Sample records for biogenic iron microminerals

  1. The Irony of IronBiogenic Iron Oxides as an Iron Source to the Ocean

    PubMed Central

    Emerson, David

    2016-01-01

    Primary productivity in at least a third of the sunlit open ocean is thought to be iron-limited. Primary sources of dissolved iron (dFe) to the ocean are hydrothermal venting, flux from the sediments along continental margins, and airborne dust. This article provides a general review of sources of hydrothermal and sedimentary iron to the ocean, and speculates upon the role that iron-cycling microbes play in controlling iron dynamics from these sources. Special attention is paid to iron-oxidizing bacteria (FeOB) that live by oxidizing iron and producing biogenic iron oxides as waste products. The presence and ubiquity of FeOB both at hydrothermal systems and in sediments is only beginning to be appreciated. The biogenic oxides they produce have unique properties that could contribute significantly to the dynamics of dFe in the ocean. Changes in the physical and chemical characteristics of the ocean due to climate change and ocean acidification will undoubtedly impact the microbial iron cycle. A better understanding of the contemporary role of microbes in the iron cycle will help in predicting how these changes could ultimately influence marine primary productivity. PMID:26779157

  2. Analysis of micromineral contents of school meals.

    PubMed

    Shin, Dongsoon

    2014-08-01

    Korean ordinary diets are referred to be good for human health in worldwide. However it is uncertain whether they provide microminerals enough for growth and health of teenagers. A main purpose of this study was to identify micromineral contents in school meals. The fifty cuisines were collected from elementary schools and middle schools in Gyeongnam area. The contents of Fe, Zn, Cu and Mn among microminerals were analyzed by using ICP-OES method. Data were expressed as mean, standard deviation and range value and linear regression analysis performed. Fe level of Pangibuseotpaprika-salad was the highest among side-dishes (average 346.6 µg) and Zn level of Sullung-tang was highest among soups (average 229.1 µg). Cu level of Buchu-kimchi was the highest among kimchies (average 217.5 µg) and Mn level of Gumeunkongyangnyum-gui was highest among side-dishes (average 198.4 µg). Generally cooked-rices as main dish had relative smaller amounts of microminerals than the other cuisines. The results showed that the ratio of Cu : Fe : Zn was approximately 12 : 4 : 1 and the relationship between Fe versus Zn or Fe versus Cu was significantly positive. Comparing to Korean Dietary Recommended Intakes (KDRI) level, school meals provided not sufficient amount (<25% DRI) of Fe, Zn or Mn, while they did excessive amount (>125% DRI) of Cu.

  3. The effect of heat acclimation on sweat microminerals: Artifact of surface contamination

    USDA-ARS?s Scientific Manuscript database

    Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of w...

  4. Comparative study of biogenic and abiotic iron-containing materials

    NASA Astrophysics Data System (ADS)

    Cherkezova-Zheleva, Z.; Shopska, M.; Paneva, D.; Kovacheva, D.; Kadinov, G.; Mitov, I.

    2016-12-01

    Series of iron-based biogenic materials prepared by cultivation of Leptothrix group of bacteria in different feeding media ( Sphaerotilus-Leptothrix group of bacteria isolation medium, Adler, Lieske and silicon-iron-glucose-peptone) were studied. Control samples were obtained in the same conditions and procedures but the nutrition media were not infected with bacteria, i.e. they were sterile. Room and low temperature Mössbauer spectroscopy, powder X-ray diffraction (XRD), and infrared spectroscopy (IRS) were used to reveal the composition and physicochemical properties of biomass and respective control samples. Comparative analysis showed differences in their composition and dispersity of present phases. Sample composition included different ratio of nanodimensional iron oxyhydroxide and oxide phases. Relaxation phenomena such as superparamagnetism or collective magnetic excitation behaviour were registered for some of them. The experimental data showed that the biogenic materials were enriched in oxyhydroxides of high dispersion. Catalytic behaviour of a selected biomass and abiotic material were studied in the reaction of CO oxidation. In situ diffuse-reflectance (DR) IRS was used to monitor the phase transformations in the biomass and CO conversion.

  5. Biogenic iron mineralization at Iron Mountain, CA with implications for detection with the Mars Curiosity rover

    USGS Publications Warehouse

    Williams, Amy J.; Sumner, Dawn Y.; Alpers, Charles N.; Campbell, Kate M.; Nordstrom, D. Kirk

    2014-01-01

    (Introduction) Microbe-mineral interactions and biosignature preservation in oxidized sulfidic ore bodies (gossans) are prime candidates for astrobiological study. Such oxidized iron systems have been proposed as analogs for some Martian environments. Recent studies identified microbial fossils preserved as mineral-coated filaments. This study documents microbially-mediated mineral biosignatures in hydrous ferric oxide (HFO) and ferric oxyhydroxysulfates (FOHS) in three environments at Iron Mountain, CA. We investigated microbial community preservation via HFO and FOHS precipitation and the formation of filamentous mineral biosignatures. These environments included 1) actively precipitating (1000's yrs), naturally weathered HFO from in situ gossan, and 3) remobilized iron deposits, which contained lithified clastics and zones of HFO precipitate. We used published biogenicity criteria as guidelines to characterize the biogenicity of mineral filaments. These criteria included A) an actively precipitating environment where microbes are known to be coated in minerals, B) presence of extant microbial communities with carbon signatures, C) structures observable as a part of the host rock, and D) biological morphology, including cellular lumina, multiple member population, numerous taxa, variable and 3-D preservation, biological size ranges, uniform diameter, and evidence of flexibility. This study explores the relevance and detection of these biosignatures to possible Martian biosignatures. Similar filamentous biosignatures are resolvable by the Mars Hand Lens Imager (MAHLI) onboard the Mars Science Laboratory (MSL) rover, Curiosity, and may be identifiable as biogenic if present on Mars.

  6. Sorption of Ferric Iron from Ferrioxamine B to Synthetic and Biogenic Layer Type Manganese Oxides

    NASA Astrophysics Data System (ADS)

    Duckworth, O.; John, B.; Sposito, G.

    2006-12-01

    Siderophores are biogenic chelating agents produced in terrestrial and marine environments to increase the bioavailablity of ferric iron. Recent work has suggested that both aqueous and solid-phase Mn(III) may affect siderophore-mediated iron transport, but no information appears to be available about the effect of solid-phase Mn(IV). To probe the effects of predominantly Mn(IV) oxides, we studied the sorption reaction of ferrioxamine B [Fe(III)HDFOB+, an Fe(III) chelate of the trihydroxamate siderophore desferrioxamine B (DFOB)] with two synthetic birnessites [layer type Mn(III, IV) oxides] and a biogenic birnessite produced by Pseudomonas putida MnB1. We found that all of these predominantly Mn(IV) oxides greatly reduced the aqueous concentration of Fe(III)HDFOB+ over at pH 8. After 72 hours equilibration time, the sorption behavior for the synthetic birnessites could be accurately described by a Langmuir isotherm; for the biogenic oxide, a Freundlich isotherm was best utilized to model the sorption data. To study the molecular nature of the interaction between the Fe(III)HDFOB+ complex and the oxide surface, Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy was employed. Analysis of the EXAFS spectra indicated that Fe(III) associated with the Mn(IV) oxides is not complexed by DFOB as in solution, but instead Fe(III) is specifically adsorbed to into the mineral structure at multiple sites with no evidence of DFOB complexation, thus indicating that the Mn(IV) oxides displaced Fe(III) from the siderophore complex. These results indicate that manganese oxides, including biominerals, may strongly sequester iron from soluble ferric complexes and thus may play a significant role in the biogeochemical cycling of iron in marine and terrestrial environments.

  7. Arsenic Bioremediation by Biogenic Iron Oxides and Sulfides

    PubMed Central

    Couture, Raoul-Marie; Van Cappellen, Philippe; Corkhill, Claire L.; Charnock, John M.; Polya, David A.; Vaughan, David; Vanbroekhoven, Karolien; Lloyd, Jonathan R.

    2013-01-01

    Microcosms containing sediment from an aquifer in Cambodia with naturally elevated levels of arsenic in the associated groundwater were used to evaluate the effectiveness of microbially mediated production of iron minerals for in situ As remediation. The microcosms were first incubated without amendments for 28 days, and the release of As and other geogenic chemicals from the sediments into the aqueous phase was monitored. Nitrate or a mixture of sulfate and lactate was then added to stimulate biological Fe(II) oxidation or sulfate reduction, respectively. Without treatment, soluble As concentrations reached 3.9 ± 0.9 μM at the end of the 143-day experiment. However, in the nitrate- and sulfate-plus-lactate-amended microcosms, soluble As levels decreased to 0.01 and 0.41 ± 0.13 μM, respectively, by the end of the experiment. Analyses using a range of biogeochemical and mineralogical tools indicated that sorption onto freshly formed hydrous ferric oxide (HFO) and iron sulfide mineral phases are the likely mechanisms for As removal in the respective treatments. Incorporation of the experimental results into a one-dimensional transport-reaction model suggests that, under conditions representative of the Cambodian aquifer, the in situ precipitation of HFO would be effective in bringing groundwater into compliance with the World Health Organization (WHO) provisional guideline value for As (10 ppb or 0.13 μM), although soluble Mn release accompanying microbial Fe(II) oxidation presents a potential health concern. In contrast, production of biogenic iron sulfide minerals would not remediate the groundwater As concentration below the recommended WHO limit. PMID:23666325

  8. Study on the Composition of Biogenic Iron-Containing Materials Obtained Under Cultivation of the Leptothrix sp. on Different Media.

    PubMed

    Shopska, M; Paneva, D; Kadinov, G; Cherkezova-Zheleva, Z; Mitov, I; Iliev, M

    2017-03-01

    The biogenic iron oxide/hydroxide materials possess useful combination of physicochemical properties and are considered for application in various areas. Their production does not require special investments because these compounds are formed during cultivation of neurophilic iron bacteria. Bacteria from genus Leptothrix develop intensively in the Sphaerotilus-Leptothrix group of bacteria isolation medium and feeding media of Fedorov and Lieske. These media are different in their composition which determined the present study as an attempt to clear up the reasons that define the differences in the composition of the laboratory-obtained biomasses and the natural biomass finds. FTIRS, Mössbauer spectroscopy, and XRD were used in the research. Comparative analysis showed that the biomass and control samples contain iron compounds (α-FeOOH, γ-FeOOH, β-FeOOH, γ-Fe 2 O 3 ) in different ratios. The biomass samples were enriched in oxyhydroxides of higher dispersion. Organic residuals of bacterial origin, SO 4 , CO 3 , and PO 4 groups were registered in the biogenic materials.

  9. The Biochemical Role of Macro and Micro-Minerals in the Management of Diabetes Mellitus and its Associated Complications: A Review.

    PubMed

    Mwiti Kibiti, Cromwell; Jide Afolayan, Anthony

    2015-01-01

    Diabetes mellitus is a chronic physiological glucose metabolic disorder. Its high prevalence globally has a significant impact on the quality of life. The management of diabetes includes non-pharmacological and glucose lowering agents. Although these methods are effective, they have drawbacks. This has led to a search for alternative therapy in macro and micro-minerals from dietary foods and plants. There is therefore a need to review, identify and classify their modes of action in diabetes mellitus therapy. This review was carried out using comprehensive literature reports on the use of mineral elements in the management of diabetes. Empirical online searches were conducted for different elements that have been studied for their anti-diabetic potentials both in vivo and in vitro. The University of Fort Hare's online database was also used. The results indicate that magnesium, molybdenum, zinc, vanadium and manganese facilitate glucose catabolism. Chromium, vanadium, zinc, molybdenum and magnesium can enhance insulin activity while molybdenum, manganese and zinc stimulate lipogenesis. Zinc and iron can modulate glucose, metabolizing enzymes in the gastrointestinal tract and limit oxidative stress, respectively. These agents have similar mechanisms to conventional drugs in ameliorating diabetic status and other associated complications. The mechanisms of these elements are well known, however, the synergetic effects of their combinations are still obscure. Literature on their safe dose(s) is still scanty. Evaluation of other useful macro and micro-minerals should also be undertaken. It is envisaged that the use of mineral supplements will promote good health in diabetics.

  10. Sorption of arsenic to biogenic iron (oxyhydr)oxides produced in circumneutral environments

    NASA Astrophysics Data System (ADS)

    Sowers, Tyler D.; Harrington, James M.; Polizzotto, Matthew L.; Duckworth, Owen W.

    2017-02-01

    Arsenic (As) is a widespread and problematic pollutant that can be derived from natural or anthropogenic sources. Iron (oxyhydr)oxides readily sorb As and thus play critical roles in As cycling in terrestrial environments; however, little is known about the affinity and mechanism of As sorption by biogenic iron (oxyhydr)oxides formed in circumneutral environments. To investigate this, we conducted sorption isotherm and kinetics experiments to compare As(V) and As(III) sorption to synthetic 2-line ferrihydrite and iron biominerals harvested from the hyporheic zone of an uncontaminated creek. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify both As(V) and As(III), and X-ray absorption spectroscopy (XAS) was utilized to obtain As and Fe K-edge spectra for As(V) and As(III) sorbed to environmentally collected and laboratory produced Fe(III) minerals. All environmental Fe(III) biominerals were determined to be structurally similar to 2-line ferrihydrite. However, environmental Fe(III) biominerals have a surface area normalized affinity for As(V) and for As(III) that is greater than or equivalent to synthetic 2-line ferrihydrite. Whereas the extent of sorption was similar for As(III) on all minerals, As(V) sorption to environmental Fe(III) biominerals was approximately three times higher than what was observed for synthetic 2-line ferrihydrite. Structural modeling of EXAFS spectra revealed that the same surface complexation structure was formed by As(V) and by As(III) on environmental Fe(III) biominerals and ferrihydrite. These results suggest that, despite similarities in binding mechanisms, Fe(III) biominerals may be more reactive sorbents that synthetic surrogates often used to model environmental reactivity.

  11. Erythrocyte CuZn superoxide dismutase activity is decreased in iron-deficiency anemia.

    PubMed

    Olivares, M; Araya, M; Pizarro, F; Letelier, A

    2006-09-01

    Iron and copper are essential microminerals that are intimately related. The present study was performed to determine the effect of iron-deficiency anemia (IDA) and treatment with iron on laboratory indicators of copper status. Hemoglobin, mean corpuscular volume erythrocyte Zn protoporphyrin, serum ferritin, serum copper, serum ceruloplasmin, and erythrocyte CuZn-superoxide dismutase (SOD) activity were studied in 12 adult women with IDA before and after iron treatment for 60-90 d (100 mg/d Fe, as ferric polymaltose) and in 27 women with normal iron status. Prior to treatment with iron, serum copper and ceruloplasmin were not different between the groups and treatment with iron did not affect these measures. IDA women, before and after treatment with iron, presented a 2.9- and 2-fold decrease in erythrocyte CuZn-SOD activity compared to women with normal iron status (p < 0.001). Treatment with iron increased erythrocyte CuZn-SOD activity of the IDA group; however, this change was not statistically significant. In conclusion, CuZn-SOD activity is decreased in IDA. Measurement of this enzyme activity is not useful for evaluating copper nutrition in iron-deficient subjects.

  12. Effect of dietary calcium and phosphorus levels on the total tract digestibility of innate and supplemental organic and inorganic microminerals in a corn-soybean meal based diet of grower pigs.

    PubMed

    Jolliff, J S; Mahan, D C

    2013-06-01

    The effects of Ca and P (CaP) levels and micromineral sources on mineral digestibility were evaluated in growing pigs. Treatments consisted of 2 levels of CaP and 3 trace mineral (TM) treatments arranged as a 2 × 3 factorial in a randomized complete block design with 8 replicates. The CaP levels evaluated were: 1) 0.65% Ca and 0.55% P [standard CaP (Std CaP)], and 2) 1.00% Ca and 0.85% P (High CaP). The TM treatments were: 1) Basal, without supplemental TM, 2) Basal supplemented with organic TM, and 3) Basal supplemented with inorganic TM. Both organic and inorganic TM premixes added 15 mg Cu, 150 mg Fe, 10 mg Mn, 0.3 mg Se, and 140 mg Zn/kg diet. Diets were formulated using corn soybean meal with a Ca to P ratio of 1.18 in both CaP treatments. Barrows with an initial BW of 45 kg were acclimated to stainless steel metabolism crates where diets were fed for 14 d before a 10-d collection period. Pigs within replicates were fed equivalent amounts of feed at 0800 and 1600 h each day with water provided free choice. Total feces, urine, and feed orts were collected daily. Essential macro- and microminerals were analyzed by inductively coupled plasma analysis. Increasing dietary CaP decreased the digestibility of Ca and Zn. Phosphorus digestibility did not change when the P inclusion level increased from 0.55 to 0.85% Ptotal. The High CaP level resulted in a lower urinary excretion of most minerals, particularly Cu (P < 0.05) and Mn (P < 0.05), as dietary CaP level increased but the others were not statistically significant. A summary of the ATTD for each of the experimental variables was statistically analyzed and averaged for the experiment. Although there were few statistical differences with individual minerals, they generally demonstrated a decline in digestibility when the High CaP was fed, averaging a 3% lower digestibility consistently than when the Std CaP level was fed. Organic TM averaged an approximately 5% greater digestibility than the average inorganic

  13. Biogenic catalysis of soil formation on Mars?

    NASA Technical Reports Server (NTRS)

    Bishop, J. L.

    1998-01-01

    The high iron abundance and the weak ferric iron spectral features of martian surface material are consistent with nanophase (nm-sized) iron oxide minerals as a major source of iron in the bright region soil on Mars. Nanophase iron oxide minerals, such as ferrihydrite and schwertmannite, and nanophase forms of hematite and goethite are formed by both biotic and abiotic processes on Earth. The presence of these minerals on Mars does not indicate biological activity on Mars, but it does raise the possibility. This work includes speculation regarding the possibility of biogenic soils on Mars based on previous observations and analyses. A remote sensing goal of upcoming missions should be to determine if nanophase iron oxide minerals, clay silicates and carbonates are present in the martian surface material. These minerals are important indicators for exobiology and their presence on Mars would invoke a need for further investigation and sample return from these sites.

  14. From urban municipalities to polar bioremediation: the characterisation and contribution of biogenic minerals for water treatment.

    PubMed

    Freidman, Benjamin L; Northcott, Kathy A; Thiel, Peta; Gras, Sally L; Snape, Ian; Stevens, Geoff W; Mumford, Kathryn A

    2017-06-01

    Minerals of biological origin have shown significant potential for the separation of contaminants from water worldwide. This study details the contribution of biologically derived minerals to water treatment operations, with a focus on filtration media from urban municipalities and remote cold regions. The results support biofilm-embedded iron and manganese to be the building blocks of biogenic mineral development on activated carbon and nutrient-amended zeolites. The presence of similar iron and manganese oxidising bacterial species across all filter media supports the analogous morphologies of biogenic minerals between sites and suggests that biological water treatment processes may be feasible across a range of climates. This is the first time the stages of biogenic mineral formation have been aligned with comprehensive imaging of the biofilm community and bacterial identification; especially with respect to cold regions. Where biogenic mineral formation occurs on filter media, the potential exists for enhanced adsorption for a range of organic and inorganic contaminants and improved longevity of filter media beyond the adsorption or exchange capacities of the raw material.

  15. Sorption of Ferrioxime B to Synthetic and Biogenic layer type Mn Oxides

    NASA Astrophysics Data System (ADS)

    Duckworth, O. W.; Bargar, J. R.; Sposito, G.

    2005-12-01

    Siderophores are biogenic chelating agents produced in terrestrial and marine environments to increase the bioavailablity of ferric iron. Recent work has suggested that both aqueous and solid-phase Mn(III) may affect siderophore-mediated iron transport, but no information appears to be available about the effect of solid-phase Mn(IV). To probe the effect of solid-phase Mn(IV), we studied the sorption reaction of ferrioxamine B [principally the species, Fe(III)HDFOB+, an Fe(III) chelate of the trihydroxamate siderophore, desferrioxamine B (DFOB)] with two synthetic birnessites [layer type Mn(IV) oxides] and a biogenic birnessite produced by Pseudomonas putida MnB1. We found that all of these predominantly Mn(IV) oxides greatly reduced the aqueous concentration of Fe(III)HDFOB+ over the pH range between 5 and 9. After 72 h equilibration time at pH 8, the sorption behavior for the synthetic birnessites could be accurately described by a Langmuir isotherm; for the biogenic oxide, a Freundlich isotherm was best utilized to model the sorption data. To study the molecular nature of the interaction between the Fe(III)HDFOB+ complex and the oxide surface, Fe K-edge extended X-Ray absorption fine structure (EXAFS) spectroscopy was employed. Analysis of the X-ray absorption spectra indicated that Fe(III) associated with the Mn(IV) oxides is not complexed with DFOB, but instead is incorporated into the mineral structure, thus implying that the Mn(IV) oxides displaced Fe(III) from the siderophore complex. These results indicate that manganese oxides, including biominerals, may strongly sequester iron from soluble ferric complexes and thus may play a significant role in the biogeochemical cycling of iron.

  16. Non-enzymatic U(VI) interactions with biogenic mackinawite

    NASA Astrophysics Data System (ADS)

    Veeramani, H.; Qafoku, N. P.; Kukkadapu, R. K.; Murayama, M.; Hochella, M. F.

    2011-12-01

    Reductive immobilization of hexavalent uranium [U(VI)] by stimulation of dissimilatory metal and/or sulfate reducing bacteria (DMRB or DSRB) has been extensively researched as a remediation strategy for subsurface U(VI) contamination. These bacteria derive energy by reducing oxidized metals as terminal electron acceptors, often utilizing organic substrates as electron donors. Thus, when evaluating the potential for in-situ uranium remediation in heterogeneous subsurface media, it is important to understand how the presence of alternative electron acceptors such as Fe(III) and sulfate affect U(VI) remediation and the long term behavior and reactivity of reduced uranium. Iron, an abundant subsurface element, represents a substantial sink for electrons from DMRB, and the reduction of Fe(III) leads to the formation of dissolved Fe(II) or to reactive biogenic Fe(II)- and mixed Fe(II)/Fe(III)- mineral phases. Consequently, abiotic U(VI) reduction by reactive forms of biogenic Fe(II) minerals could be a potentially important process for uranium immobilization. In our study, the DMRB Shewanella putrefaciens CN32 was used to synthesize a biogenic Fe(II)-bearing sulfide mineral: mackinawite, that has been characterized by XRD, SEM, HRTEM and Mössbauer spectroscopy. Batch experiments involving treated biogenic mackinawite and uranium (50:1 molar ratio) were carried out at room temperature under strict anoxic conditions. Following complete removal of uranium from solution, the biogenic mackinawite was analyzed by a suite of analytical techniques including XAS, HRTEM and Mössbauer spectroscopy to determine the speciation of uranium and investigate concomitant Fe(II)-phase transformation. Determining the speciation of uranium is critical to success of a remediation strategy. The present work elucidates non-enzymatic/abiotic molecular scale redox interactions between biogenic mackinawite and uranium.

  17. Use of Bacteria To Stabilize Archaeological Iron

    PubMed Central

    Comensoli, Lucrezia; Maillard, Julien; Albini, Monica; Sandoz, Frederic

    2017-01-01

    ABSTRACT Iron artifacts are common among the findings of archaeological excavations. The corrosion layer formed on these objects requires stabilization after their recovery, without which the destruction of the item due to physicochemical damage is likely. Current technologies for stabilizing the corrosion layer are lengthy and generate hazardous waste products. Therefore, there is a pressing need for an alternative method for stabilizing the corrosion layer on iron objects. The aim of this study was to evaluate an alternative conservation-restoration method using bacteria. For this, anaerobic iron reduction leading to the formation of stable iron minerals in the presence of chlorine was investigated for two strains of Desulfitobacterium hafniense (strains TCE1 and LBE). Iron reduction was observed for soluble Fe(III) phases as well as for akaganeite, the most troublesome iron compound in the corrosion layer of archaeological iron objects. In terms of biogenic mineral production, differential efficiencies were observed in assays performed on corroded iron coupons. Strain TCE1 produced a homogeneous layer of vivianite covering 80% of the corroded surface, while on the coupons treated with strain LBE, only 10% of the surface was covered by the same mineral. Finally, an attempt to reduce iron on archaeological objects was performed with strain TCE1, which led to the formation of both biogenic vivianite and magnetite on the surface of the artifacts. These results demonstrate the potential of this biological treatment for stabilizing archaeological iron as a promising alternative to traditional conservation-restoration methods. IMPORTANCE Since the Iron Age, iron has been a fundamental material for the building of objects used in everyday life. However, due to its reactivity, iron can be easily corroded, and the physical stability of the object built is at risk. This is particularly true for archaeological objects on which a potentially unstable corrosion layer is

  18. Evidence for Biogenic Iron in Ediacaran Limestones of the Yenisei Ridge Vorogovka Series (South-Western Framing of the Siberian Craton).

    NASA Astrophysics Data System (ADS)

    Vinogradov, E.; Kosareva, L.; Metelkin, D. V.; Vishnevskaya, I.

    2017-12-01

    The composition and origin of magnetic minerals are used for reconstructing paleogeography and changes in paleoenvironments. Ediacaran limestones of the Vorogovka Series were studied in the Yenisei Ridge. Rock magnetism of the upper part of the Vorogovka Series completely depends on terrigenous admixture of iron. Non-carbonate residue consists of quartz, plagioclase, muscovite, Fe-Mg chlorite, smectite and pyrite. A prominent positive correlation is observed between the Fe content (1550…9350 ppm) and the amount of insoluble residue. Magnetization of the lower part of Vorogovka Series is due to authigenic iron. There are several indirect indications of the presence of magnetotactic bacteria and seaweed remains in these limestones. While Fe content is high (1200…8330 ppm), Fe-hydroxides, pyrite and other minerals indicating secondary transformations were not detected. Thus, iron was included in the carbonate material during sedimentation. There is no correlation between iron content and the amount of insoluble residue, which indicates that iron could not have been taken from terrigenous admixture. Study of the dependence of magnetic susceptibility from temperature in inert atmosphere (argon) revealed magnetic minerals with demagnetization temperatures of 320°C and 580°C. The former may correspond to greigite (Curie Temperature 307°C) or hexagonal pyrrhotine (325°C). The latter indicates magnetite (Curie Temperature 586°C) which may be authigenic or newly formed during the experiment. Both magnetite and greigite, are major biogenic minerals produced by magnetotactic bacteria. The main environment of modern magnetotactic bacteria is microaerophilic habitat. Therefore, their abundant presence in the Ediacaran sediments is quite natural. All of these are preliminary conclusions until bacteria can be visualized by electron microscopy, which is an ongoing. The work was supported by the Ministry of Education and Science of Russia 5.2324.2017/4.6 and the RFBR 15-05-01428.

  19. Biogenic hydroxysulfate green rust, a potential electron acceptor for SRB activity

    NASA Astrophysics Data System (ADS)

    Zegeye, Asfaw; Huguet, Lucie; Abdelmoula, Mustapha; Carteret, Cédric; Mullet, Martine; Jorand, Frédéric

    2007-11-01

    Microbiological reduction of a biogenic sulfated green rust (GR2(SO42-)), was examined using a sulfate reducing bacterium ( Desulfovibrio alaskensis). Experiments investigated whether GR2(SO42-) could serve as a sulfate source for D. alaskensis anaerobic respiration by analyzing mineral transformation. Batch experiments were conducted using lactate as the electron donor and biogenic GR2(SO42-) as the electron acceptor, at circumneutral pH in unbuffered medium. GR2(SO42-) transformation was monitored with time by X-ray diffraction (XRD), Transmission Mössbauer Spectroscopy (TMS), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The reduction of sulfate anions and the formation of iron sulfur mineral were clearly identified by XPS analyses. TMS showed the formation of additional mineral as green rust (GR) and vivianite. XRD analyses discriminated the type of the newly formed GR as GR1. The formed GR1 was GR1(CO32-) as indicated by DRIFTS analysis. Thus, the results presented in this study indicate that D. alaskensis cells were able to use GR2(SO42-) as an electron acceptor. GR1(CO32-), vivianite and an iron sulfur compound were formed as a result of GR2(SO42-) reduction by D. alaskensis. Hence, in environments where geochemical conditions promote biogenic GR2(SO42-) formation, this mineral could stimulate the anaerobic respiration of sulfate reducing bacteria.

  20. Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.

    PubMed

    Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

    2014-03-01

    Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. Copyright © 2014. Published by Elsevier B.V.

  1. Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

    NASA Astrophysics Data System (ADS)

    Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

    2016-05-01

    Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

  2. [Effect of temperature on activity of Acidithiobacillus ferrooxidan and formation of biogenic secondary iron minerals].

    PubMed

    Song, Yong-Wei; Zhao, Bo-Wen; Huo, Min-Bo; Cui, Chun-Hong; Zhou, Li-Xiang

    2013-08-01

    In this study, batch experiments were performed to investigate the effect of temperature on the Fe (II) oxidation and the formation of biogenic secondary iron minerals by Acidithiobacillus ferrooxidan. Results showed that the low temperature significantly inhibited the oxidation activity of A. ferrooxidan. In the FeSO4-H2O biological oxidation system facilitated by A. ferrooxidan, it was found that after 5 days culture, the oxidation rates of Fe (II) in treatments of 10 degrees C and 28 degrees C were 11.81% and 100%, respectively. In addition, it rapidly rose to 95.10% when the temperature was adjusted from 10 degrees C (cultured for 7 days) to 28 degrees C in 1 day, and the maximum oxidation rates were as follows: 10 degrees C (cultured for 7 days) +28 degrees C (2.25 h(-1)) > 28 degrees C (1.42 h(-1)) >10 degrees C (0.81 h(-1)). Furthermore, the XRD patterns showed that the lower Fe (III) supply rate was more conducive to the formation of amorphous schwertmannite in 9K medium at 10 degrees C. Correspondingly, the generation of amorphous schwertmannite was preceded to ihleite at 28 degrees C, and the crystallinity degree of ihleite was getting better with the extension of culture time. Combined with the SEM characteristics, it was judged that the 28 degrees C sample contained jarosite and schwertmannite.

  3. Biogenic Emission Inventories: Scaling Local Biogenic Measurements to Regions

    NASA Astrophysics Data System (ADS)

    Lamb, B.; Pressley, S.; Westberg, H.; Guenther, A.

    2002-12-01

    Biogenic Hydrocarbons, such as isoprene, are important trace gas species that are naturally emitted by vegetation and that affect the oxidative capacity of the atmosphere. Biogenic emissions are regulated by many environmental variables; the most important variables are thought to be temperature and light. Long-term isoprene flux measurements are useful for verifying existing canopy models and exploring other correlations between isoprene fluxes and environmental parameters. Biogenic Emission Models, such as BEIS (Biogenic Emission Inventory System) rely on above canopy environmental parameters and below canopy scaling factors to estimate canopy scale biogenic hydrocarbon fluxes. Other models, which are more complex, are coupled micrometeorological and physiological modules that provide feedback mechanisms present in a canopy environment. These types of models can predict biogenic emissions well, however, the required input is extensive, and for regional applications, they can be cumbersome. This paper presents analyses based on long-term isoprene flux measurements that have been collected since 1999 at the AmeriFlux site located at the University of Michigan Biological Station (UMBS) as part of the Program for Research on Oxidants: PHotochemistry, Emissions, and Transport (PROPHET). The goals of this research were to explore a potential relationship between the surface energy budget (primarily sensible heat flux) and isoprene emissions. Our hypothesis is that the surface energy flux is a better model parameter for isoprene emissions at the canopy scale than temperature and light levels, and the link to the surface energy budget will provide a significant improvement in isoprene emission models. Preliminary results indicate a significant correlation between daily isoprene emissions and sensible heat fluxes for a predominantly aspen/oak stand located in northern Michigan. Since surface energy budgets are an integral part of mesoscale meteorological models, this

  4. Preserved Filamentous Microbial Biosignatures in the Brick Flat Gossan, Iron Mountain, California.

    PubMed

    Williams, Amy J; Sumner, Dawn Y; Alpers, Charles N; Karunatillake, Suniti; Hofmann, Beda A

    2015-08-01

    A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous

  5. Preserved filamentous microbial biosignatures in the Brick Flat gossan, Iron Mountain, California

    USGS Publications Warehouse

    Williams, Amy J.; Sumner, Dawn Y.; Alpers, Charles N.; Karunatillake, Suniti; Hofmann, Beda A

    2015-01-01

    A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous

  6. Evaluating the influence of National Research Council levels of copper, iron, manganese, and zinc using organic (Bioplex) minerals on resulting tissue mineral concentrations, metallothionein, and liver antioxidant enzymes in grower-finisher swine diets.

    PubMed

    Gowanlock, D W; Mahan, D C; Jolliff, J S; Hill, G M

    2015-03-01

    Graded levels of a trace mineral premix containing an organic (Bioplex) source of Cu, Fe, Mn, and Zn was evaluated with additional treatments containing organic Zn or Fe. Grower-finisher pigs were fed from 25 to 115 kg BW. The number of pigs in the experiment, the breeding/genetics of the pigs, the management, and the average age of the pigs were previously reported. The experiment was conducted as a randomized complete block design in 7 replicates. Treatments were 1) basal diet without supplemental Cu, Fe, Mn, and Zn; 2) basal diet + 2.5 mg/kg Cu, 50 mg/kg Fe, 1.5 mg/kg Mn, and 40 mg/kg Zn (50% NRC); 3) basal diet + 5 mg/kg Cu, 100 mg/kg Fe, 3 mg/kg Mn, and 80 mg/kg Zn (100% NRC); 4) basal diet + 25 mg Zn/kg; 5) basal diet + 50 mg Zn/kg; and 6) basal diet + 50 mg Fe/kg. Selenium and I were added to all diets at 0.3 and 0.14 mg/kg, respectively. Diets were composed of corn-soybean meal, dicalcium phosphate, and limestone with phytase added to enhance mineral availability. Three pigs per pen were bled at 55, 80, and 115 kg BW and plasma was analyzed for microminerals. When the average replicate BW was 115 kg, 3 pigs per pen of an equal gender ratio were killed. The liver, kidney, and heart were removed and analyzed for microminerals. Liver, duodenum, and jejunal metallothionein and the antioxidant enzymes in the liver containing these microminerals were determined. The results demonstrated that plasma minerals were unaffected at the 3 BW intervals. Liver and duodenum metallothionein protein were greater ( < 0.05) as dietary micromineral levels increased but jejunum metallothionein did not change as microminerals increased. The activity of Cu/Zn superoxide dismutase (SOD) was not affected as the levels of the micromineral increased, whereas the activity of Mn SOD increased slightly ( < 0.05) to the 50% NRC treatment level. Liver Zn (relative and total) increased ( < 0.05) as dietary micromineral levels increased and also when Zn was added singly to the diet. Liver

  7. Biogenic iron oxide transformation by hyperthermophiles: spectral and physiological potentials

    NASA Astrophysics Data System (ADS)

    Kashyap, S.; Sklute, E.; Dyar, M. D.; Holden, J. F.

    2017-12-01

    It is likely that any putative life in our Solar System beyond Earth, extinct or extant, is microbial. However, to detect such life, distinct organic or mineral biosignatures need to be established. Microbe-mineral interactions and mineral transformations deserve further examination in this regard. This study focused on hyperthermophilic iron oxide-reducing archaea and addressed the types of iron-oxide minerals that are favored for growth, the kinetics of such reactions, and the mineral transformations that occur depending upon the electron acceptor. Two hyperthermophilic archaea (Pyrodictium delaneyi and Pyrobaculum islandicum) and six laboratory-synthesized nanophase iron oxide minerals (2-line ferrihydrite, lepidocrocite, akaganéite, goethite, hematite and maghemite) were tested for cell growth and Fe(II) production. The mineral end-products were further characterized by examining the spectral signatures associated with these transformations using reflectance, Raman, and Mössbauer spectroscopies and electron diffraction patterns. Additionally, we critically examined how sample preparation techniques influence the end products of these transformations by comparing freeze-dried samples against those still in solution. Results showed that both organisms utilize all six nanophase iron oxides, although with varying success. The best candidates for microbial reduction were ferrihydrite, akaganéite, and lepidocrocite. The mineral transformation products and the extent of reduction varied and showed subtle differences based on organism and the type of iron oxide used. The subtle spectral differences were best characterized using combined spectroscopy techniques. This research provides new insights into microbe-mineral interactions and the discrimination of potential biosignatures in the search for life beyond Earth.

  8. Biogenic formation and growth of uraninite (UO₂).

    PubMed

    Lee, Seung Yeop; Baik, Min Hoon; Choi, Jong Won

    2010-11-15

    Biogenic UO₂ (uraninite) nanocrystals may be formed as a product of a microbial reduction process in uranium-enriched environments near the Earth's surface. We investigated the size, nanometer-scale structure, and aggregation state of UO₂ formed by iron-reducing bacterium, Shewanella putrefaciens CN32, from a uranium-rich solution. Characterization of biogenic UO₂ precipitates by high-resolution transmission electron microscopy (HRTEM) revealed that the UO₂ nanoparticles formed were highly aggregated by organic polymers. Nearly all of the nanocrystals were networked in more or less 100 nm diameter spherical aggregates that displayed some concentric UO₂ accumulation with heterogeneity. Interestingly, pure UO₂ nanocrystals were piled on one another at several positions via UO₂-UO₂ interactions, which seem to be intimately related to a specific step in the process of growing large single crystals. In the process, calcium that was easily complexed with aqueous uranium(VI) appeared not to be combined with bioreduced uranium(IV), probably due to its lower binding energy. However, when phosphate was added to the system, calcium was found to be easily associated with uranium(IV), forming a new uranium phase, ningyoite. These results will extend the limited knowledge of microbial uraniferous mineralization and may provide new insights into the fate of aqueous uranium complexes.

  9. Digestibility and retention of zinc, copper, manganese, iron, calcium, and phosphorus in pigs fed diets containing inorganic or organic minerals.

    PubMed

    Liu, Y; Ma, Y L; Zhao, J M; Vazquez-Añón, M; Stein, H H

    2014-08-01

    The objective of this experiment was to measure the apparent total tract digestibility (ATTD) and the retention rate of Zn, Cu, Mn, and Fe in pigs fed either inorganic or organic sources of Zn, Cu, Mn, and Fe. The experimental design was a randomized complete block design with a 2 × 3 factorial arrangement of treatments. There were 2 types of diets (corn grits-based or corn-soybean meal [SBM]-based diets) and 3 micromineral treatments (basal micromineral premix [BMM], inorganic micromineral premix [IMM], and organic micromineral premix [OMM]). The BMM contained no added Zn, Cu, Mn, or Fe; the IMM microminerals were provided as sulfates of Zn, Cu, Mn, and Fe at 40, 50, 20, and 100 mg/kg, respectively. The OMM contained the same levels of the 4 microminerals as IMM, but Zn, Cu, Mn, and Fe in this premix were provided by Zn(2-hydroxy-4-methylthio butanoic acid [HMTBa])2, Cu(HMTBa)2, Mn(HMTBa)2, and FeGly, respectively. Forty-eight barrows (initial BW: 31.1 ± 4.2 kg) were housed individually and allowed ad libitum access to the corn grits diet with BMM for 2 wk. All pigs were then moved to metabolism cages and randomly assigned to 1 of the 6 treatment diets with 8 replicates per diet. Fecal and urine samples were collected for 5 d following a 5-d adaptation period. Compared with corn grits diets, pigs fed corn-SBM diets had greater (P < 0.05) absorption and retention of Zn, Cu, and Mn but less (P < 0.05) ATTD of Zn and Cu. Compared with BMM, supplementation of IMM or OMM increased (P < 0.05) absorption, retention, ATTD, and retention rate of Zn, Cu, Mn, and Fe. Compared with IMM, adding OMM to the corn-SBM diet improved (P < 0.05) the absorption and retention of Cu and Mn and the ATTD of Cu, but these differences were not observed in the corn grits diets (interaction, P < 0.05). In addition, adding OMM to the corn-SBM diet increased (P < 0.05) absorption and retention of Zn and Fe and ATTD of Zn, Mn, and Fe compared with adding IMM to the corn-SBM diet

  10. Preserved Filamentous Microbial Biosignatures in the Brick Flat Gossan, Iron Mountain, California

    PubMed Central

    Sumner, Dawn Y.; Alpers, Charles N.; Karunatillake, Suniti; Hofmann, Beda A.

    2015-01-01

    Abstract A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses

  11. Hexagonal platelet-like magnetite as a biosignature of thermophilic iron-reducing bacteria and its applications to the exploration of the modern deep, hot biosphere and the emergence of iron-reducing bacteria in early precambrian oceans.

    PubMed

    Li, Yi-Liang

    2012-12-01

    Dissimilatory iron-reducing bacteria are able to enzymatically reduce ferric iron and couple to the oxidation of organic carbon. This mechanism induces the mineralization of fine magnetite crystals characterized by a wide distribution in size and irregular morphologies that are indistinguishable from authigenic magnetite. Thermoanaerobacter are thermophilic iron-reducing bacteria that predominantly inhabit terrestrial hot springs or deep crusts and have the capacity to transform amorphous ferric iron into magnetite with a size up to 120 nm. In this study, I first characterize the formation of hexagonal platelet-like magnetite of a few hundred nanometers in cultures of Thermoanaerobacter spp. strain TOR39. Biogenic magnetite with such large crystal sizes and unique morphology has never been observed in abiotic or biotic processes and thus can be considered as a potential biosignature for thermophilic iron-reducing bacteria. The unique crystallographic features and strong ferrimagnetic properties of these crystals allow easy and rapid screening for the previous presence of iron-reducing bacteria in deep terrestrial crustal samples that are unsuitable for biological detection methods and, also, the search for biogenic magnetite in banded iron formations that deposited only in the first 2 billion years of Earth with evidence of life.

  12. Identifying and Quantifying Chemical Forms of Sediment-Bound Ferrous Iron.

    NASA Astrophysics Data System (ADS)

    Kohler, M.; Kent, D. B.; Bekins, B. A.; Cozzarelli, I.; Ng, G. H. C.

