extraction of iron and alumina from red mud were researched. The optimum reaction parameters were obtained as the following:the ratio of carbon to oxygen is 1.8,the time of direct reduction at 1 250℃ is 60 min,the time of smelting at 1 500℃is 20 min,slag cooling rate must be less than 20℃/min,the ratio of calcium oxide to alumina is 1.6. With these optimum parameters,the phos-phorus and sulfur content in the pig iron were 0.047%and 0.017%respectively,the ferrous oxide content in the slag was 1.26%,the slag can disintegrate completely,and the alumina leaching ratio can reach 86.65%.

  10. Initial experience of using an iron-containing fiducial marker for radiotherapy of prostate cancer: Advantages in the visualization of markers in Computed Tomography and Magnetic Resonance Imaging

    Science.gov (United States)

    Tanaka, Osamu; Iida, Takayoshi; Komeda, Hisao; Tamaki, Masayoshi; Seike, Kensaku; Kato, Daiki; Yokoyama, Takamasa; Hirose, Shigeki; Kawaguchi, Daisuke

    2016-12-01

    Visualization of markers is critical for imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). However, the size of the marker varies according to the imaging technique. While a large-sized marker is more useful for visualization in MRI, it results in artifacts on CT and causes substantial pain on administration. In contrast, a small-sized marker reduces the artifacts on CT but hampers MRI detection. Herein, we report a new ironcontaining marker and compare its utility with that of non-iron-containing markers. Five patients underwent CT/MRI fusion-based intensity-modulated radiotherapy, and the markers were placed by urologists. A Gold Anchor™ (GA; diameter, 0.28 mm; length, 10 mm) was placed using a 22G needle on the right side of the prostate. A VISICOIL™ (VIS; diameter, 0.35 mm; length, 10 mm) was placed using a 19G needle on the left side. MRI was performed using T2*-weighted imaging. Three observers evaluated and scored the visual qualities of the acquired images. The mean score of visualization was almost identical between the GA and VIS in radiography and cone-beam CT (Novalis Tx). The artifacts in planning CT were slightly larger using the GA than using the VIS. The visualization of the marker on MRI using the GA was superior to that using the VIS. In conclusion, the visualization quality of radiography, conebeam CT, and planning CT was roughly equal between the GA and VIS. However, the GA was more strongly visualized than was the VIS on MRI due to iron containing.

  11. Mechanisms of heme iron absorption: Current questions and controversies

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heine iron is absorbed by different mechanisms than non-heine iron, but despite considerable study over many years these mechanisms remain poorly understood. This review provides an overview of the importance of heme iron in the diet and discusses the two prevailing hypotheses of heine absorption; namely receptor mediated endocytosis of heme, and direct transport into the intestinal enterocyte by recently discovered heine transporters. A specific emphasis is placed on the questions surrounding the site of heme catabolism and the identity of the enzyme that performs this task. Additionally, we present the hypothesis that a nonheme iron transport protein may be required for heine iron absorption and discuss the experiences of our laboratory in examining this hypothesis.

  12. High Efficient Enrichment and Activated Dissolution of Refractory Low Grade Rh-containing Material

    Institute of Scientific and Technical Information of China (English)

    WU Xiaofeng; DONG Haigang; TONG Weifeng; ZHAO Jiachun; ZENG Rui

    2012-01-01

    Aiming to the low-grade rhodium-containing waste materials,a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator.A rhodium concentrate was obtained by the separation of base metals and precious metals.The concentrate was reacted with dilute aqua regia to obtain rhodium solution.The factors influencing the enrichment and activation effects were discussed in this paper.The results showed that the dissolution rate is greater than 99% under the optimum conditions.In this process,the activation of rhodium was finished in the enrichment process.The iron oxide is both a trapping agent and activator,which simplifies the process and reduce the cost.

  13. Life detection experiments of the Viking Mission on Mars can be best interpreted with a Fenton oxidation reaction composed of H2O2 and Fe2+ and iron-catalysed decomposition of H2O2

    Science.gov (United States)

    Apak, Resat

    2008-10-01

    The findings of the life detection experiments carried out during the Viking mission to Mars were reinterpreted with a chemical hypothesis. The labelled release (LR), pyrolytic release (PR) and gas exchange (GEx) experiments were interpreted with Fenton chemistry. Oxygen and carbon dioxide evolution from Martian soil upon wetting and nutrient addition could be attributed to competition reactions between the Fenton-type oxidation of organic nutrients with the aqueous (hydrogen peroxide+Fe(II)) combination and the iron-catalysed decomposition of hydrogen peroxide. A substantial evolution of radioactive gas upon addition of labelled organic nutrient solution to soil, whereas the ceasing of this gas with a heat treated sample in the LR experiments, was attributed to Fenton oxidation and hydrogen peroxide thermal decomposition, respectively. The peculiar kinetics of LR and PR experiments that cannot be fully explained by other chemical or biochemical scenarios were easily explained with this new hypothesis, i.e. limitation of the Fenton reaction may arise from the depletion of reactants, the build-up of ferric hydroxide on soil and excessive scavenging by the organic nutrients of the generated hydroxyl radicals. Reabsorption or adsorption of evolved or introduced CO2 may involve the formation of carbonate compounds (e.g., magnesium carbonate and bicarbonate) on the surface of alkalinized soil as a result of the Fenton reaction. A critical evaluation of the recent biological hypothesis assuming the utilization of a hydrogen peroxide water intracellular fluid by putative organisms (Houtkooper & Schulze-Makuch 2007) is also made.

  14. Effects of dust enrichment on oxygen fugacity of cosmic gases

    Science.gov (United States)

    Fedkin, Alexei V.; Grossman, Lawrence

    2016-05-01

    The degree to which dust enrichment enhances the oxygen fugacity (fO2) of a system otherwise solar in composition depends on the dust composition. Equilibrium calculations were performed at 10-3 bar in systems enriched by a factor of 104 in two fundamentally different types of dust to investigate the iron oxidation state in both cases. One type of dust, called SC for solar condensate, stopped equilibrating with solar gas at too high a temperature for FeO or condensed water to be stabilized in any form, and thus has the composition expected of a nebular condensate. The other has CI chondrite composition, appropriate for a parent body that accreted from SC dust and low-temperature ice. Upon total vaporization at 2300 K, both systems have high fO2, >IW. In the SC dust-enriched system, FeO of the bulk silicate reaches ~10 wt% at 1970 K but decreases to <1 wt% below 1500 K. The FeO undergoes reduction because consumption of gaseous oxygen by silicate recondensation causes a precipitous drop in fO2. Thus, enrichment in dust having the composition of likely nebular condensates cannot yield a sufficiently oxidizing environment to account for the FeO contents of chondrules. The fO2 of the system enriched in water-rich, CI dust, however, remains high throughout condensation, as gaseous water remains uncondensed until very low temperatures. This allows silicate condensates to achieve and maintain FeO contents of 27-35 wt%. Water-rich parent bodies are thus excellent candidate sources of chondrule precursors. Impacts on such bodies may have created the combination of high dust enrichment, total pressure, and fO2 necessary for chondrule formation.

  15. Burial Records of Reactive Iron in Cretaceous Black Shales and Oceanic Red Beds from Southern Tibet

    Institute of Scientific and Technical Information of China (English)

    HUANG Yongjian; WANG Chengshan; HU Xiumian; CHEN Xi

    2007-01-01

    One of the new directions in the field of Cretaceous research is to elucidate the mechanism of the sedimentary transition from the Cretaceous black shales to oceanic red beds. A chemical sequential extraction method was applied to these two types of rocks from southern Tibet to investigate the burial records of reactive iron. Results indicate that carbonate-associated iron and pyrite are relatively enriched in the black shales, but depleted or absent in red beds. The main feature of the reactive iron in the red beds is relative enrichment of iron oxides (largely hematite), which occurred during syn-depostion or early diagenesis. The ratio between iron oxides and the total iron indicates an oxygen-enriched environment for red bed deposition. A comparison between the reactive iron burial records and proxies of paleo-productivity suggests that paleo-productivity decreases when the ratio between iron oxides and the total iron increases in the red beds. This phenomenon could imply that the relationship between marine redox and productivity might be one of the reasons for the sedimentary transition from Cretaceous black shale to oceanic red bed deposition.

  16. Tucum-Do-Cerrado (Bactris setosa Mart.) Consumption Modulates Iron Homeostasis and Prevents Iron-Induced Oxidative Stress in the Rat Liver.

    Science.gov (United States)

    Fustinoni-Reis, Adriana M; Arruda, Sandra F; Dourado, Lívia P S; da Cunha, Marcela S B; Siqueira, Egle M A

    2016-02-17

    This study investigated the effect of tucum-do-cerrado consumption in the oxidative status of iron-supplemented rats. Four groups of rats were treated: Control (AIN-93G), Tuc (AIN-93G added of tucum-do-cerrado), Fe (AIN-93G iron-enriched), or TucFe (AIN-93G with tucum-do-cerrado and iron-enriched) diet, for 30 days. Iron-enriched diet increased serum, liver, spleen, and intestine iron levels; transferrin saturation; liver lipid oxidation; mRNA levels of hepatic Hamp and Bmp6, and Nrf2 in the intestine. Tucum-do-cerrado consumption reduced spleen lipid and protein oxidation; mRNA levels of hepatic Hamp and Ftl, and increased serum antioxidant capacity and hepatic mRNA levels of Bmp6, Hmox1, Nqo1, and Nrf2. TucFe diet consumption abrogated the liver Hamp iron-induced up-regulation, prevented intestinal iron accumulation; hepatic lipid peroxidation; splenic protein damage, and the increase of catalase, glutathione reductase, and glutathione peroxidase activity in some tissues. These results suggest that tucum-do-cerrado protects tissues against oxidative damage, by reducing iron availability in liver and consequently inhibiting liver Hamp expression.

  17. Tucum-Do-Cerrado (Bactris setosa Mart.) Consumption Modulates Iron Homeostasis and Prevents Iron-Induced Oxidative Stress in the Rat Liver

    Science.gov (United States)

    Fustinoni-Reis, Adriana M.; Arruda, Sandra F.; Dourado, Lívia P. S.; da Cunha, Marcela S. B.; Siqueira, Egle M. A.

    2016-01-01

    This study investigated the effect of tucum-do-cerrado consumption in the oxidative status of iron-supplemented rats. Four groups of rats were treated: Control (AIN-93G), Tuc (AIN-93G added of tucum-do-cerrado), Fe (AIN-93G iron-enriched), or TucFe (AIN-93G with tucum-do-cerrado and iron-enriched) diet, for 30 days. Iron-enriched diet increased serum, liver, spleen, and intestine iron levels; transferrin saturation; liver lipid oxidation; mRNA levels of hepatic Hamp and Bmp6, and Nrf2 in the intestine. Tucum-do-cerrado consumption reduced spleen lipid and protein oxidation; mRNA levels of hepatic Hamp and Ftl, and increased serum antioxidant capacity and hepatic mRNA levels of Bmp6, Hmox1, Nqo1, and Nrf2. TucFe diet consumption abrogated the liver Hamp iron-induced up-regulation, prevented intestinal iron accumulation; hepatic lipid peroxidation; splenic protein damage, and the increase of catalase, glutathione reductase, and glutathione peroxidase activity in some tissues. These results suggest that tucum-do-cerrado protects tissues against oxidative damage, by reducing iron availability in liver and consequently inhibiting liver Hamp expression. PMID:26901220

  18. Tucum-Do-Cerrado (Bactris setosa Mart. Consumption Modulates Iron Homeostasis and Prevents Iron-Induced Oxidative Stress in the Rat Liver

    Directory of Open Access Journals (Sweden)

    Adriana M. Fustinoni-Reis

    2016-02-01

    Full Text Available This study investigated the effect of tucum-do-cerrado consumption in the oxidative status of iron-supplemented rats. Four groups of rats were treated: Control (AIN-93G, Tuc (AIN-93G added of tucum-do-cerrado, Fe (AIN-93G iron-enriched, or TucFe (AIN-93G with tucum-do-cerrado and iron-enriched diet, for 30 days. Iron-enriched diet increased serum, liver, spleen, and intestine iron levels; transferrin saturation; liver lipid oxidation; mRNA levels of hepatic Hamp and Bmp6, and Nrf2 in the intestine. Tucum-do-cerrado consumption reduced spleen lipid and protein oxidation; mRNA levels of hepatic Hamp and Ftl, and increased serum antioxidant capacity and hepatic mRNA levels of Bmp6, Hmox1, Nqo1, and Nrf2. TucFe diet consumption abrogated the liver Hamp iron-induced up-regulation, prevented intestinal iron accumulation; hepatic lipid peroxidation; splenic protein damage, and the increase of catalase, glutathione reductase, and glutathione peroxidase activity in some tissues. These results suggest that tucum-do-cerrado protects tissues against oxidative damage, by reducing iron availability in liver and consequently inhibiting liver Hamp expression.