    2015-12-01

    Aqueous Fe(II) produced by dissimilatory iron reduction comprises only a small fraction of total biogenic Fe(II) within an aquifer. Most biogenic Fe(II) is bound to sediments on ion exchange sites; as surface complexes and, possibly, surface precipitates; or incorporated into solid phases (e.g., siderite, magnetite). Different chemical forms of sediment-bound Fe(II) have different reactivities (e.g., with dissolved oxygen) and their formation or destruction by sorption/desorption and precipitation/dissolution is coupled to different solutes (e.g., major cations, H+, carbonate). We are quantifying chemical forms of sediment-bound Fe(II) using previously published extractions, novel extractions, and experimental studies (e.g., Fe isotopic exchange). Sediments are from Bemidji, Minnesota, where biodegradation of hydrocarbons from a burst oil pipeline has driven extensive dissimilatory Fe(III) reduction, and sites potentially impacted by unconventional oil and gas development. Generally, minimal Fe(II) was mobilized from ion exchange sites (batch desorption with MgCl2 and repeated desorption with NH4Cl). A < 2mm sediment fraction from the iron-reducing zone at Bemidji had 1.8umol/g Fe(II) as surface complexes or carbonate phases (sodium acetate at pH 5) of which ca. 13% was present as surface complexes (FerroZine extractions). Total bioavailable Fe(III) and biogenic Fe(II) (HCl extractions) was 40-50 umole/g on both background and iron-reducing zone sediments . Approximately half of the HCl-extractable Fe from Fe-reducing zone sediments was Fe(II) whereas 12 - 15% of Fe extracted from background sediments was present as Fe(II). One-third to one-half of the total biogenic Fe(II) extracted from sediments collected from a Montana prairie pothole located downgradient from a produced-water disposal pit was present as surface-complexed Fe(II).

  13. Microbial Communities Associated with Biogenic Iron Oxide Mineralization in Circumneutral pH Environments

    NASA Astrophysics Data System (ADS)

    Chan, C. S.; Banfield, J. F.

    2002-12-01

    Lithotrophic growth on iron is a metabolism that has been found in a variety of neutral pH environments and is likely important in sustaining life in microaerophilic solutions, especially those low in organics. The composition of the microbial communities, especially the organisms that are responsible for iron oxidation, and carbon and nitrogen fixation, are not known, yet the ability to recognize these contributions is vital to our understanding of iron cycling in natural environments. Our approach has been to study the microbial community structure, mineralogy, and geochemistry of ~20 cm thick, 100's meters long, fluffy iron oxide-encrusted biological mats growing in the Piquette Mine tunnel, and to compare the results to those from geochemically similar environments. In situ measurements (Hydrolab) and geochemical characterization of bulk water samples and peepers (dialysis sampling vials) indicate that the environment is microaerobic, with micromolar levels of iron, high carbonate and sulfate, and typical groundwater nitrate and nitrite concentrations. 16S rDNA clone libraries show that the microbial mat and water contain communities with considerable diversity within the Bacterial domain, a large proportion of Nitrospira and Betaproteobacteria, and no Archaea. Because clone library data are not necessarily indicative of actual abundance, fluorescence in-situ hybridization (FISH) was performed on water, mat, and sediment samples from the Piquette mine and two circumneutral iron- and carbonate-rich springs in the Oregon Cascade Range. Domain- and phylum-level probes were chosen based on the clone library results (Nitrospira, Beta- and Gammaproteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Planctomyces). FISH data reveal spatial associations between specific microbial groups and mineralized structures. The organisms responsible for making the mineralized sheaths that compose the bulk of the iron oxide mat are Betaproteobacteria (probably Leptothrix

  14. Iron biomineralization of brain tissue and neurodegenerative disorders

    NASA Astrophysics Data System (ADS)

    Mikhaylova (Mikhailova), Albina

    The brain is an organ with a high concentration of iron in specific areas, particularly in the globus pallidus, the substantia nigra, and the red nucleus. In certain pathological states, such as iron overload disease and neurodegenerative disorders, a disturbed iron metabolism can lead to increased accumulation of iron not only in these areas, but also in the brain regions that are typically low in iron content. Recent studies of the physical and magnetic properties of metalloproteins, and in particular the discovery of biogenic magnetite in human brain tissue, have raised new questions about the role of biogenic iron formations in living organisms. Further investigations revealed the presence of magnetite-like crystalline structures in human ferritin, and indicated that released ferritin iron might act as promoter of oxidative damage to tissue, therefore contributing to pathogenesis of neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases. The purpose of this work was to examine the elemental composition and structure of iron deposits in normal brain tissue as well as tissue affected by neurodegenerative disorders. Employing the methods of X-ray microfocus fluorescence mapping, X-ray Absorption Near Edge Structure (XANES), X-ray Absorption Fine Structure spectroscopy (XAFS), and light and electron microscopic examinations allows one to obtain qualitative as well as quantitative data with respect to the cellular distribution and chemical state of iron at levels not detected previously. The described tissue preparation technique allows not only satisfactory XAS iron elemental imaging in situ but also multimodal examination with light and electron microscopes of the same samples. The developed protocol has assured consistent and reproducible results on relatively large sections of flat-embedded tissue. The resulting tissue samples were adequate for XAS examination as well as sufficiently well-preserved for future microscopy studies

  15. Arsenic removal from acidic solutions with biogenic ferric precipitates.

    PubMed

    Ahoranta, Sarita H; Kokko, Marika E; Papirio, Stefano; Özkaya, Bestamin; Puhakka, Jaakko A

    2016-04-05

    Treatment of acidic solution containing 5g/L of Fe(II) and 10mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7h, 96-98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pH<2.4. As(III) was partially oxidized to As(V) in the system. In shake flask experiments, As(V) sorbed onto jarosite better than As(III). Moreover, the sorption capacity of biogenic jarosite was significantly higher than that of synthetic jarosite. The developed bioprocess simultaneously and efficiently removes iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Framework for Assessing Biogenic CO2 Emissions from ...

    EPA Pesticide Factsheets

    This revision of the 2011 report, Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, evaluates biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with assessing biogenic carbon dioxide emissions from stationary sources. EPA developed the revised report, Framework for Assessing Biogenic CO2 Emissions from Stationary Sources, to present a methodological framework for assessing the extent to which the production, processing, and use of biogenic material at stationary sources for energy production results in a net atmospheric contribution of biogenic CO2 emissions. Biogenic carbon dioxide emissions are defined as CO2 emissions related to the natural carbon cycle, as well as those resulting from the production, harvest, combustion, digestion, decomposition, and processing of biologically-based materials. The EPA is continuing to refine its technical assessment of biogenic CO2 emissions through another round of targeted peer review of the revised study with the EPA Science Advisory Board (SAB). This study was submitted to the SAB's Biogenic Carbon Emissions Panel in February 2015. http://yosemite.epa.gov/sab/sabproduct.nsf/0/3235dac747c16fe985257da90053f252!OpenDocument&TableRow=2.2#2 The revised report will inform efforts by policymakers, academics, and other stakeholders to evaluate the technical aspects related to assessments of biogenic feedstocks used for energy at s

  17. To what extent can biogenic SOA be controlled?

    PubMed

    Carlton, Annmarie G; Pinder, Robert W; Bhave, Prakash V; Pouliot, George A

    2010-05-01

    The implicit assumption that biogenic secondary organic aerosol (SOA) is natural and can not be controlled hinders effective air quality management. Anthropogenic pollution facilitates transformation of naturally emitted volatile organic compounds (VOCs) to the particle phase, enhancing the ambient concentrations of biogenic secondary organic aerosol (SOA). It is therefore conceivable that some portion of ambient biogenic SOA can be removed by controlling emissions of anthropogenic pollutants. Direct measurement of the controllable fraction of biogenic SOA is not possible, but can be estimated through 3-dimensional photochemical air quality modeling. To examine this in detail, 22 CMAQ model simulations were conducted over the continental U.S. (August 15 to September 4, 2003). The relative contributions of five emitted pollution classes (i.e., NO(x), NH(3), SO(x), reactive non methane carbon (RNMC) and primary carbonaceous particulate matter (PCM)) on biogenic SOA were estimated by removing anthropogenic emissions of these pollutants, one at a time and all together. Model results demonstrate a strong influence of anthropogenic emissions on predicted biogenic SOA concentrations, suggesting more than 50% of biogenic SOA in the eastern U.S. can be controlled. Because biogenic SOA is substantially enhanced by controllable emissions, classification of SOA as biogenic or anthropogenic based solely on VOC origin is not sufficient to describe the controllable fraction.

  18. Quantification of Biogenic Magnetite by Synchrotron X-ray Microscopy During the PETM

    NASA Astrophysics Data System (ADS)

    Wang, H.; Wang, J.; Kent, D. V.; Chen-Wiegart, Y. C. K.

    2014-12-01

    Exceptionally large biogenic magnetite crystals, including spearhead-like and spindle-like ones up to 4 microns, have been reported in clay-rich sediments recording the ~56 Ma Paleocene-Eocene thermal maximum (PETM) and carbon isotope excursion (CIE) in a borehole at Ancora, NJ and along with magnetotactic bacteria (MTB) chains, were suggested [Schumann et al. 2008 PNAS; Kopp et al. 2009 Paleoceanography] to account for the distinctive single domain (SD) rock magnetic properties of these sediments [Lanci et al. 2002 JGR]. However, because uncalibrated magnetic extraction techniques were used to provide material for TEM imaging of the biogenic magnetite, it is difficult to quantitatively analyze their concentration in the bulk clay. In this study, we use a synchrotron transmission X-ray microscope to image bulk CIE clay. We first take mosaic images of sub-millimeter-sized bulk clay samples, in which we can identify many of the various types of giant biogenic magnetite crystals, as well as several other types of iron minerals, such as pyrite framboids, siderite, and detrital magnetite. However, limited by the instrument resolution (~50 nm), we are not able to identify MTB chains let alone isolated magnetic nanoparticles that may be abundant the clay. To quantitatively estimate the concentration of the giant biogenic magnetite, we re-deposited the bulk clay sample in an alcohol solution on a silicon nitride membrane for 2D X-ray scans. After scanning a total area of 0.55 mm2 with average clay thickness of 4 μm, we identified ~40 spearheads, ~5 spindles and a few elongated rods and estimated their total magnetization as SD particles to be less than about 10% of the mass normalized clay for the scanned area. This result suggests that the giant biogenic magnetite is not a major source of the SD signal for the clay and is in good agreement with rock magnetic analyses using high-resolution first-order reversal curves and thermal fluctuation tomography on bulk CIE clay

  19. Influence of iron sulfides on abiotic oxidation of UO2 by nitrite and dissolved oxygen in natural sediments.

    PubMed

    Carpenter, Julian; Bi, Yuqiang; Hayes, Kim F

    2015-01-20

    Iron sulfide precipitates formed under sulfate reducing conditions may buffer U(IV) insoluble solid phases from reoxidation after oxidants re-enter the reducing zone. In this study, sediment column experiments were performed to quantify the effect of biogenic mackinawite on U(IV) stability in the presence of nitrite or dissolved oxygen (DO). Two columns, packed with sediment from an abandoned U contaminated mill tailings site near Rifle, CO, were biostimulated for 62 days with an electron donor (3 mM acetate) in the presence (BRS+) and absence (BRS−) of 7 mM sulfate. The bioreduced sediment was supplemented with synthetic uraninite (UO2(s)), sterilized by gamma-irradiation, and then subjected to a sequential oxidation by nitrite and DO. Biogenic iron sulfides produced in the BRS+ column, mostly as mackinawite, inhibited U(IV) reoxidation and mobilization by both nitrite and oxygen. Most of the influent nitrite (0.53 mM) exited the columns without oxidizing UO2, while a small amount of nitrite was consumed by iron sulfides precipitates. An additional 10-day supply of 0.25 mM DO influent resulted in the release of about 10% and 49% of total U in BRS+ and BRS– columns, respectively. Influent DO was effectively consumed by biogenic iron sulfides in the BRS+ column, while DO and a large U spike were detected after only a brief period in the effluent in the BRS– column.

  20. The role of heterotrophic bacteria in iron-limited ocean ecosystems

    NASA Astrophysics Data System (ADS)

    Tortell, Philippe D.; Maldonado, Maria T.; Price, Nell M.

    1996-09-01

    IRON availability limits phytoplankton growth in large areas of the world's oceans1-3 and may influence the strength of the biological carbon pump4,5. Very little is known of the iron requirements of oceanic heterotrophic bacteria, which constitute up to 50% of the total particulate organic carbon in open ocean waters6,7 and are important in carbon cycling as remineralizers of dissolved organic matter and hence producers of CO2 (ref. 8). Here we report that oceanic bacteria contain more iron per biomass than phytoplankton. In the subarctic Pacific, they constitute a large fraction of biogenic iron and account for 20-45% of biological iron uptake. Bacterial iron quotas in the field are similar to those of iron-deficient laboratory cultures, which exhibit reduced elec-tron transport, slow growth, and low carbon growth efficiency. Heterotrophic bacteria therefore play a major role in the biogeo-chemical cycling of iron. In situ iron limitation of heterotrophic metabolism may have profound effects on carbon flux in the ocean.

  1. Iron, zinc and iodide status in Mexican children under 12 years and women 12-49 years of age. A probabilistic national survey.

    PubMed

    Villalpando, Salvador; García-Guerra, Armando; Ramírez-Silva, Claudia Ivonne; Mejía-Rodríguez, Fabiola; Matute, Guadalupe; Shamah-Levy, Teresa; Rivera, Juan A

    2003-01-01

    To describe the epidemiology of iron, zinc and iodide deficiencies in a probabilistic sample of Mexican women and children and explore its association with some dietary and socio-demographic variables. We carried out in 1999 an epidemiological description of iron (percent transferrin saturation, PTS, < 16%), serum zinc (< 65 ug/dl) and iodide (< 50 ug/l urine) deficiencies in a probabilistic sample of 1,363 Mexican children under 12 years and of 731 women of child-bearing age. Serum iron, Total Iron Binding Capacity (TIBC) and zinc were measured by atomic absorption spectrometry, and urinary iodide by a colorimetric method. Logistic regression models explored determinants for such micromineral deficiencies. Iron deficiency was higher (67%) in infants < 2 years of age. Prevalence declined (34-39%) at school age. The prevalence for iron deficiency in women was 40%. Zinc deficiency was higher in infants < 2 years of age (34%) than in school-age children (19-24%). Prevalence in women was 30%, with no rural/urban difference. In women the likelihood of iron deficiency decreased as SEL improved (p = 0.04) and increased with the intake of cereals (p = 0.01). The likelihood of low serum zinc levels was greater in women and children of low socioeconomic level (SEL) (p < 0.02 and p = 0.001) iodide deficiency was negligible in both children and women. The data shows high prevalence of iron deficiency-specially in infants 12 to 24 months of age. It is suggested that in older children and women 12 to 49 years of age that iron bioavailability is low. The prevalence of zinc deficiency was also very high. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

  2. Biogenic nanomaterials from photosynthetic microorganisms.

    PubMed

    Jeffryes, Clayton; Agathos, Spiros N; Rorrer, Gregory

    2015-06-01

    The use of algal cell cultures represents a sustainable and environmentally friendly platform for the biogenic production of nanobiomaterials and biocatalysts. For example, advances in the production of biogeneic nanomaterials from algal cell cultures, such as crystalline β-chitin nanofibrils and gold and silver nanoparticles, could enable the 'green' production of biomaterials such as tissue-engineering scaffolds or drug carriers, supercapacitors and optoelectric materials. The in vivo functionalization, as well as newly demonstrated methods of production and modification, of biogenic diatom biosilica have led to the development of organic-inorganic hybrid catalytic systems as well as new biomaterials for drug delivery, biosensors and heavy-metal adsorbents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

    NASA Astrophysics Data System (ADS)

    Hamilton, J. F.; Alfarra, M. R.; Robinson, N.; Ward, M. W.; Lewis, A. C.; McFiggans, G. B.; Coe, H.; Allan, J. D.

    2013-11-01

    Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding these transformation processes has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a Southeast Asian tropical rainforest in Borneo were characterised using liquid chromatography-ion trap mass spectrometry, high-resolution aerosol mass spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyl tetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

  4. Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

    NASA Astrophysics Data System (ADS)

    Hamilton, J. F.; Alfarra, M. R.; Robinson, N.; Ward, M. W.; Lewis, A. C.; McFiggans, G. B.; Coe, H.; Allan, J. D.

    2013-07-01

    Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding the process of these transformations has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a South East Asian tropical rainforest in Borneo were characterised using liquid chromatography-ion trap mass spectrometry, high resolution aerosol mass spectrometry and fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyltetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

  5. MEASUREMENT OF BIOGENIC EMISSION FROM CORN

    EPA Science Inventory

    A pilot study was conducted to determine whether techniques for measuring biogenic emissions from tree saplings, branches, and leaves could be adapted to the measurement of biogenic emissions from individual plants of agricultural species. easurements were then made to determine ...

  6. Controlled cobalt doping in biogenic magnetite nanoparticles

    PubMed Central

    Byrne, J. M.; Coker, V. S.; Moise, S.; Wincott, P. L.; Vaughan, D. J.; Tuna, F.; Arenholz, E.; van der Laan, G.; Pattrick, R. A. D.; Lloyd, J. R.; Telling, N. D.

    2013-01-01

    Cobalt-doped magnetite (CoxFe3 −xO4) nanoparticles have been produced through the microbial reduction of cobalt–iron oxyhydroxide by the bacterium Geobacter sulfurreducens. The materials produced, as measured by superconducting quantum interference device magnetometry, X-ray magnetic circular dichroism, Mössbauer spectroscopy, etc., show dramatic increases in coercivity with increasing cobalt content without a major decrease in overall saturation magnetization. Structural and magnetization analyses reveal a reduction in particle size to less than 4 nm at the highest Co content, combined with an increase in the effective anisotropy of the magnetic nanoparticles. The potential use of these biogenic nanoparticles in aqueous suspensions for magnetic hyperthermia applications is demonstrated. Further analysis of the distribution of cations within the ferrite spinel indicates that the cobalt is predominantly incorporated in octahedral coordination, achieved by the substitution of Fe2+ site with Co2+, with up to 17 per cent Co substituted into tetrahedral sites. PMID:23594814

  7. Controlled cobalt doping in biogenic magnetite nanoparticles.

    PubMed

    Byrne, J M; Coker, V S; Moise, S; Wincott, P L; Vaughan, D J; Tuna, F; Arenholz, E; van der Laan, G; Pattrick, R A D; Lloyd, J R; Telling, N D

    2013-06-06

    Cobalt-doped magnetite (CoxFe3 -xO4) nanoparticles have been produced through the microbial reduction of cobalt-iron oxyhydroxide by the bacterium Geobacter sulfurreducens. The materials produced, as measured by superconducting quantum interference device magnetometry, X-ray magnetic circular dichroism, Mössbauer spectroscopy, etc., show dramatic increases in coercivity with increasing cobalt content without a major decrease in overall saturation magnetization. Structural and magnetization analyses reveal a reduction in particle size to less than 4 nm at the highest Co content, combined with an increase in the effective anisotropy of the magnetic nanoparticles. The potential use of these biogenic nanoparticles in aqueous suspensions for magnetic hyperthermia applications is demonstrated. Further analysis of the distribution of cations within the ferrite spinel indicates that the cobalt is predominantly incorporated in octahedral coordination, achieved by the substitution of Fe(2+) site with Co(2+), with up to 17 per cent Co substituted into tetrahedral sites.

  8. Comparative Analysis of Microbial Communities in Iron-Dominated Flocculent Mats in Deep-Sea Hydrothermal Environments

    PubMed Central

    Kikuchi, Sakiko; Mitsunobu, Satoshi; Takaki, Yoshihiro; Yamanaka, Toshiro; Toki, Tomohiro; Noguchi, Takuroh; Nakamura, Kentaro; Abe, Mariko; Hirai, Miho; Yamamoto, Masahiro; Uematsu, Katsuyuki; Miyazaki, Junichi; Nunoura, Takuro; Takahashi, Yoshio; Takai, Ken

    2016-01-01

    ABSTRACT It has been suggested that iron is one of the most important energy sources for photosynthesis-independent microbial ecosystems in the ocean crust. Iron-metabolizing chemolithoautotrophs play a key role as primary producers, but little is known about their distribution and diversity and their ecological role as submarine iron-metabolizing chemolithotrophs, particularly the iron oxidizers. In this study, we investigated the microbial communities in several iron-dominated flocculent mats found in deep-sea hydrothermal fields in the Mariana Volcanic Arc and Trough and the Okinawa Trough by culture-independent molecular techniques and X-ray mineralogical analyses. The abundance and composition of the 16S rRNA gene phylotypes demonstrated the ubiquity of zetaproteobacterial phylotypes in iron-dominated mat communities affected by hydrothermal fluid input. Electron microscopy with energy-dispersive X-ray microanalysis and X-ray absorption fine structure (XAFS) analysis revealed the chemical and mineralogical signatures of biogenic Fe-(oxy)hydroxide species and the potential contribution of Zetaproteobacteria to the in situ generation. These results suggest that putative iron-oxidizing chemolithoautotrophs play a significant ecological role in producing iron-dominated flocculent mats and that they are important for iron and carbon cycles in deep-sea low-temperature hydrothermal environments. IMPORTANCE We report novel aspects of microbiology from iron-dominated flocculent mats in various deep-sea environments. In this study, we examined the relationship between Zetaproteobacteria and iron oxides across several hydrothermally influenced sites in the deep sea. We analyzed iron-dominated mats using culture-independent molecular techniques and X-ray mineralogical analyses. The scanning electron microscopy–energy-dispersive X-ray spectroscopy SEM-EDS analysis and X-ray absorption fine structure (XAFS) analysis revealed chemical and mineralogical signatures of

  9. Comparative Analysis of Microbial Communities in Iron-Dominated Flocculent Mats in Deep-Sea Hydrothermal Environments.

    PubMed

    Makita, Hiroko; Kikuchi, Sakiko; Mitsunobu, Satoshi; Takaki, Yoshihiro; Yamanaka, Toshiro; Toki, Tomohiro; Noguchi, Takuroh; Nakamura, Kentaro; Abe, Mariko; Hirai, Miho; Yamamoto, Masahiro; Uematsu, Katsuyuki; Miyazaki, Junichi; Nunoura, Takuro; Takahashi, Yoshio; Takai, Ken

    2016-10-01

    It has been suggested that iron is one of the most important energy sources for photosynthesis-independent microbial ecosystems in the ocean crust. Iron-metabolizing chemolithoautotrophs play a key role as primary producers, but little is known about their distribution and diversity and their ecological role as submarine iron-metabolizing chemolithotrophs, particularly the iron oxidizers. In this study, we investigated the microbial communities in several iron-dominated flocculent mats found in deep-sea hydrothermal fields in the Mariana Volcanic Arc and Trough and the Okinawa Trough by culture-independent molecular techniques and X-ray mineralogical analyses. The abundance and composition of the 16S rRNA gene phylotypes demonstrated the ubiquity of zetaproteobacterial phylotypes in iron-dominated mat communities affected by hydrothermal fluid input. Electron microscopy with energy-dispersive X-ray microanalysis and X-ray absorption fine structure (XAFS) analysis revealed the chemical and mineralogical signatures of biogenic Fe-(oxy)hydroxide species and the potential contribution of Zetaproteobacteria to the in situ generation. These results suggest that putative iron-oxidizing chemolithoautotrophs play a significant ecological role in producing iron-dominated flocculent mats and that they are important for iron and carbon cycles in deep-sea low-temperature hydrothermal environments. We report novel aspects of microbiology from iron-dominated flocculent mats in various deep-sea environments. In this study, we examined the relationship between Zetaproteobacteria and iron oxides across several hydrothermally influenced sites in the deep sea. We analyzed iron-dominated mats using culture-independent molecular techniques and X-ray mineralogical analyses. The scanning electron microscopy-energy-dispersive X-ray spectroscopy SEM-EDS analysis and X-ray absorption fine structure (XAFS) analysis revealed chemical and mineralogical signatures of biogenic Fe

  10. Biogenic Hydroxyapatite: A New Material for the Preservation and Restoration of the Built Environment.

    PubMed

    Turner, Ronald J; Renshaw, Joanna C; Hamilton, Andrea

    2017-09-20

    Ordinary Portland cement (OPC) is by weight the world's most produced man-made material and is used in a variety of applications in environments ranging from buildings, to nuclear wasteforms, and within the human body. In this paper, we present for the first time the direct deposition of biogenic hydroxyapatite onto the surface of OPC in a synergistic process which uses the composition of the cement substrate. This hydroxyapatite is very similar to that found in nature, having a similar crystallite size, iron and carbonate substitution, and a semi-crystalline structure. Hydroxyapatites with such a structure are known to be mechanically stronger and more biocompatible than synthetic or biomimetic hydroxyapatites. The formation of this biogenic hydroxyapatite coating therefore has significance in a range of contexts. In medicine, hydroxyapatite coatings are linked to improved biocompatibility of ceramic implant materials. In the built environment, hydroxyapatite coatings have been proposed for the consolidation and protection of sculptural materials such as marble and limestone, with biogenic hydroxyapatites having reduced solubility compared to synthetic apatites. Hydroxyapatites have also been established as effective for the adsorption and remediation of environmental contaminants such as radionuclides and heavy metals. We identify that in addition to providing a biofilm scaffold for nucleation, the metabolic activity of Pseudomonas fluorescens increases the pH of the growth medium to a suitable level for hydroxyapatite formation. The generated ammonia reacts with phosphate in the growth medium, producing ammonium phosphates which are a precursor to the formation of hydroxyapatite under conditions of ambient temperature and pressure. Subsequently, this biogenic deposition process takes place in a simple reaction system under mild chemical conditions and is cheap and easy to apply to fragile biological or architectural surfaces.

  11. Biogenic Emission Sources

    EPA Pesticide Factsheets

    Biogenic emissions sources come from natural sources and need to accounted for in photochemical grid models. They are computed using a model which utilizes spatial information on vegetation and land use.

  12. Isolation of iron bacteria from terrestrial and aquatic environments

    NASA Astrophysics Data System (ADS)

    Schmidt, Bertram; Szewzyk, Ulrich

    2010-05-01

    Bacteria, which are capable of iron oxidation or at least iron deposition are widely distributed in environments where zones of dissolved ferrous iron and oxygen gradients are overlapping [1]. They take part in the biological cycling of iron and influence other cycles of elements for example carbon [2]. Manganese can be used for similar metabolic purposes as iron, because it can be biologically oxidized by chemolithotrophs or can be reduced by respirating bacteria as well [3, 4]. Bacterial activity is responsible for the accumulation of ferric iron compounds in their surroundings. The formation of bog ore is a well known example for a soil horizon, with an extreme enrichment of biogenic ferric iron [5]. We focused on the isolation of neutrophilic iron bacteria and bacteria capable of manganese oxidation. We used samples from Tierra del Fuego (Argentina) the National Park "Unteres Odertal" (Germany) and Berlin ground water wells. Microscopic examination of the samples revealed a considerable diversity of iron encrusted structures of bacterial origin. Most of these morphologic types are already well known. The taxonomic classification of many of these organisms is based on morphologic features and is not reliable compared to recent methods of molecular biology. That is mainly due to the fact, that most of these bacteria are hardly culturable or do not show their characteristic morphologic features under culture conditions. We established a collection of more than 300 iron depositing strains. Phylogenetic analyses showed that we have many yet uncultured strains in pure culture. We obtained many isolates which form distinct branches within long known iron bacteria groups like the Sphaerotilus-Leptothrix cluster. But some of the strains belong to groups, which have not yet been associated with iron oxidation activity. The strains deposit high amounts of oxidized iron and manganese compounds under laboratory conditions. However it is unclear if these precipitations are

  13. IMPROVING BIOGENIC EMISSION ESTIMATES WITH SATELLITE IMAGERY

    EPA Science Inventory

    This presentation will review how existing and future applications of satellite imagery can improve the accuracy of biogenic emission estimates. Existing applications of satellite imagery to biogenic emission estimates have focused on characterizing land cover. Vegetation dat...

  14. Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site, Nevada City, CA

    USGS Publications Warehouse

    Foster, Andrea L.; Ashley, Roger P.; Rytuba, James J.

    2011-01-01

    Sub- to anoxic conditions minimize dissolution of arsenopyrite at the LCMS site, but may accelerate the dissolution of As-bearing secondary iron phases such as Fe3+-oxyhydroxides and arseniosiderite, if sufficient organic matter is present to spur anaerobic microbial activity. Oxidizing, dry conditions favor the stabilization of secondary phases, while promoting oxidative breakdown of the primary sulfides. The stability of both primary and secondary As phases is likely to be at a minimum under cyclic wet-dry conditions. Biogenic iron (hydr)oxide flocs can sequester significant amounts of arsenic; this property may be useful for treatment of perpetual sources of As such as mine adit water, but the fate of As associated with natural accumulations of floc material needs to be assessed.

  15. Induction of Biogenic Magnetization and Redox Control by a Component of the Target of Rapamycin Complex 1 Signaling Pathway

    PubMed Central

    Nishida, Keiji; Silver, Pamela A.

    2012-01-01

    Most organisms are simply diamagnetic, while magnetotactic bacteria and migratory animals are among organisms that exploit magnetism. Biogenic magnetization not only is of fundamental interest, but also has industrial potential. However, the key factor(s) that enable biogenic magnetization in coordination with other cellular functions and metabolism remain unknown. To address the requirements for induction and the application of synthetic bio-magnetism, we explored the creation of magnetism in a simple model organism. Cell magnetization was first observed by attraction towards a magnet when normally diamagnetic yeast Saccharomyces cerevisiae were grown with ferric citrate. The magnetization was further enhanced by genetic modification of iron homeostasis and introduction of ferritin. The acquired magnetizable properties enabled the cells to be attracted to a magnet, and be trapped by a magnetic column. Superconducting quantum interference device (SQUID) magnetometry confirmed and quantitatively characterized the acquired paramagnetism. Electron microscopy and energy-dispersive X-ray spectroscopy showed electron-dense iron-containing aggregates within the magnetized cells. Magnetization-based screening of gene knockouts identified Tco89p, a component of TORC1 (Target of rapamycin complex 1), as important for magnetization; loss of TCO89 and treatment with rapamycin reduced magnetization in a TCO89-dependent manner. The TCO89 expression level positively correlated with magnetization, enabling inducible magnetization. Several carbon metabolism genes were also shown to affect magnetization. Redox mediators indicated that TCO89 alters the intracellular redox to an oxidized state in a dose-dependent manner. Taken together, we demonstrated that synthetic induction of magnetization is possible and that the key factors are local redox control through carbon metabolism and iron supply. PMID:22389629

  16. Biogenic Silver for Disinfection of Water Contaminated with Viruses▿

    PubMed Central

    De Gusseme, Bart; Sintubin, Liesje; Baert, Leen; Thibo, Ellen; Hennebel, Tom; Vermeulen, Griet; Uyttendaele, Mieke; Verstraete, Willy; Boon, Nico

    2010-01-01

    The presence of enteric viruses in drinking water is a potential health risk. Growing interest has arisen in nanometals for water disinfection, in particular the use of silver-based nanotechnology. In this study, Lactobacillus fermentum served as a reducing agent and bacterial carrier matrix for zerovalent silver nanoparticles, referred to as biogenic Ag0. The antiviral action of biogenic Ag0 was examined in water spiked with an Enterobacter aerogenes-infecting bacteriophage (UZ1). Addition of 5.4 mg liter−1 biogenic Ag0 caused a 4.0-log decrease of the phage after 1 h, whereas the use of chemically produced silver nanoparticles (nAg0) showed no inactivation within the same time frame. A control experiment with 5.4 mg liter−1 ionic Ag+ resulted in a similar inactivation after 5 h only. The antiviral properties of biogenic Ag0 were also demonstrated on the murine norovirus 1 (MNV-1), a model organism for human noroviruses. Biogenic Ag0 was applied to an electropositive cartridge filter (NanoCeram) to evaluate its capacity for continuous disinfection. Addition of 31.25 mg biogenic Ag0 m−2 on the filter (135 mg biogenic Ag0 kg−1 filter medium) caused a 3.8-log decline of the virus. In contrast, only a 1.5-log decrease could be obtained with the original filter. This is the first report to demonstrate the antiviral efficacy of extracellular biogenic Ag0 and its promising opportunities for continuous water disinfection. PMID:20038697

  17. Framework for Assessing Biogenic CO2 Emissions from Stationary Sources

    EPA Science Inventory

    This revision of the 2011 report, Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, evaluates biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with assessing biogenic carbon dioxide...

  18. Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Toner, Brandy M.; Santelli, Cara M.; Marcus, Matthew A.

    2008-05-22

    Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focusedmore » ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and secondary oxyhydroxide minerals was resolved. The Fe-encrusted biofilms formed preferentially at pyrrhotite-rich (Fe1-xS, 0<_ x<_ 0.2) regions of the incubated chimney sulfide. At the nanometer spatial scale, particles within the biofilm exhibiting lattice fringing and diffraction patterns consistent with 2-line ferrihydrite were identified infrequently. At the micron spatial scale, Fe mu EXAFS spectroscopy and mu XRD measurements indicate that the dominant form of biofilm Fe is a short-range ordered Fe oxyhydroxide characterized by pervasive edge-sharing Fe-O6 octahedral linkages. Double corner-sharing Fe-O6 linkages, which are common to Fe oxyhydroxide mineral structures of 2-line ferrihydrite, 6-line ferrihydrite, and goethite, were not detected in the biogenic iron oxyhydroxide (BIO). The suspended development of the BIO mineral structure is consistent with Fe(III) hydrolysis and polymerization in the presence of high concentrations of Fe-complexing ligands. We hypothesize that

  19. Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Toner, Brandy M.; Santelli, Cara M.; Marcus, Matthew A.; Wirth, Richard; Chan, Clara S.; McCollom, Thomas; Bach, Wolfgang; Edwards, Katrina J.

    2009-01-01

    Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (μXRF), X-ray absorption spectroscopy (μΕXAFS), and X-ray diffraction (μXRD) in conjunction with focused ion beam (FIB) sectioning, and high resolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and secondary oxyhydroxide minerals was resolved. The Fe-encrusted biofilms formed preferentially at pyrrhotite-rich (Fe 1-xS, 0 ⩽ x ⩽ 0.2) regions of the incubated chimney sulfide. At the nanometer spatial scale, particles within the biofilm exhibiting lattice fringing and diffraction patterns consistent with 2-line ferrihydrite were identified infrequently. At the micron spatial scale, Fe μEXAFS spectroscopy and μXRD measurements indicate that the dominant form of biofilm Fe is a short-range ordered Fe oxyhydroxide characterized by pervasive edge-sharing Fe-O 6 octahedral linkages. Double corner-sharing Fe-O 6 linkages, which are common to Fe oxyhydroxide mineral structures of 2-line ferrihydrite, 6-line ferrihydrite, and goethite, were not detected in the biogenic iron oxyhydroxide (BIO). The suspended development of the BIO mineral structure is consistent with Fe(III) hydrolysis and polymerization in the presence of high concentrations of Fe-complexing ligands. We hypothesize that

  20. Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum.

    PubMed

    Schumann, Dirk; Raub, Timothy D; Kopp, Robert E; Guerquin-Kern, Jean-Luc; Wu, Ting-Di; Rouiller, Isabelle; Smirnov, Aleksey V; Sears, S Kelly; Lücken, Uwe; Tikoo, Sonia M; Hesse, Reinhard; Kirschvink, Joseph L; Vali, Hojatollah

    2008-11-18

    We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the Paleocene-Eocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 microm long and hexaoctahedral prisms up to 1.4 microm long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition, lattice perfection, and oxygen isotopes consistent with an aquatic origin. Electron holography indicates single-domain magnetization despite their large crystal size. We suggest that the development of a thick suboxic zone with high iron bioavailability--a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming--drove diversification of magnetite-forming organisms, likely including eukaryotes.

  1. Marine sulfate-reducing bacteria cause serious corrosion of iron under electroconductive biogenic mineral crust

    PubMed Central

    Enning, Dennis; Venzlaff, Hendrik; Garrelfs, Julia; Dinh, Hang T; Meyer, Volker; Mayrhofer, Karl; Hassel, Achim W; Stratmann, Martin; Widdel, Friedrich

    2012-01-01

    Iron (Fe0) corrosion in anoxic environments (e.g. inside pipelines), a process entailing considerable economic costs, is largely influenced by microorganisms, in particular sulfate-reducing bacteria (SRB). The process is characterized by formation of black crusts and metal pitting. The mechanism is usually explained by the corrosiveness of formed H2S, and scavenge of ‘cathodic’ H2 from chemical reaction of Fe0 with H2O. Here we studied peculiar marine SRB that grew lithotrophically with metallic iron as the only electron donor. They degraded up to 72% of iron coupons (10 mm × 10 mm × 1 mm) within five months, which is a technologically highly relevant corrosion rate (0.7 mm Fe0 year−1), while conventional H2-scavenging control strains were not corrosive. The black, hard mineral crust (FeS, FeCO3, Mg/CaCO3) deposited on the corroding metal exhibited electrical conductivity (50 S m−1). This was sufficient to explain the corrosion rate by electron flow from the metal (4Fe0 → 4Fe2+ + 8e−) through semiconductive sulfides to the crust-colonizing cells reducing sulfate (8e− + SO42− + 9H+ → HS− + 4H2O). Hence, anaerobic microbial iron corrosion obviously bypasses H2 rather than depends on it. SRB with such corrosive potential were revealed at naturally high numbers at a coastal marine sediment site. Iron coupons buried there were corroded and covered by the characteristic mineral crust. It is speculated that anaerobic biocorrosion is due to the promiscuous use of an ecophysiologically relevant catabolic trait for uptake of external electrons from abiotic or biotic sources in sediments. PMID:22616633

  2. The ABAG biogenic emissions inventory project

    NASA Technical Reports Server (NTRS)

    Carson-Henry, C. (Editor)

    1982-01-01

    The ability to identify the role of biogenic hydrocarbon emissions in contributing to overall ozone production in the Bay Area, and to identify the significance of that role, were investigated in a joint project of the Association of Bay Area Governments (ABAG) and NASA/Ames Research Center. Ozone, which is produced when nitrogen oxides and hydrocarbons combine in the presence of sunlight, is a primary factor in air quality planning. In investigating the role of biogenic emissions, this project employed a pre-existing land cover classification to define areal extent of land cover types. Emission factors were then derived for those cover types. The land cover data and emission factors were integrated into an existing geographic information system, where they were combined to form a Biogenic Hydrocarbon Emissions Inventory. The emissions inventory information was then integrated into an existing photochemical dispersion model.

  3. Iron Sulfide Minerals Record Microbe-Mineral Interactions in Anoxic Environments

    NASA Astrophysics Data System (ADS)

    Picard, A.; Gartman, A.; Cosmidis, J.; Clarke, D. R.; Girguis, P. R.

    2017-12-01

    The precipitation of most minerals in low-temperature environments on Earth is directly or indirectly influenced by the presence of organic substances and/or microbial biomass. Notably, the influence of microorganisms on the formation of Mn and Fe oxides/oxyhydroxides at the surface of the Earth has been well characterized (Chan et al., 2011; Estes et al., 2017). However, an oxygenated atmosphere is a unique feature of planet Earth. It is therefore critical for the search of life on other planetary bodies to characterize microbe-mineral interactions that form in anoxic conditions. Here we explore the role of microorganisms on the formation of iron sulfide minerals, which form under anoxic conditions. On modern Earth, sulfate-reducing microorganisms (SRM) are the major source of dissolved sulfide in low-temperature sedimentary environments. We experimentally demonstrate that SRM play a role in the nucleation and growth of iron sulfide minerals by acting as organic templates. The physical characteristics of the resulting minerals are different from those formed under abiotic conditions. Moreover, upon forming, iron sulfide minerals become associated with organic carbon, producing a potential organo-mineral signature. We also evaluate how the presence of various organic substances affect the formation of abiotic minerals and how this could produce false biosignatures that could be mistaken as biogenic minerals. Chan, C.S., Fakra, S.C., Emerson, D., Fleming, E.J. and Edwards, K.J. (2011) Lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation. Isme Journal 5, 717-727. Estes, E.R., Andeer, P.F., Nordlund, D., Wankel, S.D. and Hansel, C.M. (2017) Biogenic manganese oxides as reservoirs of organic carbon and proteins in terrestrial and marine environments. Geobiology 15, 158-172.

  4. Controls on Deglacial Changes in Biogenic Fluxes and Authigenic Uranium in the North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Kohfeld, K. E.; Chase, Z.