  19. Iron-iron oxide core-shell nanoparticles synthesized by laser pyrolysis followed by superficial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Dumitrache, F. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania)]. E-mail: fdumit@inflpr.ro; Morjan, I. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Alexandrescu, R. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Ciupina, V. [' Ovidius' University of Constanta, Bd. Mamaia 124, Constanta (Romania); Prodan, G. [' Ovidius' University of Constanta, Bd. Mamaia 124, Constanta (Romania); Voicu, I. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Fleaca, C. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Albu, L. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Savoiu, M. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Sandu, I. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Popovici, E. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania); Soare, I. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, 077125 Bucharest (Romania)

    2005-07-15

    Iron-based core-shell nanostructures were synthesized by laser pyrolysis in a two-steps procedure. In a first step, using a cross-flow configuration, the laser radiation was heating a gas phase mixture containing iron pentacarbonyl (vapors) entrained by an ethylene flow, which plays also the role of an energy transfer agent. Secondly, a carefully controlled in situ passivation of the freshly formed pyrophoric iron nanoparticles created a protective iron oxide shell. The produced nanoparticles (22 nm size diameters) with core-shell features were analyzed by TEM, XRD, SAED and Raman spectroscopy. Majoritary iron and gamma iron oxide/magnetite and minoritary carbon phases were identified. In laser pyrolysis experiments in which the reaction temperature was increased, the catalyzed homogeneous nucleation and growth of carbon nanotubes in the gas phase was observed and is presented here for the first time.

  20. Iron iron oxide core shell nanoparticles synthesized by laser pyrolysis followed by superficial oxidation

    Science.gov (United States)

    Dumitrache, F.; Morjan, I.; Alexandrescu, R.; Ciupina, V.; Prodan, G.; Voicu, I.; Fleaca, C.; Albu, L.; Savoiu, M.; Sandu, I.; Popovici, E.; Soare, I.

    2005-07-01

    Iron-based core-shell nanostructures were synthesized by laser pyrolysis in a two-steps procedure. In a first step, using a cross-flow configuration, the laser radiation was heating a gas phase mixture containing iron pentacarbonyl (vapors) entrained by an ethylene flow, which plays also the role of an energy transfer agent. Secondly, a carefully controlled in situ passivation of the freshly formed pyrophoric iron nanoparticles created a protective iron oxide shell. The produced nanoparticles (22 nm size diameters) with core-shell features were analyzed by TEM, XRD, SAED and Raman spectroscopy. Majoritary iron and gamma iron oxide/magnetite and minoritary carbon phases were identified. In laser pyrolysis experiments in which the reaction temperature was increased, the catalyzed homogeneous nucleation and growth of carbon nanotubes in the gas phase was observed and is presented here for the first time.

  1. Study on flotation experiments of monomer acid from dimmer acid byproduct for Anshan iron ores%二聚酸副产物单体酸对鞍山式赤铁矿浮选试验研究

    Institute of Scientific and Technical Information of China (English)

    梅建庭; 曹翠; 陈敏; 杨威

    2016-01-01

    为了提高二聚酸副产物单体酸的价值,分析了单体酸成分,主要含有饱和、不饱和和异构脂肪酸。采用尿素包合法获得含量较高的异构脂肪酸,分别与原料、油酸复配后构成了一系列捕收剂,并用于鞍山齐大山铁矿石浮选试验。通过实验室开路和闭路浮选试验结果表明:浮选温度为25℃时,精矿铁品位66.38%,尾矿铁品位14.90%,铁回收率84.19%。与KS‐Ⅱ浮选药剂相比,在降尾、铁回收率和降低药剂用量方面有优势。%To improve the value of monomer acid from dimmer acid byproduct ,the compositions of the monomer acid ,w hich are mixed by saturated ,unsaturated and isomeric fatty acid compose ,are analyzed . Isomeric fatty acid by wraping urea is mixed with monomer acid ,oleic acid to form some flotation reagents , which is used in Anshan iron ores flotation tests .The results of open circuit and close circuit shows that , when the temperature is 25℃ ,the Fe concentration was enriched to a concentration of 66 .38% .The Fe concentration in tailing was reduced to only 14 .90% .The recovery of Fe is 84 .19% .Compared with KS‐Ⅱflotation reagents ,it can improve Fe recovery ,decrease Fe in tailing and reduce the consumption of collector .

  2. Enrichment and purification of proteins of Haemophilus influenzae by chromatofocusing.

    Science.gov (United States)

    Fountoulakis, M; Langen, H; Gray, C; Takács, B

    1998-05-15

    Haemophilus influenzae is a bacterium of pharmaceutical interest of which the entire genome has been sequenced. Identification of low-abundance proteins in a two-dimensional map is important for the detection of new drug targets. We applied chromatography on Polybuffer Exchanger (chromatofocusing) in order to fractionate and enrich H. influenzae proteins, possibly low-copy-number gene products, from larger volumes. Two proteins, major ferric iron-binding protein (HI0097) and 5'-nucleotidase (HI0206) were obtained in pure form and hypothetical protein HI0052 was purified to near homogeneity by this single purification step. Four other proteins, aspartate ammonia lyase (HI0534), peptidase D (HI0675), elongation factor Ts (HI0914) and 5-methyltetrahydropteroyltriglutamate methyltransferase (HI1702), were strongly enriched so that chromatography on Polybuffer Exchanger can be used as an initial step for their isolation. Approximately 125 proteins were identified in the fractions collected from the column. Seventy of these were for the first time identified after chromatography on Polybuffer Exchanger. The proteins enriched by the chromatofocusing step include both low-abundance as well as high-copy-number gene products. They do not belong to a single protein class and the majority of them are enzymes with various functions. The results include a list and a two-dimensional map of the proteins enriched by chromatofocusing. They may be useful in the search of drug targets and in the design of purification protocols for the isolation of homologous proteins from related microorganisms.

  3. Dust in an acidified ocean: iron bioavailability, phytoplankton growth and DMS

    Science.gov (United States)

    Mélançon, J.; Levasseur, M.; Lizotte, M.; Scarratt, M. G.; Tremblay, J. E.; Tortell, P. D.; Yang, G.; Shi, G. Y.; Gao, H.; Semeniuk, D.; Robert, M.; Arychuk, M.; Johnson, K.; Sutherland, N.; Davelaar, M.; Nemcek, N.; Pena, A.; Richardson, W.

    2015-12-01

    Ocean acidification (OA) is likely to have an effect on the fertilizing potential of desert dust in high-nutrient, low-chlorophyll oceanic regions, either by modifying Fe speciation and bioavailability, or by altering phytoplankton Fe requirements and acquisition. To address this issue, short incubations (4 days) of northeast subarctic Pacific waters enriched with either FeSO4 or dust, and maintained at pH 8.0 (in situ) and 7.8 were conducted in August 2010. We assessed the impact of a decrease in pH on dissolved Fe concentration, phytoplankton biomass, taxonomy and productivity, and the production of dimethylsulfide (DMS) and its algal precursor dimethylsulfoniopropionate (DMSP). Chlorophyll a (chl a) remained unchanged in the controls and doubled in both the FeSO4-enriched and dust-enriched incubations, confirming the Fe-limited status of the plankton assemblage during the experiment. In the acidified treatments, a significant reduction (by 16-38%) of the final concentration of chl a was measured compared to their non-acidified counterparts, and a 15% reduction in particulate organic carbon (POC) concentration was measured in the dust-enriched acidified treatment compared to the dust-enriched non-acidified treatment. FeSO4 and dust additions had a fertilizing effect mainly on diatoms and cyanobacteria. Lowering the pH affected mostly the haptophytes, but pelagophyte concentrations were also reduced in some acidified treatments. Acidification did not significantly alter DMSP and DMS concentrations. These results show that dust deposition events in a low-pH iron-limited Northeast subarctic Pacific are likely to stimulate phytoplankton growth to a lesser extent than in today's ocean during the few days following fertilization and point to a low initial sensitivity of the DMSP and DMS dynamics to OA.

  4. Structural and Magnetic Properties of Trigonal Iron

    CERN Document Server

    Fox, S

    1995-01-01

    First principles calculations of the electronic structure of trigonal iron were performed using density function theory. The results are used to predict lattice spacings, magnetic moments and elastic properties; these are in good agreement with experiment for both the bcc and fcc structures. We find however, that in extracting these quantities great care must be taken in interpreting numerical fits to the calculated total energies. In addition, the results for bulk iron give insight into the properties of thin iron films. Thin films grown on substrates with mismatched lattice constants often have non-cubic symmetry. If they are thicker than a few monolayers their electronic structure is similar to a bulk material with an appropriately distorted geometry, as in our trigonal calculations. We recast our bulk results in terms of an iron film grown on the (111) surface of an fcc substrate, and find the predicted strain energies and moments accurately reflect the trends for iron growth on a variety of substrates.

  5. APPLICATION OF AUSTEMPERED DUCTILE IRON TO RAIL WHEEL SETS

    Directory of Open Access Journals (Sweden)

    Sacit DÜNDAR

    2003-03-01

    Full Text Available Austempered Ductile Iron (ADI is made up of a composite structure of acicular ferrite and carbon-enriched austenite. The transformation of austenite to martensite under certain stress levels results in a material with a hard rim and a tough internal structure. These properties makes it an alternate material for the production of railcar wheelsets.

  6. APPLICATION OF AUSTEMPERED DUCTILE IRON TO RAIL WHEEL SETS

    OpenAIRE

    Sacit DÜNDAR

    2003-01-01

    Austempered Ductile Iron (ADI) is made up of a composite structure of acicular ferrite and carbon-enriched austenite. The transformation of austenite to martensite under certain stress levels results in a material with a hard rim and a tough internal structure. These properties makes it an alternate material for the production of railcar wheelsets.

  7. Fossilization of Iron-Oxidizing Bacteria at Hydrothermal Vents: a Useful Biosignature on Mars?

    Science.gov (United States)

    Leveille, R. J.; Lui, S.