    2011-12-01

    The re-organization of high-CO2 deep waters in the North Pacific Ocean may have played a crucial role in the degassing of carbon dioxide to the atmosphere during the last deglaciation. This reorganization would leave an imprint on productivity and on oxygen concentrations. We present 230Th-normalized biogenic fluxes and aU concentrations from an intermediate depth sediment core in the Northwest Pacific (RC10-196, 54.7N, 177.1E, 1007 m) and place them within the context of a synthesis of previously-published biogenic flux and aU data from the North Pacific Ocean. We evaluate several mechanisms as possible drivers of deglacial change, including changes in preservation, sediment focusing, sea ice extent, iron inputs, stratification, and circulation shifts initiated in the North Atlantic and North Pacific. Biogenic fluxes were lowest during the last glacial period (LGM, 19-23 ka). With the exception of a site at 5500 m, all sites including RC10-196, 1007 m, had higher concentrations of aU during the LGM, which implies lower pore water oxygen. Since organic carbon accumulation rates were generally lower during the LGM, these results support the idea that export production and deep-water oxygen were both reduced during the LGM in response to physical changes. Biogenic fluxes increased marginally at some locations in the NW Pacific during Heinrich Event 1 (H1; 15-18 ka) relative to the LGM. This increase may be consistent with an enhancement of ventilation to 2500-3000 m during H1, which may have helped to destratify the glacial ocean and increase nutrient delivery to surface waters. Although consistent with aU data at 2980 m water depth in the far NW Pacific, this interpretation is at odds with the relatively high concentration of aU measured during H1 at RC10-196 in the NW Pacific at 1007 m. High aU concentrations, in the absence of elevated biogenic flux, imply low oxygen bottom waters, which is inconsistent with increased ventilation. Similarly high values of aU are

  5. Production of biogenic amines in "Salamini italiani alla cacciatora PDO".

    PubMed

    Coı X0308 Sson, Jean Daniel; Cerutti, Caterina; Travaglia, Fabiano; Arlorio, Marco

    2004-06-01

    Various fermented and seasoned foods such as cheese, sauerkraut, wine, beer and meat products may contain biogenic amines. The aim of this paper was to describe the presence of some biogenic amines (histamine, tyramine, tryptamine, 2-phenylethylamine) in "Salamini italiani alla cacciatora PDO", a typical fermented-ripened dry sausage widely consumed in Italy. Total level of biogenic amines in commercial samples ranged from 71 to 586 mg kg(-1). The amine recovered in higher concentrations was tyramine (372 mg kg(-1)) followed by histamine (165 mg kg(-1)). The second aim of this work was the quality control of the production in order to determine the parameters influencing the presence of biogenic amines in ripened salami. Sausages sampled for analysis during production, manipulation and ripening showed the presence of tyramine (64.4 mg kg(-1)) only after 15 days of fermentation. All investigated biogenic amines were detected in "Salamini" after 21 days of fermentation. We suggest the control of biogenic as important tool to establish the better condition of preservation of "Salamini italiani alla cacciatore PDO" during their shelf-life.

  6. Determination of Biogenic Amines with HPLC-APCI-MS

    USDA-ARS?s Scientific Manuscript database

    Determination of biogenic amines in fish samples can be used as a quality attribute and are commonly performed using a derivatization step followed by high pressure liquid chromatography (HPLC) and UV detection. Over estimation and misidentification of biogenic amines can occur when interfering comp...

  7. Biogenic uraninite precipitation and its reoxidation by iron(III) (hydr)oxides: A reaction modeling approach

    NASA Astrophysics Data System (ADS)

    Spycher, Nicolas F.; Issarangkun, Montarat; Stewart, Brandy D.; Sevinç Şengör, S.; Belding, Eileen; Ginn, Tim R.; Peyton, Brent M.; Sani, Rajesh K.

    2011-08-01

    One option for immobilizing uranium present in subsurface contaminated groundwater is in situ bioremediation, whereby dissimilatory metal-reducing bacteria and/or sulfate-reducing bacteria are stimulated to catalyze the reduction of soluble U(VI) and precipitate it as uraninite (UO 2). This is typically accomplished by amending groundwater with an organic electron donor. It has been shown, however, that once the electron donor is entirely consumed, Fe(III) (hydr)oxides can reoxidize biogenically produced UO 2, thus potentially impeding cleanup efforts. On the basis of published experiments showing that such reoxidation takes place even under highly reducing conditions (e.g., sulfate-reducing conditions), thermodynamic and kinetic constraints affecting this reoxidation are examined using multicomponent biogeochemical simulations, with particular focus on the role of sulfide and Fe(II) in solution. The solubility of UO 2 and Fe(III) (hydr)oxides are presented, and the effect of nanoscale particle size on stability is discussed. Thermodynamically, sulfide is preferentially oxidized by Fe(III) (hydr)oxides, compared to biogenic UO 2, and for this reason the relative rates of sulfide and UO 2 oxidation play a key role on whether or not UO 2 reoxidizes. The amount of Fe(II) in solution is another important factor, with the precipitation of Fe(II) minerals lowering the Fe +2 activity in solution and increasing the potential for both sulfide and UO 2 reoxidation. The greater (and unintuitive) UO 2 reoxidation by hematite compared to ferrihydrite previously reported in some experiments can be explained by the exhaustion of this mineral from reaction with sulfide. Simulations also confirm previous studies suggesting that carbonate produced by the degradation of organic electron donors used for bioreduction may significantly increase the potential for UO 2 reoxidation through formation of uranyl carbonate aqueous complexes.

  8. Biogenic barite preciptiation at micromolar ambient sulfate

    NASA Astrophysics Data System (ADS)

    Horner, T. J.; Pryer, H. V.; Nielsen, S.; Ricketts, R. D.

    2016-12-01

    Earth's early oceans were essentially devoid of sulfate, yet barium sulfate (barite) deposits are common to ancient sediments. Most explanations for this `barite paradox' overlook biogenic barite precipitation—the dominant vector of particulate barium cycling in modern seawater—as the ancient oceans were presumably strongly undersaturated with respect to barite. We tested whether biogenic barite could indeed precipitate at trace sulfate by examining the particulate multi-element and Ba-isotopic geochemistry of one of the largest trace-sulfate ecosystems on Earth: Lake Superior. Despite exceptional levels of barite undersaturation in Lake Superior, we find unambiguous evidence of biogenic barite precipitation that is correlated with the depths of greatest organic matter remineralization in the water column. The overall pattern of particulate barium cycling in Lake Superior is strikingly similar to that seen in the open ocean, supporting the critical role of particle-associated `microenvironments' that become rich in respired sulfate as protected sites of biogenic barite formation. Our observations offer a microbially-mediated mechanism for barite formation at micromolar ambient sulfate and thus also a potential resolution to the barite paradox in the ancient oceans.

  9. Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site, Nevada City, CA.

    PubMed

    Foster, Andrea L; Ashley, Roger P; Rytuba, James J

    2011-01-24

    A realistic estimation of the health risk of human exposure to solid-phase arsenic (As) derived from historic mining operations is a major challenge to redevelopment of California's famed "Mother Lode" region. Arsenic, a known carcinogen, occurs in multiple solid forms that vary in bioaccessibility. X-ray absorption fine-structure spectroscopy (XAFS) was used to identify and quantify the forms of As in mine wastes and biogenic solids at the Lava Cap Mine Superfund (LCMS) site, a historic "Mother Lode" gold mine. Principal component analysis (PCA) was used to assess variance within water chemistry, solids chemistry, and XAFS spectral datasets. Linear combination, least-squares fits constrained in part by PCA results were then used to quantify arsenic speciation in XAFS spectra of tailings and biogenic solids. The highest dissolved arsenic concentrations were found in Lost Lake porewater and in a groundwater-fed pond in the tailings deposition area. Iron, dissolved oxygen, alkalinity, specific conductivity, and As were the major variables in the water chemistry PCA. Arsenic was, on average, 14 times more concentrated in biologically-produced iron (hydr)oxide than in mine tailings. Phosphorous, manganese, calcium, aluminum, and As were the major variables in the solids chemistry PCA. Linear combination fits to XAFS spectra indicate that arsenopyrite (FeAsS), the dominant form of As in ore material, remains abundant (average: 65%) in minimally-weathered ore samples and water-saturated tailings at the bottom of Lost Lake. However, tailings that underwent drying and wetting cycles contain an average of only 30% arsenopyrite. The predominant products of arsenopyrite weathering were identified by XAFS to be As-bearing Fe (hydr)oxide and arseniosiderite (Ca2Fe(AsO4)3O3•3H2O). Existence of the former species is not in question, but the presence of the latter species was not confirmed by additional measurements, so its identification is less certain. The linear combination

  10. Title: Biogenic Magnetite Prevails in Oxic Pelagic Red Clay Core in the South Pacific Gyre

    NASA Astrophysics Data System (ADS)

    Shimono, T.; Yamazaki, T.

    2012-12-01

    Magnetotactic bacteria have been observed in wide variety of environments, including soils, freshwater lakes, and marine sediments, since Blakemore (1975) first described in 1975. Magnetotactic bacteria, which most commonly live within the oxic-anoxic transition zone (OATZ) of aquatic environments, produce intracellular crystals of magnetic minerals, specifically magnetite or greigite. It is considered that the magnetite/greigite crystals facilitate the bacteria's search for optimal conditions within the sharp chemical gradients of the OATZ. Petermann and Bleil (1993) reported living magnetotactic bacteria in pelagic and hemipelagic sediments near OATZ in the eastern South Atlantic at water depths to about 3,000 m, but they couldn't find actively swimming magnetotactic bacteria in sediments of deeper water depths. The South Pacific Gyre (SPG) is far from continents and the lowest productivity region on Earth. IODP site U1365 (water depth ~5,700 m) cored pelagic red clay of 75.5 m thick above ~100 Ma basement (except for the chart layer from ~42 to 63.5 m) in the western edge of the SPG. The core mainly consists of iron rich clay. The color is dark reddish and/or dark brown throughout the core. We conducted a paleomagnetic and environmental rock magnetic study of the pelagic clay core. The magnetostratigraphy revealed the top 5 m sediments cover the last 5 My, and sedimentation rate decreases downward from 1.7 to 0.6 m/m.y. Geochemical measurements of pore water indicate that dissolved oxygen was present throughout the core (>50 μM). Thus oxygen penetrates through the entire sediment column to the sediment/basalt interface, and there is no OATZ. Magnetic mineral assemblage of this core is dominated by biogenic magnetite despite no OATZ. First-order reversal curve (FORC) diagrams of all specimens have a narrow central ridge along the Hc axis with very small vertical spread. This indicates very weak magnetostatic interaction (Roberts et al., 2000), and is the

  11. Unconventional shallow biogenic gas systems

    USGS Publications Warehouse

    Shurr, G.W.; Ridgley, J.L.

    2002-01-01

    Unconventional shallow biogenic gas falls into two distinct systems that have different attributes. Early-generation systems have blanketlike geometries, and gas generation begins soon after deposition of reservoir and source rocks. Late-generation systems have ringlike geometries, and long time intervals separate deposition of reservoir and source rocks from gas generation. For both types of systems, the gas is dominantly methane and is associated with source rocks that are not thermally mature. Early-generation biogenic gas systems are typified by production from low-permeability Cretaceous rocks in the northern Great Plains of Alberta, Saskatchewan, and Montana. The main area of production is on the southeastern margin of the Alberta basin and the northwestern margin of the Williston basin. The huge volume of Cretaceous rocks has a generalized regional pattern of thick, non-marine, coarse clastics to the west and thinner, finer grained marine lithologies to the east. Reservoir rocks in the lower part tend to be finer grained and have lower porosity and permeability than those in the upper part. Similarly, source beds in the units have higher values of total organic carbon. Patterns of erosion, deposition, deformation, and production in both the upper and lower units are related to the geometry of lineament-bounded basement blocks. Geochemical studies show that gas and coproduced water are in equilibrium and that the fluids are relatively old, namely, as much as 66 Ma. Other examples of early-generation systems include Cretaceous clastic reservoirs on the southwestern margin of Williston basin and chalks on the eastern margin of the Denver basin. Late-generation biogenic gas systems have as an archetype the Devonian Antrim Shale on the northern margin of the Michigan basin. Reservoir rocks are fractured, organic-rich black shales that also serve as source rocks. Although fractures are important for production, the relationships to specific geologic structures are

  12. Uranium isotope fractionation in biogenic carbonates: biological effects

    NASA Astrophysics Data System (ADS)

    Chen, X.; Romaniello, S. J.; Herrmann, A. D.; Anbar, A. D.

    2017-12-01

    Recent laboratory experiments have demonstrated small but potentially significant isotope fractionation ( 0.10 ‰ for 238U/235U) during uranium (U) incorporation into abiotic calcite and aragonite, with heavier U isotopes preferentially enriched in the precipitates [1]. In contrast, measurements of natural biogenic carbonates to date have not been able to resolve significant U isotopic fractionation from seawater although this might be expected given a typical measurement precision of ± 0.10 ‰. Determining whether or not biogenic carbonates display U isotope fractionation similar to abiotic carbonates could have important implications for understanding the mechanisms of U incorporation into various biogenic carbonates. Furthermore, because most marine carbonates are biogenic, the extent of isotopic fractionation, if any, could have important implications for the interpretation of sedimentary carbonates record similar to effects observed for Cr and B isotopes [2, 3]. To resolve this discrepancy, we utilized a higher precision 238U/235U method which uses larger sample sizes to improve measurement precision of natural samples to ± 0.02 ‰ (2 se, N = 6) [4]. Using this method, we have surveyed 238U/235U in primary biogenic skeletal carbonates including scleractinian corals, green and red algae, and mollusks, as well as non-skeletal carbonates such as stromatolites, ooids, and carbonate sands from the Bahamas, Gulf of California, and French Polynesia. New high-precision U isotopes measurements reveal that biogenic skeletal carbonates are typically 0.02 - 0.08 ‰ heavier than modern seawater. Scleractinian corals display values closest to seawater (- 0.37 ‰), while green algae, red algae, mollusks, and echinoderms display variable but larger extents of fractionation up to 0.08 ‰. The direction and magnitude of U isotope fractionation in these biogenic precipitates are generally consistent with results from abiotic coprecipitation experiments, but may be

  13. Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: Is there a connection?

    NASA Astrophysics Data System (ADS)

    Boyd, P. W.; Wong, C. S.; Merrill, J.; Whitney, F.; Snow, J.; Harrison, P. J.; Gower, J.

    1998-09-01

    Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that long time series pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a (> 2.0 μg L-1) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OSP). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more productive waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean.

  14. Zooplankton Gut Passage Mobilizes Lithogenic Iron for Ocean Productivity.

    PubMed

    Schmidt, Katrin; Schlosser, Christian; Atkinson, Angus; Fielding, Sophie; Venables, Hugh J; Waluda, Claire M; Achterberg, Eric P

    2016-10-10

    Iron is an essential nutrient for phytoplankton, but low concentrations limit primary production and associated atmospheric carbon drawdown in large parts of the world's oceans [1, 2]. Lithogenic particles deriving from aeolian dust deposition, glacial runoff, or river discharges can form an important source if the attached iron becomes dissolved and therefore bioavailable [3-5]. Acidic digestion by zooplankton is a potential mechanism for iron mobilization [6], but evidence is lacking. Here we show that Antarctic krill sampled near glacial outlets at the island of South Georgia (Southern Ocean) ingest large amounts of lithogenic particles and contain 3-fold higher iron concentrations in their muscle than specimens from offshore, which confirms mineral dissolution in their guts. About 90% of the lithogenic and biogenic iron ingested by krill is passed into their fecal pellets, which contain ∼5-fold higher proportions of labile (reactive) iron than intact diatoms. The mobilized iron can be released in dissolved form directly from krill or via multiple pathways involving microbes, other zooplankton, and krill predators. This can deliver substantial amounts of bioavailable iron and contribute to the fertilization of coastal waters and the ocean beyond. In line with our findings, phytoplankton blooms downstream of South Georgia are more intensive and longer lasting during years with high krill abundance on-shelf. Thus, krill crop phytoplankton but boost new production via their nutrient supply. Understanding and quantifying iron mobilization by zooplankton is essential to predict ocean productivity in a warming climate where lithogenic iron inputs from deserts, glaciers, and rivers are increasing [7-10]. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Accounting for urban biogenic fluxes in regional carbon budgets.

    PubMed

    Hardiman, Brady S; Wang, Jonathan A; Hutyra, Lucy R; Gately, Conor K; Getson, Jackie M; Friedl, Mark A

    2017-08-15

    Many ecosystem models incorrectly treat urban areas as devoid of vegetation and biogenic carbon (C) fluxes. We sought to improve estimates of urban biomass and biogenic C fluxes using existing, nationally available data products. We characterized biogenic influence on urban C cycling throughout Massachusetts, USA using an ecosystem model that integrates improved representation of urban vegetation, growing conditions associated with urban heat island (UHI), and altered urban phenology. Boston's biomass density is 1/4 that of rural forests, however 87% of Massachusetts' urban landscape is vegetated. Model results suggest that, kilogram-for-kilogram, urban vegetation cycles C twice as fast as rural forests. Urban vegetation releases (R E ) and absorbs (GEE) the equivalent of 11 and 14%, respectively, of anthropogenic emissions in the most urban portions of the state. While urban vegetation in Massachusetts fully sequesters anthropogenic emissions from smaller cities in the region, Boston's UHI reduces annual C storage by >20% such that vegetation offsets only 2% of anthropogenic emissions. Asynchrony between temporal patterns of biogenic and anthropogenic C fluxes further constrains the emissions mitigation potential of urban vegetation. However, neglecting to account for biogenic C fluxes in cities can impair efforts to accurately monitor, report, verify, and reduce anthropogenic emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Intolerance to dietary biogenic amines: a review.

    PubMed

    Jansen, Sophia C; van Dusseldorp, Marijke; Bottema, Kathelijne C; Dubois, Anthony E J

    2003-09-01

    To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature. Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive. A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache. The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

  17. Biogenic Emission Inventory System (BEIS)

    EPA Pesticide Factsheets

    Biogenic Emission Inventory System (BEIS) estimates volatile organic compound (VOC) emissions from vegetation and nitric oxide (NO) emission from soils. Recent BEIS development has been restricted to the SMOKE system

  18. Biogenic amine formation and bacterial contribution in Natto products.

    PubMed

    Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

    2012-12-01

    Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

    PubMed Central

    Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

    2012-01-01

    Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

  20. Occurence of sulfate- and iron-reducing bacteria in stratal waters of the Romashkinskoe oil field

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nazina, T.N.; Ivanova, A.E.; Goulbeva, O.V.

    1995-03-01

    The occurrence of microorganisms and the rates of terminal biogenic processes-sulfate reduction and methane synthesis-were studied in stratial waters in bed 302 of the Bashkir Carboniferous deposit at the Romashkinskoe oil field. It was shown that bed 302 was a dynamic, highly reduced ecosystem containing sulfates and hydrogen sulfide in considerable concentrations, in which active biogenic processes occurred. Sulfate reduction was a dominating anaerobic process by which the transformation of organic matter occurred. The sulfate-reducing microflora was diverse and characterized by a wide range of metabolic potentials. Enrichment cultures capable of oxidizing many organic substances, such as benzoate, acetate, ethanol,more » or lactate, at the expense of reduction of sulfates and ferric ion were isolated from 302. It was suggested that the sulfate-reducing microflora might be responsible not only for sulfate reduction in the stratum but also for mobilization of some insoluble iron oxides in the oil-bearing rock. These findings indicate that bacteria carrying out dissimilatory reduction of sulfate and iron can contribute to the geochemistry of organic and mineral compounds in subsurface ecosystems. 24 refs., 2 figs., 6 tabs.« less

  1. Rett syndrome: stimulation of endogenous biogenic amines.

    PubMed

    Pelligra, R; Norton, R D; Wilkinson, R; Leon, H A; Matson, W R

    1992-06-01

    Transient hypercapnic hyperoxemia was induced in two Rett syndrome children by the administration of a gaseous mixture of 80% O2 and 20% CO2. Time course studies of neurotransmitters and their metabolites showed an immediate and marked increase in central biogenic amine turnover following inhalation of the gas mixture. The increased turnover of biogenic amines was associated with improved clinical changes. This suggests a coupled relationship and provides further support for an etiological role of neurotransmitter dysfunction in Rett syndrome. In a complementary study, elevation of pulmonary CO2 by application of a simple rebreathing device resulted in improvement of abnormal blood gases and elimination of the Cheyne-Stokes-like respiratory pattern of the Rett syndrome. Near normalization of the EEG occurred when a normal respiratory pattern was imposed by means of a respirator. Taken together, these results lead to the preliminary conclusion that cerebral hypoxemia secondary to abnormal respiratory function may contribute to diminished production of biogenic amines in Rett syndrome.

  2. Rett syndrome - Stimulation of endogenous biogenic amines

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Norton, R. D.; Wilkinson, R.; Leon, H. A.; Matson, W. R.

    1992-01-01

    Transient hypercapnic hyperoxemia was induced in two Rett syndrome children by the administration of a gaseous mixture of 80 percent O2 and 20 percent CO2. Time course studies of neurotransmitters and their metabolites showed an immediate and marked increase in central biogenic amine turnover following inhalation of the gas mixture. The increased turnover of biogenic amines was associated with improved clinical changes. This suggests a coupled relationship and provides further support for an etiological role of neurotransmitter dysfunction in Rett syndrome. In a complementary study, elevation of pulmonary CO2 by application of a simple rebreathing device resulted in improvement of abnormal blood gases and elimination of the Cheyne-Stokes-like respiratory pattern of the Rett syndrome. Near normalization of the EEG occurred when a normal respiratory pattern was imposed by means of a respirator. Taken together, these results lead to the preliminary conclusion that cerebral hypoxemia secondary to abnormal respiratory function may contribute to diminished production of biogenic amines in Rett syndrome.

  3. A Darwinian mechanism for biogenic ocean mixing

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Dabiri, John

    2009-11-01

    Recent observations of biogenic turbulence in the ocean have led to conflicting ideas regarding the contribution of animal swimming to ocean mixing. Previous measurements indicate elevated turbulent dissipation in the vicinity of large populations of planktonic animals swimming in concert. However, elevated turbulent dissipation is by itself insufficient proof of substantial biogenic mixing. We conducted field measurements of mixing efficiency by individual Mastigias sp. (a Palauan jellyfish) using a self-contained underwater velocimetry apparatus. These measurements revealed another mechanism that contributes to animal mixing besides wake turbulence. This mechanism was first described by Sir Charles Galton Darwin and is in fact the dominant mechanism of mixing by swimming animals. The efficiency of Darwin's mechanism (or drift) is dependent on animal shape rather than fluid length scale and, unlike turbulent wake mixing, is enhanced by the fluid viscosity. Therefore, it provides a means of biogenic mixing that can be equally effective in small plankton and large mammals.

  4. Biogenic amines in dry fermented sausages: a review.

    PubMed

    Suzzi, Giovanna; Gardini, Fausto

    2003-11-15

    Biogenic amines are compounds commonly present in living organisms in which they are responsible for many essential functions. They can be naturally present in many foods such as fruits and vegetables, meat, fish, chocolate and milk, but they can also be produced in high amounts by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern because their not equilibrate assumption in human organism can generate different degrees of diseases determined by their action on nervous, gastric and intestinal systems and blood pressure. High microbial counts, which characterise fermented foods, often unavoidably lead to considerable accumulation of biogenic amines, especially tyramine, 2-phenylethylamine, tryptamine, cadaverine, putrescine and histamine. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the quali-quantitative composition of microbial microflora, the chemico-physical variables, the hygienic procedure adopted during production, and the availability of precursors. Dry fermented sausages are worldwide diffused fermented meat products that can be a source of biogenic amines. Even in the absence of specific rules and regulations regarding the presence of these compounds in sausages and other fermented products, an increasing attention is given to biogenic amines, especially in relation to the higher number of consumers with enhanced sensitivity to biogenic amines determined by the inhibition of the action of amino oxidases, the enzymes involved in the detoxification of these substances. The aim of this paper is to give an overview on the presence of these compounds in dry fermented sausages and to discuss the most important factors influencing their accumulation. These include process and implicit factors as well as the role of starter and nonstarter microflora growing in the different steps of sausage production

  5. Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters

    NASA Astrophysics Data System (ADS)

    Takeda, Shigenobu

    1998-06-01

    The major nutrients (nitrate, phosphate and silicate) needed for phytoplankton growth are abundant in the surface waters of the subarctic Pacific, equatorial Pacific and Southern oceans, but this growth is limited by the availability of iron. Under iron-deficient conditions, phytoplankton exhibit reduced uptake of nitrate and lower cellular levels of carbon, nitrogen and phosphorus. Here I describe seawater and culture experiments which show that iron limitation can also affect the ratio of consumed silicate to nitrate and phosphate. In iron-limited waters from all three of the aforementioned environments, addition of iron to phytoplankton assemblages in incubation bottles halved the silicate:nitrate and silicate:phosphate consumption ratios, in spite of the preferential growth of diatoms (silica-shelled phytoplankton). The nutrient consumption ratios of the phytoplankton assemblage from the Southern Ocean were similar to those of an iron-deficient laboratory culture of Antarctic diatoms, which exhibit increased cellular silicon or decreased cellular nitrogen and phosphorus in response to iron limitation. Iron limitation therefore increases the export of biogenic silicon, relative to nitrogen and phosphorus, from the surface to deeper waters. These findings suggest how the sedimentary records of carbon and silicon deposition in the glacial Southern Ocean can be consistent with the idea that changes in productivity, and thus in drawdown of atmospheric CO2, during the last glaciation were stimulated by changes in iron inputs from atmospheric dust.

  6. Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site, Nevada City, CA

    PubMed Central

    2011-01-01

    Background A realistic estimation of the health risk of human exposure to solid-phase arsenic (As) derived from historic mining operations is a major challenge to redevelopment of California's famed "Mother Lode" region. Arsenic, a known carcinogen, occurs in multiple solid forms that vary in bioaccessibility. X-ray absorption fine-structure spectroscopy (XAFS) was used to identify and quantify the forms of As in mine wastes and biogenic solids at the Lava Cap Mine Superfund (LCMS) site, a historic "Mother Lode" gold mine. Principal component analysis (PCA) was used to assess variance within water chemistry, solids chemistry, and XAFS spectral datasets. Linear combination, least-squares fits constrained in part by PCA results were then used to quantify arsenic speciation in XAFS spectra of tailings and biogenic solids. Results The highest dissolved arsenic concentrations were found in Lost Lake porewater and in a groundwater-fed pond in the tailings deposition area. Iron, dissolved oxygen, alkalinity, specific conductivity, and As were the major variables in the water chemistry PCA. Arsenic was, on average, 14 times more concentrated in biologically-produced iron (hydr)oxide than in mine tailings. Phosphorous, manganese, calcium, aluminum, and As were the major variables in the solids chemistry PCA. Linear combination fits to XAFS spectra indicate that arsenopyrite (FeAsS), the dominant form of As in ore material, remains abundant (average: 65%) in minimally-weathered ore samples and water-saturated tailings at the bottom of Lost Lake. However, tailings that underwent drying and wetting cycles contain an average of only 30% arsenopyrite. The predominant products of arsenopyrite weathering were identified by XAFS to be As-bearing Fe (hydr)oxide and arseniosiderite (Ca2Fe(AsO4)3O3•3H2O). Existence of the former species is not in question, but the presence of the latter species was not confirmed by additional measurements, so its identification is less certain. The

  7. Impact of iron on silicon utilization by diatoms in the Southern Ocean: A case study of Si/N cycle decoupling in a naturally iron-enriched area

    NASA Astrophysics Data System (ADS)

    Mosseri, Julie; Quéguiner, Bernard; Armand, Leanne; Cornet-Barthaux, Véronique

    2008-03-01

    Biogenic silica stocks and fluxes were investigated in austral summer over the naturally iron-fertilized Kerguelen Plateau and in nearby high-nutrient, low-chlorophyll (HNLC) off-plateau surface waters. The Kerguelen Plateau hosted a large-diatom bloom, with high levels of biogenic silica (BSi) but relatively low silicic acid (Si(OH) 4) uptake rates (1100±600 mmol m -2 and 8±4 mmol m -2 d -1, respectively). Diatoms of the naturally iron-enriched area presented high affinities for silicic acid, allowing them in combination with a beneficial nutrient vertical supply to grow in low silicic acid waters (<2 μM). Si(OH) 4 acid uptake rates were also compared with carbon and nitrogen uptake rates. As expected for diatoms growing in favourable nutrient conditions, and from previous artificial iron-enrichment experiments, Si:C and Si:NO 3 elemental uptake ratios of the natural diatom community of the plateau were close to 0.13 and 1, respectively. In contrast, diatom communities in the HNLC waters were composed of strongly silicified (high Si:C, Si:NO 3 uptake ratios) diatoms with low affinities for Si(OH) 4. Although the Si:NO 3 uptake ratio in the surface waters of the plateau was close to 1, the apparent consumption of nitrate on a seasonal basis was much lower (˜5 μM) than the apparent consumption of silicic acid (˜15 μM). This was mainly due to diatoms growing actively on ammonium (i.e. 39-77% of the total nitrogen uptake) produced by an intense heterotrophic activity. Thus we find that while Fe fertilization does increase N uptake with respect to Si uptake, rapid recycling of N decouples nitrogen and carbon export from silica export so that the "silicate pump" remains more efficient than that of N (or P). For this reason an iron-fertilized Southern Ocean is unlikely to experience nitrate exhaustion or export silicic acid to the global ocean.

  8. Mesophilic, Circumneutral Anaerobic Iron Oxidation as a Remediation Mechanism for Radionuclides, Nitrate and Perchlorate

    NASA Astrophysics Data System (ADS)

    Bose, S.; Thrash, J. C.; Coates, J. D.

    2008-12-01

    Iron oxidation is a novel anaerobic metabolism where microorganisms obtain reducing equivalents from the oxidization of Fe(II) and assimilate carbon from organic carbon compounds or CO2. Recent evidence indicates that in combination with the activity of dissimilatory Fe(III)-reducing bacteria, anaerobic microbial Fe(II) oxidation can also contribute to the global iron redox cycle. Studies have also proved that Fe(II)- oxidation is ubiquitous in diverse environments and produce a broad range of insoluble iron forms as end products. These biogenic Fe(III)-oxides and mixed valence Fe minerals have a very high adsorption capacity of heavy metals and radionuclides. Adsorption and immobilization by these biogenic Fe phases produced at circumneutral pH, is now considered a very effective mode of remediation of radionuclides like Uranium, especially under variable redox conditions. By coupling soluble and insoluble Fe(II) oxidation with nitrate and perchlorate as terminal electron acceptors in-situ, anaerobic Fe-oxidation can also be used for environmental cleanup of Fe through Fe-mineral precipitation, as well as nitrate and perchlorate through reduction. Coupling of Fe as the sole electron and energy source to the reduction of perchlorate or nitrate boosts the metabolism without building up biomass hence also taking care of biofouling. To understand the mechanisms by which microorganisms can grow at circumneutral pH by mesophilic, anaerobic iron oxidation and the ability of microorganisms to reduce nitrate and perchlorate coupled to iron oxidation recent work in our lab involved the physiological characterization of Dechlorospirillum strain VDY which was capable of anaerobic iron-oxidation with either nitrate or perchlorate serving as terminal electron acceptor. Under non-growth conditions, VDY oxidized 3mM Fe(II) coupled to nitrate reduction, and 2mM Fe(II) coupled to perchlorate reduction, in 24 hours. It contained a copy of the RuBisCO cbbM subunit gene which was

  9. Spectral features of biogenic calcium carbonates and implications for astrobiology

    NASA Astrophysics Data System (ADS)

    Berg, B. L.; Ronholm, J.; Applin, D. M.; Mann, P.; Izawa, M.; Cloutis, E. A.; Whyte, L. G.

    2014-09-01

    The ability to discriminate biogenic from abiogenic calcium carbonate (CaCO3) would be useful in the search for extant or extinct life, since CaCO3 can be produced by both biotic and abiotic processes on Earth. Bioprecipitated CaCO3 material was produced during the growth of heterotrophic microbial isolates on medium enriched with calcium acetate or calcium citrate. These biologically produced CaCO3, along with natural and synthetic non-biologically produced CaCO3 samples, were analysed by reflectance spectroscopy (0.35-2.5 μm), Raman spectroscopy (532 and 785 nm), and laser-induced fluorescence spectroscopy (365 and 405 nm excitation). Optimal instruments for the discrimination of biogenic from abiogenic CaCO3 were determined to be reflectance spectroscopy, and laser-induced fluorescence spectroscopy. Multiple absorption features in the visible light region occurred in reflectance spectra for most biogenic CaCO3 samples, which are likely due to organic pigments. Multiple fluorescence peaks occurred in emission spectra (405 nm excitation) of biogenic CaCO3 samples, which also are best attributed to the presence of organic compounds; however, further analyses must be performed in order to better determine the cause of these features to establish criteria for confirming the origin of a given CaCO3 sample. Raman spectroscopy was not useful for discrimination since any potential Raman peaks in spectra of biogenic carbonates collected by both the 532 and 785 nm lasers were overwhelmed by fluorescence. However, this also suggests that biogenic carbonates may be identified by the presence of this organic-associated fluorescence. No reliable spectroscopic differences in terms of parameters such as positions or widths of carbonate-associated absorption bands were found between the biogenic and abiogenic carbonate samples. These results indicate that the presence or absence of organic matter intimately associated with carbonate minerals is the only potentially useful

  10. Calcification response of Pleurochrysis carterae to iron concentrations in batch incubations: implication for the marine biogeochemical cycle

    NASA Astrophysics Data System (ADS)

    Zou, Xiang; Sun, Shiyong; Lin, Sen; Shen, Kexuan; Dong, Faqin; Tan, Daoyong; Nie, Xiaoqin; Liu, Mingxue; Wei, Jie

    2017-12-01

    Calcified coccolithophores, a diverse and widely distributed group of marine microalgae, produce biogenic calcite in the form of coccoliths located on the cell surface. Using batch incubations of the coccolithophorid Pleurochrysis carterae, we investigated the responses of this calcification process to iron concentrations by changing the iron supply in the initial culture media from a normal concentration to 1 ppm (parts per million), 5 ppm, and 10 ppm. Time-dependent measurements of cell population, production of inorganic carbon (coccoliths), and organic carbon (organic cellular components) showed that elevated iron supply in the growth medium of P. carterae stimulates carbon sequestration by increasing growth along enhanced photosynthetic activity and calcification. In addition, the acquired time-dependent UV-Vis and FT-IR spectra revealed that iron fertilization-enhanced coccolith calcification is accompanied by a crystalline phase transition from calcite to aragonite or amorphous phase. Our results suggest that iron concentration has a significant influence on the marine carbon cycle of coccolithophores.

  11. Measurement of carbon storage in landfills from the biogenic carbon content of excavated waste samples.

    PubMed

    De la Cruz, Florentino B; Chanton, Jeffrey P; Barlaz, Morton A

    2013-10-01

    Landfills are an anaerobic ecosystem and represent the major disposal alternative for municipal solid waste (MSW) in the U.S. While some fraction of the biogenic carbon, primarily cellulose (Cel) and hemicellulose (H), is converted to carbon dioxide and methane, lignin (L) is essentially recalcitrant. The biogenic carbon that is not mineralized is stored within the landfill. This carbon storage represents a significant component of a landfill carbon balance. The fraction of biogenic carbon that is not reactive in the landfill environment and therefore stored was derived for samples of excavated waste by measurement of the total organic carbon, its biogenic fraction, and the remaining methane potential. The average biogenic carbon content of the excavated samples was 64.6±18.0% (average±standard deviation), while the average carbon storage factor was 0.09±0.06g biogenic-C stored per g dry sample or 0.66±0.16g biogenic-C stored per g biogenic C. Published by Elsevier Ltd.

  12. Southern Ocean biological iron cycling in the pre-whaling and present ecosystems

    NASA Astrophysics Data System (ADS)

    Maldonado, Maria T.; Surma, Szymon; Pakhomov, Evgeny A.

    2016-11-01

    This study aimed to create the first model of biological iron (Fe) cycling in the Southern Ocean food web. Two biomass mass-balanced Ecopath models were built to represent pre- and post-whaling ecosystem states (1900 and 2008). Functional group biomasses (tonnes wet weight km-2) were converted to biogenic Fe pools (kg Fe km-2) using published Fe content ranges. In both models, biogenic Fe pools and consumption in the pelagic Southern Ocean were highest for plankton and small nektonic groups. The production of plankton biomass, particularly unicellular groups, accounted for the highest annual Fe demand. Microzooplankton contributed most to biological Fe recycling, followed by carnivorous zooplankton and krill. Biological Fe recycling matched previous estimates, and, under most conditions, could entirely meet the Fe demand of bacterioplankton and phytoplankton. Iron recycling by large baleen whales was reduced 10-fold by whaling between 1900 and 2008. However, even under the 1900 scenario, the contribution of whales to biological Fe recycling was negligible compared with that of planktonic consumers. These models are a first step in examining oceanic-scale biological Fe cycling, highlighting gaps in our present knowledge and key questions for future research on the role of marine food webs in the cycling of trace elements in the sea. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  13. Southern Ocean biological iron cycling in the pre-whaling and present ecosystems.

    PubMed

    Maldonado, Maria T; Surma, Szymon; Pakhomov, Evgeny A

    2016-11-28

    This study aimed to create the first model of biological iron (Fe) cycling in the Southern Ocean food web. Two biomass mass-balanced Ecopath models were built to represent pre- and post-whaling ecosystem states (1900 and 2008). Functional group biomasses (tonnes wet weight km -2 ) were converted to biogenic Fe pools (kg Fe km -2 ) using published Fe content ranges. In both models, biogenic Fe pools and consumption in the pelagic Southern Ocean were highest for plankton and small nektonic groups. The production of plankton biomass, particularly unicellular groups, accounted for the highest annual Fe demand. Microzooplankton contributed most to biological Fe recycling, followed by carnivorous zooplankton and krill. Biological Fe recycling matched previous estimates, and, under most conditions, could entirely meet the Fe demand of bacterioplankton and phytoplankton. Iron recycling by large baleen whales was reduced 10-fold by whaling between 1900 and 2008. However, even under the 1900 scenario, the contribution of whales to biological Fe recycling was negligible compared with that of planktonic consumers. These models are a first step in examining oceanic-scale biological Fe cycling, highlighting gaps in our present knowledge and key questions for future research on the role of marine food webs in the cycling of trace elements in the sea.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'. © 2016 The Author(s).

  14. Control of Biogenic Amines in Food—Existing and Emerging Approaches

    PubMed Central

    Naila, Aishath; Flint, Steve; Fletcher, Graham; Bremer, Phil; Meerdink, Gerrit

    2010-01-01

    Biogenic amines have been reported in a variety of foods, such as fish, meat, cheese, vegetables, and wines. They are described as low molecular weight organic bases with aliphatic, aromatic, and heterocyclic structures. The most common biogenic amines found in foods are histamine, tyramine, cadaverine, 2-phenylethylamine, spermine, spermidine, putrescine, tryptamine, and agmatine. In addition octopamine and dopamine have been found in meat and meat products and fish. The formation of biogenic amines in food by the microbial decarboxylation of amino acids can result in consumers suffering allergic reactions, characterized by difficulty in breathing, itching, rash, vomiting, fever, and hypertension. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth through chilling and freezing. However, for many fishing based subsistence populations, such measures are not practical. Therefore, secondary control measures to prevent biogenic amine formation in foods or to reduce their levels once formed need to be considered as alternatives. Such approaches to limit microbial growth may include hydrostatic pressures, irradiation, controlled atmosphere packaging, or the use of food additives. Histamine may potentially be degraded by the use of bacterial amine oxidase or amine-negative bacteria. Only some will be cost-effective and practical for use in subsistence populations. PMID:21535566

  15. Picoplankton contribution to biogenic silica stocks and production rates in the Sargasso Sea

    NASA Astrophysics Data System (ADS)

    Krause, J. W.; Brzezinski, M. A.; Baines, S. B.; Collier, J.; Ohnemus, D.; Twining, B. S.

    2016-02-01

    The picoplankton size class (< 3 µm) was observed to contribute a measurable, and at times significant, proportion of the total biogenic silica (>0.4 µm) standing stock and to its rate of production in the Sargasso Sea. These trends were robust after correcting biogenic silica, and the calculated rates which use these data, for interference by lithogenic silica. The 100-m total integrated biogenic silica concentration was low and ranged from 0.7 - 5.0 mmol Si m-2, with the highest value within a mesoscale eddy. Material within the picoplankton size fraction was present at every low-biomass station and provided a relatively consistent contribution to total biogenic silica (10 - 24%, average 14%). The integrated rates of total biogenic silica production were reflective of the low biomass: 0.2 - 1.8 mmol Si m-2 d-1 in non-eddy stations and 6.0 mmol Si m-2 d-1 within the eddy. The average proportion of biogenic silica production in the picoplankton was 16% (range 3 - 38%), with a lower value within the eddy. Outside the eddy, the biomass-normalized rates of silica production were similar for each size class, 0.6 d-1. Using Synechococcus abundance data in the upper 30 m and assuming this group was the only contributor to the picoplankton biogenic silica, we calculate an average Si quota of 229 amol Si cell-1; this is two-fold higher than reported previously by direct measurement on cells using x-ray fluorescence. In the eddy, the estimated Synechococcus Si-quotas were up to 50-fold higher than estimated at other stations, suggesting that most of the pico-sized biogenic silica in this feature may have been diatom fragments. This interpretation is also supported by the eddy having the lowest biomass-normalized production rates for the picoplankton. Our results suggest picoplankton may have a small, but relatively stable, contribution to biogenic silica in this region, which underlies a more dynamic microplankton biogenic silica pool driven by diatoms.

  16. Biogenic silica in Lake Baikal sediments: results from 1990-1992 American cores

    USGS Publications Warehouse

    Carter, Susan J.; Colman, Steven M.

    1994-01-01

    The Lake Baikal Paleoclimate Project is a joint Russian-American program established to study the paleoclimate of Central Asia. During three summer field seasons, duplicate Russian and American cores were taken at a number of sites in different sedimentary environments in the lake. Eight cores returned to the U.S. were quantitatively analyzed for biogenic silica using a single-step 5-hour alkaline leach, followed by dissolved silicon analysis by inductively-coupled-plasma atomic-emission spectroscopy. Sediments of Holocene age in these cores have biogenic silica maxima that range from about 15 to 80 percent. An underlying zone in each core with low biogenic-silica concentrations (0 to 5 percent) dates from the last glacial maximum. The transition from the last glaciation to the present interglaciation, recorded by biogenic silica, began about 13,000 years ago. Biogenic silica profiles from these cores appear to be a good measure of past diatom productivity and a useful basis for paleoclimatic interpretations.

  17. NEW BIOGENIC VOC EMISSIONS MODEL

    EPA Science Inventory

    We intend to develop new prognostic models for the prediction of biogenic volatile organic compound emissions from forest ecosystems in the face of possible future changes in the climate and the concentration of carbon dioxide in the atmosphere. These models will b...