    2009-05-01

    Iron oxidizing bacteria are ubiquitous in marine and terrestrial environments on Earth, where they often display distinctive cell morphologies and are commonly encrusted by minerals, especially bacteriogenic iron oxides and silica. Putative microfossils of iron oxidizing bacteria have been found in jaspers as old as 490Ma and microbial iron oxidation may be an ancient metabolic pathway. In order to investigate the usefulness of mineralized iron oxidizing bacteria as a biosignature, we have examined mineral samples collected from relict hydrothermal systems along Explorer Ridge, NE Pacific Ocean. In addition, microaerophilic, neutrophilic iron oxidizing bacteria, isolated from Pacific hydrothermal vents, were grown in a Fe-enriched seawater medium at constant pH (6.5) and oxygen concentration (5 percent) in a controlled bioreactor system. Both natural samples and experimental products were examined with a combination of variable pressure scanning electron microscopy (SEM), field emission gun SEM, and in some cases by preparing samples with a focused ion beam (FIB) milling system. Natural seafloor samples display abundant filamentous forms often resembling, in both size and shape, the twisted stalks of Gallionella and the elongated filaments of Leptothrix. Generally, these filamentous features are 1-5 microns in diameter and up to several microns in length. Some samples consist entirely of low- density, porous masses of silica encrusted filamentous forms. Presumably, these masses were formed by a rapid precipitation by the influx of silica-rich fluids into a microbial mat dominated by bacteria with filamentous morphologies. The presence of rare, amorphous (unmineralized) filamentous matter rich in C and Fe suggests that these bacteria were iron oxidizers. There is no evidence that sulfur oxidizers were present. Filamentous features sectioned by FIB milling show internal material within semi-hollow tubular-like features. Silica encrustations also show pseudo

  8. Survival of indicator organisms during enrichment on tetrachloroethene.

    Science.gov (United States)

    Skramstad, J D; Hurst, C J; Novak, P J

    2003-01-01

    A laboratory study was performed as the basis for a full-scale bioaugmentation project at a site contaminated with chlorinated ethenes. The objectives of this study were to 1) develop a protocol to enrich for a tetrachloroethene (PCE)-dechlorinating culture from waste activated sludge and anaerobic digester biosolids and 2) monitor the survival of fecal coliform bacteria and bacteriophage, which model enteric viruses, during the enrichment process. A culture was enriched in 8 days with the ability to degrade 6-microM PCE to cis-dichloroethene. Using the enrichment protocol in two identical experiments, significant inactivation of fecal coliform bacteria (2 log) and somatic coliphage (0.33 log) was observed in one of the experiments; no inactivation occurred in the second experiment. The number of F-specific coliphage decreased in both experiments (0.87 and 1.26 log inactivation). Despite the decrease in some of the coliform and bacteriophage numbers, the quantity of organisms and phage particles present after enrichment was still high (approximately 7.5 x 10(5) most probable number/L, 6.9 x 10(6) plaque-forming units (PFU)/L, and 3.3 x 10(5) PFU/L, for fecal coliform bacteria, somatic coliphage, and F-specific coliphage, respectively). This may be cause for concern, depending on the current and future groundwater use at or near a site undergoing bioaugmentation with cultures derived from waste activated sludge and anaerobic digester biosolids.

  9. Intravenous Iron Carboxymaltose as a Potential Therapeutic in Anemia of Inflammation.

    Directory of Open Access Journals (Sweden)

    Niklas Lofruthe

    Full Text Available Intravenous iron supplementation is an effective therapy in iron deficiency anemia (IDA, but controversial in anemia of inflammation (AI. Unbound iron can be used by bacteria and viruses for their replication and enhance the inflammatory response. Nowadays available high molecular weight iron complexes for intravenous iron substitution, such as ferric carboxymaltose, might be useful in AI, as these pharmaceuticals deliver low doses of free iron over a prolonged period of time. We tested the effects of intravenous iron carboxymaltose in murine AI: Wild-type mice were exposed to the heat-killed Brucella abortus (BA model and treated with or without high molecular weight intravenous iron. 4h after BA injection followed by 2h after intravenous iron treatment, inflammatory cytokines were upregulated by BA, but not enhanced by iron treatment. In long term experiments, mice were fed a regular or an iron deficient diet and then treated with intravenous iron or saline 14 days after BA injection. Iron treatment in mice with BA-induced AI was effective 24h after iron administration. In contrast, mice with IDA (on iron deficiency diet prior to BA-IA required 7d to recover from AI. In these experiments, inflammatory markers were not further induced in iron-treated compared to vehicle-treated BA-injected mice. These results demonstrate that intravenous iron supplementation effectively treated the murine BA-induced AI without further enhancement of the inflammatory response. Studies in humans have to reveal treatment options for AI in patients.

  10. Intravenous Iron Carboxymaltose as a Potential Therapeutic in Anemia of Inflammation

    Science.gov (United States)

    Traeger, Lisa; Bäumer, Nicole; Schulze, Isabell; Kuhlmann, Tanja; Müller-Tidow, Carsten

    2016-01-01

    Intravenous iron supplementation is an effective therapy in iron deficiency anemia (IDA), but controversial in anemia of inflammation (AI). Unbound iron can be used by bacteria and viruses for their replication and enhance the inflammatory response. Nowadays available high molecular weight iron complexes for intravenous iron substitution, such as ferric carboxymaltose, might be useful in AI, as these pharmaceuticals deliver low doses of free iron over a prolonged period of time. We tested the effects of intravenous iron carboxymaltose in murine AI: Wild-type mice were exposed to the heat-killed Brucella abortus (BA) model and treated with or without high molecular weight intravenous iron. 4h after BA injection followed by 2h after intravenous iron treatment, inflammatory cytokines were upregulated by BA, but not enhanced by iron treatment. In long term experiments, mice were fed a regular or an iron deficient diet and then treated with intravenous iron or saline 14 days after BA injection. Iron treatment in mice with BA-induced AI was effective 24h after iron administration. In contrast, mice with IDA (on iron deficiency diet) prior to BA-IA required 7d to recover from AI. In these experiments, inflammatory markers were not further induced in iron-treated compared to vehicle-treated BA-injected mice. These results demonstrate that intravenous iron supplementation effectively treated the murine BA-induced AI without further enhancement of the inflammatory response. Studies in humans have to reveal treatment options for AI in patients. PMID:27404499

  11. Iron therapy for the treatment of iron deficiency in chronic heart failure: intravenous or oral?

    Science.gov (United States)

    McDonagh, Theresa; Macdougall, Iain C

    2015-03-01

    This article considers the use and modality of iron therapy to treat iron deficiency in patients with heart failure, an aspect of care which has received relatively little attention compared with the wider topic of anaemia management. Iron deficiency affects up to 50% of heart failure patients, and is associated with poor quality of life, impaired exercise tolerance, and mortality independent of haematopoietic effects in this patient population. The European Society of Cardiology Guidelines for heart failure 2012 recommend a diagnostic work-up for iron deficiency in patients with suspected heart failure. Iron absorption from oral iron preparations is generally poor, with slow and often inefficient iron repletion; moreover, up to 60% of patients experience gastrointestinal side effects. These problems may be exacerbated in heart failure due to decreased gastrointestinal absorption and poor compliance due to pill burden. Evidence for clinical benefits using oral iron is lacking. I.v. iron sucrose has consistently been shown to improve exercise capacity, cardiac function, symptom severity, and quality of life. Similar findings were observed recently for i.v. ferric carboxymaltose in patients with systolic heart failure and impaired LVEF in the double-blind, placebo-controlled FAIR-HF and CONFIRM-HF trials. I.v. iron therapy may be better tolerated than oral iron, although confirmation in longer clinical trials is awaited. Routine diagnosis and management of iron deficiency in patients with symptomatic heart failure regardless of anaemia status is advisable, and, based on current evidence, prompt intervention using i.v. iron therapy should now be considered.

  12. Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila, Mexico

    Science.gov (United States)

    Núñez-Ramírez, Diola Marina; Solís-Soto, Aquiles; López-Miranda, Javier; Pereyra-Alférez, Benito; Rutiaga-Quiñónes, Miriam; Medina-Torres, Luis; Medrano-Roldán, Hiram

    2011-10-01

    The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans ( A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.

  13. 优质蠕墨铸铁的生产实践与体会%Production Practice and Experience of High Quality Vermicular Graphite Cast Iron

    Institute of Scientific and Technical Information of China (English)

    唐力; 袁礼东; 周永寿; 李连杰

    2012-01-01

    对“随流冲入法”、“引爆法”、“SinterCast法”生产蠕墨铸铁的生产实践进行了总结,分析了它们各自的特点,并对应用不同蠕化处理工艺的铸件性能进行了对比;指出企业应根据自身生产条件选择合适的蠕化处理工艺.%The production practice and e xperience of using different vermicularizing process to produce vermicular iron was summarized including "cupola spout stream adding vermicularizing alloy process", "vermicularizing alloy + stirring alloy pour over process (bi-alloy pour-over process) , "SinterCast process ,the characteristics of different processses were analyzed,and the properties of castings produced with different processes were compared. It was pointed out that every foundry should choose appropriate vermicularizing process according to its production conditions.

  14. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  15. Response of Streptococcus suis to iron-restricted growth conditions at high and low oxygen availability.

    Science.gov (United States)

    Winterhoff, Nora; Goethe, Ralph; Gruening, Petra; Valentin-Weigand, Peter

    2004-01-01

    Streptococcus suis (S. suis) is an important pathogen in pigs and has to overcome strict iron limitations in its host environment. Here, we studied iron-restricted growth of a highly virulent S. suis strain in vitro at aerobic and CO2-enriched growth conditions. At both conditions, depleting of iron in the culture medium with nitrilotriacetic acid (NTA) resulted in decreased growth rates and down regulation of several proteins. Sensitivity to NTA was significantly higher at aerobic versus CO2-enriched conditions. Growth could not be restored by addition of host iron sources such as ferritin, hemin, hemoglobin, lactoferrin or transferrin. Accordingly, S. suis was not able to produce detectable amounts of siderophores. On the other hand, growth at iron-restricted conditions was fully restored by addition of Mn2+ (at aerobic and CO2-enriched conditions) or Mg2+ (only at CO2-enriched conditions). In conclusion our results suggest that, unlike many other bacteria, S. suis adapts to iron restricted conditions by a change in its metabolism in order to replace Fe2+ by Mn2+ or Mg2+ rather than by expressing specific iron uptake systems.

  16. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang; Dali; Devlin, David; Barbero, Robert S.; Carrera, Martin E.; Colling, Craig W.

    2010-08-10

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  17. Iron Abundance Diagnostics in High-Redshift QSOs

    CERN Document Server

    Corbin, M R; Freduling, N K W; Corbin, Michael R.; Korista, Kirk T.; Freduling, Nalaka Kodituwakku & Wolfram

    2004-01-01

    The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies. We investigate the relationship between Fe/Mg and Fe/C abundance ratios and the resulting Fe II / Mg II 2800A and Fe II / 1900A-blend flux ratios, both of which have been measured in QSOs out to redshifts of approximately six. Using a galactic chemical evolution model based on a starburst in a giant elliptical galaxy, we find that these flux ratios are good tracers of the chemical enrichment of the nuclei. However, the values of these ratios measured in objects at redshifts of approximately six suggest that iron enrichment has occurred more rapidly in these objects than predicted by the assumed elliptical starburst model, under currently favored cosmologies.

  18. 31 CFR 540.316 - Uranium enrichment.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium enrichment. 540.316 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium enrichment means the process...

  19. The causes and consequences of deeper rooting distributions under elevated [CO2]: Improved understanding of root-soil interactions from a Free-Air CO2 Enrichment experiment in a sweetgum plantation (Invited)

    Science.gov (United States)

    Iversen, C. M.; Childs, J.; Norby, R. J.