  18. Altervalent substitution of sodium for calcium in biogenic calcite and aragonite

    NASA Astrophysics Data System (ADS)

    Yoshimura, Toshihiro; Tamenori, Yusuke; Suzuki, Atsushi; Kawahata, Hodaka; Iwasaki, Nozomu; Hasegawa, Hiroshi; Nguyen, Luan T.; Kuroyanagi, Azumi; Yamazaki, Toshitsugu; Kuroda, Junichiro; Ohkouchi, Naohiko

    2017-04-01

    Sodium concentrations in biogenic CaCO3 are several thousands of parts per million, and, on a molar basis, Na is among the most abundant constituent minor element in these carbonates. Nevertheless, the chemical form of Na in CaCO3 is not well constrained. We used synchrotron X-ray spectroscopy to identify the dominant molecular host sites for Na in biogenic calcite and aragonite precipitated by corals, bivalves, and foraminifera. We also used the K-edge X-ray absorption near-edge structure to investigate the chemical environment of Na in biogenic calcium carbonates and identify the altervalent substitution of Na into Ca sites in the lattice structures of calcite and aragonite. Minor cation and anion concentrations in biogenic CaCO3 suggest that the principal substitution mechanism involves charge compensation through the creation of CO32- vacancies. The mostly homogeneous Na concentrations in the skeletal microstructures of the various biota we examined indicate that environmental and biological controls, such as temperature, skeletal microstructure, and calcification rates, have only minor influences on skeletal Na concentrations. A decrease of Na:Ca ratios with increasing age of foraminiferal shells picked from a Quaternary sediment core, indicates progressive release of Na, which suggests that structurally-substituted Na in biogenic CaCO3 is readily leached during burial diagenesis. Whereas the sediment that undergo diagenesis release some Na back to the water column, sodium co-precipitation in biogenic CaCO3 serves as a potential sink of Na for the ocean.

  19. Dissolution of Biogenic and Synthetic UO2 under Varied Reducing Conditions

    PubMed Central

    ULRICH, KAI – UWE; SINGH, ABHAS; SCHOFIELD, ELEANOR J.; BARGAR, JOHN R.; VEERAMANI, HARISH; SHARP, JONATHAN O.; LATMANI, RIZLAN BERNIER -; GIAMMAR, DANIEL E.

    2008-01-01

    The chemical stability of biogenic UO2, a nanoparticulate product of environmental bioremediation, may be impacted by the particles’ surface free energy, structural defects, and compositional variability in analogy to abiotic UO2+x (0 ≤ x ≤ 0.25). This study quantifies and compares intrinsic solubility and dissolution rate constants of biogenic nano-UO2 and synthetic bulk UO2.00, taking molecular-scale structure into account. Rates were determined under anoxic conditions as a function of pH and dissolved inorganic carbon in continuous-flow experiments. The dissolution rates of biogenic and synthetic UO2 solids were lowest at near neutral pH and increased with decreasing pH. Similar surface area-normalized rates of biogenic and synthetic UO2 suggest comparable reactive surface site densities. This finding is consistent with the identified structural homology of biogenic UO2 and stoichiometric UO2.00. Compared to carbonate-free anoxic conditions, dissolved inorganic carbon accelerated the dissolution rate of biogenic UO2 by 3 orders of magnitude. This phenomenon suggests continuous surface oxidation of U(IV) to U(VI), with detachment of U(VI) as the rate-determining step in dissolution. Although reducing conditions were maintained throughout the experiments, the UO2 surface can be oxidized by water and radiogenic oxidants. Even in anoxic aquifers, UO2 dissolution may be controlled by surface U(VI) rather than U(IV) phases. PMID:18754482

  20. Anthropogenically induced changes in sediment and biogenic silica fluxes in Chesapeake Bay

    USGS Publications Warehouse

    Colman, Steven M.; Bratton, John F.

    2003-01-01

    Sediment cores as long as 20 m, dated by 14C, 210Pb, and 137Cs methods and pollen stratigraphy, provide a history of diatom productivity and sediment-accumulation rates in Chesapeake Bay. We calculated the flux of biogenic silica and total sediment for the past 1500 yr for two high-sedimentation-rate sites in the mesohaline section of the bay. The data show that biogenic silica flux to sediments, an index of diatom productivity in the bay, as well as its variability, were relatively low before European settlement of the Chesapeake Bay watershed. In the succeeding 300–400 yr, the flux of biogenic silica has increased by a factor of 4 to 5. Biogenic silica fluxes still appear to be increasing, despite recent nutrient-reduction efforts. The increase in diatom-produced biogenic silica has been partly masked (in concentration terms) by a similar increase in total sediment flux. This history suggests the magnitude of anthropogenic disturbance of the estuary and indicates that significant changes had occurred long before the twentieth century.

  1. Antropogenically induced changes in sediment and biogenic silica fluxes in Chesapeake Bay

    USGS Publications Warehouse

    Colman, Steven M.; Bratton, J.F.

    2003-01-01

    Sediment cores as long as 20 m, dated by 14C, 210Pb, and 137Cs methods and pollen stratigraphy, provide a history of diatom productivity and sediment-accumulation rates in Chesapeake Bay. We calculated the flux of biogenic silica and total sediment for the past 1500 yr for two high-sedimentation-rate sites in the mesohaline section of the bay. The data show that biogenic silica flux to sediments, an index of diatom productivity in the bay, as well as its variability, were relatively low before European settlement of the Chesapeake Bay watershed. In the succeeding 300-400 yr, the flux of biogenic silica has increased by a factor of 4 to 5. Biogenic silica fluxes still appear to be increasing, despite recent nutrient-reduction efforts. The increase in diatom-produced biogenic silica has been partly masked (in concentration terms) by a similar increase in total sediment flux. This history suggests the magnitude of anthropogenic disturbance of the estuary and indicates that significant changes had occurred long before the twentieth century.

  2. Biogenic contribution to PM-2.5 ambient aerosol from radiocarbon measurements

    NASA Astrophysics Data System (ADS)

    Lewis, C.; Klouda, G.; Ellenson, W.

    2003-04-01

    Knowledge of the relative contributions of biogenic versus anthropogenic sources to ambient aerosol is of great interest in the formulation of strategies to achieve nationally mandated air quality standards. Radiocarbon (14C) measurements provide a means to quantify the biogenic fraction of any carbon-containing sample of ambient aerosol. In the absence of an impact from biomass burning (e.g., during summertime) such measurements can provide an estimate of the contribution of biogenic secondary organic aerosol, from biogenic volatile organic compound precursors. Radiocarbon results for 11.5-h PM-2.5 samples collected near Nashville, Tennessee, USA, during summer 1999 will be presented. On average the measured biogenic fraction was surprisingly large (more than half), with the average biogenic fraction for night samples being only slightly smaller than for day samples. Discussion will include (a) description of the radiocarbon methodology, (b) use of radiocarbon measurements on local vegetation and fuel samples as calibration data, (c) concurrent measurements of organic carbon and elemental carbon ambient concentrations, (d) assessment of organic aerosol sampling artifact through use of organic vapor denuders, variable face velocities, and filter extraction, and (e) comparison with published radiocarbon results obtained in Houston, Texas in a similar study. Disclaimer: This work has been funded wholly or in part by the United States Environmental Protection Agency under Interagency Agreement No. 13937923 to the National Institute of Standards and Technology, and Contract No. 68-D5-0049 to ManTech Environmental Tecnology, Inc. It has been subjected to Agency review and approved for publication.

  3. Study on biogenic amines in various dry salted fish consumed in China

    NASA Astrophysics Data System (ADS)

    Wu, Yanyan; Chen, Yufeng; Li, Laihao; Yang, Xianqing; Yang, Shaoling; Lin, Wanling; Zhao, Yongqiang; Deng, Jianchao

    2016-08-01

    This study was carried out to investigate the biogenic amines (BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine (CAD) and putrescine (PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret ( Pampus argenteus) (347.79 mg kg-1). Five of forty three samples exceeded the acceptable content of TYR (100 mg kg-1), and 23.26% of dried-salted fish contained high contents of biogenic amines (above 600 mg kg-1). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count (TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.

  4. Integration of biogenic emissions in environmental fate, transport, and exposure systems

    NASA Astrophysics Data System (ADS)

    Efstathiou, Christos I.

    Biogenic emissions make a significant contribution to the levels of aeroallergens and secondary air pollutants such as ozone. Understanding major factors contributing to allergic airway diseases requires accurate characterization of emissions and transport/transformation of biogenic emissions. However, biogenic emission estimates are laden with large uncertainties. Furthermore, the current biogenic emission estimation models use low-resolution data for estimating land use, vegetation biomass and VOC emissions. Furthermore, there are currently no established methods for estimating bioaerosol emissions over continental or regional scale, which can impact the ambient levels of pollent that have synergestic effects with other gaseous pollutants. In the first part of the thesis, an detailed review of different approaches and available databases for estimating biogenic emissions was conducted, and multiple geodatabases and satellite imagery were used in a consistent manner to improve the estimates of biogenic emissions over the continental United States. These emissions represent more realistic, higher resolution estimates of biogenic emissions (including those of highly reactive species such as isoprene). The impact of these emissions on tropospheric ozone levels was studied at a regional scale through the application of the USEPA's Community Multiscale Air Quality (CMAQ) model. Minor, but significant differences in the levels of ambient ozone were observed. In the second part of the thesis, an algorithm for estimating emissions of pollen particles from major allergenic tree and plant families in the United States was developed, extending the approach for modeling biogenic gas emissions in the Biogenic Emission Inventory System (BEIS). A spatio-temporal vegetation map was constructed from different remote sensing sources and local surveys, and was coupled with a meteorological model to develop pollen emissions rates. This model overcomes limitations posed by the lack of

  5. What, Where, When, Who and How: Accounting for Biogenic CO2 Emissions Fluxes

    NASA Astrophysics Data System (ADS)

    Ohrel, S. B.

    2013-12-01

    The world is facing a future with a changing climate as well as increasing energy needs. Many countries, including the United States, are therefore considering an increased role of biomass in domestic energy portfolios. Accounting for emissions related to biomass production and use for energy is a complex issue: determining the extent to which biomass utilization can contribute to meeting energy needs while not contributing additional GHG emissions to the atmosphere necessitates further research. Such analysis becomes more challenging when evaluating biogenic feedstocks with long rotations (i.e., woody biomass). Detailed analysis and new accounting methods are needed in order to better assess and understand the potential implications of increased bioenergy utilization in the United States energy portfolio. In response to the EPA's 2011 Draft Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, the Biogenic Carbon Emissions Panel (BCE Panel) appointed by the Science Advisory Board (2013) found that 'Carbon neutrality cannot be assumed for all biomass energy a priori. There are circumstances in which biomass is grown, harvested and combusted in a carbon neutral fashion but carbon neutrality is not an appropriate a priori assumption; it is a conclusion that should be reached only after considering a particular feedstock's production and consumption cycle. There is considerable heterogeneity in feedstock types, sources and production methods and thus net biogenic carbon emissions will vary considerably.' In that light, this study discusses the current policy discussion on biogenic feedstock use for energy in the United States. It then evaluates the question: how can we account for stationary source biogenic CO2 emissions while considering the biological cycling of carbon on the biogenic feedstock production landscape? The analysis discusses current biogenic feedstock usage in the U.S. and potential future impacts of increased biogenic feedstock

  6. Biogenic and non-biogenic Si pools in terrestrial ecosystems: results from a novel analysis method

    NASA Astrophysics Data System (ADS)

    Barao, Lucia; Vandevenne, Floor; Clymans, Wim; Meire, Patrick; Frings, Patrick; Conley, Daniel; Struyf, Eric

    2015-04-01

    Silicon (Si) is a chemical element frequently associated with highly abundant silicate minerals in the Earth crust. Over millions of years, the interaction of such minerals with the atmosphere and hydrosphere produces a myriad of processed compounds, and the mineral weathering consumes CO2 during the process. The weathering of minerals also triggers the export of dissolved Si (DSi) to coastal waters and the ocean. Here, DSi is deposited in diatom frustules, in an amorphous biogenic form (BSi). Diatoms account for 50% of the primary production and are crucial for the export of carbon into the deep sea. In recent years, it was acknowledged that terrestrial systems filter the Si transition from the terrestrial mineral to the marine and coastal biological pool, by the incorporation of DSi into plants. In this process, DSi is taken up by roots together with other nutrients and precipitates in plant cells in amorphous structures named phytoliths. After dead, plant tissues become mixed in the top soil, where BSi is available for dissolution and will control the DSi availability in short time scales. Additionally, Si originated from soil forming processes can also significantly interfere with the global cycle. The Si cycle in terrestrial ecosystems is a key factor to coastal ecology, plant ecology, biogeochemistry and agro-sciences, but the high variability of different biogenic and non-biogenic Si pools remains as an obstacle to obtain accurate measurements. The traditional methods, developed to isolate diatoms in ocean sediments, only account for simple mineral corrections. In this dissertation we have adapted a novel continuous analysis method (during alkaline extraction) that uses Si-Al ratios and reactivity to differ biogenic from non-biogenic fractions. The method was originally used in marine sediments, but we have developed it to be applicable in a wide range of terrestrial, aquatic and coastal ecosystems. We first focused on soils under strong human impact in

  7. Global comparison reveals biogenic weathering as driven by nutrient limitation at ecosystem scale

    NASA Astrophysics Data System (ADS)

    Boy, Jens; Godoy, Roberto; Dechene, Annika; Shibistova, Olga; Amir, Hamid; Iskandar, Issi; Fogliano, Bruno; Boy, Diana; McCulloch, Robert; Andrino, Alberto; Gschwendtner, Silvia; Marin, Cesar; Sauheitl, Leopold; Dultz, Stefan; Mikutta, Robert; Guggenberger, Georg

    2017-04-01

    A substantial contribution of biogenic weathering in ecosystem nutrition, especially by symbiotic microorganisms, has often been proposed, but large-scale in vivo studies are still missing. Here we compare a set of ecosystems spanning from the Antarctic to tropical forests for their potential biogenic weathering and its drivers. To address biogenic weathering rates, we installed mineral mesocosms only accessible for bacteria and fungi for up to 4 years, which contained freshly broken and defined nutrient-baring minerals in soil A horizons of ecosystems along a gradient of soil development differing in climate and plant species communities. Alterations of the buried minerals were analyzed by grid-intersection, confocal lascer scanning microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy on the surface and on thin sections. On selected sites, carbon fluxes were tracked by 13C labeling, and microbial community was identified by DNA sequencing. In young ecosystems (protosoils) biogenic weathering is almost absent and starts after first carbon accumulation by aeolian (later litter) inputs and is mainly performed by bacteria. With ongoing soil development and appearance of symbiotic (mycorrhized) plants, nutrient availability in soil increasingly drove biogenic weathering, and fungi became the far more important players than bacteria. We found a close relation between fungal biogenic weathering and available potassium across all 16 forested sites in the study, regardless of the dominant mycorrhiza type (AM or EM), climate, and plant-species composition. We conclude that nutrient limitations at ecosystem scale are generally counteracted by adapted fungal biogenic weathering. The close relation between fungal weathering and plant-available nutrients over a large range of severely contrasting ecosystems points towards a direct energetic support of these weathering processes by the photoautotrophic community, making biogenic weathering a

  8. Formation temperatures of thermogenic and biogenic methane

    USGS Publications Warehouse

    Stolper, D.A.; Lawson, M.; Davis, C.L.; Ferreira, A.A.; Santos Neto, E. V.; Ellis, G.S.; Lewan, M.D.; Martini, Anna M.; Tang, Y.; Schoell, M.; Sessions, A.L.; Eiler, J.M.

    2014-01-01

    Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models.

  9. Condensed-phase biogenic-anthropogenic interactions with implications for cold cloud formation

    DOE PAGES

    Charnawskas, Joseph C.; Alpert, Peter A.; Lambe, Andrew; ...

    2017-01-24

    Anthropogenic and biogenic gas emissions contribute to the formation of secondary organic aerosol (SOA). When present, soot particles from fossil-fuel combustion can acquire a coating of SOA. We investigate SOA-soot biogenic-anthropogenic interactions and their impact on ice nucleation in relation to the particles’ organic phase state. SOA particles were generated from the OH oxidation of naphthalene, α-pinene, longifolene, or isoprene, with or without presence of sulfate or soot particles. Corresponding particle glass transition (T g) and full deliquescence relative humidity (FDRH) were estimated by a numerical diffusion model. Longifolene SOA particles are solid-like and all biogenic SOA sulfate mixtures exhibitmore » a core-shell configuration (i.e. a sulfate-rich core coated with SOA). Biogenic SOA with or without sulfate formed ice at conditions expected for homogeneous ice nucleation in agreement with respective T g and FDRH. α-pinene SOA coated soot particles nucleated ice above the homogeneous freezing temperature with soot acting as ice nuclei (IN). At lower temperatures the α-pinene SOA coating can be semisolid inducing ice nucleation. Naphthalene SOA coated soot particles acted as IN above and below the homogeneous freezing limit, which can be explained by the presence of a highly viscous SOA phase. Our results suggest that biogenic SOA does not play a significant role in mixed-phase cloud formation and the presence of sulfate further renders this even less likely. Furthermore, anthropogenic SOA may have an enhancing effect on cloud glaciation under mixed-phase and cirrus cloud conditions compared to biogenic SOA that dominate during preindustrial times or in pristine areas.« less

  10. Condensed-phase biogenic-anthropogenic interactions with implications for cold cloud formation.

    PubMed

    Charnawskas, Joseph C; Alpert, Peter A; Lambe, Andrew T; Berkemeier, Thomas; O'Brien, Rachel E; Massoli, Paola; Onasch, Timothy B; Shiraiwa, Manabu; Moffet, Ryan C; Gilles, Mary K; Davidovits, Paul; Worsnop, Douglas R; Knopf, Daniel A

    2017-08-24

    Anthropogenic and biogenic gas emissions contribute to the formation of secondary organic aerosol (SOA). When present, soot particles from fossil fuel combustion can acquire a coating of SOA. We investigate SOA-soot biogenic-anthropogenic interactions and their impact on ice nucleation in relation to the particles' organic phase state. SOA particles were generated from the OH oxidation of naphthalene, α-pinene, longifolene, or isoprene, with or without the presence of sulfate or soot particles. Corresponding particle glass transition (T g ) and full deliquescence relative humidity (FDRH) were estimated using a numerical diffusion model. Longifolene SOA particles are solid-like and all biogenic SOA sulfate mixtures exhibit a core-shell configuration (i.e. a sulfate-rich core coated with SOA). Biogenic SOA with or without sulfate formed ice at conditions expected for homogeneous ice nucleation, in agreement with respective T g and FDRH. α-pinene SOA coated soot particles nucleated ice above the homogeneous freezing temperature with soot acting as ice nuclei (IN). At lower temperatures the α-pinene SOA coating can be semisolid, inducing ice nucleation. Naphthalene SOA coated soot particles acted as ice nuclei above and below the homogeneous freezing limit, which can be explained by the presence of a highly viscous SOA phase. Our results suggest that biogenic SOA does not play a significant role in mixed-phase cloud formation and the presence of sulfate renders this even less likely. However, anthropogenic SOA may have an enhancing effect on cloud glaciation under mixed-phase and cirrus cloud conditions compared to biogenic SOA that dominate during pre-industrial times or in pristine areas.

  11. Land use change affects biogenic silica pool distribution in a subtropical soil toposequence

    NASA Astrophysics Data System (ADS)

    Unzué-Belmonte, Dácil; Ameijeiras-Mariño, Yolanda; Opfergelt, Sophie; Cornelis, Jean-Thomas; Barão, Lúcia; Minella, Jean; Meire, Patrick; Struyf, Eric

    2017-07-01

    Land use change (deforestation) has several negative consequences for the soil system. It is known to increase erosion rates, which affect the distribution of elements in soils. In this context, the crucial nutrient Si has received little attention, especially in a tropical context. Therefore, we studied the effect of land conversion and erosion intensity on the biogenic silica pools in a subtropical soil in the south of Brazil. Biogenic silica (BSi) was determined using a novel alkaline continuous extraction where Si / Al ratios of the fractions extracted are used to distinguish BSi and other soluble fractions: Si / Al > 5 for the biogenic AlkExSi (alkaline-extractable Si) and Si / Al < 5 for the non-biogenic AlkExSi. Our study shows that deforestation can rapidly (< 50 years) deplete the biogenic AlkExSi pool in soils depending on the slope of the study site (10-53 %), with faster depletion in steeper sites. We show that higher erosion in steeper sites implies increased accumulation of biogenic Si in deposition zones near the bottom of the slope, where rapid burial can cause removal of BSi from biologically active zones. Our study highlights the interaction of erosion strength and land use for BSi redistribution and depletion in a soil toposequence, with implications for basin-scale Si cycling.

  12. Characterization of a large biogenic secondary organic aerosol event from eastern Canadian forests

    NASA Astrophysics Data System (ADS)

    Slowik, J. G.; Stroud, C.; Bottenheim, J. W.; Brickell, P. C.; Chang, R. Y.-W.; Liggio, J.; Makar, P. A.; Martin, R. V.; Moran, M. D.; Shantz, N. C.; Sjostedt, S. J.; van Donkelaar, A.; Vlasenko, A.; Wiebe, H. A.; Xia, A. G.; Zhang, J.; Leaitch, W. R.; Abbatt, J. P. D.

    2010-03-01

    Measurements of aerosol composition, volatile organic compounds, and CO are used to determine biogenic secondary organic aerosol (SOA) concentrations at a rural site 70 km north of Toronto. These biogenic SOA levels are many times higher than past observations and occur during a period of increasing temperatures and outflow from Northern Ontario and Quebec forests in early summer. A regional chemical transport model approximately predicts the event timing and accurately predicts the aerosol loading, identifying the precursors as monoterpene emissions from the coniferous forest. The agreement between the measured and modeled biogenic aerosol concentrations contrasts with model underpredictions for polluted regions. Correlations of the oxygenated organic aerosol mass with tracers such as CO support a secondary aerosol source and distinguish biogenic, pollution, and biomass burning periods during the field campaign. Using the Master Chemical Mechanism, it is shown that the levels of CO observed during the biogenic event are consistent with a photochemical source arising from monoterpene oxidation. The biogenic aerosol mass correlates with satellite measurements of regional aerosol optical depth, indicating that the event extends across the eastern Canadian forest. This regional event correlates with increased temperatures, indicating that temperature-dependent forest emissions can significantly affect climate through enhanced direct optical scattering and higher cloud condensation nuclei numbers.

  13. Cytotoxicity and genotoxicity of biogenic silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Lima, R.; Feitosa, L. O.; Ballottin, D.; Marcato, P. D.; Tasic, L.; Durán, N.

    2013-04-01

    Biogenic silver nanoparticles with 40.3 ± 3.5 nm size and negative surface charge (- 40 mV) were prepared with Fusarium oxysporum. The cytotoxicity of 3T3 cell and human lymphocyte were studied by a TaliTM image-based cytometer and the genotoxicity through Allium cepa and comet assay. The results of BioAg-w (washed) and BioAg-nw (unwashed) biogenic silver nanoparticles showed cytotoxicity exceeding 50 μg/mL with no significant differences of response in 5 and 10 μg/mL regarding viability. Results of genotoxicity at concentrations 5.0 and 10.0 ug/mL show some response, but at concentrations 0.5 and 1.0 μg/mL the washed and unwashed silver nanoparticles did not present any effect. This in an important result since in tests with different bacteria species and strains, including resistant, MIC (minimal inhibitory concentration) had good answers at concentrations less than 1.9 μg/mL. This work concludes that biogenic silver nanoparticles may be a promising option for antimicrobial use in the range where no cyto or genotoxic effect were observed. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other cells.

  14. Managing Your Wine Fermentation to Reduce the Risk of Biogenic Amine Formation

    PubMed Central

    Smit, Anita Yolandi; Engelbrecht, Lynn; du Toit, Maret

    2012-01-01

    Biogenic amines are nitrogenous organic compounds produced in wine from amino acid precursors mainly by microbial decarboxylation. The concentration of biogenic amines that can potentially be produced is dependent on the amount of amino acid precursors in the medium, the presence of decarboxylase positive microorganisms and conditions that enable microbial or biochemical activity such as the addition of nutrients to support the inoculated starter cultures for alcoholic and malolactic fermentation (MLF). MLF can be conducted using co-inoculation or an inoculation after the completion of alcoholic fermentation that may also affect the level of biogenic amines in wine. This study focused on the impact of the addition of complex commercial yeast and bacterial nutrients and the use of different MLF inoculation scenarios on the production of biogenic amines in wine. Results showed that the addition of complex nutrients to real grape must could potentially increase histamine concentrations in wine. The same experiment in synthetic grape must showed a similar trend for putrescine and cadaverine. The effect of different MLF inoculation scenarios was examined in two cultivars, Pinotage and Shiraz. Conflicting results was obtained. In the Shiraz, co-inoculation resulted in lower biogenic amine concentrations after MLF compared to before MLF, while the concentration was higher in the Pinotage. However, the production of biogenic amines was affected more by the presence of decarboxylase positive lactic acid bacteria than by the addition of complex nutrients or the inoculation scenario. PMID:22419915

  15. Biogenic amines in table olives. Analysis by high-performance liquid chromatography.

    PubMed

    Hornero-Méndez, D; Garrido-Fernández, A

    1994-09-01

    Biogenic amines in fermented vegetables have scarcely been studied. Available data show that in table olives and fermented cucumbers their presence is rare and any determinations made have been restricted mainly to histamine. However, some microorganisms, especially those related to spoilage, found in the fermentation brines of such products may have amino acid decarboxylase activity and give rise to biogenic amines by unusual processes. A method for the simultaneous determination of eight biogenic amines (tryptamine, beta-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) has been developed to study their occurrence in fermented vegetables in more detail. The method consists of extraction of the amines from olive paste with 5% m/v trichloracetic acid and successive transfers into water-saturated n-BuOH and 0.1 mol l-1 HCl. An aliquot of this mixture is dried and derivatized with dansyl chloride. The dansyl derivatives are then analysed by high-performance liquid chromatography. Special emphasis has been given to optimization of the n-BuOH and 0.1 mol l-1 HCl extractions and to the derivatization conditions. By applying this method to the analysis of spoilt olives, the presence of some biogenic amines has been demonstrated. Thus a new method for monitoring the presence of biogenic amines during the fermentation of olives and for detecting anomalous fermentations is envisaged.

  16. Microbial mediated iron redox cycling in Fe (hydr)oxides for nitrite removal.

    PubMed

    Lu, Yongsheng; Xu, Lu; Shu, Weikang; Zhou, Jizhi; Chen, Xueping; Xu, Yunfeng; Qian, Guangren

    2017-01-01

    Nitrite, at an environmentally relevant concentration, was significantly reduced with iron (hydr)oxides mediated by Shewanella oneidensis MR-1. The average nitrite removal rates of 1.28±0.08 and 0.65±0.02(mgL -1 )h -1 were achieved with ferrihydrite and magnetite, respectively. The results showed that nitrite removal was able to undergo multiple redox cycles with iron (hydr)oxides mediated by Shewanella oneidensis MR-1. During the bioreduction of the following cycles, biogenic Fe(II) was subsequently chemically oxidized to Fe(III), which is associated with nitrite reduction. There was 11.18±1.26mgL -1 of NH 4 + -N generated in the process of redox cycling of ferrihydrite. Additionally, results obtained by using X-ray diffraction showed that ferrihydrite and magnetite remained mainly stable in the system. This study indicated that redox cycling of Fe in iron (hydr)oxides was a potential process associated with NO 2 - -N removal from solution, and reduced most nitrite abiotically to gaseous nitrogen species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. An intercomparison of biogenic emissions estimates from BEIS2 and BIOME: Reconciling the differences

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilkinson, J.G.; Emigh, R.A.; Pierce, T.E.

    1996-12-31

    Biogenic emissions play a critical role in urban and regional air quality. For instance, biogenic emissions contribute upwards of 76% of the daily hydrocarbon emissions in the Atlanta, Georgia airshed. The Biogenic Emissions Inventory System-Version 2.0 (BEIS2) and the Biogenic Model for Emissions (BIOME) are two models that compute biogenic emissions estimates. BEIS2 is a FORTRAN-based system, and BIOME is an ARC/INFO{reg_sign} - and SAS{reg_sign}-based system. Although the technical formulations of the models are similar, the models produce different biogenic emissions estimates for what appear to be essentially the same inputs. The goals of our study are the following: (1)more » Determine why BIOME and BEIS2 produce different emissions estimates; (2) Attempt to understand the impacts that the differences have on the emissions estimates; (3) Reconcile the differences where possible; and (4) Present a framework for the use of BEIS2 and BIOME. In this study, we used the Coastal Oxidant Assessment for Southeast Texas (COAST) biogenics data which were supplied to us courtesy of the Texas Natural Resource Conservation Commission (TNRCC), and we extracted the BEIS2 data for the same domain. We compared the emissions estimates of the two models using their respective data sets BIOME Using TNRCC data and BEIS2 using BEIS2 data.« less

  18. CO2 EMISSIONS FROM BIOENERGY AND OTHER BIOGENIC SOURCES IN STATIONARY SOURCES

    EPA Science Inventory

    On January 12, 2011, EPA announced a series of steps to address the treatment of biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with accounting for biogenic carbon dioxide emissions from stationary sour...

  19. Contribution of biogenic emissions to the formation of ozone and particulate matter in the eastern United States.

    PubMed

    Pun, Betty K; Wu, Shiang-Yuh; Seigneur, Christian

    2002-08-15

    As anthropogenic emissions of ozone (O3) precursors, fine particulate matter (PM2.5), and PM2.5 precursors continue to decrease in the United States, the fraction of O3 and PM2.5 attributable to natural sources may become significant in some locations, reducing the efficacy that can be expected from future controls of anthropogenic sources. Modeling studies were conducted to estimate the contribution of biogenic emissions to the formation of O3 and PM2.5 in Nashville/TN and the northeastern United States. Two approaches were used to bound the estimates. In an anthropogenic simulation, biogenic emissions and their influence at the domain boundaries were eliminated. Contributions of biogenic compounds to the simulated concentrations of O3 and PM2.5 were determined by the deviation of the concentrations in the anthropogenic case from those in the base case. A biogenic simulation was used to assess the amounts of O3 and PM2.5 produced in an environment free from anthropogenic influences in emissions and boundary conditions. In both locations, the contribution of biogenic emissions to O3 was small (<23%) on a domain-wide basis, despite significant biogenic volatile organic compounds (VOC) emissions (65-89% of total VOC emissions). However, the production of O3 was much more sensitive to biogenic emissions in urban areas (22-34%). Therefore, the effects of biogenic emissions on O3 manifested mostly via their interaction with anthropogenic emissions of NOx. In the anthropogenic simulations, the average contribution of biogenic and natural sources to PM2.5 was estimated at 9% in Nashville/TN and 12% in the northeast domain. Because of the long atmospheric lifetimes of PM2.5, the contribution of biogenic/natural PM2.5 from the boundary conditions was higher than the contribution of biogenic aerosols produced within the domain. The elimination of biogenic emissions also affected the chemistry of other secondary PM2.5 components. Very little PM2.5 was formed in the biogenic

  20. Fossilization of Iron-Oxidizing Bacteria at Hydrothermal Vents: a Useful Biosignature on Mars?

    NASA Astrophysics Data System (ADS)

    Leveille, R. J.; Lui, S.

    2009-05-01

    -concentric growth bands. In the bioreactor cultures, constant conditions led to abundant microbial growth and formation of an iron oxyhydroxide precipitate, either in direct association with the cells or within the growth medium. This suggests that not all of the iron precipitation is biogenic in origin. Cells typically show a filamentous morphology reminiscent of the mineral-encrusted forms observed in the natural samples. Continuing work includes high-resolution TEM observations of cultured organisms, examination of 2-year long in situ seafloor incubation experiments, and bioreactor silicification experiments in order to better understand the roles of iron and silica in the fossilization process. Microaerophilic iron oxidation could have existed on the early Earth in environments containing small amounts of oxygen produced either by locally concentrated photosynthetic microorganisms (e.g., cyanobacteria) or abiotically, as proposed for the subsurface of the Fe-dominated Rio Tinto (Spain) basin system. By analogy, similar subsurface or near-surface microaerophilic environments could have existed on Mars in the past. The distinctive morphologies and mineralization patterns of iron oxidizing bacteria could be a useful biosignature to search for on Mars. Deposits and biogenic features similar to those described here could theoretically be identified on Mars with existing imaging and analytical technologies. Therefore, future missions to Mars should target ancient hydrothermal systems, some of which have been putatively identified already.

  1. Biogenic Mn-Oxides in Subseafloor Basalts

    PubMed Central

    Ivarsson, Magnus; Broman, Curt; Gustafsson, Håkan; Holm, Nils G.

    2015-01-01

    The deep biosphere of the subseafloor basalts is recognized as a major scientific frontier in disciplines like biology, geology, and oceanography. Recently, the presence of fungi in these environments has involved a change of view regarding diversity and ecology. Here, we describe fossilized fungal communities in vugs in subseafloor basalts from a depth of 936.65 metres below seafloor at the Detroit Seamount, Pacific Ocean. These fungal communities are closely associated with botryoidal Mn oxides composed of todorokite. Analyses of the Mn oxides by Electron Paramagnetic Resonance spectroscopy (EPR) indicate a biogenic signature. We suggest, based on mineralogical, morphological and EPR data, a biological origin of the botryoidal Mn oxides. Our results show that fungi are involved in Mn cycling at great depths in the seafloor and we introduce EPR as a means to easily identify biogenic Mn oxides in these environments. PMID:26107948

  2. Global Biogenic Emission of Carbon Dioxide from Landfills

    NASA Astrophysics Data System (ADS)

    Lima, R.; Nolasco, D.; Meneses, W.; Salazar, J.; Hernández, P.; Pérez, N.

    2002-12-01

    Human-induced increases in the atmospheric concentrations of greenhouse gas components have been underway over the past century and are expected to drive climate change in the coming decades. Carbon dioxide was responsible for an estimated 55 % of the antropogenically driven radiactive forcing of the atmosphere in the 1980s and is predicted to have even greater importance over the next century (Houghton et al., 1990). A highly resolved understanding of the sources and sinks of atmospheric CO2, and how they are affected by climate and land use, is essential in the analysis of the global carbon cycle and how it may be impacted by human activities. Landfills are biochemical reactors that produce CH4 and CO2 emissions due to anaerobic digestion of solid urban wastes. Estimated global CH4 emission from landfills is about 44 millions tons per year and account for a 7.4 % of all CH4 sources (Whiticar, 1989). Observed CO2/CH4 molar ratios from landfill gases lie within the range of 0.7-1.0; therefore, an estimated global biogenic emission of CO2 from landfills could reach levels of 11.2-16 millions tons per year. Since biogas extraction systems are installed for extracting, purifying and burning the landfill gases, most of the biogenic gas emission to the atmosphere from landfills occurs through the surface environment in a diffuse and disperse form, also known as non-controlled biogenic emission. Several studies of non-controlled biogenic gas emission from landfills showed that CO2/CH4 weight ratios of surface landfill gases, which are directly injected into the atmosphere, are about 200-300 times higher than those observed in the landfill wells, which are usually collected and burned by gas extraction systems. This difference between surface and well landfill gases is mainly due to bacterial oxidation of the CH4 to CO2 inducing higher CO2/CH4 ratios for surface landfill gases than those well landfill gases. Taking into consideration this observation, the global biogenic

  3. Biogenic VOC Emissions from Tropical Landscapes

    NASA Astrophysics Data System (ADS)

    Guenther, A.; Greenberg, J.; Harley, P.; Otter, L.; Vanni Gatti, L.; Baker, B.

    2003-04-01

    Biogenic VOC have an important role in determining the chemical composition of atmosphere. As a result, these compounds are important for visibility, biogeochemical cycling, climate and radiative forcing, and the health of the biosphere. Tropical landscapes are estimated to release about 80% of total global biogenic VOC emissions but have been investigated to lesser extent than temperate regions. Tropical VOC emissions are particularly important due to the strong vertical transport and the rapid landuse change that is occurring there. This presentation will provide an overview of field measurements of biogenic VOC emissions from tropical landscapes in Amazonia (Large-scale Biosphere-atmosphere experiment in Amazonia, LBA) Central (EXPRESSO) and Southern (SAFARI 2000) Africa, Asia and Central America. Flux measurement methods include leaf-scale (enclosure measurements), canopy-scale (above canopy tower measurements), landscape-scale (tethered balloon), and regional-scale (aircraft measurements) observations. Typical midday isoprene emission rates for different landscapes vary by more than a factor of 20 with the lowest emissions observed from degraded forests. Emissions of alpha-pinene vary by a similar amount with the highest emissions associated with landscapes dominated by light dependent monoterpene emitting plants. Isoprene emissions tend to be higher for neotropical forests (Amazon and Costa Rica) in comparison to Africa and Asian tropical forests but considerable differences are observed within regions. Strong seasonal variations were observed in both the Congo and the Amazon rainforests with peak emissions during the dry seasons. Substantial emissions of light dependent monoterpenes, methanol and acetone are characteristic of at least some tropical landscapes.

  4. Biomass burning - Combustion emissions, satellite imagery, and biogenic emissions

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Cofer, Wesley R., III; Winstead, Edward L.; Rhinehart, Robert P.; Cahoon, Donald R., Jr.; Sebacher, Daniel I.; Sebacher, Shirley; Stocks, Brian J.

    1991-01-01

    After detailing a technique for the estimation of the instantaneous emission of trace gases produced by biomass burning, using satellite imagery, attention is given to the recent discovery that burning results in significant enhancement of biogenic emissions of N2O, NO, and CH4. Biomass burning accordingly has an immediate and long-term impact on the production of atmospheric trace gases. It is presently demonstrated that satellite imagery of fires may be used to estimate combustion emissions, and could be used to estimate long-term postburn biogenic emission of trace gases to the atmosphere.

  5. Biosafety of the application of biogenic nanometal powders in husbandry

    NASA Astrophysics Data System (ADS)

    Anatolievna Nazarova, Anna; Dmitrievna Polischuk, Svetlana; Anatolievna Stepanova, Irina; Ivanovich Churilov, Gennady; Chau Nguyen, Hoai; Buu Ngo, Quoc

    2014-03-01

    Effects of iron and copper nanopowders (particle size of 20-40 nm) were investigated on rabbits of 1 month age and heifers of 6 months. For introduction of nanometals into the animal's ration, the mixed fodder was treated with the nanometal powder suspension in such a way: 0.08 mg of nanoiron per kg of animal's body weight and 0.04 mg kg-1 for nanocopper. The weight gain of the heifers who received nanoiron and nanocopper after 8 months was 22.4 and 10.7% higher than that of the control, respectively. For the rabbits who received nano Fe and Cu after 3 months, the weight gain was 11.7 and 7.3% compared to the control, respectively. Under the action of metal nanopowders morphological indices of blood were changed in comparison with the control: after 8 months the quantity of erythrocytes increased by 19.6%, hemoglobin by 17.1% and leukocytes by 7.6%. There was a realignment in leukocytic formula: the quantity of lymphocytes increased by 9% compared to the control. Biogenic metals in superdispersive state were able to stimulate immune, enzymatic and humoral systems of the animal's organism, promoting metabolism. Adding Co and Cu metal nanopowders to the bull-calves’ fodder rations increased content of Ca by 31.8 and 0%, Fe by 38.8 and 37.5%, K by 19.2 and 15.3%, Mg by 17.6 and 23.5%, Mn by 9.8 and 45% and Na by 20.5 and 8.8%, respectively, compared to control. Metal nanopowders improved the quality indices and meat productivity of black-white bull-calves, expressed in intensive growth of muscle, tissue and more nutritious meat. The conducted veterinary-sanitary expertise showed that the supplements based on iron, cobalt and copper nanopowders can be used as safe bioactive supplements in animal husbandry.

  6. In situ removal of arsenic from groundwater by using permeable reactive barriers of organic matter/limestone/zero-valent iron mixtures.

    PubMed

    Gibert, O; de Pablo, J; Cortina, J-L; Ayora, C

    2010-08-01

    In this study, two mixtures of municipal compost, limestone and, optionally, zero-valent iron were assessed in two column experiments on acid mine treatment. The effluent solution was systematically analysed throughout the experiment and precipitates from both columns were withdrawn for scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry analysis and, from the column containing zero-valent iron, solid digestion and sequential extraction analysis. The results showed that waters were cleaned of arsenic, metals and acidity, but chemical and morphological analysis suggested that metal removal was not due predominantly to biogenic sulphide generation but to pH increase, i.e. metal (oxy)hydroxide and carbonate precipitation. Retained arsenic and metal removal were clearly associated to co-precipitation with and/or sorption on iron and aluminum (oxy)hydroxides. An improvement on the arsenic removal efficiency was achieved when the filling mixture contained zero-valent iron. Values of arsenic concentrations were then always below 10 microg/L.

  7. Biogenic volatile organic compounds in the Earth system.

    PubMed

    Laothawornkitkul, Jullada; Taylor, Jane E; Paul, Nigel D; Hewitt, C Nicholas

    2009-01-01

    Biogenic volatile organic compounds produced by plants are involved in plant growth, development, reproduction and defence. They also function as communication media within plant communities, between plants and between plants and insects. Because of the high chemical reactivity of many of these compounds, coupled with their large mass emission rates from vegetation into the atmosphere, they have significant effects on the chemical composition and physical characteristics of the atmosphere. Hence, biogenic volatile organic compounds mediate the relationship between the biosphere and the atmosphere. Alteration of this relationship by anthropogenically driven changes to the environment, including global climate change, may perturb these interactions and may lead to adverse and hard-to-predict consequences for the Earth system.

  8. INTEGRATION OF THE BIOGENIC EMISSIONS INVENTORY SYSTEM (BEIS3) INTO THE COMMUNITY MULTISCALE AIR QUALITY MODELING SYSTEM

    EPA Science Inventory

    The importance of biogenic emissions for regional air quality modeling is generally recognized [Guenther et al., 2000]. Since the 1980s, biogenic emission estimates have been derived from algorithms such as the Biogenic Emissions Inventory System (BEIS) [Pierce et. al., 1998]....