    2013-12-01

    Belowground processes are increasingly recognized as an important foundation for ecosystem responses to rising atmospheric [CO2]. Elevated [CO2] has been shown to increase the proportion of biomass in fine roots, and experimental evidence from a diverse set of forested ecosystems indicates that CO2-enrichment may lead to deeper rooting distributions. Deeper rooting distributions in CO2-enriched forests are likely a result of three interacting factors: (1) increased resource demand, (2) greater carbon (C) available for belowground allocation, and (3) increased competition for scarce resources in shallower soil. Increased production of fine roots at depth in the soil could drive changes in C cycling because fine roots turn over quickly in forests. However, the consequences of increased fine-root proliferation and turnover at depth are still poorly understood; this is in part because belowground research is often truncated at relatively shallow soil depths. We examined soil C dynamics after 12 years of CO2-enrichment and at soil depths to 90 cm in soil pits harvested at the conclusion of the Oak Ridge National Laboratory (ORNL) Free-Air CO2 Enrichment (FACE) located in a sweetgum plantation in eastern Tennessee, USA. We hypothesized that: (1) soil C content would increase in response to elevated [CO2], especially at deeper soil depths where large increases in root production and mortality were observed, and (2) greater C inputs under elevated [CO2] would lead to increased potential C mineralization in long-term laboratory incubations. As we hypothesized, total soil C content under elevated [CO2] was 20% greater throughout the soil profile to 90 cm depth. The CO2 effect was driven by an increase in the C content of the relatively labile particulate organic matter (POM) pool, which is likely derived primarily from fine roots. Contrary to what we hypothesized, we did not observe a significant increase in potential soil C mineralization under elevated [CO2]. While C

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... This Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video— ... treatment. For more information about living with and managing iron-deficiency anemia, go to the Health Topics ...

  1. Iron in diet

    Science.gov (United States)

    ... meat (especially beef) Oysters Poultry, dark red meat Salmon Tuna Whole grains Reasonable amounts of iron are ... iron up to three times. Foods rich in vitamin C ( such as citrus, strawberries, tomatoes, and potatoes) ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-rich protein that carries oxygen from the lungs to the rest of the body. Iron-deficiency ... 2011 This video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... deficiency anemia may require treatment in a hospital, blood transfusions , iron injections, or intravenous iron therapy. Rate This ... video—presented by the National Heart, Lung, and Blood Institute, part of the National ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... easily treated condition that occurs if you don't have enough iron in your body. Low iron ... can occur if your red blood cells don't contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin ...

  5. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... muh-glow-bin). Hemoglobin is an iron-rich protein that carries oxygen from the lungs to the ... other complications. Infants and young children and women are the two groups at highest risk for iron- ...

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... severity of the condition. Treatments may include dietary changes, medicines, and surgery. Severe iron-deficiency anemia may require treatment in a hospital, blood ... With and Managing Iron-Deficiency Anemia 05/18/2011 This video— ...

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Events Spokespeople Email Alerts E-Newsletters About NHLBI Organization NHLBI Director Budget, Planning, & Legislative Advisory Committees Jobs ... the body. Iron-deficiency anemia usually develops over time if your body doesn't have enough iron ...

  8. Iron supplements (image)

    Science.gov (United States)

    The mineral iron is an essential nutrient for humans because it is part of blood cells, which carry oxygen to all body cells. There is no conclusive evidence that iron supplements contribute to heart attacks.

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... easily treated condition that occurs if you don't have enough iron in your body. Low iron ... can occur if your red blood cells don't contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin ...

  10. Iron Chelation and Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Kelsey J. Weigel

    2014-01-01

    Full Text Available Histochemical and MRI studies have demonstrated that MS (multiple sclerosis patients have abnormal deposition of iron in both gray and white matter structures. Data is emerging indicating that this iron could partake in pathogenesis by various mechanisms, e.g., promoting the production of reactive oxygen species and enhancing the production of proinflammatory cytokines. Iron chelation therapy could be a viable strategy to block iron-related pathological events or it can confer cellular protection by stabilizing hypoxia inducible factor 1α, a transcription factor that normally responds to hypoxic conditions. Iron chelation has been shown to protect against disease progression and/or limit iron accumulation in some neurological disorders or their experimental models. Data from studies that administered a chelator to animals with experimental autoimmune encephalomyelitis, a model of MS, support the rationale for examining this treatment approach in MS. Preliminary clinical studies have been performed in MS patients using deferoxamine. Although some side effects were observed, the large majority of patients were able to tolerate the arduous administration regimen, i.e., 6–8 h of subcutaneous infusion, and all side effects resolved upon discontinuation of treatment. Importantly, these preliminary studies did not identify a disqualifying event for this experimental approach. More recently developed chelators, deferasirox and deferiprone, are more desirable for possible use in MS given their oral administration, and importantly, deferiprone can cross the blood–brain barrier. However, experiences from other conditions indicate that the potential for adverse events during chelation therapy necessitates close patient monitoring and a carefully considered administration regimen.

  11. Control of Cast Iron Microstructure

    Science.gov (United States)

    Graham, J.; Lillybeck, N.; Franco, N.; Stefanescu, D. M.

    1985-01-01

    The use of microgravity for industrial research in the processing of cast iron was investigated. Solidification experiments were conducted using the KC-135 and F-104 aircraft, and an experiment plan was developed for follow-on experiments using the Shuttle. Three areas of interest are identified: (1) measurement of thermophysical properties in the melt; (2) understanding of the relative roles of homogeneous nucleation, grain multiplication, and innocultants in forming the microstructure; and (3) exploring the possibility of obtaining an aligned graphite structure in hypereutectic Fe, Ni, and Co.

  12. Iron age: novel targets for iron overload.

    Science.gov (United States)

    Casu, Carla; Rivella, Stefano

    2014-12-05

    Excess iron deposition in vital organs is the main cause of morbidity and mortality in patients affected by β-thalassemia and hereditary hemochromatosis. In both disorders, inappropriately low levels of the liver hormone hepcidin are responsible for the increased iron absorption, leading to toxic iron accumulation in many organs. Several studies have shown that targeting iron absorption could be beneficial in reducing or preventing iron overload in these 2 disorders, with promising preclinical data. New approaches target Tmprss6, the main suppressor of hepcidin expression, or use minihepcidins, small peptide hepcidin agonists. Additional strategies in β-thalassemia are showing beneficial effects in ameliorating ineffective erythropoiesis and anemia. Due to the suppressive nature of the erythropoiesis on hepcidin expression, these approaches are also showing beneficial effects on iron metabolism. The goal of this review is to discuss the major factors controlling iron metabolism and erythropoiesis and to discuss potential novel therapeutic approaches to reduce or prevent iron overload in these 2 disorders and ameliorate anemia in β-thalassemia.

  13. Iron deficiency anemia

    OpenAIRE

    Naigamwalla, Dinaz Z.; Webb, Jinelle A.; Giger, Urs

    2012-01-01

    Iron is essential to virtually all living organisms and is integral to multiple metabolic functions. The most important function is oxygen transport in hemoglobin. Iron deficiency anemia in dogs and cats is usually caused by chronic blood loss and can be discovered incidentally as animals may have adapted to the anemia. Severe iron deficiency is characterized by a microcytic, hypochromic, potentially severe anemia with a variable regenerative response. Iron metabolism and homeostasis will be ...

  14. Iron-Deficiency Anemia

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, ... Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by ...

  15. Iron-Deficiency Anemia

    Science.gov (United States)

    ... the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, easily ... Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the ...

  16. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, easily ... Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the ...

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, easily ... Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the ...

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... blood transfusions , iron injections, or intravenous iron therapy. Rate This Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the National Heart, Lung, and Blood Institute, part of the National ...

  19. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... blood transfusions , iron injections, or intravenous iron therapy. Rate This Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the National Heart, Lung, and Blood Institute, part of the National ...

  20. Enrichment of the African catfish Clarias gariepinus (Burchell) with functional selenium originating from garlic: effect of enrichment period and depuration on total selenium level and sensory properties

    NARCIS (Netherlands)

    Schram, E.; Schelvis-Smit, A.A.M.; Heul, van der J.W.; Luten, J.B.

    2010-01-01

    We wanted to optimize the procedure for the selenium enrichment of farmed African catfish, using garlic as dietary selenium source. In the first experiment we established the relation between the length of the selenium enrichment period and the resulting total selenium level in the fillet of the fis

  1. Enrichment of the African catfish Clarias gariepinus (Burchell) with functional selenium originating from garlic: effect of enrichment period and depuration on total selenium level and sensory properties

    NARCIS (Netherlands)

    Schram, E.; Schelvis-Smit, A.A.M.; Heul, van der J.W.; Luten, J.B.

    2010-01-01

    We wanted to optimize the procedure for the selenium enrichment of farmed African catfish, using garlic as dietary selenium source. In the first experiment we established the relation between the length of the selenium enrichment period and the resulting total selenium level in the fillet of the

  2. Coronary MR angiography using citrate-coated very small superparamagnetic iron oxide particles as blood-pool contrast agent: initial experience in humans.

    Science.gov (United States)

    Wagner, Moritz; Wagner, Susanne; Schnorr, Jörg; Schellenberger, Eyk; Kivelitz, Dietmar; Krug, Lasse; Dewey, Marc; Laule, Michael; Hamm, Bernd; Taupitz, Matthias

    2011-10-01

    To evaluate very small superparamagnetic iron oxide particles (VSOP-C184) as blood-pool contrast agent for coronary MR angiography (CMRA) in humans. Six healthy volunteers and 14 patients with suspected coronary artery disease underwent CMRA after administration of VSOP-C184 at the following doses: 20 μmol Fe/kg (4 patients), 40 μmol Fe/kg (5 patients), 45 μmol Fe/kg (6 healthy volunteers), and 60 μmol Fe/kg (5 patients). In healthy volunteers, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and vessel edge definition (VED) of contrast-enhanced CMRA were compared with non-contrast-enhanced CMRA. In patients, a per-segment intention-to-diagnose evaluation of contrast-enhanced CMRA for detection of significant coronary stenosis (≥50%) was performed. Three healthy volunteers (45 μmol Fe/kg VSOP-C184) and two patients (60 μmol Fe/kg VSOP-C184) had adverse events of mild or moderate intensity. VSOP-C184 significantly increased CNR (15.1 ± 4.6 versus 6.9 ± 1.9; P = 0.010), SNR (21.7 ± 5.3 versus 15.4 ± 1.6; P = 0.048), and VED (2.3 ± 0.6 versus 1.2 ± 0.2; P VSOP-C184 was feasible and yielded moderate diagnostic accuracy for detection of significant coronary stenosis within this proof-of-concept setting. Copyright © 2011 Wiley-Liss, Inc.

  3. In vitro and in vivo experiments with iron oxide nanoparticles functionalized with DEXTRAN or polyethylene glycol for medical applications: magnetic targeting.

    Science.gov (United States)

    Mojica Pisciotti, M L; Lima, E; Vasquez Mansilla, M; Tognoli, V E; Troiani, H E; Pasa, A A; Creczynski-Pasa, T B; Silva, A H; Gurman, P; Colombo, L; Goya, G F; Lamagna, A; Zysler, R D

    2014-05-01

    In this research work, DEXTRAN- and polyethylene glycol (PEG)-coated iron-oxide superparamagnetic nanoparticles were synthetized and their cytotoxicity and biodistribution assessed. Well-crystalline hydrophobic Fe3 O4 SPIONs were formed by a thermal decomposition process with d = 18 nm and σ = 2 nm; finally, the character of SPIONs was changed to hydrophilic by a post-synthesis procedure with the functionalization of the SPIONs with PEG or DEXTRAN. The nanoparticles present high saturation magnetization and superparamagnetic behavior at room temperature, and the hydrodynamic diameters of DEXTRAN- and PEG-coated SPIONs were measured as 170 and 120 nm, respectively. PEG- and DEXTRAN-coated SPIONs have a Specific Power Absorption SPA of 320 and 400 W/g, respectively, in an ac magnetic field with amplitude of 13 kA/m and frequency of 256 kHz. In vitro studies using VERO and MDCK cell lineages were performed to study the cytotoxicity and cell uptake of the SPIONs. For both cell lineages, PEG- and DEXTRAN-coated nanoparticles presented high cell viability for concentrations as high as 200 μg/mL. In vivo studies were conducted using BALB/c mice inoculating the SPIONs intravenously and exposing them to the presence of an external magnet located over the tumour. It was observed that the amount of PEG-coated SPIONs in the tumor increased by up to 160% when using the external permanent magnetic as opposed to those animals that were not exposed to the external magnetic field.