  9. Inhibitory Effects of Spices on Biogenic Amine Accumulation during Fish Sauce Fermentation.

    PubMed

    Zhou, Xuxia; Qiu, Mengting; Zhao, Dandan; Lu, Fei; Ding, Yuting

    2016-04-01

    The presence of high levels of biogenic amines is detrimental to the quality and safety of fish sauce. This study investigated the effects of ethanol extracts of spices, including garlic, ginger, cinnamon, and star anise extracts, in reducing the accumulation of biogenic amines during fish sauce fermentation. The concentrations of biogenic amines, which include histamine, putrescine, tyramine, and spermidine, all increased during fish sauce fermentation. When compared with the samples without spices, the garlic and star anise extracts significantly reduced these increases. The greatest inhibitory effect was observed for the garlic ethanolic extracts. When compared with controls, the histamine, putrescine, tyramine, and spermidine contents and the overall biogenic amine levels of the garlic extract-treated samples were reduced by 30.49%, 17.65%, 26.03%, 37.20%, and 27.17%, respectively. The garlic, cinnamon, and star anise extracts showed significant inhibitory effects on aerobic bacteria counts. Furthermore, the garlic and star anise extracts showed antimicrobial activity against amine producers. These findings may be helpful for enhancing the safety of fish sauce. © 2016 Institute of Food Technologists®

  10. Mineral ecophysiological evidence for microbial activity in banded iron formation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Dr. Yi-Liang; Konhauser, Dr, Kurt; Cole, David R

    2011-01-01

    The phosphorus composition of banded-iron formations (BIFs) has been used as a proxy for Precambrian seawater composition and the paleoeredox state of Earth's surface environment. However, it is unclear whether the phosphorus in BIFs originally entered the sediment as a sorbed component of the iron oxyhydroxide particles, or whether it was incorporated into the biomass of marine phytoplankton. We conducted high-resolution mineral analyses and report here the first detection of an Fe(III) acetate salt, as well as nanocrystals of apatite in association with magnetite, in the 2.48 Ga Dales Gorge Member of the Brockman Iron Formation (a BIF), Hamersley, Westernmore » Australia. The clusters of apatite are similar in size and morphology to biogenic apatite crystals resulting from biomass decay in Phanerozoic marine sediments, while the formation of an Fe(III) acetate salt and magnetite not only implies the original presence of biomass in the BIF sediments, but also that organic carbon likely served as an electron donor during bacterial Fe(III) reduction. This study is important because it suggests that phytoplankton may have played a key role in the transfer of phosphorus (and other trace elements) from the photic zone to the seafloor.« less

  11. Ocean acidification can mediate biodiversity shifts by changing biogenic habitat

    NASA Astrophysics Data System (ADS)

    Sunday, Jennifer M.; Fabricius, Katharina E.; Kroeker, Kristy J.; Anderson, Kathryn M.; Brown, Norah E.; Barry, James P.; Connell, Sean D.; Dupont, Sam; Gaylord, Brian; Hall-Spencer, Jason M.; Klinger, Terrie; Milazzo, Marco; Munday, Philip L.; Russell, Bayden D.; Sanford, Eric; Thiyagarajan, Vengatesen; Vaughan, Megan L. H.; Widdicombe, Stephen; Harley, Christopher D. G.

    2017-01-01

    The effects of ocean acidification (OA) on the structure and complexity of coastal marine biogenic habitat have been broadly overlooked. Here we explore how declining pH and carbonate saturation may affect the structural complexity of four major biogenic habitats. Our analyses predict that indirect effects driven by OA on habitat-forming organisms could lead to lower species diversity in coral reefs, mussel beds and some macroalgal habitats, but increases in seagrass and other macroalgal habitats. Available in situ data support the prediction of decreased biodiversity in coral reefs, but not the prediction of seagrass bed gains. Thus, OA-driven habitat loss may exacerbate the direct negative effects of OA on coastal biodiversity; however, we lack evidence of the predicted biodiversity increase in systems where habitat-forming species could benefit from acidification. Overall, a combination of direct effects and community-mediated indirect effects will drive changes in the extent and structural complexity of biogenic habitat, which will have important ecosystem effects.

  12. Mineralization of Bacteria in Terrestrial Basaltic Rocks: Comparison With Possible Biogenic Features in Martian Meteorite Allan Hills 84001

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; McKay, D. S.; Wentworth, S. J.; Stevens, T. O.; Taunton, A. E.; Allen, C. C.; Gibson, E. K., Jr.; Romanek, C. S.

    1998-01-01

    The identification of biogenic features altered by diagenesis or mineralization is important in determining whether specific features in terrestrial rocks and in meteorites may have a biogenic origin. Unfortunately, few studies have addressed the formation of biogenic features in igneous rocks, which may be important to these phenomena, including the controversy over possible biogenic features in basaltic martian meteorite ALH84001. To explore the presence of biogenic features in igneous rocks, we examined microcosms growing in basaltic small-scale experimental growth chambers or microcosms. Microbial communities were harvested from aquifers of the Columbia River Basalt (CRB) group and grown in a microcosm containing unweathered basalt chips and groundwater (technique described in. These microcosms simulated natural growth conditions in the deep subsurface of the CRB, which should be a good terrestrial analog for any putative martian subsurface ecosystem that may have once included ALH84001. Here we present new size measurements and photomicrographs comparing the putative martian fossils to biogenic material in the CRB microcosms. The range of size and shapes of the biogenic features on the CRB microcosm chips overlaps with and is similar to those on ALH84001 chips. Although this present work does not provide evidence for the biogenicity of ALH84001 features, we believe that, based on criteria of size, shape, and general morphology, a biogenic interpretation for the ALH84001 features remains plausible.

  13. Organosulfate Formation in Biogenic Secondary Organic Aerosol

    EPA Science Inventory

    Organosulfates of isoprene, α-pinene, and β-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive seri...

  14. Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue

    PubMed Central

    Watts, Mathew P.; Coker, Victoria S.; Parry, Stephen A.; Pattrick, Richard A.D.; Thomas, Russell A.P.; Kalin, Robert; Lloyd, Jonathan R.

    2015-01-01

    Highly reactive nano-scale biogenic magnetite (BnM), synthesized by the Fe(III)-reducing bacterium Geobacter sulfurreducens, was tested for the potential to remediate alkaline Cr(VI) contaminated waters associated with chromite ore processing residue (COPR). The performance of this biomaterial, targeting aqueous Cr(VI) removal, was compared to a synthetic alternative, nano-scale zero valent iron (nZVI). Samples of highly contaminated alkaline groundwater and COPR solid waste were obtained from a contaminated site in Glasgow, UK. During batch reactivity tests, Cr(VI) removal from groundwater was inhibited by ∼25% (BnM) and ∼50% (nZVI) when compared to the treatment of less chemically complex model pH 12 Cr(VI) solutions. In both the model Cr(VI) solutions and contaminated groundwater experiments the surface of the nanoparticles became passivated, preventing complete coupling of their available electrons to Cr(VI) reduction. To investigate this process, the surfaces of the reacted samples were analyzed by TEM-EDX, XAS and XPS, confirming Cr(VI) reduction to the less soluble Cr(III) on the nanoparticle surface. In groundwater reacted samples the presence of Ca, Si and S was also noted on the surface of the nanoparticles, and is likely responsible for earlier onset of passivation. Treatment of the solid COPR material in contact with water, by addition of increasing weight % of the nanoparticles, resulted in a decrease in aqueous Cr(VI) concentrations to below detection limits, via the addition of ⩾5% w/w BnM or ⩾1% w/w nZVI. XANES analysis of the Cr K edge, showed that the % Cr(VI) in the COPR dropped from 26% to a minimum of 4–7% by the addition of 5% w/w BnM or 2% w/w nZVI, with higher additions unable to reduce the remaining Cr(VI). The treated materials exhibited minimal re-mobilization of soluble Cr(VI) by re-equilibration with atmospheric oxygen, with the bulk of the Cr remaining in the solid fraction. Both nanoparticles exhibited a considerable

  15. Biogenic nano-magnetite and nano-zero valent iron treatment of alkaline Cr(VI) leachate and chromite ore processing residue

    DOE PAGES

    Watts, Mathew P.; Coker, Victoria S.; Parry, Stephen A.; ...

    2014-12-11

    Highly reactive nano-scale biogenic magnetite (BnM), synthesized by the Fe(III)-reducing bacterium Geobacter sulfurreducens, was tested for the potential to remediate alkaline Cr(VI) contaminated waters associated with chromite ore processing residue (COPR). The performance of this biomaterial, targeting aqueous Cr(VI) removal, was compared to a synthetic alternative, nano-scale zero valent iron (nZVI). Samples of highly contaminated alkaline groundwater and COPR solid waste were obtained from a contaminated site in Glasgow, UK. During batch reactivity tests, Cr(VI) removal from groundwater was inhibited by ~25% (BnM) and ~50% (nZVI) when compared to the treatment of less chemically complex model pH 12 Cr(VI) solutions.more » In both the model Cr(VI) solutions and contaminated groundwater experiments the surface of the nanoparticles became passivated, preventing complete coupling of their available electrons to Cr(VI) reduction. To investigate this process, the surfaces of the reacted samples were analyzed by TEM-EDX, XAS and XPS, confirming Cr(VI) reduction to the less soluble Cr(III) on the nanoparticle surface. In groundwater reacted samples the presence of Ca, Si and S was also noted on the surface of the nanoparticles, and is likely responsible for earlier onset of passivation. Treatment of the solid COPR material in contact with water, by addition of increasing weight % of the nanoparticles, resulted in a decrease in aqueous Cr(VI) concentrations to below detection limits, via the addition of ≥5% w/w BnM or ≥1% w/w nZVI. XANES analysis of the Cr K edge, showed that the % Cr(VI) in the COPR dropped from 26% to a minimum of 4–7% by the addition of 5% w/w BnM or 2% w/w nZVI, with higher additions unable to reduce the remaining Cr(VI). The treated materials exhibited minimal re-mobilization of soluble Cr(VI) by re-equilibration with atmospheric oxygen, with the bulk of the Cr remaining in the solid fraction. Both nanoparticles exhibited a considerable

  16. Biogenic Aldehydes as Therapeutic Targets for Cardiovascular Disease

    PubMed Central

    Nelson, Margaret-Ann M; Baba, Shahid P; Andersonc, Ethan J

    2017-01-01

    Aldehydes are continuously formed in biological systems through enzyme-dependent and spontaneous oxidation of lipids, glucose, and primary amines. These highly reactive, biogenic electrophiles can become toxic via covalent modification of proteins, lipids and DNA. Thus, agents that scavenge aldehydes through conjugation have therapeutic value for a number of major cardiovascular diseases. Several commonly-prescribed drugs (e.g., hydralazine) have been shown to have potent aldehyde-conjugating properties which may contribute to their beneficial effects. Herein, we briefly describe the major sources and toxicities of biogenic aldehydes in cardiovascular system, and provide an overview of drugs that are known to have aldehyde-conjugating effects. Some compounds of phytochemical origin, and histidyl-dipeptides with emerging therapeutic value in this area are also discussed. PMID:28528297

  17. Operation of marine diesel engines on biogenic fuels: modification of emissions and resulting climate effects.

    PubMed

    Petzold, Andreas; Lauer, Peter; Fritsche, Uwe; Hasselbach, Jan; Lichtenstern, Michael; Schlager, Hans; Fleischer, Fritz

    2011-12-15

    The modification of emissions of climate-sensitive exhaust compounds such as CO(2), NO(x), hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fuel life cycle analysis which included land use changes associated with the growth of energy plants. Emissions of CO(2) and NO(x) per kWh were found to be similar for fossil fuels and biogenic fuels. PM mass emission was reduced to 10-15% of HFO emissions for all low-sulfur fuels including MGO as a fossil fuel. Black carbon emissions were reduced significantly to 13-30% of HFO. Changes in emissions were predominantly related to particulate sulfate, while differences between low-sulfur fossil fuels and low-sulfur biogenic fuels were of minor significance. GHG emissions from the biogenic fuel life cycle (FLC) depend crucially on energy plant production conditions and have the potential of shifting the overall GHG budget from positive to negative compared to fossil fuels.

  18. Transformation of Strontium during formation of biogenic calcium carbonate

    NASA Astrophysics Data System (ADS)

    Ohnuki, T.; Kozai, N.; Sakamoto, F.; Yamashita, M.; Horiieke, T.; Utsunomiya, S.

    2016-12-01

    Some amounts of radionuclides contaminated water containing 90Sr generated in the Fukushima Daiichi Nuclear Power Plant were leaked to sea water in the port. One of the possible method to eliminate 90Sr is co-precipitated with biogenic carbonates minerals (CCM). Specific bacteria are known to form biogenic CCM in groundwater. In the present study, we have screened specific bacterium to form CCM in saline water, and studied transformation of Sr during biogenic CCM. A marine microbe of strain TK2d, which is screened from Tokyo bay to form CCM in saline solution, was grown in the medium solution contained urea and Sr. The concentratuion of Sr2+ in the solution was monitored by ICP-OES (ICP-OES; 720 Agilent Technologies, Inc., USA) during the formation of biogenic CCM. The precipitates were analyzed by SEM, TEM, and XAFS. When 1.0 mM Sr was dissolved in the medium solution, the concentration of Sr decreased up to 0.02 mM within 10 days, indicating that most of Sr in the solution was eliminated within 10 days. SEM and TEM analyses showed that needle shaped CCM containing Ca and Sr were formed. The CCM was not single crystalline, but poly-crystalline of calcite and aragonite. The elemental mapping showed that Sr was present at the same position of Ca, indicating that Sr was coprecipitated with Ca. The XANES analysis of Sr in the precipitates showed that the XANES spectrum was not the same as that of Sr coprecipitated with an abiotic Ca carbonates. Linear combination fitting of XANES spectra by those of SrCl2 and SrCO3 showed that both Sr2+ and SrCO3 were present in CCM. Longer contact time resulted in higher content of SrCO3, indicating that Sr was incorporated gradually with time into CCM structure. Thus, Sr was changed its chemical species from adsorbed one to the incorporated one in biogenic CCM in saline solution. This work was partially supported by a research grant from the Japan Science and Technology Agency, Japan (research grant No. 260502).

  19. Safety assessment of the biogenic amines in fermented soya beans and fermented bean curd.

    PubMed

    Yang, Juan; Ding, Xiaowen; Qin, Yingrui; Zeng, Yitao

    2014-08-06

    To evaluate the safety of biogenic amines, high performance liquid chromatography (HPLC) was used to evaluate the levels of biogenic amines in fermented soya beans and fermented bean curd. In fermented soya beans, the total biogenic amines content was in a relatively safe range in many samples, although the concentration of histamine, tyramine, and β-phenethylamine was high enough in some samples to cause a possible safety threat, and 8 of the 30 samples were deemed unsafe. In fermented bean curd, the total biogenic amines content was more than 900 mg/kg in 19 white sufu amples, a level that has been determined to pose a safety hazard; putrescine was the only one detected in all samples and also had the highest concentration, which made samples a safety hazard; the content of tryptamine, β-phenethylamine, tyramine, and histamine had reached the level of threat to human health in some white and green sufu samples, and that may imply another potential safety risk; and 25 of the 33 samples were unsafe. In conclusion, the content of biogenic amines in all fermented soya bean products should be studied and appropriate limits determined to ensure the safety of eating these foods.

  20. Fibrous materials on polyhydroxybutyrate and ferric iron (III)-based porphyrins basis: physical-chemical and antibacterial properties

    NASA Astrophysics Data System (ADS)

    Olkhov, A.; Lobanov, A.; Staroverova, O.; Tyubaeva, P.; Zykova, A.; Pantyukhov, P.; Popov, A.; Iordanskii, A.

    2017-02-01

    Ferric iron (III)-based complexes with porphyrins are the homogenous catalysts of auto-oxidation of several biogenic substances. The most perspective carrier for functional low-molecular substances is the polymer fibers with nano-dimensional parameters. Application of natural polymers, poly-(3-hydroxybutyrate) or polylactic acid for instance, makes possible to develop fiber and matrice systems to solve ecological problem in biomedicine The aim of the article is to obtain fibrous material on poly-(3-hydroxybutyrate) and ferric iron (III)-based porphyrins basis and to examine its physical-chemical and antibacterial properties. The work is focused on possibility to apply such material to biomedical purposes. Microphotographs of obtained material showed that addition of 1% wt. ferric iron (III)-based porphyrins to PHB led to increased average diameter and disappeared spindly structures in comparison with initial PHB. Biological tests of nonwoven fabrics showed that fibers, containing ferric iron (III)-based tetraphenylporphyrins, were active in relation to bacterial test-cultures. It was found that materials on polymer and metal complexes with porphyrins basis can be applied to production of decontamination equipment in relation to pathogenic and opportunistic microorganisms.

  1. Suitability of biogenic carbonate of Lithospermum fruits for 14C dating

    NASA Astrophysics Data System (ADS)

    Pustovoytov, Konstantin; Riehl, Simone

    2006-05-01

    Lithospermum (Boraginaceae) belongs to a small group of plant taxa that accumulate biogenic carbonate in their fruits. In this genus, carbonate incrustations form in the cells of the epidermis and sclerenchyma of the pericarp. Fossil Lithospermum fruits (nutlets) with well-preserved calcified tissues commonly occur in Quaternary sediments and cultural layers. We tested the suitability of biogenic carbonate of Lithospermum fruits for radiocarbon dating using a total of 15 AMS measurement results from four modern and 11 fossil samples. The 14C data from modern samples suggest that Lithospermum utilises only atmospheric carbon to synthesise calcite in the nutlets. In general, the ages determined through 14C dating of fossil fruitscorresponded well with the absolute-age intervals for archaeological sites over the last 5000 yr. Biogenic carbonate of Lithospermum fruits, like that of Celtis, represents a new source of chronological information for late Quaternary studies.

  2. Wound healing applications of biogenic colloidal silver and gold nanoparticles: recent trends and future prospects.

    PubMed

    Ovais, Muhammad; Ahmad, Irshad; Khalil, Ali Talha; Mukherjee, Sudip; Javed, Rabia; Ayaz, Muhammad; Raza, Abida; Shinwari, Zabta Khan

    2018-05-01

    Nanotechnology has emerged as a prominent scientific discipline in the technological revolution of this millennium. The scientific community has focused on the green synthesis of metal nanoparticles as compared to physical and chemical methods due to its eco-friendly nature and high efficacy. Medicinal plants have been proven as the paramount source of various phytochemicals that can be used for the biogenic synthesis of colloidal silver and gold nanoparticles as compared to other living organisms, e.g., microbes and fungi. According to various scientific reports, the biogenic nanoparticles have shown promising potential as wound healing agents. However, not a single broad review article was present that demonstrates the wound healing application of biogenic silver and gold nanoparticles. Foreseeing the overall literature published, we for the first time intended to discuss the current trends in wound healing via biogenic silver and gold nanoparticles. Furthermore, light has been shed on the mechanistic aspects of wound healing along with futuristic discussion on the faith of biogenic silver and gold nanoparticles as potential wound healing agents.

  3. Improved MEGAN predictions of biogenic isoprene in the contiguous United States

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Schade, Gunnar; Estes, Mark; Ying, Qi

    2017-01-01

    Isoprene emitted from biogenic sources significantly contributes to ozone and secondary organic aerosol formation in the troposphere. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) has been widely used to estimate isoprene emissions from local to global scales. However, previous studies have shown that MEGAN significantly over-predicts isoprene emissions in the contiguous United States (US). In this study, ambient isoprene concentrations in the US were simulated by the Community Multiscale Air Quality (CMAQ) model (v5.0.1) using biogenic emissions estimated by MEGAN v2.10 with several different gridded isoprene emission factor (EF) fields. Best isoprene predictions were obtained with the EF field based on the Biogenic Emissions Landcover Database v4 (BELD4) from US EPA for its Biogenic Emission Inventory System (BEIS) model v3.61 (MEGAN-BEIS361). A seven-month simulation (April to October 2011) of isoprene emissions with MEGAN-BEIS361 and ambient concentrations using CMAQ shows that observed spatial and temporal variations (both diurnal and seasonal) of isoprene concentrations can be well predicted at most non-urban monitors using isoprene emission estimation from the MEGAN-BEIS361 without significant biases. The predicted monthly average vertical column density of formaldehyde (HCHO), a reactive volatile organic compound with significant contributions from isoprene oxidation, generally agree with the spatial distribution of HCHO column density derived using satellite data collected by the Ozone Monitoring Instrument (OMI), although summer month vertical column densities in the southeast US were overestimated, which suggests that isoprene emission might still be overestimated in that region. The agreement between observation and prediction may be further improved if more accurate PAR values, such as those derived from satellite-based observations, were used in modeling the biogenic emissions.

  4. High-resolution mapping of biogenic carbon fluxes to improve urban CO2 monitoring, reporting, and verification

    NASA Astrophysics Data System (ADS)

    Hardiman, B. S.; Hutyra, L.; Gately, C.; Raciti, S. M.

    2014-12-01

    Urban areas are home to 80% of the US population and 70% of energy related fossil fuel emissions originate from urban areas. Efforts to accurately monitor, report, and verify anthropogenic CO2 missions using atmospheric measurements require reliable partitioning of anthropogenic and biogenic sources. Anthropogenic emissions peak during the daytime, coincident with biogenic drawdown of CO2. In contrast, biogenic respiration emissions peak at night when anthropogenic emissions are lower. This temporal aliasing of fluxes requires careful modeling of both biogenic and anthropogenic fluxes for accurate source attribution through inverse modeling. Biogenic fluxes in urban regions can be a significant component of the urban carbon cycle. However, vegetation in urban areas is subject to longer growing seasons, reduced competition, higher rates of nitrogen deposition, and altered patterns of biomass inputs, all interacting to elevate C turnover rates relative to analogous non-urban ecosystems. These conditions suggest that models that ignore urban vegetation or base biogenic flux estimates on non-urban forests are likely to produce inaccurate estimates of anthropogenic CO2 emissions. Biosphere models often omit biogenic fluxes in urban areas despite potentially extensive vegetation coverage. For example, in Massachusetts, models mask out as much as 40% of land area, effectively assuming they have no biological flux. This results in a ~32% underestimate of aboveground biomass (AGB) across the state as compared to higher resolution vegetation maps. Our analysis suggests that some common biomass maps may underestimate forest biomass by ~520 Tg C within the state of Massachusetts. Moreover, omitted portions of the state have the highest population density, indicating that we know least about regions where most people live. We combine remote sensing imagery of urban vegetation cover with ground surveys of tree growth and mortality to improve estimates of aboveground biomass and

  5. Effect of salt-tolerant yeast of Candida versatilis and Zygosaccharomyces rouxii on the production of biogenic amines during soy sauce fermentation.

    PubMed

    Qi, Wei; Hou, Li-Hua; Guo, Hong-Lian; Wang, Chun-Ling; Fan, Zhen-Chuan; Liu, Jin-Fu; Cao, Xiao-Hong

    2014-06-01

    This study aimed to enhance and improve the quality and safety of soy sauce. In the present work, the change of biogenic amines, such as histamine, tyramine, cadaverine, spermidine, was examined by the treatment of Candida versatilis and Zygosaccharomyces rouxii, and the influence of salt-tolerant yeast on biogenic amines was analysed during the whole fermentation process. The results showed that the content of biogenic amines was elevated after yeast treatment and the content of biogenic amines was influenced by using yeast. The dominating biogenic amine in soy sauce was tyramine. At the end of fermentation, the concentrations of biogenic amines produced by Zygosaccharomyces rouxii and Candida versatilis in the soy mash were 122.71 mg kg(-1) and 69.96 mg kg(-1) . The changes of biogenic amines in high-salt liquid soy mash during fermentation process indicated that a variety of biogenic amines were increased in the fermentation ageing period, which may be due to amino acid decarboxylation to form biogenic amines by yeast decarboxylase. The fermentation period of soy sauce should be longer than 5 months because biogenic amines began to decline after this time period. © 2013 Society of Chemical Industry.

  6. Biogenic nanoparticle-mediated augmentation of seed germination, growth, and antioxidant level of Eruca sativa mill. varieties.

    PubMed

    Ushahra, Jyoti; Bhati-Kushwaha, Himakshi; Malik, C P

    2014-09-01

    A study was undertaken to examine the influence of biogenic nanoparticles synthesized from Tridax procumbens on different parameters of seed germination, seedling growth, and various biochemical parameters in four Eruca sativa varieties having low percentage of germination. Seeds were treated with different concentrations (30 and 40 ppm) of biogenic nanoparticles, of which 30 ppm was found to be the most effective and was therefore used for subsequent studies. Initially, the effect of biogenic nanoparticles on germination percentage, speed of germination, coefficient of germination, mean germination time, shoot and root length, fresh and dry matter, and vigor index was studied. From the experiments performed and the results obtained, it was evident that the treatment with biogenic nanoparticles decreased the electrolyte leakage and level of malondialdehyde as compared to control. The treatment with biogenic nanoparticles enhanced the levels of proline and ascorbic acid and stimulated the antioxidant enzyme activities resulting in the reduced level of reactive oxygen species. These activities were found to be variety-dependent. The possible involvement of biogenic nanoparticles in the production of new pores in seed coat during their penetration, resulting in the influx of the nutrients inside the seed, is suggested. This accelerated seed germination is followed by rapid seedling growth. The present findings indicated that biogenic nanoparticles promote seed germination in E. sativa by overcoming the detrimental effects of reactive oxygen species (ROS) and improving the antioxidative defense system which finally result in increased seedling growth.

  7. Biogenic Aldehydes as Therapeutic Targets for Cardiovascular Disease.

    PubMed

    Nelson, Margaret-Ann M; Baba, Shahid P; Anderson, Ethan J

    2017-04-01

    Aldehydes are continuously formed in biological systems through enzyme-dependent and spontaneous oxidation of lipids, glucose, and primary amines. These highly reactive, biogenic electrophiles can become toxic via covalent modification of proteins, lipids and DNA. Thus, agents that scavenge aldehydes through conjugation have therapeutic value for a number of major cardiovascular diseases. Several commonly-prescribed drugs (e.g., hydralazine) have been shown to have potent aldehyde-conjugating properties which may contribute to their beneficial effects. Herein, we briefly describe the major sources and toxicities of biogenic aldehydes in cardiovascular system, and provide an overview of drugs that are known to have aldehyde-conjugating effects. Some compounds of phytochemical origin, and histidyl-dipeptides with emerging therapeutic value in this area are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments.

    PubMed

    Durán, Nelson; Nakazato, Gerson; Seabra, Amedea B

    2016-08-01

    The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations (Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols.

  9. Effect of In Vitro Human Digestion on Biogenic Amine (Tyramine) Formation in Various Fermented Sausages.

    PubMed

    Kim, Hyeong Sang; Hur, Sun Jin

    2018-03-01

    Biogenic amines are formed in various fermented foods by microbial amino acid decarboxylation activities, and ingestion of these amines may cause human illness. However, the effect of digestion on the biogenic amines in fermented sausages has not been studied. This study was conducted to determine the effect of in vitro human digestion with the enterobacteria Escherichia coli and Lactobacillus casei on concentrations of the biogenic amine tyramine in six types of fermented sausages. Tyramine concentration was not significantly changed until simulated digestion in the small intestine. However, tyramine concentration for all sausage samples was increased after simulated digestion in the large intestine. Addition of E. coli and L. casei dramatically increased the tyramine concentrations ( P < 0.05). This result indicates that enterobacteria increase biogenic amine concentrations during human digestion.

  10. Processes occurring in reservoirs receiving biogenic and polluting substances

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vasil'ev, Yu.S.; Rolle, N.N.

    1988-04-01

    Various aspects of biogenic pollution on the water quality of reservoirs and its effect on ichthyofauna were analyzed. The effects of fertilizer runoffs and other pollutant pathways, such as the decay of flooded vegetation, into reservoirs were addressed. The dependence of fish survival times on nitrite concentrations was charted. On the basis of an optimization model for the economic development of drainage basins with ecological limitations, the Leningrad Polytechnic Institute developed instructions for calculating the removal of biogenic elements and selecting water protection measures which were tested on a number of streams of the Lake Ladoga Basin and other areasmore » and which provide engineering means for evaluating and controlling the eutrophication of reservoirs.« less

  11. To What Extent Can Biogenic SOA Be Controlled?

    EPA Science Inventory

    Anthropogenic pollution facilitates transformation of naturally emitted volatile organic compounds (VOCs) to the particle phase, enhancing the ambient concentrations of material commonly referred to as biogenic secondary organic aerosol (SOA). It is therefore conceivable that som...

  12. Ratios of Biogenic Elements for Distinguishing Recent from Fossil Microorganisms

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    2007-01-01

    The ability to distinguish possible microfossils from recent biological contaminants is of great importance to Astrobiology. In this paper we discuss the application of the ratios of life critical biogenic elements (C/O; C/N; and C/S) as determined by Energy Dispersive X-ray Spectroscopy (EDS) to this problem. Biogenic element ratios will be provided for a wide variety of living cyanobacteria and other microbial extremophiles, preserved herbarium materials, and ancient biota from the Antarctic Ice Cores and Siberian and Alaskan Permafrost for comparison with megafossils and microfossils in ancient terrestrial rocks and carbonaceous meteorites.

  13. Fermented functional foods based on probiotics and their biogenic metabolites.

    PubMed

    Stanton, Catherine; Ross, R Paul; Fitzgerald, Gerald F; Van Sinderen, Douwe

    2005-04-01

    The claimed health benefits of fermented functional foods are expressed either directly through the interaction of ingested live microorganisms, bacteria or yeast with the host (probiotic effect) or indirectly as a result of ingestion of microbial metabolites produced during the fermentation process (biogenic effect). Although still far from fully understood, several probiotic mechanisms of action have been proposed, including competitive exclusion, competition for nutrients and/or stimulation of an immune response. The biogenic properties of fermented functional foods result from the microbial production of bioactive metabolites such as certain vitamins, bioactive peptides, organic acids or fatty acids during fermentation.

  14. Genome Sequence Analysis of the Biogenic Amine-Degrading Strain Lactobacillus casei 5b

    PubMed Central

    Ladero, Victor; Herrero-Fresno, Ana; Martinez, Noelia; del Río, Beatriz; Linares, Daniel M.; Fernández, María; Martín, María Cruz

    2014-01-01

    We here report a 3.02-Mbp annotated draft assembly of the Lactobacillus casei 5b genome. The sequence of this biogenic amine-degrading dairy isolate may help identify the mechanisms involved in the catabolism of biogenic amines and perhaps shed light on ways to reduce the presence of these toxic compounds in food. PMID:24435875

  15. BG 12: BG 00012, BG 12/Oral Fumarate, FAG-201, second-generation fumarate derivative--Fumapharm/Biogen Idec.

    PubMed

    2005-01-01

    Fumapharm AG has developed a second-generation fumarate (fumaric acid) derivative, BG 12 [BG 00012, FAG-201, BG 12/Oral Fumarate], for the oral treatment of psoriasis. Biogen Idec is currently evaluating the product in clinical trials as an oral treatment for multiple sclerosis (phase II) and psoriasis (phase III) trials.BG 12 has an immunomodulatory mechanism of action. It seems that this product has been developed to reduce the adverse effects associated with a first-generation product containing fumaric acid esters (mixed dimethylfumarate and monoethylfumarate salts), Fumaderm. Fumaderm was approved in Germany in August 1994 and is currently the leading oral systemic therapy for moderate-to-severe psoriasis in Germany. One of the problems associated with Fumaderm capsules has been its gastrointestinal adverse effects (including diarrhoea and nausea). In September 2003, Biogen (now Biogen Idec) licensed exclusive worldwide rights (excluding Germany) from Fumapharm to develop and market BG 12. Biogen plans to collaborate with Fumapharm to accelerate phase III development for psoriasis and the registration programme worldwide. Financial terms of the agreement were not disclosed. Development plans for BG 12 include other autoimmune and inflammatory disorders, such as multiple sclerosis. In November 2003, Biogen and IDEC Pharmaceuticals merged to form Biogen Idec. Fumapharm completed phase II trials of this second-generation fumarate derivative for psoriasis prior to licensing of the product to Biogen, also with positive results.

  16. Cocaine affects foraging behaviour and biogenic amine modulated behavioural reflexes in honey bees.

    PubMed

    Søvik, Eirik; Even, Naïla; Radford, Catherine W; Barron, Andrew B

    2014-01-01

    In humans and other mammals, drugs of abuse alter the function of biogenic amine pathways in the brain leading to the subjective experience of reward and euphoria. Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear. Previously, it has been shown that bees are more likely to dance (a signal of perceived reward) when returning from a sucrose feeder after cocaine treatment. Here we examined more broadly whether cocaine altered reward-related behaviour, and biogenic amine modulated behavioural responses in bees. Bees developed a preference for locations at which they received cocaine, and when foraging at low quality sucrose feeders increase their foraging rate in response to cocaine treatment. Cocaine also increased reflexive proboscis extension to sucrose, and sting extension to electric shock. Both of these simple reflexes are modulated by biogenic amines. This shows that systemic cocaine treatment alters behavioural responses that are modulated by biogenic amines in insects. Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees. We discuss the implications of these results for understanding the ecology of cocaine as a plant defence compound. Our findings further validate the honey bee as a model system for understanding the behavioural impacts of cocaine, and potentially other drugs of abuse.

  17. Stable silicon isotope signatures of marine pore waters - Biogenic opal dissolution versus authigenic clay mineral formation

    NASA Astrophysics Data System (ADS)

    Ehlert, Claudia; Doering, Kristin; Wallmann, Klaus; Scholz, Florian; Sommer, Stefan; Grasse, Patricia; Geilert, Sonja; Frank, Martin

    2016-10-01

    Dissolved silicon isotope compositions have been analysed for the first time in pore waters (δ30SiPW) of three short sediment cores from the Peruvian margin upwelling region with distinctly different biogenic opal content in order to investigate silicon isotope fractionation behaviour during early diagenetic turnover of biogenic opal in marine sediments. The δ30SiPW varies between +1.1‰ and +1.9‰ with the highest values occurring in the uppermost part close to the sediment-water interface. These values are of the same order or higher than the δ30Si of the biogenic opal extracted from the same sediments (+0.3‰ to +1.2‰) and of the overlying bottom waters (+1.1‰ to +1.5‰). Together with dissolved silicic acid concentrations well below biogenic opal saturation, our collective observations are consistent with the formation of authigenic alumino-silicates from the dissolving biogenic opal. Using a numerical transport-reaction model we find that approximately 24% of the dissolving biogenic opal is re-precipitated in the sediments in the form of these authigenic phases at a relatively low precipitation rate of 56 μmol Si cm-2 yr-1. The fractionation factor between the precipitates and the pore waters is estimated at -2.0‰. Dissolved and solid cation concentrations further indicate that off Peru, where biogenic opal concentrations in the sediments are high, the availability of reactive terrigenous material is the limiting factor for the formation of authigenic alumino-silicate phases.

  18. DEVELOPMENT OF SEASONAL AND ANNUAL BIOGENIC EMISSIONS INVENTORIES FOR THE U.S. AND CANADA

    EPA Science Inventory

    The report describes the development of a biogenic emissions inventory for the U.S. and Canada, to assess the role of biogenic emissions in ozone formation. Emission inventories were developed at hourly and grid (1/4 x 116 degree) level from input data at the same scales. Emissio...

  19. Rn-222 tracing and stable isotope measurements of biogenic gas fluxes from methane saturated sediments

    NASA Technical Reports Server (NTRS)

    Martens, Christopher S.; Green, C. D.; Blair, Neal; Chanton, J. P.

    1985-01-01

    Transport of reduced biogenic gases from anoxic sediments and soils to the atmosphere can be quantitatively studied through measurement of radon-222/radium-226 disequilibrium. In previous work, seasonal variations in biogenic gas transport mechanisms, net fluxes and overall composition were documented. Now presented are direct field measurements of radon-222 activity in gases exiting organic rich sediments which show their usefulness for tracing of the stripping of dissolved biogenic gases from within the sediment column and transport via bubble ebullition. Methane is depleted in deuterium during the summer as compared with winter months and is in general lighter than in most marine sediments signaling the probable importance of acetate as an important precursor molecule. The significant seasonal isotopic variations observed illustrate the importance of understanding mechanisms and rates of biogenic gas production in order to interpret observed tropospheric isotopic data.

  20. Biogenic carbon in combustible waste: waste composition, variability and measurement uncertainty.

    PubMed

    Larsen, Anna W; Fuglsang, Karsten; Pedersen, Niels H; Fellner, Johann; Rechberger, Helmut; Astrup, Thomas

    2013-10-01

    Obtaining accurate data for the contents of biogenic and fossil carbon in thermally-treated waste is essential for determination of the environmental profile of waste technologies. Relations between the variability of waste chemistry and the biogenic and fossil carbon emissions are not well described in the literature. This study addressed the variability of biogenic and fossil carbon in combustible waste received at a municipal solid waste incinerator. Two approaches were compared: (1) radiocarbon dating ((14)C analysis) of carbon dioxide sampled from the flue gas, and (2) mass and energy balance calculations using the balance method. The ability of the two approaches to accurately describe short-term day-to-day variations in carbon emissions, and to which extent these short-term variations could be explained by controlled changes in waste input composition, was evaluated. Finally, the measurement uncertainties related to the two approaches were determined. Two flue gas sampling campaigns at a full-scale waste incinerator were included: one during normal operation and one with controlled waste input. Estimation of carbon contents in the main waste types received was included. Both the (14)C method and the balance method represented promising methods able to provide good quality data for the ratio between biogenic and fossil carbon in waste. The relative uncertainty in the individual experiments was 7-10% (95% confidence interval) for the (14)C method and slightly lower for the balance method.

  1. Distinguishing black carbon from biogenic humic substances in soil clay fractions

    USGS Publications Warehouse

    Laird, D.A.; Chappell, M.A.; Martens, D.A.; Wershaw, R. L.; Thompson, M.

    2008-01-01

    Most models of soil humic substances include a substantial component of aromatic C either as the backbone of humic heteropolymers or as a significant component of supramolecular aggregates of degraded biopolymers. We physically separated coarse (0.2-2.0????m e.s.d.), medium (0.02-0.2????m e.s.d.), and fine (> 0.02????m e.s.d.) clay subfractions from three Midwestern soils and characterized the organic material associated with these subfractions using 13C-CPMAS-NMR, DTG, SEM-EDX, incubations, and radiocarbon age. Most of the C in the coarse clay subfraction was present as discrete particles (0.2-5????m as seen in SEM images) of black carbon (BC) and consisted of approximately 60% aromatic C, with the remainder being a mixture of aliphatic, anomeric and carboxylic C. We hypothesize that BC particles were originally charcoal formed during prairie fires. As the BC particles aged in soil their surfaces were oxidized to form carboxylic groups and anomeric and aliphatic C accumulated in the BC particles either by adsorption of dissolved biogenic compounds from the soil solution or by direct deposition of biogenic materials from microbes living within the BC particles. The biogenic soil organic matter was physically separated with the medium and fine clay subfractions and was dominated by aliphatic, anomeric, and carboxylic C. The results indicate that the biogenic humic materials in our soils have little aromatic C, which is inconsistent with the traditional heteropolymer model of humic substances.

  2. Time Resolved Measurements of Primary Biogenic Aerosol Particles in Amazonia

    NASA Astrophysics Data System (ADS)

    Wollny, A. G.; Garland, R.; Pöschl, U.

    2009-04-01

    Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the Amazonian Aerosol Characterization Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. This presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 µm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as "viable aerosols" or "fluorescent bioparticles" (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. Data from the UVAPS were averaged over 5 minute time intervals. The presence of bioparticles in the observed size range has been

  3. Performance of the JULES land surface model for UK Biogenic VOC emissions

    NASA Astrophysics Data System (ADS)

    Hayman, Garry; Comyn-Platt, Edward; Vieno, Massimo; Langford, Ben

    2017-04-01

    Emissions of biogenic non-methane volatile organic compounds (NMVOCs) are important for air quality and tropospheric composition. Through their contribution to the production of tropospheric ozone and secondary organic aerosol (SOA), biogenic VOCs indirectly contribute to climate forcing and climate feedbacks [1]. Biogenic VOCs encompass a wide range of compounds and are produced by plants for growth, development, reproduction, defence and communication [2]. There are both biological and physico-chemical controls on emissions [3]. Only a few of the many biogenic VOCs are of wider interest and only two or three (isoprene and the monoterpenes, α- and β-pinene) are represented in chemical transport models. We use the Joint UK Land Environment Simulator (JULES), the UK community land surface model, to estimate biogenic VOC emission fluxes. JULES is a process-based model that describes the water, energy and carbon balances and includes temperature, moisture and carbon stores [4, 5]. JULES currently provides emission fluxes of the 4 largest groups of biogenic VOCs: isoprene, terpenes, methanol and acetone. The JULES isoprene scheme uses gross primary productivity (GPP), leaf internal carbon and the leaf temperature as a proxy for the electron requirement for isoprene synthesis [6]. In this study, we compare JULES biogenic VOC emission estimates of isoprene and terepenes with (a) flux measurements made at selected sites in the UK and Europe and (b) gridded estimates for the UK from the EMEP/EMEP4UK atmospheric chemical transport model [7, 8], using site-specific or EMEP4UK driving meteorological data, respectively. We compare the UK-scale emission estimates with literature estimates. We generally find good agreement in the comparisons but the estimates are sensitive to the choice of the base or reference emission potentials. References (1) Unger, 2014: Geophys. Res. Lett., 41, 8563, doi:10.1002/2014GL061616; (2) Laothawornkitkul et al., 2009: New Phytol., 183, 27, doi

  4. Morphological and chemical evidence of stromatolitic deposits in the 2.75 Ga Carajás banded iron formation, Brazil

    USGS Publications Warehouse

    Ribeiro da Luz, Beatriz; Crowley, James K.

    2012-01-01

    We describe evidence of biogenicity in the morphology and carbon content of well-preserved, Neoarchean samples of banded iron formation (BIF) from Carajás, Brazil. Silica-rich BIF layers contain translucent ellipsoidal or trapezoidal structures (∼5–10 μm diameter) composed of silica, hematite, and kerogen, which are arranged in larger ring-like forms (rosettes). Stable carbon isotope analysis yields a δ13C value of −24.5‰ indicating that the contained carbon is likely biogenic. Raman and SEM analyses, as well as wavelength-dispersive X-ray elemental maps, show kerogen inside the rosette forms. Within the iron-rich BIF layers, tubular structures (0.5–5 μm) were observed between hematite granules and blades. Kerogen and kaolinite are present in these structures. Both the rosettes and the tubular structures resemble morphologies that are characteristic of some bacterial species.We hypothesize that the Carajás BIFs originated as biomats formed by one or more species that over time produced large stromatolitic structures. The rosettes and the tubular structures, associated with chert-rich and iron-rich BIF layers, respectively, may represent two different species, or perhaps, two phases of a bacterium life cycle. For example, some modern myxobacteria exhibit similar morphologies in their resting and vegetative stages.Fe(III) precipitation may have occurred by contact of Fe(II) with bacterial slime, leading to oxidation by chemical reactions with exposed polysaccharide hydroxyl and carboxyl groups. The Fe(III) would then have been available for use as a source of energy in a dissimilatory iron reduction type of metabolism. Organic carbon input presumably came from primary producers (not necessarily aerobic) within the local water column, perhaps in shallow-water communities. Alternatively, the carbon may have originated by Fischer–Tropsch synthesis at ocean hydrothermal vents. The observed lateral continuity of BIF layers may perhaps be explained by

  5. Bioassay for estimating the biogenic methane-generating potential of coal samples

    USGS Publications Warehouse

    Jones, Elizabeth J.P.; Voytek, Mary A.; Warwick, Peter D.; Corum, Margo D.; Cohn, Alexander G.; Bunnell, Joseph E.; Clark, Arthur C.; Orem, William H.

    2008-01-01

    Generation of secondary biogenic methane in coal beds is likely controlled by a combination of factors such as the bioavailability of coal carbon, the presence of a microbial community to convert coal carbon to methane, and an environment supporting microbial growth and methanogenesis. A set of treatments and controls was developed to bioassay the bioavailability of coal for conversion to methane under defined laboratory conditions. Treatments included adding a well-characterized consortium of bacteria and methanogens (enriched from modern wetland sediments) and providing conditions to support endemic microbial activity. The contribution of desorbed methane in the bioassays was determined in treatments with bromoethane sulfonic acid, an inhibitor of microbial methanogenesis. The bioassay compared 16 subbituminous coal samples collected from beds in Texas (TX), Wyoming (WY), and Alaska (AK), and two bituminous coal samples from Pennsylvania (PA). New biogenic methane was observed in several samples of subbituminous coal with the microbial consortium added, but endemic activity was less commonly observed. The highest methane generation [80 µmol methane/g coal (56 scf/ton or 1.75 cm3/g)] was from a south TX coal sample that was collected from a non-gas-producing well. Subbituminous coals from the Powder River Basin, WY and North Slope Borough, AK contained more sorbed (original) methane than the TX coal sample and generated 0–23 µmol/g (up to 16 scf/ton or 0.5 cm3/g) new biogenic methane in the bioassay. Standard indicators of thermal maturity such as burial depth, nitrogen content, and calorific value did not explain differences in biogenic methane among subbituminous coal samples. No original methane was observed in two bituminous samples from PA, nor was any new methane generated in bioassays of these samples. The bioassay offers a new tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the

  6. Iron-magnesium silicate bioweathering on Earth (and Mars?).

    PubMed

    Fisk, M R; Popa, R; Mason, O U; Storrie-Lombardi, M C; Vicenzi, E P

    2006-02-01

    We examined the common, iron-magnesium silicate minerals olivine and pyroxene in basalt and in mantle rocks to determine if they exhibit textures similar to bioweathering textures found in glass. Our results show that weathering in olivine may occur as long, narrow tunnels (1-3 microm in diameter and up to 100 microm long) and as larger irregular galleries, both of which have distinctive characteristics consistent with biological activity. These weathering textures are associated with clay mineral by-products and nucleic acids. We also examined olivine and pyroxene in martian meteorites, some of which experienced preterrestrial aqueous alteration. Some olivines and pyroxenes in the martian meteorite Nakhla were found to contain tunnels that are similar in size and shape to tunnels in terrestrial iron-magnesium silicates that contain nucleic acids. Though the tunnels found in Nakhla are similar to the biosignatures found in terrestrial minerals, their presence cannot be used to prove that the martian alteration features had a biogenic origin. The abundance and wide distribution of olivine and pyroxene on Earth and in the Solar System make bioweathering features in these minerals potentially important new biosignatures that may play a significant role in evaluating whether life ever existed on Mars.

  7. 76 FR 80368 - Notification of Teleconferences of the Science Advisory Board Biogenic Carbon Emissions Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... Accounting Framework for Biogenic CO2 Emissions from Stationary Sources (September 2011). DATES: The... teleconferences to discuss draft responses to charge questions on EPA's draft Accounting Framework for Biogenic CO... (OAP) in EPA's Office of Air and Radiation requested SAB review of the draft report and accounting...

  8. Influence on wine biogenic amine composition of modifications to soil N availability and grapevine N by cover crops.

    PubMed

    Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; Cabrita, Maria João; García-Escudero, Enrique; Peregrina, Fernando

    2017-11-01

    Vineyard soil management can modify the nitrogen soil availability and, therefore, grape amino acid content. These compounds are precursors of biogenic amines, which have negative effects on wine quality and human health. The objective was to study whether the effect of conventional tillage and two cover crops (barley and clover) on grapevine nitrogen status could be related to wine biogenic amines. Over 4 years, soil NO 3 - -N, nitrogen content in leaf and wine biogenic amine concentration were determined. Barley reduced soil NO 3 - -N availability and clover increased it. In 2011, at bloom, nitrogen content decreased with barley treatment in both blade and petiole. In 2012, nitrogen content in both leaf tissues at bloom was greater with clover than with tillage and barley treatments. Also, total biogenic amines decreased in barley with respect to tillage and clover treatments. There were correlations between some individual and total biogenic amine concentrations with respect to nitrogen content in leaf tissues. Wine biogenic amine concentration can be affected by the grapevine nitrogen status, provoked by changes in the soil NO 3 - -N availability with both cover crop treatments. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Biogenic silica from the BDP93 drill site and adjacent areas of the Selenga Delta, Lake Baikal, Siberia

    USGS Publications Warehouse

    Colman, Steven M.; Peck, John A.; Hatton, Josephine; Karabanov, Eugene B.; King, John W.

    1999-01-01

    Biogenic silica contents of sediments on the lower Selenga Delta and Buguldeika saddle in Lake Baikal show distinct fluctuations that reflect changes in diatom productivity, and ultimately, climate. The pattern of the upper 50 m of the section, dating from about 334 ka, is similar to that of the marine oxygen-isotope record, increasingly so as the younger sediments become progressively finer grained and less locally derived with time. The last two interglaciations are marked by biogenic silica abundances similar to those of the Holocene. The equivalent of marine oxygen-isotope stage 3 is distinctly intermediate in character between full glacial and full interglacial biogenic silica values. Following near-zero values during the last glacial maximum, biogenic silica began to increase at about 13 ka. The rise in biogenic silica to Holocene values was interrupted by an abrupt decrease during Younger Dryas time, about 11 to 10 14C ka.

  10. BOREAS TGB-5 Biogenic Soil Emissions of NO and N2O

    NASA Technical Reports Server (NTRS)

    Levine, J. S.; Winstead, E. L.; Parsons, D. A. B.; Scholes, M. C.; Cofer, W. R.; Cahoon, D. R.; Sebacher, D. I.; Scholes, R. J.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB)-5 team made several measurements of trace gas concentrations and fluxes at various NSA sites. This data set contains biogenic soil emissions of nitric oxide and nitrous oxide that were measured over a wide range of spatial and temporal site parameters. Since very little is known about biogenic soil emissions of nitric oxide and nitrous oxide from the boreal forest, the goal of the measurements was to characterize the biogenic soil fluxes of nitric oxide and nitrous oxide from black spruce and jack pine areas in the boreal forest. The diurnal variation and monthly variation of the emissions was examined as well as the impact of wetting through natural or artificial means. Temporally, the data cover mid-August 1993, June to August 1994, and mid-July 1995. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884).

  11. 78 FR 50135 - Soil Biogenics Ltd., File No. 500-1; Order of Suspension of Trading

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... SECURITIES AND EXCHANGE COMMISSION Soil Biogenics Ltd., File No. 500-1; Order of Suspension of Trading August 14, 2013. It appears to the Securities and Exchange Commission that there is a lack of current and accurate information concerning the securities of Soil Biogenics Ltd. because it has not filed...

  12. 77 FR 21772 - Notification of Two Public Teleconferences of the Science Advisory Board Biogenic Carbon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... the Panel's draft report on EPA's draft Accounting Framework for Biogenic CO2 Emissions from...'s draft report on EPA's draft Accounting Framework for Biogenic CO2 Emissions from Stationary... Radiation requested SAB review of EPA's draft accounting framework. As noticed in 76 FR 61100-61101, the SAB...

  13. Biogenic sedimentation in the equatorial Pacific: Carbon cycling and paleoproduction, 12-24 Ma

    NASA Astrophysics Data System (ADS)

    Piela, Christine; Lyle, Mitchell; Marcantonio, Franco; Baldauf, Jack; Olivarez Lyle, Annette

    2012-06-01

    The equatorial Pacific is an important part of the global carbon cycle and has been affected by climate change through the Cenozoic (65 Ma to present). We present a Miocene (12-24 Ma) biogenic sediment record from Deep Sea Drilling Project (DSDP) Site 574 and show that a CaCO3 minimum at 17 Ma was caused by elevated CaCO3 dissolution. When Pacific Plate motion carried Site 574 under the equator at about 16.2 Ma, there is a minor increase in biogenic deposition associated with passing under the equatorial upwelling zone. The burial rates of the primary productivity proxies biogenic silica (bio-SiO2) and biogenic barium (bio-Ba) increase, but biogenic CaCO3 decreases. The carbonate minimum is at ˜17 Ma coincident with the beginning of the Miocene climate optimum; the transient lasts from 18 to 15 Ma. Bio-SiO2 and bio-Ba are positively correlated and increase as the equator was approached. Corg is poorly preserved, and is strongly affected by changing carbonate burial. Terrestrial 232Th deposition, a proxy for aeolian dust, increases only after the Site 574 equator crossing. Since surface production of bio-SiO2, bio-Ba, and CaCO3 correlate in the modern equatorial Pacific, the decreased CaCO3 burial rate during the Site 574 equator crossing is driven by elevated CaCO3 dissolution, representing elevated ocean carbon storage and elevated atmospheric CO2. The length of the 17 Ma CaCO3 dissolution transient requires interaction with a `slow' part of the carbon cycle, perhaps elevated mantle degassing associated with the early stages of Columbia River Basalt emplacement.

  14. Impacts of Interannual Variability in Biogenic VOC Emissions near Transitional Ozone Production Regimes

    NASA Astrophysics Data System (ADS)

    Geddes, J.

    2017-12-01

    Due to successful NOx emission controls, summertime ozone production chemistry in urban areas across North America is transitioning from VOC-limited to increasingly NOx-limited. In some regions where ozone production sensitivity is in transition, interannual variability in surrounding biogenic VOC emissions could drive fluctuations in the prevailing chemical regime and modify the impact of anthropogenic emission changes. I use satellite observations of HCHO and NO2 column density, along with a long-term simulation of atmospheric chemistry, to investigate the impact of interannual variability in biogenic isoprene sources near large metro areas. Peak emissions of isoprene in the model can vary by up to 20-60% in any given year compared to the long term mean, and this variability drives the majority of the variability in simulated local HCHO:NO2 ratios (a common proxy for ozone production sensitivity). The satellite observations confirm increasingly NOx-limited chemical regimes with large interannual variability. In several instances, the model and satellite observations suggest that variability in biogenic isoprene emissions could shift summertime ozone production from generally VOC- to generally NOx- sensitive (or vice versa). This would have implications for predicting the air quality impacts of anthropogenic emission changes in any given year, and suggests that drivers of biogenic emissions need to be well understood.

  15. Development and validation of an LC-MS/MS method for the determination of biogenic amines in wines and beers.

    PubMed

    Nalazek-Rudnicka, Katarzyna; Wasik, Andrzej

    2017-01-01

    Biogenic amines are group of organic, basic, nitrogenous compounds that naturally occur in plant, microorganism, and animal organisms. Biogenic amines are mainly produced through decarboxylation of amino acids. They are formed during manufacturing of some kind of food and beverages such as cheese, wine, or beer. Histamine, cadaverine, agmatine, tyramine, putrescine, and β -phenylethylamine are the most common biogenic amines found in wines and beers. This group of compounds can be toxic at high concentrations; therefore, their control is very important. Analysis of biogenic amines in alcoholic drinks (beers and wines) was carried out by HPLC-MS/MS after their derivatization with p -toluenesulfonyl chloride (tosyl chloride). The developed method has been applied for analysis of seventeen biogenic amines in twenty-eight samples of lager beers and in twelve samples of different homemade wines (white grape, red grape, strawberry, chokeberry, black currant, plum, apple, raspberry, and quince). The developed method is sensitive and repeatable for majority of the analytes. It is versatile and can be used for the determination of biogenic amines in various alcoholic beverages.

  16. Microbialites vs detrital micrites: Degree of biogenicity, parameter suitable for Mars analogues

    NASA Astrophysics Data System (ADS)

    Blanco, Armando; D'Elia, Marcella; Orofino, Vincenzo; Mancarella, Francesca; Fonti, Sergio; Mastandrea, Adelaide; Guido, Adriano; Tosti, Fabio; Russo, Franco

    2014-07-01

    In upcoming years several space missions will investigate the habitability of Mars and the possibility of extinct or extant life on the planet. In previous laboratory works we have investigated the infrared spectral modifications induced by thermal processing on different carbonate samples, in the form of recent shells and fossils of different ages, whose biogenic origin is indisputable. The goal was to develop a method able to discriminate biogenic carbonate samples from their abiogenic counterparts. The method has been successfully applied to microbialites, i.e. bio-induced microcrystalline carbonate deposits, and particularly to stromatolites, the laminated fabric of microbialites, some of which can be ascribed among the oldest traces of biological activity known on Earth. In this work we show that, by applying our method to different parts of the same carbonate rock, we are able to discriminate the presence, nature and biogenicity of various micrite types (i.e. detrital vs autochthonous) and to distinguish them from the skeletal grains. To test our methodology we preliminarily used the epifluorescence technique to select on polished samples, skeletal grains, autochthonous and allochthonous micrites, each one characterized by different organic matter content. The results on the various components show that, applying the infrared spectral modifications induced by thermal processing, it is possible to determine the degree of biogenicity of the different carbonate samples. The results are of valuable importance since such carbonates are linked to primitive living organisms that can be considered as good analogues for putative Martian life forms.

  17. Biogenic tellurium nanorods as a novel antivirulence agent inhibiting pyoverdine production in Pseudomonas aeruginosa.

    PubMed

    Mohanty, Anee; Kathawala, Mustafa Hussain; Zhang, Jianhua; Chen, Wei Ning; Loo, Joachim Say Chye; Kjelleberg, Staffan; Yang, Liang; Cao, Bin

    2014-05-01

    While antibiotic resistance in bacteria is rapidly increasing, the development of new antibiotics has decreased in recent years. Antivirulence drugs disarming rather than killing pathogens have been proposed to alleviate the problem of resistance inherent to existing biocidal antibiotics. Here, we report a nontoxic biogenic nanomaterial as a novel antivirulence agent to combat bacterial infections caused by Pseudomonas aeruginosa. We synthesized, in an environmentally benign fashion, tellurium nanorods (TeNRs) using the metal-reducing bacterium Shewanella oneidensis, and found that the biogenic TeNRs could effectively inhibit the production of pyoverdine, one of the most important virulence factors in P. aeruginosa. Our results suggest that amyloids and extracellular polysaccharides Pel and Psl are not involved in the interactions between P. aeruginosa and the biogenic TeNRs, while flagellar movement plays an important role in the cell-TeNRs interaction. We further showed that the TeNRs (up to 100 µg/mL) did not exhibit cytotoxicity to human bronchial epithelial cells and murine macrophages. Thus, biogenic TeNRs hold promise as a novel antivirulence agent against P. aeruginosa. © 2013 Wiley Periodicals, Inc.

  18. A BIOGENIC ROLE IN EXPOSURE TO TWO TOXIC COMPOUNDS

    EPA Science Inventory

    Biogenic sources play an important role in ozone and particulate concentrations through emissions of volatile organic compounds. The same emissions also contribute to chronic toxic exposures from formaldehyde and acetaldehyde because each compound arises through primary and se...

  19. BIOGENIC HYDROCARBONS IN THE ATMOSPHERIC BOUNDARY LAYER: A REVIEW

    EPA Science Inventory

    Nonmethane hydrocarbons are ubiquitous trace atmospheric constituents yet they control the oxidation capacity of the atmosphere. Both anthropogenic and biogenic processes contribute to the release of hydrocarbons to the atmosphere. In this manuscript, the state of the science ...

  20. Interaction of biogenic amines with ethanol.

    PubMed

    Smith, A A

    1975-01-01

    Ethanol through its primary catabolite, acetaldehyde, competitively inhibits oxidation of aldehyde dehydrogenase substrates. As a consequence biogenic amines form increased quantities of alcohols rather than the corresponding acids. During this biotransformation, condensation reactions between deaminated and intact amines may occur which can yield tetrahydropapaverolines. These compounds are closely related to precursors of opioids which is cause to link ethanol abuse to morphine addiction. There is, however, no pharmacological or clinical evidence suggesting similarities between ethanol dependence or opiod addiction. Acetaldehyde plays an additional role in alkaloidal formation in vitro. Biogenic amines may react with acetaldehyde to form isoquinoline or carboline compounds. Some of these substances have significant pharmacological activity. Furthermore, they may enter neural stores and displace the natural neurotransmitter. Thus, they can act as false neurotransmitters. Some investigators believe that chronic ethanol ingestion leads to significant formation of such aberrant compounds which may then upset autonomic nervous system balance. This disturbance may explain the abnormal sympathetic activity seen in withdrawal. While these ideas about the etiology of alcohol abuse have a definite appeal, they are naturally based on in vitro preliminary work. Much study of the quantitative pharmacology of these compounds in animals is required before judgement can be made as to the merits of the proposed hypotheses. In the meantime, pharmacological studies on the ability of ethanol to depress respiration in the mouse has revealed that unlike opioids or barbituates, respiratory depression induced by ethanol requires the presence in brain of serotonin. This neurotransmitter also mediates the respiratory effects of several other alcohols but curiously, not chloral hydrate, yet this compound is purported to alter biogenic amine metabolism much like ethanol. Thus, the response

  1. USER'S GUIDE TO THE PERSONAL COMPUTER VERSION OF THE BIOGENIC EMISSIONS INVENTORY SYSTEM (PC-BEIS2)

    EPA Science Inventory

    The document is a user's guide for an updated Personal Computer version of the Biogenic Emissions Inventory System (PC-BEIS2), allowing users to estimate hourly emissions of biogenic volatile organic compounds (BVOCs) and soil nitrogen oxide emissions for any county in the contig...

  2. Measurements of atmospheric hydrocarbons and biogenic emission fluxes in the Amazon boundary layer

    NASA Technical Reports Server (NTRS)

    Zimmerman, P. R.; Greenberg, J. P.; Westberg, C. E.

    1988-01-01

    Tropospheric mixing ratios of methane, C2-C10 hydrocarbons, and carbon monoxide were measured over the Amazon tropical forest near Manaus, Amazonas, Brazil, in July and August 1985. The measurements, consisting mostly of altitude profiles of these gases, were all made within the atmospheric boundary layer up to an altitude of 1000 m above ground level. Data characterize the diurnal hydrocarbon composition of the boundary layer. Biogenic emissions of isoprene control hydroxyl radical concentrations over the forest. Biogenic emission fluxes of isoprene and terpenes are estimated to be 25,000 micrograms/sq m per day and 5600 micrograms/sq m per day, respectively. This isoprene emission is equivalent to 2 percent of the net primary productivity of the tropical forest. Atmospheric oxidation of biogenic isoprene and terpenes emissions from the Amazon forest may account for daily increases of 8-13 ppb for carbon monoxide in the planetary boundary layer.

  3. Iron budgets for three distinct biogeochemical sites around the Kerguelen archipelago (Southern Ocean) during the natural fertilisation experiment KEOPS-2

    NASA Astrophysics Data System (ADS)

    Bowie, A. R.; van der Merwe, P.; Quéroué, F.; Trull, T.; Fourquez, M.; Planchon, F.; Sarthou, G.; Chever, F.; Townsend, A. T.; Obernosterer, I.; Sallée, J.-B.; Blain, S.

    2014-12-01

    Iron availability in the Southern Ocean controls phytoplankton growth, community composition and the uptake of atmospheric CO2 by the biological pump. The KEOPS-2 experiment took place around the Kerguelen plateau in the Indian sector of the Southern Ocean, a region naturally fertilised with iron at the scale of hundreds to thousands of square kilometres, producing a mosaic of spring blooms which showed distinct biological and biogeochemical responses to fertilisation. This paper presents biogeochemical iron budgets (incorporating vertical and lateral supply, internal cycling, and sinks) for three contrasting sites: an upstream high-nutrient low-chlorophyll reference, over the plateau, and in the offshore plume east of Kerguelen Island. These budgets show that distinct regional environments driven by complex circulation and transport pathways are responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. Iron supply from "new" sources to surface waters of the plume was double that above the plateau and 20 times greater than at the reference site, whilst iron demand (measured by cellular uptake) in the plume was similar to the plateau but 40 times greater than the reference. "Recycled" iron supply by bacterial regeneration and zooplankton grazing was a relative minor component at all sites (<8% of "new" supply), in contrast to earlier findings from other biogeochemical iron budgets in the Southern Ocean. Over the plateau, a particulate iron dissolution term of 2.5% was invoked to balance the budget; this approximately doubled the standing stock of dissolved iron in the mixed layer. The exchange of iron between dissolved, biogenic and lithogenic particulate pools was highly dynamic in time and space, resulting in a decoupling of iron supply and carbon export and, importantly, controlling the efficiency of fertilisation.

  4. Distribution of biogenic silica and quartz in recent deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Leinen, Margaret; Cwienk, Douglas; Heath, G. Ross; Biscaye, Pierre E.; Kolla, V.; Thiede, Jørn; Dauphin, J. Paul

    1986-03-01

    All available quartz and biogenic silica concentrations from deep-sea surface sediments were intercalibrated, plotted, and contoured on a calcium-carbonate-free basis. The maps show highest concentrations of biogenic silica (opal) along the west African coast, along equatorial divergences in all oceans, and at the Polar Front in the southern Indian Ocean. These are all areas where upwelling is strong and there is high biological productivity. Quartz in pelagic sediments deposited far from land is generally eolian in origin. Its distribution reflects dominant wind systems in the Pacific, but in much of the Atlantic and Indian oceans the distribution pattern is strongly modified by turbidite deposition and bottom current processes.

  5. Separation of biogenic materials by electrophoresis under zero gravity (L-3)

    NASA Technical Reports Server (NTRS)

    Kuroda, Masao

    1993-01-01

    Electrophoresis separates electrically charged materials by imposing a voltage between electrodes. Though free-flow electrophoresis is used without carriers such as colloids to separate and purify biogenic materials including biogenic cells and proteins in blood, its resolving power and separation efficiency is very low on Earth due to sedimentation, flotation, and thermal convection caused by the specific gravity differences between separated materials and buffer solutions. The objective of this experiment is to make a comparative study of various electrophoresis conditions on the ground and in zero-gravity in order to ultimately develop a method for separating various important 'vial' components which are difficult to separate on the ground.

  6. A search for biogenic trace gases in the atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Mckay, Christopher P.

    1989-01-01

    The detection of certain trace gases in the atmosphere of Mars may serve as a possible indicator of microbial life on the surface of Mars. Candidate biogenic gases include methane CH4, ammonia NH3, nitrous oxide N2O, and several reduced sulfur species. Chemical thermodynamic equilibrium and photochemical calculations preclude the presence of these gases in any measurable concentrations in the atmosphere of Mars in the absence of biogenic production. A search for these gases utilizing either high resolution (spectral and spatial) spectroscopy from a Mars orbiter, such as the Observer, and or in situ measurements from a Mars lander or rover, is proposed.

  7. BIOGENIC SOURCES FOR FORMALDEHYDE AND ACETALDEHYDE DURING SUMMER MONTHS

    EPA Science Inventory

    Photochemical modeling estimated contributions to ambient concentrations of formaldehyde and acetaldehyde from biogenic emissions over the continental United States during January 2001 (Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract A52B-0117). Results showed that maximum co...

  8. Unraveling the atomic structure of biogenic silica: evidence of the structural association of Al and Si in diatom frustules

    NASA Astrophysics Data System (ADS)

    Gehlen, M.; Beck, L.; Calas, G.; Flank, A.-M.; Van Bennekom, A. J.; Van Beusekom, J. E. E.

    2002-05-01

    We used X-ray absorption spectroscopy at the Al K-edge to investigate the atomic structure of biogenic silica and to assess the effect of Al on its crystal chemistry. Our study provides the first direct evidence for a structural association of Al and Si in biogenic silica. In samples of cultured diatoms, Al is present exclusively in fourfold coordination. The location and relative intensity of X-ray absorption near-edge structure (XANES) features suggests the structural insertion of tetrahedral Al inside the silica framework synthesized by the organism. In diatom samples collected in the marine environment, Al is present in mixed six- and fourfold coordination. The relative intensity of XANES structures indicates the coexistence of structural Al with a clay component, which most likely reflects sample contamination by adhering mineral particles. Extended X-ray absorption fine structure spectroscopy has been used to get Al-O distances in biogenic silica of cultured diatoms, confirming a tetrahedral coordination. Because of its effect on solubility and reaction kinetics of biogenic silica, the structural association between Al and biogenic silica at the stage of biosynthesis has consequences for the use of sedimentary biogenic silica as an indicator of past environmental conditions.

  9. Biogenic amines in fish: roles in intoxication, spoilage, and nitrosamine formation--a review.

    PubMed

    Al Bulushi, Ismail; Poole, Susan; Deeth, Hilton C; Dykes, Gary A

    2009-04-01

    Biogenic amines are non-volatile amines formed by decarboxylation of amino acids. Although many biogenic amines have been found in fish, only histamine, cadaverine, and putrescine have been found to be significant in fish safety and quality determination. Despite a widely reported association between histamine and scombroid food poisoning, histamine alone appears to be insufficient to cause food toxicity. Putrescine and cadaverine have been suggested to potentiate histamine toxicity. With respect to spoilage on the other hand, only cadaverine has been found to be a useful index of the initial stage of fish decomposition. The relationship between biogenic amines, sensory evaluation, and trimethylamine during spoilage are influenced by bacterial composition and free amino acid content. A mesophilic bacterial count of log 6-7 cfu/g has been found to be associated with 5 mg histamine/100 g fish, the Food and Drug Administration (FDA) maximum allowable histamine level. In vitro studies have shown the involvement of cadaverine and putrescine in the formation of nitrosamines, nitrosopiperidine (NPIP), and nitrosopyrrolidine (NPYR), respectively. In addition, impure salt, high temperature, and low pH enhance nitrosamine formation, whereas pure sodium chloride inhibits their formation. Understanding the relationships between biogenic amines and their involvement in the formation of nitrosamines could explain the mechanism of scombroid poisoning and assure the safety of many fish products.

  10. Linking phytoplankton and bacterioplankton community dynamics to iron-binding ligand production in a microcosm experiment

    NASA Astrophysics Data System (ADS)

    Hogle, S. L.; Bundy, R.; Barbeau, K.

    2016-02-01

    Several significant lines of evidence implicate heterotrophic bacterioplankton as agents of iron cycling and sources of iron-binding ligands in seawater, but direct and mechanistic linkages have mostly remained elusive. Currently, it is unknown how microbial community composition varies during the course of biogenic particle remineralization and how shifts in community structure are related to sources and sinks of Fe-binding ligands. In order to simulate the rise, decline, and ultimate remineralization of a phytoplankton bloom, we followed the production of different classes of Fe-binding ligands as measured by electrochemical techniques, Fe concentrations, and macronutrient concentrations in a series of iron-amended whole seawater incubations over a period of six days during a California Current Ecosystem Long Term Ecological Research (CCE-LTER) process cruise. At the termination of the experiment phytoplankton communities were similar across iron treatments, but high iron conditions generated greater phytoplankton biomass and increased nutrient drawdown suggesting that phytoplankton communities were in different phases of bloom development. Strikingly, L1 ligands akin to siderophores in binding strength were only observed in high iron treatments implicating phytoplankton bloom phase as an important control. Using high-throughput 16S rRNA gene surveys, we observed that the abundance of transiently dominant copiotroph bacteria were strongly correlated with L1 concentrations. However, incubations with similar L1 concentrations and binding strengths produced distinct copiotroph community profiles dominated by a few strains. We suggest that phytoplankton bloom maturity influences algal-associated heterotrophic community succession, and that L1 production is either directly or indirectly tied to the appearance and eventual dominance of rarely abundant copiotroph bacterial strains.

  11. The degree of biogenicity of micrites and terrestrial Mars analogues .

    NASA Astrophysics Data System (ADS)

    D'Elia, M.; Blanco, A.; Orofino, V.; Fonti, S.; Mastandrea, A.; Guido, A.; Tosti, F.; Russo, F.

    A number of indications, as the past presence of water, a denser atmosphere and a mild climate on early Mars, suggest that environmental conditions favorable to the emergence of life must have been present on that planet in the first hundred million years, or even more recently. If life actually existed on Mars, biomarkers could be still preserved with some degree of degradation. In previous laboratory works we have investigated the infrared spectral modifications induced by thermal processing on different carbonate samples, in the form of recent shells and fossils of different ages, whose biogenic origin is indisputable. The goal was to develop a method able to discriminate carbonate biogenic samples from their abiogenic counterparts. The method has been successfully applied to microbialites, i.e. bio-induced carbonates deposits, and particularly to stromatolites, the laminated fabric of microbialites, some of which can be ascribed among the oldest traces of biological activity known on Earth. This result is of valuable importance since such carbonates are linked to primitive living organisms which can be considered as good analogues for putative Martian life forms. In this work we show that, studying different parts of the same carbonate rock sample, we are able to distinguish, on the base of the degree of biogenicity, the various micrite types (i.e. detrital vs autochthonous).

  12. 76 FR 61100 - Notification of a Public Meeting of the Science Advisory Board Biogenic Carbon Emissions Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... demonstrated expertise in forestry, agriculture, measurement and carbon accounting methodologies, land use... draft Accounting Framework for Biogenic CO 2 Emissions from Stationary Sources (September 2011). DATES... review EPA's draft Accounting Framework for Biogenic CO 2 Emissions from Stationary Sources (September...

  13. Structure, Function, and Evolution of Biogenic Amine-binding Proteins in Soft Ticks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mans, Ben J.; Ribeiro, Jose M.C.; Andersen, John F.

    2008-08-19

    Two highly abundant lipocalins, monomine and monotonin, have been isolated from the salivary gland of the soft tick Argas monolakensis and shown to bind histamine and 5-hydroxytryptamine (5-HT), respectively. The crystal structures of monomine and a paralog of monotonin were determined in the presence of ligands to compare the determinants of ligand binding. Both the structures and binding measurements indicate that the proteins have a single binding site rather than the two sites previously described for the female-specific histamine-binding protein (FS-HBP), the histamine-binding lipocalin of the tick Rhipicephalus appendiculatus. The binding sites of monomine and monotonin are similar to themore » lower, low affinity site of FS-HBP. The interaction of the protein with the aliphatic amine group of the ligand is very similar for the all of the proteins, whereas specificity is determined by interactions with the aromatic portion of the ligand. Interestingly, protein interaction with the imidazole ring of histamine differs significantly between the low affinity binding site of FS-HBP and monomine, suggesting that histamine binding has evolved independently in the two lineages. From the conserved features of these proteins, a tick lipocalin biogenic amine-binding motif could be derived that was used to predict biogenic amine-binding function in other tick lipocalins. Heterologous expression of genes from salivary gland libraries led to the discovery of biogenic amine-binding proteins in soft (Ornithodoros) and hard (Ixodes) tick genera. The data generated were used to reconstruct the most probable evolutionary pathway for the evolution of biogenic amine-binding in tick lipocalins.« less

  14. Biogenic amine concentrations and evolution in "chilled" Canadian pork for the Japanese market.

    PubMed

    Ngapo, Tania M; Vachon, Lise

    2017-10-15

    The aim of this study was to evaluate concentrations and evolution of biogenic amines in Canadian pork destined for the Japanese market. At 48h post-mortem, export quality loins were aged at -1.7°C for 13, 28, 43 or 58d (chilled) or 4.0°C for 5d (fresh). Increasing concentrations of putrescine, spermine and spermidine were observed with chilled ageing period and were greater in chilled export (43d at -1.7°C) than domestic market (5d at 4.0°C) pork equivalents. Cadaverine was detected, but was not influenced by ageing conditions, and tyramine was only detected in some samples after 43days at -1.7°C. Individual biogenic amines were not correlated with their precursor amino acids. Biogenic amines in Canadian pork for the chilled export Japanese market were not in sufficiently high concentrations to pose a risk of intoxication. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  15. Factors Influencing Biogenic Amines Accumulation in Dairy Products

    PubMed Central

    Linares, Daniel M.; del Río, Beatriz; Ladero, Victor; Martínez, Noelia; Fernández, María; Martín, María Cruz; Álvarez, Miguel A.

    2012-01-01

    Fermented foods are among the food products more often complained of having caused episodes of biogenic amines (BA) poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain potentially harmful levels of BA, specially tyramine, histamine, and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report all those elaboration and processing technological aspects affecting BA biosynthesis and accumulation in dairy foods. Improved knowledge of the factors involved in the synthesis and accumulation of BA should lead to a reduction in their incidence in milk products. Synthesis of BA is possible only when three conditions converge: (i) availability of the substrate amino acids; (ii) presence of microorganisms with the appropriate catabolic pathway activated; and (iii) environmental conditions favorable to the decarboxylation activity. These conditions depend on several factors such as milk treatment (pasteurization), use of starter cultures, NaCl concentration, time, and temperature of ripening and preservation, pH, temperature, or post-ripening technological processes, which will be discussed in this chapter. PMID:22783233

  16. Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

    PubMed

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-02-01

    The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria

    PubMed Central

    2018-01-01

    A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.). Less abundant taxa include a filamentous green alga, Microspora, and the desmid Cosmarium. Biologic activity is evidenced by measured levels of chlorophyll and lipids. Bioassay methods confirm the ability of these microbes to dissolve and metabolize Fe from ferruginous minerals. Chromatographic analysis reveals citric acid as the likely chelating agent; this low molecular weight organic acid is detectable in interstitial fluid in the sandstone, measured as 0.0756 mg/mL. Bioassays using a model organism, Synechoccus elongates strain UTEX 650, show that Fe availability varies among different ferruginous minerals. In decreasing order of Fe availability: magnetite > limonite > biotite > siderite > hematite. Biotite was selected for detailed study because it is the most abundant iron-bearing mineral in the sandstone. SEM images support the microbiologic evidence, showing weathering of biotite compared to relatively undamaged grains of other silicate minerals. PMID:29342973

  18. Reducing mineral usage in feedlot diets for Nellore cattle: II. Impacts of calcium, phosphorus, copper, manganese, and zinc contents on intake, performance, and liver and bone status.

    PubMed

    Prados, L F; Sathler, D F T; Silva, B C; Zanetti, D; Valadares Filho, S C; Alhadas, H M; Detmann, E; Santos, S A; Mariz, L D S; Chizzotti, M L

    2017-04-01

    Weaned Nellore bulls ( = 36; 274 ± 34 kg) were used in a randomized block design with a 2 × 2 factorial arrangement of treatments to evaluate intake, fecal excretion, and performance with different concentrations of minerals. Experimental diets were formulated with 2 concentrations of Ca and P (macromineral factor; diet supplying 100% of Ca and P according to BR-CORTE () [CaP+] or diet without limestone and dicalcium phosphate [CaP-]) and 2 concentrations of microminerals (micromineral factor; diet with supplementation of microminerals [Zn, Mn, and Cu; CuMnZn+] or diet without supplementation of microminerals [Zn, Mn, and Cu; CuMnZn-]). The factor CaP- was formulated without the addition of limestone and dicalcium phosphate, and the factor CuMnZn- was formulated without inorganic supplementation of microminerals (premix). The diets were isonitrogenous (13.3% CP). Intake was individually monitored every day. Indigestible NDF was used as an internal marker for digestibility estimates. The bulls were slaughtered (84 or 147 d on feed), and then carcass characteristics were measured and liver and rib samples were collected. Feed, feces, rib bones, and liver samples were analyzed for DM, ash, CP, ether extract (EE), Ca, P, Zn, Mn, and Cu. There were no significant interactions ( ≥ 0.06) between macro- and micromineral supplementation for any variables in the study. Calcium, P, and micromineral concentrations did not affect ( ≥ 0.20) intake of DM, OM, NDF, EE, CP, TDN, and nonfiber carbohydrates (NFC). Calcium and P intake were affected ( < 0.01) by macromineral factor. Animals fed without Ca and P supplementation consumed less of these minerals. Dry matter and nutrient fecal excretion (OM, NDF, EE, CP, and NFC) were similar ( ≥ 0.23) among all factors. Performance and carcass characteristics were similar ( ≥ 0.09) among diets. The content of ash in rib bones was not affected by diets ( ≥ 0.06). Plasma P and phosphatase alkaline concentrations were similar (

  19. Frictional properties of the biogenic oozes from the CRISP drilling project: possible evidence of past slip-to-the-trench

    NASA Astrophysics Data System (ADS)

    Vannucchi, P.; Spagnuolo, E.; Aretusini, S.; Di Toro, G.; Tsutsumi, A.; Ujiie, K.; Namiki, Y.

    2015-12-01

    The 2011 Tohoku EQ revealed that co-seismic displacement along the megathrust can reach the deformation front of subduction zones. Since then the global significance of slip-to-the-trench has become an important field of study; hence investigation of past events at other active megathrusts is critical. Offshore SE Costa Rica the deformation front of the Caribbean forearc is formed by a ~10 km-wide accretionary wedge. Here, drill Site U141 has revealed a record of frontal thrusts detached along biogenic ooze, which correlates lithologically with the "reference" Site U1381. This biogenic ooze contains >70% of organic components.There are up to 15% silica-rich elements in the upper part of the formation, while clay increases downsection. The biogenic ooze is overlain by silty clay, in which smectite is the dominant mineral. Low- to high-velocity friction experiments were performed on the biogenic ooze and the silty clay to investigate the velocity dependence of friction and the micromechanical foundation of strain localization within fontal thrusts. These experiments were performed at slip-rates of 3 µms-1 to 3.5 ms-1and σn up to 12 MPa, under both room-humidity and water saturated conditions. These experimental results indicate that, at low slip-rates, the biogenic ooze is stronger than the silty clay. At increasing slip-rates silty clays have a positive dependence of friction, while biogenic oozes show a sharp decrease of their friction coefficient as slip-rate increases. This rate-weakening behavior of the biogenic oozes may enhance co-seismic slip along the megathrust. The implication of these mechanical measurements is that the geological structures found in the forearc toe offshore SE Costa Rica were formed by locally high slip-rates that have enhanced slip propagation to the trench. Under slow slip-rates, deformation can have localized easier by creeping within the clays than in the oozes as seen. As Tsunami earthquakes are known to form with pronounced slip

  20. Abiotic versus biotic iron mineral transformation studied by a miniaturized backscattering Mössbauer spectrometer (MIMOS II), X-ray diffraction and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Markovski, C.; Byrne, J. M.; Lalla, E.; Lozano-Gorrín, A. D.; Klingelhöfer, G.; Rull, F.; Kappler, A.; Hoffmann, T.; Schröder, C.

    2017-11-01

    Searching for biomarkers or signatures of microbial transformations of minerals is a critical aspect for determining how life evolved on Earth, and whether or not life may have existed in other planets, including Mars. In order to solve such questions, several missions to Mars have sought to determine the geochemistry and mineralogy on the Martian surface. This research includes the two miniaturized Mössbauer spectrometers (MIMOS II) on board the Mars Exploration Rovers Spirit and Opportunity, which have detected a variety of iron minerals on Mars, including magnetite (Fe2+Fe3+2O4) and goethite (α-FeO(OH)). On Earth, both minerals can derive from microbiological activity (e.g. through dissimilatory iron reduction of ferrihydrite by Fe(III)-reducing bacteria). Here we used a lab based MIMOS II to characterize the mineral products of biogenic transformations of ferrihydrite to magnetite by the Fe(III)-reducing bacteria Geobacter sulfurreducens. In combination with Raman spectroscopy and X-ray diffraction (XRD), we observed the formation of magnetite, goethite and siderite. We compared the material produced by biogenic transformations to abiotic samples in order to distinguish abiotic and biotic iron minerals by techniques that are or will be available onboard Martian based laboratories. The results showed the possibility to distinguish the abiotic and biotic origin of the minerals. Mossbauer was able to distinguish the biotic/abiotic magnetite with the interpretation of the geological context (Fe content mineral assemblages and accompanying minerals) and the estimation of the particle size in a non-destructive way. The Raman was able to confirm the biotic/abiotic principal peaks of the magnetite, as well as the organic principal vibration bands attributed to the bacteria. Finally, the XRD confirmed the particle size and mineralogy.