  4. Iron isotopes for the layered series of the Skaergaard intrusion

    Science.gov (United States)

    Lesher, C. E.; Lundstrom, C.; Brown, E.; Huang, F.; Glessner, J. J.; Hoffmann-Barfod, G.; Thy, P.

    2009-12-01

    It has long been held that magmatic evolution of the Skaergaard intrusion involved strong iron enrichment accompanying gabbro fractionation. Continued enrichment of iron in evolved liquids following FeTi oxide saturation is problematic and has been ascribed to a number of related factors, including 1) the composition of the Skaergaard parental magma, 2) changes in oxidation conditions and proportion of fractionating FeTi oxide and silicates during the course of differentiation, and 3) the effects of liquid immiscibility. In most differentiation scenarios differences in the partitioning of Fe+2 and Fe+3 between fractionating minerals and silicate melt are considered to be key to maintaining the bulk distribution coefficient for total iron below unity, thus permitting iron enrichment during magmatic evolution. Recent experimental work [1] predicts measureable fractionation of iron isotopes between magnetite and silicate melt that can lead to enrichment of isotopically lighter iron in derivative liquids compared to magnetite-rich cumulates. This possibility suggests that a signature of FeTi oxide fractionation may be recorded in the Fe isotope composition of Skaergaard gabbros. Initial investigation of this possibility is based on the analysis of 15 average gabbros from the layered series by high resolution MC-ICPMS after digestion and separation of iron using AG1X8 resin. The δ56Fe values {= [(56Fe/54Fe)sample/(56Fe/54Fe)IRMM-014 - 1] × 1000} for this suite range from a low of 0.052 per mil to a high of 0.188 per mil with external precision better than ±0.05 per mil (1σ). While the entire variation is small we find a progressive decrease in δ56Fe by 0.09 per mil passing from Lower Zone a to the base of Upper Zone c (UZc). Within UZc δ56Fe increases rapidly to 0.188 per mil approaching the Sandwich Horizon. Forward modeling of closed system fractional crystallization using fractionation factors from [1] can account for the observed decrease in δ56Fe by Fe

  5. Ethanol enrichment from ethanol-water mixtures using high frequency ultrasonic atomization.

    Science.gov (United States)

    Kirpalani, D M; Suzuki, K

    2011-09-01

    The influence of high frequency ultrasound on the enrichment of ethanol from ethanol-water mixtures was investigated. Experiments performed in a continuous enrichment system showed that the generated atomized mist was at a higher ethanol concentration than the feed and the enrichment ratio was higher than the vapor liquid equilibrium curve for ethanol-water above 40 mol%. Well-controlled experiments were performed to analyze the effect of physical parameters; temperature, carrier gas flow and collection height on the enrichment. Droplet size measurements of the atomized mist and visualization of the oscillating fountain jet formed during sonication were made to understand the separation mechanism.

  6. Iron Curtains ?

    Directory of Open Access Journals (Sweden)

    Maria Vlček

    2010-12-01

    Full Text Available This paper explores the emotional and multi-sensorial dimensions of care within a transnational family separated by the Iron Curtain during the Cold War. It will argue that processes of supportive and compassionate engagement amongst transnational kin are not only shaped by long-distance communication, financial support and practical help within specific political and economic contexts, but also by personal desires and interpersonal conflict. The dialectics of proximity and distance are explored through a focus on uses of communication technology, emotional interaction during visits, long-distance engagement through distinct sensorial experiences, and imaginary interaction through the dynamics of internalised presence. The auto/biographical analysis is mainly based on letters, faxes, diaries, interviews and personal memories.

  7. Experience of Perinatal Care of Iron Deficiency Anemia in Pregnant Women Around%浅析缺铁性贫血孕产妇围产期护理体会

    Institute of Scientific and Technical Information of China (English)

    车辐顺

    2015-01-01

    目的 研究分析缺铁性贫血孕妇围产期护理方式,对该类患者提供积极有效的护理.方法 整理收集我院2013年接收的76例缺铁性贫血患者来进行研究分析,患者年龄22~37岁,孕周19~40周.对其进行围产期护理观察,总结护理体会.结果 产后42 d门诊复查分析,除1例妊娠合并再生障碍性贫血患者的血红蛋白低于100 g/L外,其他产妇的血红蛋白均在110 g/L以上,母乳喂养率95%以上,新生儿的体重、身长、各项营养指标均达到中上水平,无1例发生营养不良.结论 对妊娠合并缺铁性贫血患者提供有效的围产期护理,能够让患者的抵抗力增强,对母婴提供保障,促进患者的生活改善.%Objective To study the analysis of iron deficiency anemia in pregnant women in perinatal nursing mode, provide active and effective nursing for the patients.Methods Colected in our hospital in 2013 received 76 cases of iron deficiency anemia patients to carry on the research analysis, patients aged 22 to 37 years of age, pregnant weeks 19 to 40. The perinatal nursing observation, to sum up the nursing experience.Results Analysis of 42 d postpartum clinic reexamination, except for 1 cases of pregnancy complicated with aplastic anemia hemoglobin below 100 g/L, other maternal hemoglobin were above 110 g/L, the breastfeeding rate above 95%, birth weight, length, nutritional indexes were achieved on the level, 1 case of malnutrition. Conclusion Provide perinatal effective nursing care of patients with iron deficiency anemia of pregnancy, can let the patient resistance increased, providing security on mother and infant, and promote the patients' life improvement.

  8. Computational modeling and analysis of iron release from macrophages.

    Directory of Open Access Journals (Sweden)

    Alka A Potdar

    2014-07-01

    Full Text Available A major process of iron homeostasis in whole-body iron metabolism is the release of iron from the macrophages of the reticuloendothelial system. Macrophages recognize and phagocytose senescent or damaged erythrocytes. Then, they process the heme iron, which is returned to the circulation for reutilization by red blood cell precursors during erythropoiesis. The amount of iron released, compared to the amount shunted for storage as ferritin, is greater during iron deficiency. A currently accepted model of iron release assumes a passive-gradient with free diffusion of intracellular labile iron (Fe2+ through ferroportin (FPN, the transporter on the plasma membrane. Outside the cell, a multi-copper ferroxidase, ceruloplasmin (Cp, oxidizes ferrous to ferric ion. Apo-transferrin (Tf, the primary carrier of soluble iron in the plasma, binds ferric ion to form mono-ferric and di-ferric transferrin. According to the passive-gradient model, the removal of ferrous ion from the site of release sustains the gradient that maintains the iron release. Subcellular localization of FPN, however, indicates that the role of FPN may be more complex. By experiments and mathematical modeling, we have investigated the detailed mechanism of iron release from macrophages focusing on the roles of the Cp, FPN and apo-Tf. The passive-gradient model is quantitatively analyzed using a mathematical model for the first time. A comparison of experimental data with model simulations shows that the passive-gradient model cannot explain macrophage iron release. However, a facilitated-transport model associated with FPN can explain the iron release mechanism. According to the facilitated-transport model, intracellular FPN carries labile iron to the macrophage membrane. Extracellular Cp accelerates the oxidation of ferrous ion bound to FPN. Apo-Tf in the extracellular environment binds to the oxidized ferrous ion, completing the release process. Facilitated-transport model can

  9. Iron isotope and REE+Y composition of the Cauê banded iron formation and related iron ores of the Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Mendes, Mônica; Lobato, Lydia M.; Kunzmann, Marcus; Halverson, Galen P.; Rosière, Carlos A.

    2016-04-01

    The Minas Supergroup banded iron formations (BIFs) of the Brazilian Quadrilátero Ferrífero (QF) mineral province experienced multiple deformational events synchronous with hypogene mineralization, which resulted in the metamorphism of BIFs to itabirites and their upgrade to high-grade iron ore. Here, we present rare earth element and yttrium (REE+Y) compositions together with iron isotope ratios of itabirites and their host iron orebodies from 10 iron deposits to constrain environmental conditions during BIF deposition and the effects of hypogene iron enrichment. The REE+Y characteristics of itabirites (positive Eu anomaly and LREE depletion) indicate hydrothermal iron contribution to the Minas basin. Iron isotope data and Ce anomalies suggest BIFs were precipitated by a combination of anoxic biological-mediated ferrous iron oxidation and abiotic oxidation in an environment with free oxygen (such as an oxygen oasis), perhaps related to increase in oxygen concentrations before the Great Oxidation Event (GOE). The similarity of the REE+Y composition of the itabirites from the different QF deformational domains, as well as to other Superior-type BIFs, indicates that the metamorphism and synchronous hydrothermal mineralization did not significantly affect the geochemical signature of the original BIFs. However, iron isotope compositions of iron ore vary systematically between deformational domains of the QF, likely reflecting the specific mineralization features in each domain.

  10. Iron isotope and REE+Y composition of the Cauê banded iron formation and related iron ores of the Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Mendes, Mônica; Lobato, Lydia M.; Kunzmann, Marcus; Halverson, Galen P.; Rosière, Carlos A.

    2017-02-01

    The Minas Supergroup banded iron formations (BIFs) of the Brazilian Quadrilátero Ferrífero (QF) mineral province experienced multiple deformational events synchronous with hypogene mineralization, which resulted in the metamorphism of BIFs to itabirites and their upgrade to high-grade iron ore. Here, we present rare earth element and yttrium (REE+Y) compositions together with iron isotope ratios of itabirites and their host iron orebodies from 10 iron deposits to constrain environmental conditions during BIF deposition and the effects of hypogene iron enrichment. The REE+Y characteristics of itabirites (positive Eu anomaly and LREE depletion) indicate hydrothermal iron contribution to the Minas basin. Iron isotope data and Ce anomalies suggest BIFs were precipitated by a combination of anoxic biological-mediated ferrous iron oxidation and abiotic oxidation in an environment with free oxygen (such as an oxygen oasis), perhaps related to increase in oxygen concentrations before the Great Oxidation Event (GOE). The similarity of the REE+Y composition of the itabirites from the different QF deformational domains, as well as to other Superior-type BIFs, indicates that the metamorphism and synchronous hydrothermal mineralization did not significantly affect the geochemical signature of the original BIFs. However, iron isotope compositions of iron ore vary systematically between deformational domains of the QF, likely reflecting the specific mineralization features in each domain.

  11. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and

  12. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and s

  13. Mineralized iron oxidizing bacteria from hydrothermal vents: targeting biosignatures on Mars

    Science.gov (United States)

    Leveille, R. J.