  1. Estimation of Biogenic VOC Emissions From Ecosystems in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Zemankova, K.; Brechler, J.

    2008-12-01

    Volatile organic compounds (VOC) are one of the crucial elements in photochemical reactions in the atmosphere which lead to tropospheric ozone formation. While modelling concentration of low-level ozone proper information about VOC sources and sinks is necessary. VOC are emitted into the atmosphere both from anthropogenic and natural sources. It has been shown in previous studies (e.g. Simpson et al, 1995) that contribution of volatile organic compounds emitted from biogenic sources to total amount of VOC in the atmosphere can be significant. Our work focuses on estimation of VOC emissions from natural ecosystems, most importantly from forests, and its application in photochemical modelling. Preliminary results have shown that inclusion of biogenic emissions in model input data leads to improvement of resulting ozone concentration which encouraged us to work on detailed biogenic VOC emission estimation. Using grid of 1x1km CORINE Land Cover over the area of the Czech Republic, emissions from deciduous, coniferous and mixed forests were estimated aplying the algorithm of Guenther et al., 1995. According to data from Forest Management Institute each cell of model grid has been assigned a proportional composition of each of thirteen tree species which are the the main forest constituents in the Czech Republic. Aggregating data of tree species composition with land cover category emission factor of particular chemical compound (isoprene, monoterpenes) has been obtained for each cell. Annual emissions of VOC on hourly basis have been calculated for domain of the Czech Republic. Biogenic emissions of isoprene and monoterpenes were compared with the emission inventory of anthropogenic sources. The inventory is provided by Czech Hydrometeorological Institute and covers emissions from major stationary sources, area sources (including domestic heating) and mobile sources. Our results show that natural emissions are approximately half the amount of organic compounds emitted

  2. Microbial analysis of Zetaproteobacteria and co-colonizers of iron mats in the Troll Wall Vent Field, Arctic Mid-Ocean Ridge

    PubMed Central

    Vander Roost, Jan; Thorseth, Ingunn Hindenes

    2017-01-01

    Over the last decade it has become increasingly clear that Zetaproteobacteria are widespread in hydrothermal systems and that they contribute to the biogeochemical cycling of iron in these environments. However, how chemical factors control the distribution of Zetaproteobacteria and their co-occurring taxa remains elusive. Here we analysed iron mats from the Troll Wall Vent Field (TWVF) located at the Arctic Mid-Ocean Ridge (AMOR) in the Norwegian-Greenland Sea. The samples were taken at increasing distances from high-temperature venting chimneys towards areas with ultraslow low-temperature venting, encompassing a large variety in geochemical settings. Electron microscopy revealed the presence of biogenic iron stalks in all samples. Using 16S rRNA gene sequence profiling we found that relative abundances of Zetaproteobacteria in the iron mats varied from 0.2 to 37.9%. Biogeographic analyses of Zetaproteobacteria, using the ZetaHunter software, revealed the presence of ZetaOtus 1, 2 and 9, supporting the view that they are cosmopolitan. Relative abundances of co-occurring taxa, including Thaumarchaeota, Euryarchaeota and Proteobacteria, also varied substantially. From our results, combined with results from previous microbiological and geochemical analyses of the TWVF, we infer that the distribution of Zetaproteobacteria is connected to fluid-flow patterns and, ultimately, variations in chemical energy landscapes. Moreover, we provide evidence for iron-oxidizing members of Gallionellaceae being widespread in TWVF iron mats, albeit at low relative abundances. PMID:28931087

  3. Biogenic precipitation of manganese oxides and enrichment of heavy metals at acidic soil pH

    NASA Astrophysics Data System (ADS)

    Mayanna, Sathish; Peacock, Caroline L.; Schäffner, Franziska; Grawunder, Anja; Merten, Dirk; Kothe, Erika; Büchel, Georg

    2014-05-01

    The precipitation of biogenic Mn oxides at acidic pH is rarely reported and poorly understood, compared to biogenic Mn oxide precipitation at near neutral conditions. Here we identified and investigated the precipitation of biogenic Mn oxides in acidic soil, and studied their role in the retention of heavy metals, at the former uranium mining site of Ronneburg, Germany. The site is characterized by acidic pH, low carbon content and high heavy metal loads including rare earth elements. Specifically, the Mn oxides were present in layers identified by detailed soil profiling and within these layers pH varied from 4.7 to 5.1, Eh varied from 640 to 660 mV and there were enriched total metal contents for Ba, Ni, Co, Cd and Zn in addition to high Mn levels. Using electron microprobe analysis, synchrotron X-ray diffraction and X-ray absorption spectroscopy, we identified poorly crystalline birnessite (δ-MnO2) as the dominant Mn oxide in the Mn layers, present as coatings covering and cementing quartz grains. With geochemical modelling we found that the environmental conditions at the site were not favourable for chemical oxidation of Mn(II), and thus we performed 16S rDNA sequencing to isolate the bacterial strains present in the Mn layers. Bacterial phyla present in the Mn layers belonged to Firmicutes, Actinobacteria and Proteobacteria, and from these phyla we isolated six strains of Mn(II) oxidizing bacteria and confirmed their ability to oxidise Mn(II) in the laboratory. The biogenic Mn oxide layers act as a sink for metals and the bioavailability of these metals was much lower in the Mn layers than in adjacent layers, reflecting their preferential sorption to the biogenic Mn oxide. In this presentation we will report our findings, concluding that the formation of natural biogenic poorly crystalline birnessite can occur at acidic pH, resulting in the formation of a biogeochemical barrier which, in turn, can control the mobility and bioavailability of heavy metals in

  4. Enhanced biogenic emissions of nitric oxide and nitrous oxide following surface biomass burning

    NASA Technical Reports Server (NTRS)

    Anderson, Iris C.; Levine, Joel S.; Poth, Mark A.; Riggan, Philip J.

    1988-01-01

    Recent measurements indicate significantly enhanced biogenic soil emissions of both nitric oxide (NO) and nitrous oxide (N2O) following surface burning. These enhanced fluxes persisted for at least six months following the burn. Simultaneous measurements indicate enhanced levels of exchangeable ammonium in the soil following the burn. Biomass burning is known to be an instantaneous source of NO and N2O resulting from high-temperature combustion. Now it is found that biomass burning also results in significantly enhanced biogenic emissions of these gases, which persist for months following the burn.

  5. Preservation efficiencies and accumulation rates for biogenic silica and organic C, N, and P in high-latitude sediments: The Ross Sea

    NASA Astrophysics Data System (ADS)

    Demaster, David J.; Ragueneau, Olivier; Nittrouer, Charles A.

    1996-08-01

    Rates of biogenic sediment accumulation (biogenic silica and organic C, N, and P) and pore water flux have been established for a variety of depositional environments in the Ross Sea. On the basis of 14C measurements in kasten cores, sediment accumulation rates ranged from 250 cm kyr-1 in the coastal basin of Granite Harbor to 1-2 cm kyr-1 in the shelf and slope environments of the northern and eastern Ross Sea. Burial of biogenic material was most rapid in the southwestern Ross Sea, where biogenic silica accumulation rates ranged from 2 to 31 g cm-2 kyr-1 and organic carbon accumulation rates ranged from 0.05 to 1.4 g cm-2 kyr-1. In the northern and eastern Ross Sea, biogenic silica and organic carbon accumulation rates typically equaled 0.02-0.03 g SiO2 cm-2 kyr-1 and 0.002-0.004 g C cm-2 kyr-1. Flux core measurements were used to estimate seabed regeneration rates for biogenic silica, organic carbon, and phosphorus. Pore water fluxes, in general, showed much less variability across the Ross Sea than did the biogenic accumulation rates. Pore water silicate fluxes in the study area ranged from 0.6 to 5.3 g SiO2 cm-2 kyr-1, whereas carbon fluxes ranged from 0.1 to 1.2 g C cm-2 kyr-1 and phosphate fluxes varied from -0.006 to 0.012 g P cm-2 kyr-1. Seabed preservation efficiencies were calculated for biogenic silica, organic carbon, and phosphorus by combining the solid-phase and pore water data. The seabed preservation efficiencies for biogenic silica (1-86%) were greater than for organic carbon (1-71%) at all nine stations examined. The preferential preservation of biogenic silica relative to organic carbon also was apparent in Ross Sea sediments because the biogenic silica/organic carbon ratio in the material buried in the seabed generally was 2 times greater than the ratio in sediment particles arriving at the sediment-water interface. Sediment accumulation rate correlated strongly with both the biogenic silica and the organic carbon preservation efficiency data

  6. Biogenic polycyclic aromatic hydrocarbons in sediments of the San Joaquin River in California (USA), and current paradigms on their formation.

    PubMed

    Wakeham, Stuart G; Canuel, Elizabeth A

    2016-06-01

    Biogenic perylene and higher plant pentacyclic triterpenoid-derived alkylated and partially aromatized tetra- and pentacyclic derivatives of chrysene (3,4,7-trimethyl- and 3,3,7-trimethyl-1,2,3,4-tetrahydrochrysene, THC) and picene (1,2,9-trimethyl- and 2,2,9-trimethyl-1,2,3,4-tetrahydropicene, THP) were two- to four-fold more abundant than pyrogenic PAH in two sediment cores from the San Joaquin River in Northern California (USA). In a core from Venice Cut (VC), located in the river, PAH concentrations varied little downcore and the whole-core PAH concentration (biogenics + pyrogenics) was 250.6 ± 73.7 ng g(-1) dw; biogenic PAH constituted 67 ± 4 % of total PAH. THC were 26 ± 9 % of total biogenic PAH, THP were 36 ± 7 %, and perylene was 38 ± 7 %. PAH distributions in a core from Franks Tract (FT), a former wetland that was converted to an agricultural tract in the late 1800s and flooded in 1938, were more variable. Surface sediments were dominated by pyrogenic PAH so that biogenic PAH were only ~30 % of total PAH. Deeper in the core, biogenic PAH constituted 60-93 % of total PAH; THC, THP and perylene were 31 ± 28 %, 24 ± 32 %, and 45 ± 36 % of biogenic PAH. At 100-103 cm depth, THP constituted 80 % of biogenic PAH and at 120-123 cm perylene was 95 % of biogenic PAH. Current concepts related to precursors and transformation processes responsible for the diagenetic generation of perylene and triterpenoid-derived PAH are discussed. Distributions of biogenic PAH in VC and FT sediments suggest that they may not form diagenetically within these sediments but rather might be delivered pre-formed from the river's watershed.

  7. [Spatial variations of biogenic elements in coastal wetland sediments of the Jiulong River Estuary].

    PubMed

    Yu, Xiao-Qing; Yang, Jun; Liu, Le-Mian; Tian, Yuan; Yu, Zheng; Wang, Chang-Fu

    2012-11-01

    To reveal the spatial distribution of biogenic elements and their influencing factors in the typical subtropical coastal wetland, both surface and core sediment samples were collected from the Jiulong River Estuary, southeast China in summer 2009. The biogenic elements including carbon, nitrogen, phosphorus, sulfur (C, N, P, S) were determined by Element Analyzer and Flow Injection Analyzer. The concentrations of TC, TN, TP, and TS were (12.64 +/- 2.66) g x kg(-1), (1.57 +/- 0.29) g x kg(-1), (0.48 +/- 0.06) g x kg(-1), and (2.61 +/- 1.37) g x kg(-1), respectively. Further, these biogenic elements showed a distinct spatial pattern which closely related with the vegetation type and tide level. Values of TC, TN, TP in the surface sediment of mangrove vegetation zones were higher than those in the cord-grass and mudflat zones, while TC, TN, TP concentrations in the high tide level regions were higher than those in the middle and low tide level regions. The TS concentration was the highest in cord-grass vegetation and middle tidal level zones. The TC and TN values in sedimentary core decreased gradually with depth, and they were the highest in the mangrove sites, followed by cord-grass and mudflat sites at the same depth. In mudflat sedimentary core, the average content of TP was the lowest, whereas TS was the highest. Redundancy analysis revealed that vegetation type, pH and tide level were the main factors influencing the distribution of biogenic elements in surface sediments of the Jiulong River Estuary, by explaining 24.0%, 19.0% and 11.6% of total variation in the four biogenic elements (C, N, P and S), respectively.

  8. Simultaneous determination of selected biogenic amines in alcoholic beverage samples by isotachophoretic and chromatographic methods.

    PubMed

    Jastrzębska, Aneta; Piasta, Anna; Szłyk, Edward

    2014-01-01

    A simple and useful method for the determination of biogenic amines in beverage samples based on isotachophoretic separation is described. The proposed procedure permitted simultaneous analysis of histamine, tyramine, cadaverine, putrescine, tryptamine, 2-phenylethylamine, spermine and spermidine. The data presented demonstrate the utility, simplicity, flexibility, sensitivity and environmentally friendly character of the proposed method. The precision of the method expressed as coefficient of variations varied from 0.1% to 5.9% for beverage samples, whereas recoveries varied from 91% to 101%. The results for the determination of biogenic amines were compared with an HPLC procedure based on a pre-column derivatisation reaction of biogenic amines with dansyl chloride. Furthermore, the derivatisation procedure was optimised by verification of concentration and pH of the buffer, the addition of organic solvents, reaction time and temperature.

  9. Remediation of arsenic-contaminated groundwater by in-situ stimulating biogenic precipitation of iron sulfides.

    PubMed

    Pi, Kunfu; Wang, Yanxin; Xie, Xianjun; Ma, Teng; Liu, Yaqing; Su, Chunli; Zhu, Yapeng; Wang, Zhiqiang

    2017-02-01

    Severe health problems due to elevated arsenic (As) in groundwater have made it urgent to develop cost-effective technologies for As removal. This field experimental study tested the feasibility of in-situ As immobilization via As incorporation into newly formed biogenic Fe(II) sulfides in a typical As-affected strongly reducing aquifer at the central part of Datong Basin, China. After periodic supply of FeSO 4 into the aquifer for 25 d to stimulate microbial sulfate reduction, dissolved sulfide concentrations increased during the experiment, but the supplied Fe(II) reacted quickly with sulfide to form Fe(II)-sulfides existing majorly as mackinawite as well as a small amount of pyrite-like minerals in sediments, thereby restricting sulfide build-up in groundwater. After the completion of field experiment, groundwater As concentration decreased from an initial average value of 593 μg/L to 159 μg/L, with an overall As removal rate of 73%, and it further declined to 136 μg/L adding the removal rate up to 77% in 30 d after the experiment. The arsenite/As total ratio gradually increased over time, making arsenite to be the predominant species in groundwater residual As. The good correlations between dissolved Fe(II), sulfide and As concentrations, the increased abundance of As in newly-formed Fe sulfides as well as the reactive-transport modeling results all indicate that As could have been adsorbed onto and co-precipitated with Fe(II)-sulfide coatings once microbial sulfate reduction was stimulated after FeSO 4 supply. Under the strongly reducing conditions, sulfide may facilitate arsenate reduction into arsenite and promote As incorporation into pyrite or arsenopyrite. Therefore, the major mechanisms for the in-situ As-contaminated groundwater remediation can be As surface-adsorption on and co-precipitation with Fe(II) sulfides produced during the experimental period. Copyright © 2016. Published by Elsevier Ltd.

  10. The Influence of Biogenic Emissions on Tropospheric Composition over Africa during 2006

    NASA Astrophysics Data System (ADS)

    Williams, J. E.; Scheele, R.; van Velthoven, P. F. J.; Cammas, J.-P.; Galy-Lacaux, C.; Thouret, V.

    2009-04-01

    Biogenic emissions of NO and Volatile Organic Compounds (BVOC's) play an important role in determining the oxidizing capacity of the troposphere near tropical regions which have sparse populations. Here we use a 3D global CTM (TM4) for the purpose of examining the effect of using a recent climatology of biogenic emissions from the ORCHIDEE model (Lathiére et al, 2006) on the distribution and concentrations of trace gas species over equatorial Africa during the AMMA measurement year of 2006. We compare the results against simulations which adopt an older biogenic inventory compiled during the POET project (Granier et al, 2005). Sensitivity studies are conducted to determine the effect of both NO emitted from soils and BVOC's emitted from vegetation (namely the cumulative effect of CO, HCHO, ethanol, acetic acid, acetone and CH3CHO) on tropospheric ozone, NOx and the nitrogen reservoir species PAN and HNO3. Comparisons with a host of measurements have been performed to assess the impact on model performance. Finally an analysis of the tropical O3 budget is performed to quantify differences introduced for the oxidizing capacity of the tropical troposphere. Granier, C., Guether, A., Lamarque, J. F., Mieville, A., Muller, J.F., Olivier, J., Orlando, J., Peters, J., Petron, G., Tyndall, G., amd Wallens, S., POET - a database of surface emissions of ozone precursors, available at: http://www.aero.jussieu.fr/project/ACCENT/POET.php, 2005. Lathiére, J., Hauglustaine, D. A., Friend, A. D., De Noblet-Ducoudré, N., Viovy, N., and Folberth, G. A., Impact of climate variability and land use changes on global biogenic volatile organic compound emissions, Atms. Chem. Phys., 6, 2129-2146, 2006.

  11. Evaluation of biogenic emission flux and its impact on oxidants and inorganic aerosols in East Asia

    NASA Astrophysics Data System (ADS)

    Han, K. M.; Song, C. H.; Park, R. S.; Woo, J.; Kim, H.

    2010-12-01

    As a major precursor during the summer season, biogenic species are of primary importance in the ozone and SOAs (secondary organic aerosols) formations. Isoprene and mono-terpene also influence the level of inorganic aerosols (i.e. sulfate and nitrate) by controlling OH radicals. However, biogenic emission fluxes are highly uncertain in East Asia. While isoprene emission fluxes from the GEIA (Global Emissions Inventory Activity) and POET (Precursors of Ozone and their Effects in the Troposphere) inventories estimate approximately 20 Tg yr-1 in East Asia, those from the MEGAN (Model of Emissions of Gases and Aerosols from Nature) and MOHYCAN (MOdel for Hydrocarbon emissions by the CANopy) estimate approximately 10 Tg yr-1 and 5 Tg yr-1, respectively. In order to evaluate and/or quantify the magnitude of biogenic emission fluxes over East Asia, the tropospheric HCHO columns obtained from the GOME (Global Ozone Monitoring Experiment) observations were compared with the HCHO columns from the CMAQ (Community Multi-scale Air Quality) simulations over East Asia. In this study, US EPA Models-3/CMAQ v4.5.1 model simulation using the ACE-ASIA (Asia Pacific Regional Aerosol Characterization Experiment) emission inventory for anthropogenic pollutants and GEIA, POET, MEGAN, and MOHYCAN emission inventories for biogenic species was carried out in conjunction with the Meteorological fields generated from the PSU/NCAR MM5 (Pennsylvania state University/National Center for Atmospheric Research Meso-scale Model 5) model for the summer episodes of the year 2002. In addition to an evaluation of the biogenic emission flux, we investigated the impact of the uncertainty in biogenic emission inventory on inorganic aerosol formations and variations of oxidants (OH, O3, and H2O2) in East Asia. In this study, when the GEIA and POET emission inventories are used, the CMAQ-derived HCHO columns are highly overestimated over East Asia, particularly South China compared with GOME-derived HCHO

  12. Measurement of biogenic hydrocarbon emissions from vegetation in the Lower Fraser Valley, British Columbia

    NASA Astrophysics Data System (ADS)

    Drewitt, G. B.; Curren, K.; Steyn, D. G.; Gillespie, T. J.; Niki, H.

    Biogenic volatile organic compounds (VOCs) participate in many chemical reactions in the atmosphere and in some cases, adversely affect air quality through increased production of photochemical ozone near urban sources of nitrogen oxides. In order to implement an effective control strategy, the relative role of these biogenic hydrocarbon emissions in producing ground-level ozone must be known. During the summers of 1995 and 1996, a field study was undertaken to determine fluxes of biogenic VOCs from both natural and agricultural surfaces in the Lower Fraser Valley located in southwestern British Columbia. Emissions from agricultural surfaces were measured using a flux gradient approach while emissions from the dominant tree species in the region were measured with a branch enclosure system. Results show very little biogenic VOC production from many agricultural crops such as pasture, Potatoes or Blueberries. Cranberries showed very high emissions during the summer of 1994 but failed to show similar results during the summer of 1995. Emissions of isoprene and monoterpenes from native tree species such as Western Red Cedar, Douglas Fir and Coastal Hemlock were quite low. Cottonwood trees on the other hand had fairly low emissions of monoterpenes but extremely high emissions of isoprene. Measurements provided here will be useful for improving our database of hydrocarbon emissions rates from vegetation for future emission inventories and model testing.

  13. Reduction of biogenic amines production by eliminating the PEP4 gene in Saccharomyces cerevisiae during fermentation of Chinese rice wine.

    PubMed

    Guo, Xuewu; Guan, Xiangyu; Wang, Yazhou; Li, Lina; Wu, Deguang; Chen, Yefu; Pei, Huadong; Xiao, Dongguang

    2015-07-01

    Biogenic amines in Chinese rice wine have a potential threat of toxicity to human health. In this study, PEP4 gene in Saccharomyces cerevisiae was knocked out in order to evaluate its effect on biogenic amines production; the enzyme encodes proteinase A (PrA), an enzyme that is responsible for the production of free amino acids. It was found that compared to the wild type strain, the PrA activity and amino acid concentration decreased significantly, and the production of biogenic amines in this knockout strain decreased by 25.5%, from 180.1mg/L to 134.2mg/L. Especially, tyramine, cadaverine and histamine concentrations were also decreased by 57.5%, 24.6% and 54.3%, respectively. The main reason for the decrease of biogenic amines may be due to the low concentration of free amino acids. Our results provide a new strategy to minimize the biogenic amine production during fermentation of Chinese rice wine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Post-speleogenetic biogenic modification of Gomantong Caves, Sabah, Borneo

    NASA Astrophysics Data System (ADS)

    Lundberg, Joyce; McFarlane, Donald A.

    2012-07-01

    The Gomantong cave system of eastern Sabah, Malaysia, is well-known as an important site for harvesting edible bird-nests and, more recently, as a tourist attraction. Although the biology of the Gomantong system has been repeatedly studied, very little attention has been given to the geomorphology. Here, we report on the impact of geobiological modification in the development of the modern aspect of the cave, an important but little recognized feature of tropical caves. Basic modeling of the metabolic outputs from bats and birds (CO2, H2O, heat) reveals that post-speleogenetic biogenic corrosion can erode bedrock by between ~ 3.0 mm/ka (1 m/~300 ka) and ~ 4.6 mm/ka (1 m/~200 ka). Modeling at high densities of bats yields rates of corrosion of ~ 34 mm/ka (or 1 m/~30 ka). Sub-aerial corrosion creates a previously undescribed speleological feature, the apse-flute, which is semicircular in cross-section and ~ 80 cm wide. It is vertical regardless of rock properties, developing in parallel but apparently completely independently, and often unbroken from roof to floor. They end at a blind hemi-spherical top with no extraneous water source. Half-dome ceiling conch pockets are remnants of previous apse-fluting. Sub-cutaneous corrosion creates the floor-level guano notch formed by organic acid dissolution of bedrock in contact with guano. Speleogenetic assessment suggests that as much as 70-95% of the total volume of the modern cave may have been opened by direct subaerial biogenic dissolution and biogenically-induced collapse, and by sub-cutaneous removal of limestone, over a timescale of 1-2 Ma.

  15. Adsorption and Desorption Characteristics of Cd2+ and Pb2+ by Micro and Nano-sized Biogenic CaCO3

    PubMed Central

    Liu, Renlu; Guan, Yong; Chen, Liang; Lian, Bin

    2018-01-01

    The purpose of this study was to elucidate the characteristics and mechanisms of adsorption and desorption for heavy metals by micro and nano-sized biogenic CaCO3 induced by Bacillus subtilis, and the pH effect on adsorption was investigated. The results showed that the adsorption characteristics of Cd2+ and Pb2+ are well described by the Langmuir adsorption isothermal equation, and the maximum adsorption amounts for Cd2+ and Pb2+ were 94.340 and 416.667 mg/g, respectively. The maximum removal efficiencies were 97% for Cd2+, 100% for Pb2+, and the desorption rate was smaller than 3%. Further experiments revealed that the biogenic CaCO3 could maintain its high adsorption capability for heavy metals within wide pH ranges (3–8). The FTIR and XRD results showed that, after the biogenic CaCO3 adsorbed Cd2+ or Pb2+, it did not produce a new phase, which indicated that biogenic CaCO3 and heavy metal ions were governed by a physical adsorption process, and the high adsorptive capacity of biogenic CaCO3 for Cd2+ and Pb2+ were mainly attributed to its large total specific surface area. The findings could improve the state of knowledge about biogenic CaCO3 formation in the environment and its potential roles in the biogeochemical cycles of heavy metals. PMID:29434577

  16. Mixing of biogenic siliceous and terrigenous clastic sediments: South Belridge field and Beta field, California

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schwartz, D.E.

    1990-05-01

    The intermixing and interbedding of biogenically derived siliceous sediment with terrigenous clastic sediment in reservoirs of upper Miocene age provides both reservoir rock and seal and influences productivity by affecting porosity and permeability. Miocene reservoirs commonly contain either biogenic-dominated cyclic diatomite, porcelanite, or chert (classic Monterey Formation) or clastic-dominated submarine fan sequences with interbedded or intermixed siliceous members of biogenic origin. Biogenic-clastic cycles, 30-180 ft thick, at South Belridge field were formed by episodic influx of clastic sediment from distant submarine fans mixing with slowly accumulating diatomaceous ooze. The cycles consist of basal silt and pelletized massive diatomaceous mudstone, overlainmore » by burrowed, faintly bedded clayey diatomite and topped by laminated diatomite. Cycle tops have higher porosity and permeability, lower grain density, and higher oil saturation than clay and silt-rich portions of the cycles. Submarine fan sediments forming reservoirs at the Beta field are comprised of interbedded sands and silts deposited in a channelized middle fan to outer fan setting. Individual turbidites display fining-upward sequences, with oil-bearing sands capped by wet micaceous silts. Average sands are moderately to poorly sorted, fine- to medium-grained arkosic arenites. Sands contain pore-filling carbonate and porcelaneous cements. Porcelaneous cement consists of a mixture of opal-A, opal-CT, and chert with montmorillonite and minor zeolite. This cement is an authigenic material precipitated in intergranular pore space. The origin of the opal is biogenic, with recrystallization of diatom frustules (opal-A) into opal-CT lepispheres and quartz crystals. Porcelaneous cement comprises 4-21% of the bulk volume of the rock. Seventy percent of the bulk volume of the cement is micropore space.« less

  17. Antifungal activity of biogenic tellurium nanoparticles against Candida albicans and its effects on squalene monooxygenase gene expression.

    PubMed

    Zare, Bijan; Sepehrizadeh, Zargham; Faramarzi, Mohammad Ali; Soltany-Rezaee-Rad, Mohammad; Rezaie, Sassan; Shahverdi, Ahmad Reza

    2014-01-01

    In this study, we evaluated the antifungal activity of biogenic tellurium nanoparticles (Te NPs) against Candida albicans (ATCC14053). In addition, the effect of these biogenic NPs on squalene monooxygenase activity and the squalene monooxygenase gene (ERG1) expression level was evaluated. Squalene monooxygenase is an important enzyme involved in the synthesis of ergosterol, cholesterol, and phytosterols. Because of the importance of the noted compound, the squalene monooxygenase gene could be considered a good antifungal target. Results showed that biogenic Te NPs had antifungal effect against C. albicans. The minimal fungicidal concentration-minimal inhibitory concentration ratios of the biogenic Te NPs revealed that these NPs exhibited fungicidal effects against the test strain. The results of an enzyme assay using quantitative high-performance liquid chromatography showed squalene accumulation in C. albicans cells because of enzyme inhibition. Real-time PCR analysis showed an increase in the expression of the ERG1 gene in C. albicans cells, which were treated with Te NPs (0.2 mg/mL). It is conclution that Te NPs can inhibit the squalene monooxygenase enzyme, and, as a result, this inhibition phenomenon can cause an increase in the expression level of the ERG1 gene. This is the first report of the anti-Candida effect of biogenic Te NPs and its possible mechanisms. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  18. Mineral ecophysiological evidence for biogeochemical cycles in 2461-2495 million year old banded iron formations (BIF).

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Y; Konhauser, Dr, Kurt; Cole, David

    2011-01-01

    The phosphorus composition of banded-iron formations (BIFs) has been used as a proxy for Precambrian seawater composition and the paleoeredox state of Earth's surface environment. However, it is unclear whether the phosphorus in BIFs originally entered the sediment as a sorbed component of the iron oxyhydroxide particles, or whether it was incorporated into the biomass of marine phytoplankton. We conducted high-resolution mineral analyses and report here the first detection of an Fe(III) acetate salt, as well as nanocrystals of apatite in association with magnetite, in the 2.48 Ga Dales Gorge Member of the Brockman Iron Formation (a BIF), Hamersley, Westernmore » Australia. The clusters of apatite are similar in size and morphology to biogenic apatite crystals resulting from biomass decay in Phanerozoic marine sediments, while the formation of an Fe(III) acetate salt and magnetite not only implies the original presence of biomass in the BIF sediments, but also that organic carbon likely served as an electron donor during bacterial Fe(III) reduction. This study is important because it suggests that phytoplankton may have played a key role in the transfer of phosphorus (and other trace elements) from the photic zone to the seafloor.« less

  19. Iron-Tolerant Cyanobacteria for Human Habitation beyond Earth

    NASA Technical Reports Server (NTRS)

    Brown, Igor; Sarkisova, Svetlana; Jones, Jeff; Sternberg, Paul; Bayless, David; Mckay, David S.

    2006-01-01

    In light of the President's Moon/Mars initiative, lunar exploration has once again become a priority for NASA. In order to establish permanent bases on the Moon and proceed with human exploration of Mars, two key problems will be addressed: first, the production of O2 and second, the production of methane (CH4). While O2 is required for life support systems (LSS), both liquid O2 and CH4 are needed as an oxidizer and a propellant, respectively for the Lunar Surface Access Module (LSAM) and the Crew Exploration Vehicle (CEV). Unlike previous propulsion systems, the new CEV will use liquid oxygen (LO2) as an oxidizer and liquid methane (LCH4) as a propellant. Existing technology (e.g. hydrogen reduction) for the production of liquid oxygen from lunar regolith is very energy intensive and requires high temperature reactors. We propose an alternative approach using iron-tolerant cyanobacteria. We have found that iron-tolerant cyanobacteria (IT CB) are capable of etching iron-bearing minerals, which may lead to bonds breaking between Fe and O of common lunar mare basalt Feoxides including ilmenite, pseudobrookite, ferropseudobrookite, and armalcolite with the subsequent release of both Fe, Ti and oxygen as by-products. We also propose to use CB biomass for CH4 production as carbon stock and a propellant. Both processes can be accomplished in an energy and cost effective manner because sunlight will be used as an energy source and allows the reactions at ambient temperatures between 10-60 C. Current evaluations include assessing the thermodynamics of such biogenic reactions using a variety of nutrients and atmospheric parameters, as well as assessing the rates and species variation effects of the driving reactions.

  20. Selection of nutrient used in biogenic healing agent for cementitious materials

    NASA Astrophysics Data System (ADS)

    Tziviloglou, Eirini; Wiktor, Virginie; Jonkers, Henk M.; Schlangen, Erik

    2017-06-01

    Biogenic self-healing cementitious materials target on the closure of micro-cracks with precipitated inorganic minerals originating from bacterial metabolic activity. Dormant bacterial spores and organic mineral compounds often constitute a biogenic healing agent. The current paper focuses on the investigation of the most appropriate organic carbon source to be used as component of a biogenic healing agent. It is of great importance to use an appropriate organic source, since it will firstly ensure an optimal bacterial performance in terms of metabolic activity, while it should secondly affect the least the properties of the cementitious matrix. The selection is made among three different organic compounds, namely calcium lactate, calcium acetate and sodium gluconate. The methodology that was used for the research was based on continuous and non-continuous oxygen consumption measurements of washed bacterial cultures and on compressive strength tests on mortar cubes. The oxygen consumption investigation revealed a preference for calcium lactate and acetate, but an indifferent behaviour for sodium gluconate. The compressive strength on mortar cubes with different amounts of either calcium lactate or acetate (up to 2.24% per cement weight) was not or it was positively affected when the compounds were dissolved in the mixing water. In fact, for calcium lactate the increase in compressive strength reached 8%, while for calcium acetate the maximum strength increase was 13.4%.

  1. Iron budgets for three distinct biogeochemical sites around the Kerguelen Archipelago (Southern Ocean) during the natural fertilisation study, KEOPS-2

    NASA Astrophysics Data System (ADS)

    Bowie, A. R.; van der Merwe, P.; Quéroué, F.; Trull, T.; Fourquez, M.; Planchon, F.; Sarthou, G.; Chever, F.; Townsend, A. T.; Obernosterer, I.; Sallée, J.-B.; Blain, S.

    2015-07-01

    Iron availability in the Southern Ocean controls phytoplankton growth, community composition and the uptake of atmospheric CO2 by the biological pump. The KEOPS-2 (KErguelen Ocean and Plateau compared Study 2) "process study", took place around the Kerguelen Plateau in the Indian sector of the Southern Ocean. This is a region naturally fertilised with iron on the scale of hundreds to thousands of square kilometres, producing a mosaic of spring blooms which show distinct biological and biogeochemical responses to fertilisation. This paper presents biogeochemical iron budgets (incorporating vertical and lateral supply, internal cycling, and sinks) for three contrasting sites: an upstream high-nutrient low-chlorophyll reference, over the plateau and in the offshore plume east of the Kerguelen Islands. These budgets show that distinct regional environments driven by complex circulation and transport pathways are responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. Iron supply from "new" sources (diffusion, upwelling, entrainment, lateral advection, atmospheric dust) to the surface waters of the plume was double that above the plateau and 20 times greater than at the reference site, whilst iron demand (measured by cellular uptake) in the plume was similar to that above the plateau but 40 times greater than at the reference site. "Recycled" iron supply by bacterial regeneration and zooplankton grazing was a relatively minor component at all sites (< 8 % of new supply), in contrast to earlier findings from other biogeochemical iron budgets in the Southern Ocean. Over the plateau, a particulate iron dissolution term of 2.5 % was invoked to balance the budget; this approximately doubled the standing stock of dissolved iron in the mixed layer. The exchange of iron between dissolved, biogenic particulate and lithogenic particulate pools was highly dynamic in time and space

  2. Emissions of biogenic sulfur gases from Alaskan tundra

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.; Morrison, Michael C.

    1992-01-01

    Fluxes of the biogenic sulfur gases carbonyl sulfide (COS), dimethyl sulfide (DMS), methyl mercaptan (MeSH), and carbon disulfide (CS2) were determined for several freshwater and coastal marine tundra habitats using a dynamic enclosure method and gas chromatography. In the freshwater tundra sites, highest emissions, with a mean of 6.0 nmol/m(sup -2)H(sup -1) (1.5-10) occurred in the water-saturated wet meadow areas inhabited by grasses, sedges, and Sphagnum mosses. In the drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol/m(sup -2)h(sup -1) (0-8.3) and lowest fluxes were from lichen-dominated areas at 0.9 nmol/m(sup -2)h(sup -1). Sulfur emissions from a lake surface were also low at 0.8 nmol/m(sup -2)h(sup -1). Of the compounds measured, DMS was the dominant gas emitted from all of these sites. Sulfure emissions from the marine sites were up to 20-fold greater than fluxes in the freshwater habitats and were also dominated by DMS. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea (150-250 nmol/m(sup -2)h(sup -1)). This Carex sp. was grazed thoroughly by geese and DMS fluxes doubled when goose feces were left within the flux chamber. Emissions were much lower from other types of vegetation which were more spatially dominant. Sulfure emissions from tundra were among the lowest reported in the literature. When emission data were extrapolated to include all tundra globally, the global flux of biogenic sulfur from this biome is 2-3 x 10(exp 8) g/yr. This represents less than 0.001 percent of the estimated annual global flux (approximately 50 Tg) of biogenic sulfur and less than 0.01 percent of the estimated terrestrial flux. The low emissions are attributed to the low availability of sulfate, certain hydrological characteristics of tundra, and the tendency for tundra to accumulate organic matter.

  3. Phase transitions in biogenic amorphous calcium carbonate

    NASA Astrophysics Data System (ADS)

    Gong, Yutao

    Geological calcium carbonate exists in both crystalline phases and amorphous phases. Compared with crystalline calcium carbonate, such as calcite, aragonite and vaterite, the amorphous calcium carbonate (ACC) is unstable. Unlike geological calcium carbonate crystals, crystalline sea urchin spicules (99.9 wt % calcium carbonate and 0.1 wt % proteins) do not present facets. To explain this property, crystal formation via amorphous precursors was proposed in theory. And previous research reported experimental evidence of ACC on the surface of forming sea urchin spicules. By using X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron emission microscopy (PEEM), we studied cross-sections of fresh sea urchin spicules at different stages (36h, 48h and 72h after fertilization) and observed the transition sequence of three mineral phases: hydrated ACC → dehydrated ACC → biogenic calcite. In addition, we unexpectedly found hydrated ACC nanoparticles that are surrounded by biogenic calcite. This observation indicates the dehydration from hydrated ACC to dehydrated ACC is inhibited, resulting in stabilization of hydrated ACC nanoparticles. We thought that the dehydration was inhibited by protein matrix components occluded within the biomineral, and we designed an in vitro assay to test the hypothesis. By utilizing XANES-PEEM, we found that SM50, the most abundant occluded matrix protein in sea urchin spicules, has the function to stabilize hydrated ACC in vitro.

  4. Biogenic organic emissions, air quality and climate

    NASA Astrophysics Data System (ADS)

    Guenther, A. B.

    2015-12-01

    Living organisms produce copious amounts of a diverse array of metabolites including many volatile organic compounds that are released into the atmosphere. These compounds participate in numerous chemical reactions that influence the atmospheric abundance of important air pollutants and short-lived climate forcers including organic aerosol, ozone and methane. The production and release of these organics are strongly influenced by environmental conditions including air pollution, temperature, solar radiation, and water availability and they are highly sensitive to stress and extreme events. As a result, releases of biogenic organics to the atmosphere have an impact on, and are sensitive to, air quality and climate leading to potential feedback couplings. Their role in linking air quality and climate is conceptually clear but an accurate quantitative representation is needed for predictive models. Progress towards this goal will be presented including numerical model development and assessments of the predictive capability of the Model of Emission of Gases and Aerosols from Nature (MEGAN). Recent studies of processes controlling the magnitude and variations in biogenic organic emissions will be described and observations of their impact on atmospheric composition will be shown. Recent advances and priorities for future research will be discussed including laboratory process studies, long-term measurements, multi-scale regional studies, global satellite observations, and the development of a next generation model for simulating land-atmosphere chemical exchange.

  5. Late-Quaternary changes of biogenic fluxes in the pacific sector of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Giglio, F.; Langone, L.; Capotondi, L.; Morigi, C.; Focaccia, P.; Frignani, M.; Ravaioli, M.

    2003-04-01

    During the last decade the research project BIOSESO of the Italian National Research Program for Antarctica (PNRA) has collected 13 gravity cores and 3 box-cores along a N-S transect at about 175^oE in the Southern Ocean. In this presentation we discuss the results from 6 sediment cores sampled between 62^oS and 71^oS. This area embraces the Polar Front and the Marginal Ice Zone. The data set includes the contents of organic carbon, biogenic silica, CaCO_3 and some metals (Ba, Al, Fe, Mn) involved in the biogeochemical cycles. Chronologies were based on 230Thex profiles and the boundaries of the isotope stages were set assuming that biological productivity was enhanced during periods of less ice cover. Then , 230Thex, organic carbon, biogenic silica and biogenic Ba distributions were compared to the glacial-interglacial stage boundaries and corresponding ages of the δ18O record of Martinson et al. (1987). At the sampling sites sediment accumulation rates range between 0.2 to 3.8 cm ka-1. The higher values characterize the interglacial stages and the southern stations. Processes of sediment redistribution at sea bottom were enlightened by a comparison of measured and expected fluxes of 230Thex . The Polar Front zone is characterized by winnowing, whereas sediments along the continental slope of the Ross Sea are mainly subject to focussing processes. The environmental factors that drive changes of biogenic particle fluxes during glacial-interglacial transitions have been investigated.

  6. Mineralized iron oxidizing bacteria from hydrothermal vents: targeting biosignatures on Mars

    NASA Astrophysics Data System (ADS)

    Leveille, R. J.

    2010-12-01

    formation of an iron oxyhydroxide precipitate, either in direct association with the cells or within the growth medium, were observed. Preliminary analyses suggest that these precipitates are different from abiotic precipitates. Continuing work includes high-resolution TEM observations of cultured organisms and biogenic iron minerals, Raman and reflectance spectroscopy of precipitates, examination of seafloor incubation experiments, and bioreactor silicification experiments in order to better understand the Fe-Si fossilization process. Microaerophilic iron oxidation could have existed on the early Earth in environments containing small amounts of oxygen produced either by locally-concentrated photosynthetic microorganisms (e.g., cyanobacteria) or by chemical reactions. By analogy, similar subsurface or near-surface microaerophilic environments could have existed on Mars in the past, including in low-temperature hydrothermal systems. The distinctive morphologies and Fe-Si mineralization patterns of iron oxidizing bacteria could be a useful biosignature to search for on Mars. Deposits and features similar to those described here could be identified on Mars with existing technologies, and thus hydrothermal systems represent an attractive target for future surface and sample return missions.