    2010-12-01

    Putative hydrothermal systems have been identified on Mars based on orbital imagery and rover-based analyses. Based on Earth analogs, hydrothermal systems on Mars would be highly attractive for their potential for preserving organic and inorganic biosignatures. For example, iron oxidizing bacteria are ubiquitous in marine and terrestrial hydrothermal systems, where they often display distinctive cell morphologies and are commonly encrusted by minerals, especially bacteriogenic iron oxides and silica. Microfossils of iron oxidizing bacteria have been found in ancient Si-Fe deposits and iron oxidation may be an ancient and widespread metabolic pathway. In order to investigate mineralized iron oxidizing bacteria as a biosignature, we have examined samples collected from extinct hydrothermal vents along Explorer Ridge, NE Pacific Ocean. In addition, microaerophilic iron oxidizing bacteria, isolated from active Pacific hydrothermal vents, were grown in a Fe-enriched seawater medium at constant pH (6.5) and O2 concentration (5%) in a controlled bioreactor system. Samples and experimental products were examined with a combination of variable-pressure and field-emission scanning electron microscopy (SEM), in some cases by preparing samples with a focused ion beam (FIB) milling system. Light-toned seafloor samples display abundant filamentous forms resembling, in both size and shape (1-5 microns in diameter and up to several microns in length), the twisted stalks of Gallionella and the elongated filaments of Leptothrix. Some samples consist entirely of low-density masses of silica (>90% Si) encrusted filamentous forms. The presence of unmineralized filamentous matter rich in C and Fe suggests that these are the remains of iron oxidizing bacteria. Mineralized filaments sectioned by FIB show variable internal material within semi-hollow, tubular-like features. Silica encrustations also show pseudo-concentric growth bands. In the bioreactor runs, abundant microbial growth and

  14. Impact of iron porphyrin complexes when hydroprocessing algal HTL biocrude

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Jacqueline M.; Sudasinghe, Nilusha M.; Albrecht, Karl O.; Schmidt, Andrew J.; Hallen, Richard T.; Anderson, Daniel B.; Billing, Justin M.; Schaub, Tanner M.

    2016-10-01

    We apply Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for direct characterization of iron-porphyrins in hydrothermal liquefaction (HTL) biocrude oils derived from two algae: Tetraselmis sp. and cyanobacteria. The ironporphyrin compounds are shown to cause catalyst bed plugging during hydroprocessing due to iron deposition. Inductively-coupled plasma optical emission spectrometry (ICPOES) was utilized for iron quantitation in the plugged catalyst beds formed through hydroprocessing of the two HTL biocrudes and identifies an enrichment of iron in the upper five centimeters of the catalyst bed for Tetraselmis sp. (Fe=100,728 ppm) and cyanobacteria (Fe=115,450 ppm). Direct infusion FT-ICR MS analysis of the two HTL biocrudes with optimized instrument conditions facilitates rapid screening and identification of iron-porphyrins without prior chromatographic separation. With FT-ICR MS we identify 138 unique iron-porphyrin compounds in the two HTL biocrudes that are structurally similar to metal-porphyrins (e.g. Ni and V) observed in petroleum. No ironporphyrins are observed in the cyanobacteria HTL biocrude after hydroprocessing, which indicates that iron-porphyrin structures in the HTL biocrude are degraded during hydroprocessing. Hydrodemetallization reactions that occur through hydroprocessing of HTL biocrudes could be responsible for the decomposition of iron-porphyrin structures leading to metal deposition in the catalyst bed that result in catalyst deactivation and bed plugging, and must be addressed for effective upgrading of algal HTL biocrudes.

  15. Iron uptake and homeostasis related genes in potato cultivated in vitro under iron deficiency and overload.

    Science.gov (United States)

    Legay, Sylvain; Guignard, Cédric; Ziebel, Johanna; Evers, Danièle

    2012-11-01

    Potato is one of the most important staple food in the world because it is a good source of vitamin C, vitamin B6 but also an interesting source of minerals including mainly potassium, but also magnesium, phosphorus, manganese, zinc and iron to a lesser extent. The lack of iron constitutes the main form of micronutrient deficiency in the world, namely iron deficiency anemia, which strongly affects pregnant women and children from developing countries. Iron biofortification of major staple food such as potato is thus a crucial issue for populations from these countries. To better understand mechanisms leading to iron accumulation in potato, we followed in an in vitro culture experiment, by qPCR, in the cultivar Désirée, the influence of media iron content on the expression of genes related to iron uptake, transport and homeostasis. As expected, plantlets grown in a low iron medium (1 mg L(-1) FeNaEDTA) displayed a decreased iron content, a strong induction of iron deficiency-related genes and a decreased expression of ferritins. Inversely, plantlets grown in a high iron medium (120 mg L(-1) FeNaEDTA) strongly accumulated iron in roots; however, no significant change in the expression of our set of genes was observed compared to control (40 mg L(-1) FeNaEDTA).

  16. Transgenerational effects of environmental enrichment on repetitive motor behavior development.

    Science.gov (United States)

    Bechard, Allison R; Lewis, Mark H

    2016-07-01

    The favorable consequences of environmental enrichment (EE) on brain and behavior development are well documented. Much less is known, however, about transgenerational benefits of EE on non-enriched offspring. We explored whether transgenerational effects of EE might extend to the development of repetitive motor behaviors in deer mice. Repetitive motor behaviors are invariant patterns of movement that, across species, can be reduced by EE. We found that EE not only attenuated the development of repetitive behavior in dams, but also in their non-enriched offspring. Moreover, maternal behavior did not seem to mediate the transgenerational effect we found, although repetitive behavior was affected by reproductive experience. These data support a beneficial transgenerational effect of EE on repetitive behavior development and suggest a novel benefit of reproductive experience.

  17. A time-resolved iron-specific X-ray absorption experiment yields no evidence for an Fe2+ --> Fe3+ transition during QA- --> QB electron transfer in the photosynthetic reaction center.

    Science.gov (United States)

    Hermes, Sabine; Bremm, Oliver; Garczarek, Florian; Derrien, Valerie; Liebisch, Peter; Loja, Paola; Sebban, Pierre; Gerwert, Klaus; Haumann, Michael

    2006-01-17

    Previous time-resolved FTIR measurements suggested the involvement of an intermediary component in the electron transfer step Q(A)- --> Q(B) in the photosynthetic reaction center (RC) from Rhodobacter sphaeroides [Remy and Gerwert (2003) Nat. Struct. Biol. 10, 637]. By a kinetic X-ray absorption experiment at the Fe K-edge we investigated whether oxidation occurs at the ferric non-heme iron located between the two quinones. In isolated reaction centers with a high content of functional Q(B), at a time resolution of 30 micros and at room temperature, no evidence for transient oxidation of Fe was obtained. However, small X-ray transients occurred, in a similar micro- to millisecond time range as in the IR experiments, which may point to changes in the Fe ligand environment due to the charges on Q(A)- and Q(B)-. In addition, VIS measurements agree with the IR data and do not exclude an intermediate in the Q(A)- --> Q(B) transition.

  18. The nature of mathematical enrichment: a case study of implementation

    Directory of Open Access Journals (Sweden)

    Jennifer Susan Piggott

    2007-12-01

    Full Text Available This paper reports a framework for describing the nature of mathematics enrichment that emerged from a case study based on the work of the NRICH Project (www.nrich.maths.org team when producing “mathematics enrichment trails” (an ordered set of related mathematics problems and support materials. A range of data sources, including the trails, trail development sessions, related literature and the views of colleagues were used to inform the findings. The data were analysed using NVivo and involved the development of two complementary coding systems. One, drawn from the data itself, gave evidence of views of the content aspects of mathematical enrichment. The other, specifically designed and informed by the literature, was used to aid the analysis of the roles of teaching and learning inherent in views of enrichment described by participants. The framework describes the content of an enrichment curriculum as well as implications for teaching and learning, the experiences of learners and the features of settings where this occurs. To support this, some detail is provided on the role, nature and purpose of problem-solving and what constitutes a good problem. While emerging from a particular context, the framework highlights the need for debate concerning the audience for mathematics enrichment, particularly in questioning the commonly held belief that its value is in supporting the needs of the mathematically most able. The framework also has potential value through offering a focus for debate within the wider community concerning the nature of mathematics enrichment and as a reference point for evaluating the potential of existing or new curriculum to deliver mathematics enrichment.

  19. Macrophages and Iron Metabolism.

    Science.gov (United States)

    Soares, Miguel P; Hamza, Iqbal

    2016-03-15

    Iron is a transition metal that due to its inherent ability to exchange electrons with a variety of molecules is essential to support life. In mammals, iron exists mostly in the form of heme, enclosed within an organic protoporphyrin ring and functioning primarily as a prosthetic group in proteins. Paradoxically, free iron also has the potential to become cytotoxic when electron exchange with oxygen is unrestricted and catalyzes the production of reactive oxygen species. These biological properties demand that iron metabolism is tightly regulated such that iron is available for core biological functions while preventing its cytotoxic effects. Macrophages play a central role in establishing this delicate balance. Here, we review the impact of macrophages on heme-iron metabolism and, reciprocally, how heme-iron modulates macrophage function.

  20. [Iron function and carcinogenesis].

    Science.gov (United States)

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models.

  1. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L. and association with seed iron accumulation QTL

    Directory of Open Access Journals (Sweden)

    Fernandez Andrea C

    2010-10-01

    Full Text Available Abstract Background Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L. take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 × G19833, to identify quantitative trait loci (QTL for this trait, and to assess possible associations with seed iron levels. Results The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Conclusions Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity

  2. Iron Solubility Depending on the Mineralogical Composition of Dust Particles

    Science.gov (United States)

    Journet, E.; Desboeufs, K.; Chevaillier, S.; Caquineau, S.

    2008-12-01

    Dust deposition in open ocean is recognised as an important supply of iron for phytoplankton community. Various previous studies have shown an extremely variable solubility (0,01-80%) and numerous factors influencing this solubility, as suspended particules concentration, chemical and photochemical atmospheric process, aerosol sources (Maholwald et al., 2005). Despite these numerous studies, any factor of influence seems to be dominant enough to enable a comprehensive parameterization of iron solubility. Recently, dissolution experiment have been conducted on pure mineral that composed dust, like illite, feldpars, smectite and iron (hydr-)oxide. This study has shown that iron solubility is extremely dependent on the mineral that is considered. Iron coming from aluminosilicates is much more soluble that iron derived from iron (hyd-)oxides (Journet et al., 2008). According to these results, dissolution experiments have been led on dust particles collected in different source areas, in West Africa, and after transport, in tropical Atlantic Ocean. These experiments show that iron solubility is very low, always under 0,6%, in agreement with others observations in these regions (e.g. Baker et al., 2006). Furthermore, from bulk mineralogical analysis of the dust samples, iron solubility in source areas seems exclusively dependent on the mineralogical composition of dust particle. The greater iron solubilities (0,3%) corresponds to dust originated from central Sahara (Algeria, Lybia, Tunisia) where smectite are abundant in comparison to the others studied area (Sahel and Western Sahara) where iron mainly comes from iron (hydr-)oxide and illite. In this case, iron solubility does not exceed 0,13%. From comparison between these results and the lab data issued from Journet et al. (2008), a parameterization to estimate iron solubility from mineralogical composition of dust has been established and validated. Far from the source, iron solubility is usually greater than dust

  3. 水泥改性铁矿石载氧体的煤化学链燃烧实验研究%Experiments on Chemical-looping Combustion of Coal With Cement-Decorated Iron Ore as Oxygen Carrier

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      对天然铁矿石混合水泥进行改性,在流化床上进行了煤化学链燃烧试验研究,考察改性后载氧体的氧化−还原反应性能。结果表明,水泥能够有效地促进水气变换反应的进行,使得煤气化产物中 CO 份额减小、H2份额增大。改性后载氧体比表面积和孔容积显著增大,反应活性得到提高,燃料反应器出口气体中仅存在微量CO、H2,其浓度远低于纯铁矿石为载氧体的实验结果。在20次循环试验中,水泥改性铁矿石能大幅提高 CO2体积份额;对不同循环后载氧体的扫描电镜表征显示,水泥能够有效阻止载氧体颗粒表面的晶粒在高温下的液相接触,降低载氧体颗粒氧化再生过程中单位体积的热量释放强度,缓解烧结现象的发生,维持载氧体颗粒多孔的结构特性。%Experiments on chemical looping combustion of coal were conducted in a fluidized bed using cement-decorated iron ore as oxygen carrier. The reactivity of the oxygen carrier during redox experiments was investigated. The results indicate that the addition of cement effectively promotes the water-gas shift reaction, leading to the decrease of CO fraction and the increase of H2 fraction in coal gasification products. After decorated the oxygen carrier gets its specific surface area and pore volume increased significantly, and reactivity improved as a result. Further, the concentrations of CO and H2 in the flue gas of the fuel reactor are far lower than that of the experiments for pure iron ore. The volume fractions of CO2 for cement-decorated iron ore increase greatly during 20 cycles. Characterization of reduced oxygen carrier with scanning electron microscope (SEM) indicates that cement can prevent the surface grains of the oxygen carrier from gathering in the liquid phase under high temperature, and reduce the heat density released in a unit volume of the oxygen carrier particle in the oxidization process

  4. New rat models of iron sucrose-induced iron overload.

    Science.gov (United States)

    Vu'o'ng Lê, Bá; Khorsi-Cauet, Hafida; Villegier, Anne-Sophie; Bach, Véronique; Gay-Quéheillard, Jérôme

    2011-07-01

    The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences. Iron overload was observed in all iron-treated rats, as evidenced by significant increases in serum iron indices, expression of liver hepcidin gene and total tissue iron content compared with control rats. We also showed that total tissue iron content was mainly associated with the dose of iron whereas serum iron indices depended essentially on the duration of iron administration. However, no differences in tissue inflammatory and antioxidant parameters from controls were observed. Furthermore, only rats exposed to daily iron injection at a dose of 75 mg/kg body weight for one week revealed a significant increase in lipid peroxidation in iron-treated rats compared with their controls. The present results suggest a correlation between iron overload levels and the dose of iron, as well as the duration and frequency of iron injection and confirm that iron sucrose may not play a crucial role in inflammation and oxidative stress. This study provides important information about iron sucrose-induced iron overload in rats and may be useful for iron sucrose therapy for iron deficiency anemia as well as for the prevention and diagnosis of iron sucrose-induced iron overload in pediatric patients.

  5. Leaching of Iron, Controlling Factors and Implication to Arsenic Mobilization in an aquifer of the Brahmaputra Floodplain

    NARCIS (Netherlands)

    Baviskar, S.M.; Mahanta, C.; Choudhary, R.

    2011-01-01

    To understand the process of iron leaching and arsenic (As) mobilization, three bore wells were drilled in suspected iron and arsenic enriched areas of Jorhat, Assam, India, to study possible release and mobilization process in the aquifer. Sediments and groundwater samples, collected from different

  6. A Novel Method for the Filterless Preconcentration of Iron

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2005-01-01

    . In the preconcentration step of the FIA accessory, the optimum efficacy was obtained when the acidity of the samples were adjusted by HCl to pH = 2.5 whereas the ammonia preconcentration buffer should be kept alkaline at pH = 9.8. After being preconcentrated on the tubular reactor, the iron species were eluted......A novel method of analysis of iron by filterless preconcentration is presented. This is the first example of efficient preconcentration of a refractory transition metal where coprecipitation and columns were omitted. The method applies a manifold of flow injection analysis (FIA) to iron species...... that are preconcentrated on the inner walls of a tubular reactor. It was found that the adsorption of iron species to the walls was particularly pronounced in reactors of nylon material and enrichment factors of 30-35 could be attained, as dependent on the length of the reactor and on the time of preconcentration...

  7. Iron cycling at corroding carbon steel surfaces.

    Science.gov (United States)

    Lee, Jason S; McBeth, Joyce M; Ray, Richard I; Little, Brenda J; Emerson, David

    2013-01-01

    Surfaces of carbon steel (CS) exposed to mixed cultures of iron-oxidizing bacteria (FeOB) and dissimilatory iron-reducing bacteria (FeRB) in seawater media under aerobic conditions were rougher than surfaces of CS exposed to pure cultures of either type of microorganism. The roughened surface, demonstrated by profilometry, is an indication of loss of metal from the surface. In the presence of CS, aerobically grown FeOB produced tight, twisted helical stalks encrusted with iron oxides. When CS was exposed anaerobically in the presence of FeRB, some surface oxides were removed. However, when the same FeOB and FeRB were grown together in an aerobic medium, FeOB stalks were less encrusted with iron oxides and appeared less tightly coiled. These observations suggest that iron oxides on the stalks were reduced and solubilized by the FeRB. Roughened surfaces of CS and denuded stalks were replicated with culture combinations of different species of FeOB and FeRB under three experimental conditions. Measurements of electrochemical polarization resistance established different rates of corrosion of CS in aerobic and anaerobic media, but could not differentiate rate differences between sterile controls and inoculated exposures for a given bulk concentration of dissolved oxygen. Similarly, total iron in the electrolyte could not be used to differentiate treatments. The experiments demonstrate the potential for iron cycling (oxidation and reduction) on corroding CS in aerobic seawater media.

  8. Algal response to nutrient enrichment in forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romaní, A.M.; Tornés, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  9. Algal response to nutrient enrichment in a forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romani, A.M.; Tornes, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  10. Algal response to nutrient enrichment in forested oligotrophic stream

    NARCIS (Netherlands)

    Veraart, A.J.; Romaní, A.M.; Tornés, E.; Sabater, S.

    2008-01-01

    Nutrient input in streams alters the density and species composition of attached algal communities in open systems. However, in forested streams, the light reaching the streambed (rather than the local nutrient levels) may limit the growth of these communities. A nutrient-enrichment experiment in a

  11. Malabsorption of iron in children with iron deficiency.

    Science.gov (United States)

    Gross, S J; Stuart, M J; Swender, P T; Oski, F A

    1976-05-01

    Inability to absorb oral iron is believed to be an extremely rare cause of therapeutic failure in the treatment of iron deficiency anemia. Six patients who had failed to respond to oral iron therapy were studied by a simple oral absorption test and contrasted with 25 patients with untreated iron deficiency anemia and 10 normal subjects. All six of the patients who were therapeutic failures demonstrated impaired iron absorption in the absence of other clinical evidence of gastrointestinal disease. In the 25 newly diagnosed patients with iron deficiency. 24 demonstrated elevated iron absorptions while 10 ironreplete normal subjects had minimal elevations in their serum iron values following the administration of the test dose of 1 mg of elemental iron per kilogram. When the therapeutic failures were treated with parenteral iron, all had a therapeutic response. In addition, after treatment the impaired absorption of iron improved transiently. All children who absorbed iron readily responded to oral iron therapy.

  12. Iron chelating agents for iron overload diseases

    Directory of Open Access Journals (Sweden)

    Guido Crisponi

    2014-09-01

    Full Text Available Although iron is an essential element for life, an excessive amount may become extremely toxic both for its ability to generate reactive oxygen species, and for the lack in humans of regulatory mechanisms for iron excretion. Chelation therapy has been introduced in clinical practice in the seventies of last century to defend thalassemic patients from the effects of iron overload and, in spite of all its limitations, it has dramatically changed both life expectancy and quality of life of patients. It has to be considered that the drugs in clinical use present some disadvantages too, this makes urgent new more suitable chelating agents. The requirements of an iron chelator have been better and better defined over the years and in this paper they will be discussed in detail. As a final point the most interesting ligands studied in the last years will be presented.

  13. Closed system Fischer-Tropsch synthesis over meteoritic iron, iron ore and nickel-iron alloy. [deuterium-carbon monoxide reaction catalysis

    Science.gov (United States)

    Nooner, D. W.; Gibert, J. M.; Gelpi, E.; Oro, J.

    1976-01-01

    Experiments were performed in which meteoritic iron, iron ore and nickel-iron alloy were used to catalyze (in Fischer-Tropsch synthesis) the reaction of deuterium and carbon monoxide in a closed vessel. Normal alkanes and alkenes and their monomethyl substituted isomers and aromatic hydrocarbons were synthesized. Iron oxide and oxidized-reduced Canyon Diablo used as Fischer-Tropsch catalysts were found to produce aromatic hydrocarbons in distributions having many of the features of those observed in carbonaceous chondrites, but only at temperatures and reaction times well above 300 C and 6-8 h.

  14. Iron deficiency anaemia.

    Science.gov (United States)

    Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent

    2016-02-27

    Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.

  15. The ubiquity of iron.

    Science.gov (United States)

    Frey, Perry A; Reed, George H

    2012-09-21

    The importance of iron in living systems can be traced to the many complexes within which it is found, to its chemical mobility in undergoing oxidation-reduction reactions, and to the abundance of iron in Earth's crust. Iron is the most abundant element, by mass, in the Earth, constituting about 80% of the inner and outer cores of Earth. The molten outer core is about 8000 km in diameter, and the solid inner core is about 2400 km in diameter. Iron is the fourth most abundant element in Earth's crust. It is the chemically functional component of mononuclear iron complexes, dinuclear iron complexes, [2Fe-2S] and [4Fe-4S] clusters, [Fe-Ni-S] clusters, iron protophorphyrin IX, and many other complexes in protein biochemistry. Metals such as nickel, cobalt, copper, and manganese are present in the crust and could in principle function chemically in place of iron, but they are scarce in Earth's crust. Iron is plentiful because of its nuclear stability in stellar nuclear fusion reactions. It seems likely that other solid planets, formed by the same processes as Earth, would also foster the evolution of life and that iron would be similarly important to life on those planets as it is on Earth.

  16. Enrichment of lanthanides in aragonite

    Institute of Scientific and Technical Information of China (English)

    瞿成利; 路波; 刘刚

    2009-01-01

    Using the constant addition technique,the coprecipitation of lanthanum,gadolinium,and lutetium with aragonite in seawater was experimentally investigated at 25 ℃.Their concentrations in aragonite overgrowths were determined by inductive coupled plasma mass spectrometer.All these lanthanides were strongly enriched in aragonite overgrowths.The amount of lanthanum,gadolinium,and lutetium incorporated into aragonite accounted for 57%-99%,50%-89%,and 40%-91% of their initial total amount,respectively.With the in...

  17. Iron deficiency anemia from diagnosis to treatment in children

    Science.gov (United States)

    Özdemir, Nihal

    2015-01-01

    Iron deficiency is the most common nutritional deficiency worldwide and an important public health problem especially in developing countries. Since the most important indicator of iron deficieny is anemia, the terms “iron deficiency” and “iron deficiency anemia” are often used interchangeably. However, iron deficiency may develop in the absence of anemia and the tissues may be affected from this condition. The most common causes of iron deficiency in children include insufficient intake together with rapid growth, low birth weight and gastrointestinal losses related to excessive intake of cow’s milk. If insufficient intake can be excluded and there is insufficient response to oral iron treatment in patients with iron deficiency especially in older children, blood loss should be considered as the underlying cause. The main principles in management of iron deficiency anemia include investigation and elimination of the cause leading to iron deficiency, replacement of deficiency, improvement of nutrition and education of the patient and family. In this article, the practical approaches in the diagnosis and treatment of iron deficiency and the experience of our center have been reviewed. PMID:26078692

  18. Enrichment and aggression in primates.

    Science.gov (United States)

    Honess, P E; Marin, C M

    2006-01-01

    There is considerable evidence that primates housed under impoverished conditions develop behavioural abnormalities, including, in the most extreme example, self-harming behaviour. This has implications for all contexts in which primates are maintained in captivity from laboratories to zoos since by compromising the animals' psychological well-being and allowing them to develop behavioural abnormalities their value as appropriate educational and research models is diminished. This review examines the extensive body of literature documenting attempts to improve living conditions with a view to correcting behavioural abnormalities and housing primates in such a way that they are encouraged to exhibit a more natural range and proportion of behaviours, including less self-directed and social aggression. The results of housing, feeding, physical, sensory and social enrichment efforts are examined with specific focus on their effect on aggressive behaviour and variation in their use and efficacy. It is concluded that while inappropriate or poorly distributed enrichment may encourage aggressive competition, enrichment that is species, sex, age and background appropriate can dramatically reduce aggression, can eliminate abnormal behaviour and substantially improve the welfare of primates maintained in captivity.

  19. The Effects of Cereals and Legumes on Iron Availability.

    Science.gov (United States)

    1982-06-01

    Figure 5. Both flours and soy products in greatest quantity are vegetarians , the concentrates may be further modified by an extrusion military...when it was added to a vegetarian meal of in a series of experiments using six cereal-based infant low iron bioavailability. foods, four of which...that depress iron absorption from cereals in- meat on the absorption of non-henie iron, and part clude some phytates and certain components of fiber

  20. Thermodynamic constraints on microbial iron oxide reduction

    Science.gov (United States)

    Bonneville, S.; Behrends, T.; Haese, R.; van Cappellen, P.

    2003-04-01

    Iron oxides are ubiquitous reactive constituents of soils, sediments and aquifers. They exhibit large surface areas which bind trace metals, nutrients and organic molecules. Under suboxic conditions, iron oxides can reductively dissolve via several abiotic and microbial pathways. In particular, they serve as terminal electron acceptors for the oxidation of organic matter by iron reducing bacteria. The aim of our study was to determine the thermodynamic energy yields of dissimilatory iron reduction for different Fe(III) substrates. We used the facultative anaerobic gram-positive bacterium Shewanella putrefaciens as model iron reducing bacterium, with ferrihydrite, hematite, goethite or Fe(III)-salicylate as electron acceptor, and lactate as electron donor. Experiments were conducted in an anaerobic pH-stat batch reactor, equipped with a polarographic electrode to monitor in situ the dissolved ferrous iron activity. The stoichiometry of total Fe(II) production and acid consumption during the experiments indicated that lactate was oxidized to acetate. From the Fe(II) activity and redox potential measurements, free energy yields were calculated for Fe(III) reduction coupled to lactate oxidation. The results showed that the redox potential of the overall reaction was poised by equilibrium between the Fe(III)-substrate and aqueous Fe(II). Hence, the energy yields decreased in the order ferrihydrite > Fe(III)-salicylate > hematite > goethite. Accumulation of Fe(II) in solution only caused small decreases in the energy yields over the course of the experiments. Cessation of iron reduction, which was observed in all experiments, was therefore not due to thermodynamic limitation, but more likely reflected the decline in cell level of activity.

  1. The Organization of Controller Motifs Leading to Robust Plant Iron Homeostasis.

    Directory of Open Access Journals (Sweden)

    Oleg Agafonov

    Full Text Available Iron is an essential element needed by all organisms for growth and development. Because iron becomes toxic at higher concentrations iron is under homeostatic control. Plants face also the problem that iron in the soil is tightly bound to oxygen and difficult to access. Plants have therefore developed special mechanisms for iron uptake and regulation. During the last years key components of plant iron regulation have been identified. How these components integrate and maintain robust iron homeostasis is presently not well understood. Here we use a computational approach to identify mechanisms for robust iron homeostasis in non-graminaceous plants. In comparison with experimental results certain control arrangements can be eliminated, among them that iron homeostasis is solely based on an iron-dependent degradation of the transporter IRT1. Recent IRT1 overexpression experiments suggested that IRT1-degradation is iron-independent. This suggestion appears to be misleading. We show that iron signaling pathways under IRT1 overexpression conditions become saturated, leading to a breakdown in iron regulation and to the observed iron-independent degradation of IRT1. A model, which complies with experimental data places the regulation of cytosolic iron at the transcript level of the transcription factor FIT. Including the experimental observation that FIT induces inhibition of IRT1 turnover we found a significant improvement in the system's response time, suggesting a functional role for the FIT-mediated inhibition of IRT1 degradation. By combining iron uptake with storage and remobilization mechanisms a model is obtained which in a concerted manner integrates iron uptake, storage and remobilization. In agreement with experiments the model does not store iron during its high-affinity uptake. As an iron biofortification approach we discuss the possibility how iron can be accumulated even during high-affinity uptake.

  2. Brain iron homeostasis.

    Science.gov (United States)

    Moos, Torben

    2002-11-01

    Iron is essential for virtually all types of cells and organisms. The significance of the iron for brain function is reflected by the presence of receptors for transferrin on brain capillary endothelial cells. The transport of iron into the brain from the circulation is regulated so that the extraction of iron by brain capillary endothelial cells is low in iron-replete conditions and the reverse when the iron need of the brain is high as in conditions with iron deficiency and during development of the brain. Whereas there is good agreement that iron is taken up by means of receptor-mediated uptake of iron-transferrin at the brain barriers, there are contradictory views on how iron is transported further on from the brain barriers and into the brain extracellular space. The prevailing hypothesis for transport of iron across the BBB suggests a mechanism that involves detachment of iron from transferrin within barrier cells followed by recycling of apo-transferrin to blood plasma and release of iron as non-transferrin-bound iron into the brain interstitium from where the iron is taken up by neurons and glial cells. Another hypothesis claims that iron-transferrin is transported into the brain by means of transcytosis through the BBB. This thesis deals with the topic "brain iron homeostasis" defined as the attempts to maintain constant concentrations of iron in the brain internal environment via regulation of iron transport through brain barriers, cellular iron uptake by neurons and glia, and export of iron from brain to blood. The first part deals with transport of iron-transferrin complexes from blood to brain either by transport across the brain barriers or by uptake and retrograde axonal transport in motor neurons projecting beyond the blood-brain barrier. The transport of iron and transport into the brain was examined using radiolabeled iron-transferrin. Intravenous injection of [59Fe-125]transferrin led to an almost two-fold higher accumulation of 59Fe than of

  3. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Chapter 3 Spheroidal Graphite Cast Iron(I) Spheroidal Graphite Cast Iron, SG iron in short, refers to the cast iron in which graphite precipitates as spheroidal shape during solidification of liquid iron. The graphite in common commercial cast iron can only be changed from flake to spheroidal shape by spheroidising treatment. Since spheroidal graphite reduces the cutting effect of stress concentration, the metal matrix strength of SG iron can be applied around 70%-90%, thus the mechanical property of SG iron is significantly superior to other cast irons;even the tensile strength of SG iron is higher than that carbon steel.

  4. Network-based functional enrichment

    Directory of Open Access Journals (Sweden)

    Poirel Christopher L

    2011-11-01

    Full Text Available Abstract Background Many methods have been developed to infer and reason about molecular interaction networks. These approaches often yield networks with hundreds or thousands of nodes and up to an order of magnitude more edges. It is often desirable to summarize the biological information in such networks. A very common approach is to use gene function enrichment analysis for this task. A major drawback of this method is that it ignores information about the edges in the network being analyzed, i.e., it treats the network simply as a set of genes. In this paper, we introduce a novel method for functional enrichment that explicitly takes network interactions into account. Results Our approach naturally generalizes Fisher’s exact test, a gene set-based technique. Given a function of interest, we compute the subgraph of the network induced by genes annotated to this function. We use the sequence of sizes of the connected components of this sub-network to estimate its connectivity. We estimate the statistical significance of the connectivity empirically by a permutation test. We present three applications of our method: i determine which functions are enriched in a given network, ii given a network and an interesting sub-network of genes within that network, determine which functions are enriched in the sub-network, and iii given two networks, determine the functions for which the connectivity improves when we merge the second network into the first. Through these applications, we show that our approach is a natural alternative to network clustering algorithms. Conclusions We presented a novel approach to functional enrichment that takes into account the pairwise relationships among genes annotated by a particular function. Each of the three applications discovers highly relevant functions. We used our methods to study biological data from three different organisms. Our results demonstrate the wide applicability of our methods. Our algorithms are

  5. Iron and Stony-iron Meteorites

    Science.gov (United States)

    Haack, H.; McCoy, T. J.

    2003-12-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich sampling of the deep interiors of differentiated asteroids.Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar to that continuing on Earth - although on much smaller length- and timescales - with melting of the metal and silicates, differentiation into core, mantle, and crust, and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth and other terrestrial planets. This fact has been recognized since the work of Chladni (1794), who argued that stony-iron meteorites must have originated in outer space and fallen during fireballs and that they provide our closest analogue to the material that comprises our own planet's core. This chapter deals with our current knowledge of these meteorites. How did they form? What can they tell us about the early evolution of the solar system and its solid bodies? How closely do they resemble the materials from planetary interiors? What do we know and don't we know?Iron and stony-iron meteorites constitute ˜6% of meteorite falls (Grady, 2000). Despite their scarcity among falls, iron meteorites are our only samples of ˜75 of the ˜135 asteroids from which meteorites originate ( Keil et al., 1994; Scott, 1979; Meibom and Clark, 1999; see also Chapter 1.05), suggesting that both differentiated asteroids and the geologic processes that produced them were common.Despite the highly evolved nature of iron and stony-iron meteorites, their chemistry provides important

  6. Investigation of the effects of elevated atmospheric CO{sub 2} on a whet crop of the Free-Air Carbondioxide Enrichment (FACE) Experiment, Maricopa, USA. Final report; Untersuchung der Auswirkungen erhoehter atmosphaerischer CO{sub 2}-Konzentrationen auf Weizenbestaende des Free-Air Carbondioxid Enrichment (FACE)-Experimentes Maricopa (USA). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kartschall, T.; Grossman, S.; Michaelis, P.; Wechsung, F. [Potsdam-Institut fuer Klimafolgenforschung e.V., Potsdam (Germany). Abt. Globaler Wandel und Natuerliche Systeme; Graefe, J.; Waloszczyk, K. [Professor-Hellriegel-Institut e.V., Bernburg (Germany); Wechsung, G. [US Water-Conservation Lab., Phoenix, AZ (United States); Blum, E.; Blum, M.

    1998-02-01

    A version of the demeter model was developed which describes both the quantitative and qualitative effects of elevated atmospheric CO{sub 2} on a wheat crop under conditions of limited water and/or nitrogen supply. In the model`s photosynthesis and energy balance modules, first versions of components were developed which it should be possible to apply in further ecosystem models (starting with the cereals models of the demeter family). Experimental data from the Maricopa FACE wheat experiments 1992-1996, in which scientists from PIK were involved, were used for the development and testing of the model. Model solutions obtained were applied for the first time of central European climatic and site conditions as part of a regional yield study for the Federal State of Brandenburg. (orig.)

  7. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Spheroidal Graphite Cast Iron(Ⅳ) 3.7 Segregation of SG iron The non-uniform distribution of solute elements during solidification results in the micro segregation of SG iron.As for the redistribution of elements in the phases of the solidification structure,there is no intrinsic difference between SG iron and grey iron[132].

  8. Cellular iron transport.

    Science.gov (United States)

    Garrick, Michael D; Garrick, Laura M

    2009-05-01

    Iron has a split personality as an essential nutrient that also has the potential to generate reactive oxygen species. We discuss how different cell types within specific tissues manage this schizophrenia. The emphasis in enterocytes is on regulating the body's supply of iron by regulating transport into the blood stream. In developing red blood cells, adaptations in transport manage the body's highest flux of iron. Hepatocytes buffer the body's stock of iron. Macrophage recycle the iron from effete red cells among other iron management tasks. Pneumocytes provide a barrier to prevent illicit entry that, when at risk of breaching, leads to a need to handle the dangers in a fashion essentially shared with macrophage. We also discuss or introduce cell types including renal cells, neurons, other brain cells, and more where our ignorance, currently still vast, needs to be removed by future research.