  7. The Moon: Biogenic elements

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K., Jr.; Chang, Sherwood

    1992-01-01

    The specific objectives of the organic chemical exploration of the Moon involve the search for molecules of possible biological or prebiological origin. Detailed knowledge of the amount, distribution, and exact structure of organic compounds present on the Moon is extremely important to our understanding of the origin and history of the Moon and to its relationship to the history of the Earth and solar system. Specifically, such knowledge is essential for determining whether life on the Moon exists, ever did exist, or could develop. In the absence of life or organic matter, it is still essential to determine the abundance, distribution, and origin of the biogenic elements (e.g., H, C, O, N, S, P) in order to understand how the planetary environment may have influenced the course of chemical evolution. The history and scope of this effort is presented.

  8. Biological attenuation of arsenic and iron in a continuous flow bioreactor treating acid mine drainage (AMD).

    PubMed

    Fernandez-Rojo, L; Héry, M; Le Pape, P; Braungardt, C; Desoeuvre, A; Torres, E; Tardy, V; Resongles, E; Laroche, E; Delpoux, S; Joulian, C; Battaglia-Brunet, F; Boisson, J; Grapin, G; Morin, G; Casiot, C

    2017-10-15

    Passive water treatments based on biological attenuation can be effective for arsenic-rich acid mine drainage (AMD). However, the key factors driving the biological processes involved in this attenuation are not well-known. Here, the efficiency of arsenic (As) removal was investigated in a bench-scale continuous flow channel bioreactor treating As-rich AMD (∼30-40 mg L -1 ). In this bioreactor, As removal proceeds via the formation of biogenic precipitates consisting of iron- and arsenic-rich mineral phases encrusting a microbial biofilm. Ferrous iron (Fe(II)) oxidation and iron (Fe) and arsenic removal rates were monitored at two different water heights (4 and 25 mm) and with/without forced aeration. A maximum of 80% As removal was achieved within 500 min at the lowest water height. This operating condition promoted intense Fe(II) microbial oxidation and subsequent precipitation of As-bearing schwertmannite and amorphous ferric arsenate. Higher water height slowed down Fe(II) oxidation, Fe precipitation and As removal, in relation with limited oxygen transfer through the water column. The lower oxygen transfer at higher water height could be partly counteracted by aeration. The presence of an iridescent floating film that developed at the water surface was found to limit oxygen transfer to the water column and delayed Fe(II) oxidation, but did not affect As removal. The bacterial community structure in the biogenic precipitates in the bottom of the bioreactor differed from that of the inlet water and was influenced to some extent by water height and aeration. Although potential for microbial mediated As oxidation was revealed by the detection of aioA genes, removal of Fe and As was mainly attributable to microbial Fe oxidation activity. Increasing the proportion of dissolved As(V) in the inlet water improved As removal and favoured the formation of amorphous ferric arsenate over As-sorbed schwertmannite. This study proved the ability of this bioreactor

  9. Iron Homeostasis and Nutritional Iron Deficiency123

    PubMed Central

    Theil, Elizabeth C.

    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 encoded in iron responsive element (IRE)-mRNA. The noncoding IRE-mRNA structures bind protein repressors, IRP1 or 2, during iron deficiency. Integration of the IRE-RNA in translation regulators (near the cap) or turnover elements (after the coding region) increases iron uptake (DMT1/TRF1) or decreases iron storage/efflux (FTN/FPN) when IRP binds. An antioxidant response element in FTN DNA binds Bach1, a heme-sensitive transcription factor that coordinates expression among antioxidant response proteins like FTN, thioredoxin reductase, and quinone reductase. FTN, an antioxidant because Fe2+ and O2 (reactive oxygen species generators) are consumed to make iron mineral, is also a nutritional iron concentrate that is an efficiently absorbed, nonheme source of iron from whole legumes. FTN protein cages contain thousands of mineralized iron atoms and enter cells by receptor-mediated endocytosis, an absorption mechanism distinct from transport of nonheme iron salts (ferrous sulfate), iron chelators (ferric-EDTA), or heme. Recognition of 2 nutritional nonheme iron sources, small and large (FTN), will aid the solution of iron deficiency, a major public health problem, and the development of new policies on iron nutrition. PMID:21346101

  10. Impacts of biogenic and anthropogenic emissions on summertime ozone formation in the Guanzhong Basin, China

    NASA Astrophysics Data System (ADS)

    Li, Nan; He, Qingyang; Greenberg, Jim; Guenther, Alex; Li, Jingyi; Cao, Junji; Wang, Jun; Liao, Hong; Wang, Qiyuan; Zhang, Qiang

    2018-05-01

    This study is the first attempt to understand the synergistic impact of anthropogenic and biogenic emissions on summertime ozone (O3) formation in the Guanzhong (GZ) Basin where Xi'an, the oldest and the most populous city (with a population of 9 million) in northwestern China, is located. Month-long (August 2011) WRF-Chem simulations with different sensitivity experiments were conducted and compared with near-surface measurements. Biogenic volatile organic compounds (VOCs) concentrations was characterized from six surface sites among the Qinling Mountains, and urban air composition was measured in Xi'an city at a tower 100 m a. s. The WRF-Chem control experiment reasonably reproduced the magnitudes and variations of observed O3, VOCs, NOx, PM2.5, and meteorological parameters, with normalized mean biases for each parameter within ±21 %. Subsequent analysis employed the factor separation approach (FSA) to quantitatively disentangle the pure and synergistic impacts of anthropogenic and/or biogenic sources on summertime O3 formation. The impact of anthropogenic sources alone was found to be dominant for O3 formation. Although anthropogenic particles reduced NO2 photolysis by up to 60 %, the anthropogenic sources contributed 19.1 ppb O3 formation on average for urban Xi'an. The abundant biogenic VOCs from the nearby forests promoted O3 formation in urban areas by interacting with the anthropogenic NOx. The calculated synergistic contribution (from both biogenic and anthropogenic sources) was up to 14.4 ppb in urban Xi'an, peaking in the afternoon. Our study reveals that the synergistic impact of individual source contributions to O3 formation should be considered in the formation of air pollution control strategies, especially for big cities in the vicinity of forests.

  11. The Labrador Sea during the Last Glacial Maximum: Calcite dissolution or low biogenic carbonate fluxes?

    NASA Astrophysics Data System (ADS)

    Marshall, Nicole; de Vernal, Anne; Mucci, Alfonso; Filippova, Alexandra; Kienast, Markus

    2017-04-01

    Low concentrations of biogenic carbonate characterize the sediments deposited in the Labrador Sea during the last glaciation. This may reflect poor calcite preservation and/or low biogenic carbonate productivity and fluxes. Regional bottom water ventilation was reduced during the Last Glacial Maximum (LGM), so the calcite lysocline might have been shallower than at present in the deep Labrador Sea making dissolution of calcite shells in the deep Labrador Sea possible. To address the issue, a multi-proxy approach based on micropaleontological counts (coccoliths, foraminifers, palynomorphs) and biogeochemical analyses (alkenones) was applied in the investigation of core HU2008-029-004-PC recovered in the northwestern Labrador Sea. Calcite dissolution indices based on the relative abundance benthic foraminifera shells to their organic linings as well as on fragmentation of planktonic foraminifera shells were used to evaluate changes in calcite dissolution/ preservation since the LGM. In addition, the ratio of the concentrations of coccoliths, specifically of the alkenone-producer Emiliania huxleyi, and alkenones (Emiliania huxleyi: alkenones) was explored as a potential new proxy of calcite dissolution. A sharp increase in coccoliths, foraminifers and organic linings from nearly none to substantial concentrations at 12 ka, reflect a jump to significantly greater biogenic fluxes at the glacial-interglacial transition. Furthermore, conventional dissolution indices (shells/linings of benthic foraminifera and fragmentation of planktic foraminifers) reveal that dissolution is not likely responsible for the lower glacial abundances of coccoliths and foraminifers. Only the low Emiliania huxleyi: alkenones ratios in glacial sediments could be interpreted as evidence of increased dissolution during the LGM. Given the evidence of allochthonous alkenone input into the glacial Labrador Sea, the latter observations must be treated with caution. Overall, the records indicate that

  12. Volcanic ash as an oceanic iron source and sink

    NASA Astrophysics Data System (ADS)

    Rogan, Nicholas; Achterberg, Eric P.; Le Moigne, Frédéric A. C.; Marsay, Chris M.; Tagliabue, Alessandro; Williams, Richard G.

    2016-03-01

    Volcanic ash deposition to the ocean forms a natural source of iron (Fe) to surface water microbial communities. Inputs of lithogenic material may also facilitate Fe removal through scavenging. Combining dissolved Fe (dFe) and thorium-234 observations alongside modeling, we investigate scavenging of Fe in the North Atlantic following the Eyjafjallajökull volcanic eruption. Under typical conditions biogenic particles dominate scavenging, whereas ash particles dominate during the eruption. The size of particles is important as smaller scavenging particles can become saturated with surface-associated ions. Model simulations indicate that ash deposition associated with Eyjafjallajökull likely led to net Fe removal. Our model suggests a threefold greater stimulation of biological activity if ash deposition had occurred later in the growing season when the region was Fe limited. The implications of ash particle scavenging, eruption timing, and particle saturation need to be considered when assessing the impact of ash deposition on the ocean Fe cycle and productivity.

  13. Biogenic Magnetite in Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Thomas-Keprta, K. L.; Bazylinski, Dennis; Wentworth, Susan J.; McKay, David S.; Kirschvink, Joseph L.; Clemett, SImon J.; Bell, Mary Sue; Golden, D. C.; Gibson, Everett K., Jr.

    1999-01-01

    Fine-grained magnetite (Fe3O4) in martian meteorite ALH84001, generally less than 200 nm in size, is located primarily in the rims that surround the carbonate globules. There are two populations of ALH84001 magnetites, which are likely formed at low temperature by inorganic and biogenic processes. Nearly 27% of ALH84001 magnetite particles, also called elongated prisms, have characteristics which make them uniquely identifiable as biological precipitates. Additional information is contained in the original extended abstract.

  14. Consistent quantification of climate impacts due to biogenic carbon storage across a range of bio-product systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guest, Geoffrey, E-mail: geoffrey.guest@ntnu.no; Bright, Ryan M., E-mail: ryan.m.bright@ntnu.no; Cherubini, Francesco, E-mail: francesco.cherubini@ntnu.no

    2013-11-15

    Temporary and permanent carbon storage from biogenic sources is seen as a way to mitigate climate change. The aim of this work is to illustrate the need to harmonize the quantification of such mitigation across all possible storage pools in the bio- and anthroposphere. We investigate nine alternative storage cases and a wide array of bio-resource pools: from annual crops, short rotation woody crops, medium rotation temperate forests, and long rotation boreal forests. For each feedstock type and biogenic carbon storage pool, we quantify the carbon cycle climate impact due to the skewed time distribution between emission and sequestration fluxesmore » in the bio- and anthroposphere. Additional consideration of the climate impact from albedo changes in forests is also illustrated for the boreal forest case. When characterizing climate impact with global warming potentials (GWP), we find a large variance in results which is attributed to different combinations of biomass storage and feedstock systems. The storage of biogenic carbon in any storage pool does not always confer climate benefits: even when biogenic carbon is stored long-term in durable product pools, the climate outcome may still be undesirable when the carbon is sourced from slow-growing biomass feedstock. For example, when biogenic carbon from Norway Spruce from Norway is stored in furniture with a mean life time of 43 years, a climate change impact of 0.08 kg CO{sub 2}eq per kg CO{sub 2} stored (100 year time horizon (TH)) would result. It was also found that when biogenic carbon is stored in a pool with negligible leakage to the atmosphere, the resulting GWP factor is not necessarily − 1 CO{sub 2}eq per kg CO{sub 2} stored. As an example, when biogenic CO{sub 2} from Norway Spruce biomass is stored in geological reservoirs with no leakage, we estimate a GWP of − 0.56 kg CO{sub 2}eq per kg CO{sub 2} stored (100 year TH) when albedo effects are also included. The large variance in GWPs across the

  15. Understanding Biogenic and Anthropogenic Trace Gas Variations Measured Near Cool, CA in June 2010

    NASA Astrophysics Data System (ADS)

    Klein, B. Z.; Flowers, B. A.; Gorkowski, K.; Dubey, M. K.; Knighton, W. B.; Floerchinger, C.; Herndon, S. C.; Fast, J. D.; Zaveri, R. A.

    2011-12-01

    Trace gas signatures produced by forested and urban areas differ greatly. Forested areas are dominated by gases produced during photosynthesis and respiration: CO2 and volatile organic compounds (VOCs) including terpenes and isoprene. Urban areas are heavily influenced by vehicle exhaust emissions and have elevated levels of CO, NOx and aromatic hydrocarbons such as benzene. Ozone is produced as a byproduct of both of these sources; it is produced when NOx from urban areas reacts with either anthropogenic or biogenic hydrocarbons. The Carbonaceous Aerosol and Radiative Effects Study (CARES) campaign was conducted during June 2010, in part to observe the evolution of urban air masses as they mix into rural locations and to better understand anthropogenic-biogenic photochemical interactions. The campaign included two ground-based sampling sites, one in Sacramento, CA (T0) and one downwind, approximately 70km NE, rurally located near Cool, CA (T1). In situ measurements of CO2, CO, O3, NO and multiple different VOCs were performed at the T1 site during the study, and are analyzed here to gain insights into the chemistry and transport of these trace gases. Comparisons between these trace gases coupled with transport modeling is used to delineate biogenic and anthropogenic sources. Additionally, comparisons between trace gases produced predominately by biogenic sources provide valuable information on how meteorology affects their production. Two atmospheric models (HYSPLIT back-trajectories and WRF forecasts) are used to predict transport episodes, where polluted air masses from the Sacramento or more distant San Francisco areas are transported to Cool. The two models display significant overlap for eleven different transport episodes during the study period. Both models also agree on two transport-free multiple-day periods. By examining the periods during which the models are in agreement, we are able to characterize with high certainty the trace gas signatures of local

  16. Biogenic Magnetite Formation through Anaerobic Biooxidation of Fe(II)

    PubMed Central

    Chaudhuri, Swades K.; Lack, Joseph G.; Coates, John D.

    2001-01-01

    The presence of isotopically light carbonates in association with fine-grained magnetite is considered to be primarily due to the reduction of Fe(III) by Fe(III)-reducing bacteria in the environment. Here, we report on magnetite formation by biooxidation of Fe(II) coupled to denitrification. This metabolism offers an alternative environmental source of biogenic magnetite. PMID:11375205

  17. Integrated on-chip derivatization and electrophoresis for the rapid analysis of biogenic amines.

    PubMed

    Beard, Nigel P; Edel, Joshua B; deMello, Andrew J

    2004-07-01

    We demonstrate the monolithic integration of a chemical reactor with a capillary electrophoresis device for the rapid and sensitive analysis of biogenic amines. Fluorescein isothiocyanate (FITC) is widely employed for the analysis of amino-group containing analytes. However, the slow reaction kinetics hinders the use of this dye for on-chip labeling applications. Other alternatives are available such as o-phthaldehyde (OPA), however, the inferior photophysical properties and the UV lambdamax present difficulties when using common excitation sources leading to a disparity in sensitivity. Consequently, we present for the first time the use of dichlorotriazine fluorescein (DTAF) as a superior in situ derivatizing agent for biogenic amines in microfluidic devices. The developed microdevice employs both hydrodynamic and electroosmotic flow, facilitating the creation of a polymeric microchip to perform both precolumn derivatization and electrophoretic analysis. The favorable photophysical properties of the DTAF and its fast reaction kinetics provide detection limits down to 1 nM and total analysis times (including on-chip mixing and reaction) of <60 s. The detection limits are two orders of magnitude lower than current limits obtained with both FITC and OPA. The optimized microdevice is also employed to probe biogenic amines in real samples.

  18. BIOGENIC CONTRIBUTIONS TO ATMOSPHERIC VOLATILE ORGANIC COMPOUNDS IN AZUSA CA

    EPA Science Inventory

    An objective of the 1997 Southern California Ozone Study (SCOS97) was to provide an up-to-date assessment of the importance of biogenic emissions for tropospheric ozone production in the South Coast Air Basin. To this end ambient air samples were collected during September 199...

  19. Modeling Global Biogenic Emission of Isoprene: Exploration of Model Drivers

    NASA Technical Reports Server (NTRS)

    Alexander, Susan E.; Potter, Christopher S.; Coughlan, Joseph C.; Klooster, Steven A.; Lerdau, Manuel T.; Chatfield, Robert B.; Peterson, David L. (Technical Monitor)

    1996-01-01

    Vegetation provides the major source of isoprene emission to the atmosphere. We present a modeling approach to estimate global biogenic isoprene emission. The isoprene flux model is linked to a process-based computer simulation model of biogenic trace-gas fluxes that operates on scales that link regional and global data sets and ecosystem nutrient transformations Isoprene emission estimates are determined from estimates of ecosystem specific biomass, emission factors, and algorithms based on light and temperature. Our approach differs from an existing modeling framework by including the process-based global model for terrestrial ecosystem production, satellite derived ecosystem classification, and isoprene emission measurements from a tropical deciduous forest. We explore the sensitivity of model estimates to input parameters. The resulting emission products from the global 1 degree x 1 degree coverage provided by the satellite datasets and the process model allow flux estimations across large spatial scales and enable direct linkage to atmospheric models of trace-gas transport and transformation.

  20. Transformation and crystallization energetics of synthetic and biogenic amorphous calcium carbonate.

    PubMed

    Radha, A V; Forbes, Tori Z; Killian, Christopher E; Gilbert, P U P A; Navrotsky, Alexandra

    2010-09-21

    Amorphous calcium carbonate (ACC) is a metastable phase often observed during low temperature inorganic synthesis and biomineralization. ACC transforms with aging or heating into a less hydrated form, and with time crystallizes to calcite or aragonite. The energetics of transformation and crystallization of synthetic and biogenic (extracted from California purple sea urchin larval spicules, Strongylocentrotus purpuratus) ACC were studied using isothermal acid solution calorimetry and differential scanning calorimetry. Transformation and crystallization of ACC can follow an energetically downhill sequence: more metastable hydrated ACC → less metastable hydrated ACC ⇒ anhydrous ACC ∼ biogenic anhydrous ACC ⇒ vaterite → aragonite → calcite. In a given reaction sequence, not all these phases need to occur. The transformations involve a series of ordering, dehydration, and crystallization processes, each lowering the enthalpy (and free energy) of the system, with crystallization of the dehydrated amorphous material lowering the enthalpy the most. ACC is much more metastable with respect to calcite than the crystalline polymorphs vaterite or aragonite. The anhydrous ACC is less metastable than the hydrated, implying that the structural reorganization during dehydration is exothermic and irreversible. Dehydrated synthetic and anhydrous biogenic ACC are similar in enthalpy. The transformation sequence observed in biomineralization could be mainly energetically driven; the first phase deposited is hydrated ACC, which then converts to anhydrous ACC, and finally crystallizes to calcite. The initial formation of ACC may be a first step in the precipitation of calcite under a wide variety of conditions, including geological CO(2) sequestration.

  1. Influence of pore structure on the effectiveness of a biogenic carbonate surface treatment for limestone conservation.

    PubMed

    De Muynck, Willem; Leuridan, Stijn; Van Loo, Denis; Verbeken, Kim; Cnudde, Veerle; De Belie, Nele; Verstraete, Willy

    2011-10-01

    A ureolytic biodeposition treatment was applied to five types of limestone in order to investigate the effect of pore structure on the protective performance of a biogenic carbonate surface treatment. Protective performance was assessed by means of transport and degradation processes, and the penetration depth of the treatment was visualized by microtomography. Pore size governs bacterial adsorption and hence the location and amount of carbonate precipitated. This study indicated that in macroporous stone, biogenic carbonate formation occurred to a larger extent and at greater depths than in microporous stone. As a consequence, the biodeposition treatment exhibited the greatest protective performance on macroporous stone. While precipitation was limited to the outer surface of microporous stone, biogenic carbonate formation occurred at depths of greater than 2 mm for Savonnières and Euville. For Savonnières, the presence of biogenic carbonate resulted in a 20-fold decreased rate of water absorption, which resulted in increased resistance to sodium sulfate attack and to freezing and thawing. While untreated samples were completely degraded after 15 cycles of salt attack, no damage was observed in biodeposition-treated Savonnières. From this study, it is clear that biodeposition is very effective and more feasible for macroporous stones than for microporous stones.

  2. Occurrence of gigantic biogenic magnetite during the Paleocene-Eocene Thermal Maximum

    NASA Astrophysics Data System (ADS)

    Schumann, D.; Raub, T. D.; Kopp, R. E.; Guerquin-Kern, J. L.; Wu, T. D.; Rouiller, I.; Smirnov, A. V.; Sears, S. K.; Lücken, U.; Tikoo, S. M.; Hesse, R.; Kirschvink, J. L.; Vali, H.

    2009-04-01

    crystals up to 4 μm long (eight times larger than magnetite produced by magnetotactic bacteria) and elongated hexaoctahedra up to 1.4 μm long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition and lattice perfection consistent with a biogenic origin. The oxygen isotopic composition of indiviual particles supports a low temperature aquatic origin. Electron holography indicates single-domain magnetization despite the large crystal size. In a few cases, we observed apparently intact, tip-outward spherical assemblages of spearhead-like particles that possibly represent the preserved original biological arrangement of these crystals in a hitherto unknown magnetite producing organism. The discovery of these exceptionally large biogenic magnetite crystals that possibly represent the remains of a new microorganism that appeared and disappeared with the PETM sheds some light upon the ecological response to biogeochemical changes that occurred during this warming event. The abundance of fossil magnetotactic bacteria on the Atlantic Coastal Plain during the PETM could be explained by enhanced production, enhanced preservation, or both. The presence of novel magnetofossils, however, argues that changes in growth conditions are a major part of the explanation. Considering that other bacterial magnetofossils are present (although less abundant) and well-preserved in sediments below and above the PETM clay, as well as in a sand lens within the PETM clay [Kopp et al., 2007], suggests that the new magnetofossils are unlikely to be a preservation artefact. We conclude, therefore, that the development of a thick suboxic zone with high iron bioavailability - a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming - resulted in diversification of magnetite-forming organisms, likely including eukaryotes. In this study we extended the search for these new magnetofossils [Schumann

  3. Clinical and radiographic evaluation of Bio-Gen with biocollagen compared with Bio-Gen with connective tissue in the treatment of class II furcation defects: a randomized clinical trial

    PubMed Central

    JENABIAN, Niloofar; HAGHANIFAR, Sina; MABOUDI, Avideh; BIJANI, Ali

    2013-01-01

    Objective Treatment of furcation defects are thought to be challenging. The purpose of this study was to evaluate the clinical and radiographic parameters of Bio-Gen with Biocollagen compared with Bio-Gen with connective tissue in the treatment of Class II furcation defects. Material and Methods In this clinical trial, 24 patients with Class II furcation defect on a buccal or lingual mandibular molar were recruited. After oral hygiene instruction, scaling and root planing and achievement of acceptable plaque control, the patients were randomly chosen to receive either connective tissue and Bio-Gen (case group) or Biocollagen and Bio-Gen (control group). The following parameters were recorded before the first and re-entry surgery (six months later): vertical clinical attachment level (VCAL), gingival index (GI), plaque index (PI), horizontal probing depth (HPD), vertical probing depth (VPD), gingival recession (GR), furcation vertical component (FVC), furcation to alveolar crest (FAC), fornix to base of defect (FBD), and furcation horizontal component (FHC) were calculated at the time of first surgery and during re-entry. A digital periapical radiograph was taken in parallel before first surgery and re-entry. The radiographs were then analyzed by digital subtraction. The differences with p value <0.05 were considered significant. Results Only the mean changes of FAC, FHC, mean of FHC, FBD in re-entry revealed statistically significant differences between the two groups. HPD, VPD, FBD, FAC, and FHC showed statistically significant differences after 6 months in the case group. However, in the control group, statistically significant differences were found in GR and HPD. We did not observe any significant difference in radiographic changes among the two groups. Conclusion The results of this trial indicate that better clinical outcomes can be obtained with connective tissue grafts in combination with bone material compared with a resorbable barrier with bone material

  4. BIOGENIC CONTRIBUTION TO PM-2.5 AMBIENT AEROSOL FROM RADIOCARBON MEASUREMENTS

    EPA Science Inventory

    Knowledge of the relative contributions of biogenic versus anthropogenic sources to ambient aerosol is of great interest in the formulation of strategies to achieve nationally mandated air quality standards. Radiocarbon (Carbon-14) measurements provide a means to quantify the ...

  5. Biogenic influence on cloud microphysics in the 'clean' oceanic atmosphere

    NASA Astrophysics Data System (ADS)

    Lana, A.; Simó, R.; Vallina, S. M.; Jurado, E.; Dachs, J.

    2009-12-01

    A 20 years old hypothesis postulates a feedback relationship between marine biota and climate through the emission of dimethylsulfide (DMS) as the principal natural source of Sulfate Secondary Aerosols (S-DMS) that are very efficient as cloud condensation nuclei (CCN). In recent years, the biological influence on cloud microphysics have been expanded to other potential biogenic cloud precursors: (i) volatile organic compounds produced by plankton and emitted to the atmosphere to form Secondary Organic Aerosols (SOA); (ii) biological particles and biogenic polymers, lifted with the seaspray by wind friction and bubble-bursting processes, that act as Primary Organic Aerosols (POA). Besides these biogenic aerosols, also seaspray-associated Sea Salt (SS) emissions, which are the dominant contribution to aerosol mass in the remote mixed boundary layer, also contribute to cloud condensation. All these aerosols affect cloud microphysics by providing new CCN, reducing the size of cloud droplets, and increasing cloud albedo. We have compared the seasonalities of the parameterized source functions of these natural cloud precursors with that of the satellite-derived cloud droplet effective radius (CLEFRA) over large regions of the ocean. Regions where big loads of continental aerosols (including anthropogenic -industrial, urban, and biomass burning) dominate during a significant part of the year were identified by use of remote sensing aerosol optical properties and excluded from our analysis. Our results show that the seasonality of cloud droplet effective radius matches those of S-DMS and SOA in the clean marine atmosphere, whereas SS and chlorophyll-associated POA on their own do not seem to play a major role in driving cloud droplet size.

  6. Contributions and source identification of biogenic and anthropogenic hydrocarbons to secondary organic aerosols at Mt. Tai in 2014.

    PubMed

    Zhu, Yanhong; Yang, Lingxiao; Kawamura, Kimitaka; Chen, Jianmin; Ono, Kaori; Wang, Xinfeng; Xue, Likun; Wang, Wenxing

    2017-01-01

    Ambient fine particulate matter (PM 2.5 ) and volatile organic compounds (VOCs) collected at Mt. Tai in summer 2014 were analysed and the data were used to identify the contribution of biogenic and anthropogenic hydrocarbons to secondary organic aerosols (SOA) and their sources and potential source areas in high mountain regions. Compared with those in 2006, the 2014 anthropogenic SOA tracers in PM 2.5 aerosols and VOC species related to vehicular emissions exhibited higher concentrations, whereas the levels of biogenic SOA tracers were lower, possibly due to decreased biomass burning. Using the SOA tracer and parameterisation method, we estimated the contributions from biogenic and anthropogenic VOCs, respectively. The results showed that the average concentration of biogenic SOA was 1.08 ± 0.51 μg m -3 , among which isoprene SOA tracers were dominant. The anthropogenic VOC-derived SOA were 7.03 ± 1.21 μg m -3 and 1.92 ± 1.34 μg m -3 under low- and high-NO x conditions, respectively, and aromatics made the greatest contribution. However, the sum of biogenic and anthropogenic SOA only contributed 18.1-49.1% of the total SOA. Source apportionment by positive matrix factorisation (PMF) revealed that secondary oxidation and biomass burning were the major sources of biogenic SOA tracers. Anthropogenic aromatics mainly came from solvent use, fuel and plastics combustion and vehicular emissions. However, for > C6 alkanes and cycloalkanes, vehicular emissions and fuel and plastics combustion were the most important contributors. The potential source contribution function (PSCF) identified the Bohai Sea Region (BSR) as the major source area for organic aerosol compounds and VOC species at Mt. Tai. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. BIOGENIC SOURCES OF FORMALDEHYDE AND ACETALDEHYDE DURING SUMMER AND WINTER CONDITIONS

    EPA Science Inventory

    Photochemical modeling estimated contributions to ambient concentrations of formaldehyde and acetaldehyde from biogenic emissions over the continental United States during January 2001 (Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract A52B-0117). Results showed that maximum co...

  8. Estimating Biogenic Non-Methane Hydrocarbon Emissions for the Wasatch Front Through a High-Resolution. Gridded, Biogenic Vola Tile Organic Compound Emissions Inventory

    DTIC Science & Technology

    2002-01-01

    1-hour and proposed 8-hour National Ambient Air Quality Standards. Reactive biogenic (natural) volatile organic compounds emitted from plants have...uncertainty in predicting plant species composition and frequency. Isoprene emissions computed for the study area from the project’s high-resolution...Landcover Database (BELD 2), while monoterpene and other reactive volatile organic compound emission rates were almost 26% and 28% lower, respectively

  9. Impact of Biogenic Emission Uncertainties on the Simulated Response of Ozone and Fine Particulate Matter to Anthropogenic Emission Reductions

    PubMed Central

    Hogrefe, Christian; Isukapalli, Sastry S.; Tang, Xiaogang; Georgopoulos, Panos G.; He, Shan; Zalewsky, Eric E.; Hao, Winston; Ku, Jia-Yeong; Key, Tonalee; Sistla, Gopal

    2011-01-01

    The role of emissions of volatile organic compounds and nitric oxide from biogenic sources is becoming increasingly important in regulatory air quality modeling as levels of anthropogenic emissions continue to decrease and stricter health-based air quality standards are being adopted. However, considerable uncertainties still exist in the current estimation methodologies for biogenic emissions. The impact of these uncertainties on ozone and fine particulate matter (PM2.5) levels for the eastern United States was studied, focusing on biogenic emissions estimates from two commonly used biogenic emission models, the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the Biogenic Emissions Inventory System (BEIS). Photochemical grid modeling simulations were performed for two scenarios: one reflecting present day conditions and the other reflecting a hypothetical future year with reductions in emissions of anthropogenic oxides of nitrogen (NOx). For ozone, the use of MEGAN emissions resulted in a higher ozone response to hypothetical anthropogenic NOx emission reductions compared with BEIS. Applying the current U.S. Environmental Protection Agency guidance on regulatory air quality modeling in conjunction with typical maximum ozone concentrations, the differences in estimated future year ozone design values (DVF) stemming from differences in biogenic emissions estimates were on the order of 4 parts per billion (ppb), corresponding to approximately 5% of the daily maximum 8-hr ozone National Ambient Air Quality Standard (NAAQS) of 75 ppb. For PM2.5, the differences were 0.1–0.25 μg/m3 in the summer total organic mass component of DVFs, corresponding to approximately 1–2% of the value of the annual PM2.5 NAAQS of 15 μg/m3. Spatial variations in the ozone and PM2.5 differences also reveal that the impacts of different biogenic emission estimates on ozone and PM2.5 levels are dependent on ambient levels of anthropogenic emissions. PMID:21305893

  10. Impact of the natural Fe-fertilization on the magnitude, stoichiometry and efficiency of particulate biogenic silica, nitrogen and iron export fluxes

    NASA Astrophysics Data System (ADS)

    Lemaitre, N.; Planquette, H.; Dehairs, F.; van der Merwe, P.; Bowie, A. R.; Trull, T. W.; Laurenceau-Cornec, E. C.; Davies, D.; Bollinger, C.; Le Goff, M.; Grossteffan, E.; Planchon, F.

    2016-11-01

    The Kerguelen Plateau is characterized by a naturally Fe-fertilized phytoplankton bloom that extends more than 1000 km downstream in the Antarctic Circumpolar Current. During the KEOPS2 study, in austral spring, we measured particulate nitrogen (PN), biogenic silica (BSi) and particulate iron (PFe) export fluxes in order to investigate how the natural fertilization impacts the stoichiometry and the magnitude of export fluxes and therefore the efficiency of the biological carbon pump. At 9 stations, we estimated elemental export fluxes based on element concentration to 234Th activity ratios for particulate material collected with in-situ pumps and 234Th export fluxes (Planchon et al., 2015). This study revealed that the natural Fe-fertilization increased export fluxes but to variable degrees. Export fluxes for the bloom impacted area were compared with those of a high-nutrient, low-chlorophyll (HNLC), low-productive reference site located to the south-west of Kerguelen and which had the lowest BSi and PFe export fluxes (2.55 mmol BSi m-2 d-1 and 1.92 μmol PFem-2 d-1) and amongst the lowest PN export flux (0.73 mmol PN m-2 d-1). The impact of the Fe fertilization was the greatest within a meander of the polar front (PF), to the east of Kerguelen, with fluxes reaching 1.26 mmol PN m-2 d-1; 20.4 mmol BSi m-2 d-1 and 22.4 μmol PFe m-2 d-1. A highly productive site above the Kerguelen Plateau, on the contrary, was less impacted by the fertilization with export fluxes reaching 0.72 mmol PN m-2 d-1; 4.50 mmol BSi m-2 d-1 and 21.4 μmol PFe m-2 d-1. Our results suggest that ecosystem features (i.e. type of diatom community) could play an important role in setting the magnitude of export fluxes of these elements. Indeed, for the PF meander, the moderate productivity was sustained by the presence of large and strongly silicified diatom species while at the higher productivity sites, smaller and slightly silicified diatoms dominated. Interestingly, our results suggest that

  11. Iron Fertilization of the Southern Ocean: Regional Simulation and Analysis of C-Sequestration in the Ross Sea

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kevin Arrigo

    2012-03-13

    A modified version of the dynamic 3-dimensional mesoscale Coupled Ice, Atmosphere, and Ocean model (CIAO) of the Ross Sea ecosystem has been used to simulate the impact of environmental perturbations upon primary production and biogenic CO2 uptake. The Ross Sea supports two taxonomically, and spatially distinct phytoplankton populations; the haptophyte Phaeocystis antarctica and diatoms. Nutrient utilization ratios predict that P. antarctica and diatoms will be driven to nitrate and phosphate limitation, respectively. Model and field data have confirmed that the Ross Sea is iron limited with only two-thirds of the macronutrients consumed by the phytoplankton by the end of themore » growing season. In this study, the CIAO model was improved to simulate a third macronutrient (phosphate), dissolved organic carbon, air-sea gas exchange, and the carbonate system. This enabled us to effectively model pCO2 and subsequently oceanic CO2 uptake via gas exchange, allowing investigations into the affect of alleviating iron limitation on both pCO2 and nutrient drawdown.« less

  12. Evolution of free amino acids, biogenic amines and n-nitrosoamines throughout ageing in organic fermented beef.

    PubMed

    Wójciak, Karolina M; Solska, Elżbieta

    2016-01-01

    In recent years, interest in uncured meat products has grown and studies were carried out on the use of substances which could replace nitrites, such as acid whey. In spite of this problem in fermented meat products, there is no information regarding the effects of prolonged ageing on the formation of chemical (nitrosoamines, biogenic amines, secondary lipid oxidation products) and microbiological (L. monocytogenes, S. aureus, OLD) toxicants in fermented beef marinated with acid whey. The aim of this study was to determine the selected pathogenic bacteria, biogenic amines, N-nitrosamines contents in fermented beef subjected to extended ageing. In this study, selected pathogenic bacteria, N-nitrosamines, biogenic amines, amino acids, TBARS values changes during the ageing of fermented beef marinated with acid whey were analyzed in 0-, 2- and 36-month-old samples. The pH values of fermented beef aged for 2 months (5.68, 5.49 and 5.68 respectively) were significantly lower (p < 0.05) than those obtained after the end of the manufacturing ripening period (5.96, 5.97 and 5.74 respectively), which confirmed the effectiveness of the fermentation process of acidification on beef. The high Lactic Acid Bacteria content (5.64-6.30 log cfu/g) confirmed this finding. Histamine was not detected in either of the products. The highest concentration of total biogenic amine (i.e. 1159.0 mg/kg) was found in fermented beef marinated with acid whey, whereas a total of only 209.8 mg/kg, was observed in control beef with nitrate and nitrite. N-nitrosamines were not detected in any of the ageing beef samples. In this study, marinating beef in acid whey did not inhibit the production of biogenic amines in the samples analyzed. The high concentration of FAAs, the potential precursor of BA, could lead to intense peptidase activity. The results obtained indicate that biogenic amines are not direct precursors for nitrosamines formation in fermented beef. The LAB strain from acid whey reduced

  13. Synthesis and Surface-Specific Analysis of Molecular Constituents Relevant to Biogenic Secondary Organic Aerosol Material

    NASA Astrophysics Data System (ADS)

    Be, A. G.; Upshur, M. A.; Chase, H. M.; Geiger, F.; Thomson, R. J.

    2017-12-01

    Secondary organic aerosol (SOA) particles formed from the oxidation of biogenic volatile organic compounds (BVOCs) remain a principal, yet elusive, class of airborne particulate matter that impacts the Earth's radiation budget. Given the characteristic molecular complexity comprising biogenic SOA particles, chemical information selective to the gas-aerosol interface may be valuable in the investigation of such systems, as surface considerations likely dictate the phenomena driving particle evolution mechanisms and climate effects. In particular, cloud activation processes may be parameterized using the surface tension depression that coincides with partitioning of surface-active organic species to the gas-droplet interface. However, the extent to which surface chemical processes, such as cloud droplet condensation, are influenced by the chemical structure and reactivity of individual surface-active molecules in SOA particles is largely unknown. We seek to study terpene-derived organic species relevant to the surfaces of biogenic SOA particles via synthesis of putative oxidation products followed by analysis using surface-selective physicochemical measurements. Using dynamic surface tension measurements, considerable differences are observed in the surface tension depression of aqueous pendant droplets that contain synthetically prepared ozonolysis products derived from abundant terpene precursors. Furthermore, sum frequency generation spectroscopy is utilized for comparison of the surface vibrational spectral responses of synthesized reference compounds with those observed for laboratory aerosol toward probing the surface composition of SOA material. Such ongoing findings highlight the underlying importance of molecular structure and reactivity when considering the surface chemistry of biogenic terpene-derived atmospheric aerosols.

  14. Urban stress-induced biogenic VOC emissions impact secondary aerosol formation in Beijing

    NASA Astrophysics Data System (ADS)

    Ghirardo, A.; Xie, J.; Zheng, X.; Wang, Y.; Grote, R.; Block, K.; Wildt, J.; Mentel, T.; Kiendler-Scharr, A.; Hallquist, M.; Butterbach-Bahl, K.; Schnitzler, J.-P.

    2015-08-01

    Trees can significantly impact the urban air chemistry by the uptake and emission of reactive biogenic volatile organic compounds (BVOCs), which are involved in ozone and particle formation. Here we present the emission potentials of "constitutive" (cBVOCs) and "stress-induced" BVOCs (sBVOCs) from the dominant broadleaf woody plant species in the megacity of Beijing. Based on an inventory of BVOC emissions and the tree census, we assessed the potential impact of BVOCs on secondary particulate matter formation in 2005 and 2010, i.e., before and after realizing the large tree-planting program for the 2008 Olympic Games. We found that sBVOCs, such as fatty acid derivatives, benzenoids and sesquiterpenes, constituted a significant fraction (∼ 15 %) of the total annual BVOC emissions, and we estimated that the overall annual BVOC budget may have doubled from ∼ 3.6 × 109 g C year-1 in 2005 to ∼ 7.1 × 109 g C year-1 in 2010 due to the increase in urban greens, while at the same time, the emission of anthropogenic VOCs (AVOCs) could be lowered by 24 %. Based on our BVOC emission assessment, we estimated the biological impact on SOA mass formation in Beijing. Compared to AVOCs, the contribution of biogenic precursors (2-5 %) for secondary particulate matter in Beijing was low. However, sBVOCs can significantly contribute (∼ 40 %) to the formation of total secondary organic aerosol (SOA) from biogenic sources; apparently, their annual emission increased from 1.05 μg m-3 in 2005 to 2.05 μg m-3 in 2010. This study demonstrates that biogenic and, in particular, sBVOC emissions contribute to SOA formation in megacities. However, the main problems regarding air quality in Beijing still originate from anthropogenic activities. Nevertheless, the present survey suggests that in urban plantation programs, the selection of plant species with low cBVOC and sBVOC emission potentials have some possible beneficial effects on urban air quality.

  15. Carbonate Biogenic Structures in Storrs Lake, Bahamas

    NASA Technical Reports Server (NTRS)

    Byrne, Monica; Morris, Penny A.; Wentworth, Susan J.; Brigmon, Robin L.; McKay, David S.

    2001-01-01

    Storr's Lake, an inland hypersaline lake on San Salvador Island, Bahamas, contains calcium carbonate-rich lithified mats of filamentous microorganisms, diatoms, associated photosynthetic and chemotrophic bacteria, and trapped sediment. In addition, 16S rRNA analysis indicates the presence of five sulfur-reducing genera of bacteria. These microbes are potential modern-day analogs to some ancient stromatolitic structures. The goals of this study are to identify unique compositional and biogenic features, possibly correlating some of these with some of the sulfate-reducing bacteria. Additional information is contained in the original extended abstract.

  16. TETHERED BALLOON MEASUREMENTS OF BIOGENIC VOCS IN THE ATMOSPHERIC BOUNDARY LAYER

    EPA Science Inventory

    Measurements of biogenic volatile organic compounds (BVOCs) have been made on a tethered balloon platform in eleven field deployments between 1985 and 1996. A series of balloon sampling packages have been developed for these campaigns and they have been used to describe boundary ...

  17. UNITED STATES LAND USE INVENTORY FOR ESTIMATING BIOGENIC OZONE PRECURSOR EMISSIONS

    EPA Science Inventory

    The U.S. Geological Survey's (USGS) Earth Resources Observation System (EROS) Data Center's (EDC) 1-km classified land cover data are combined with other land use data using a Geographic Information System (GIS) to create the Biogenic Emissions Landcover Database (BELD). The land...

  18. What do correlations tell us about anthropogenic-biogenic interactions and SOA formation in the Sacramento Plume during CARES?

    NASA Astrophysics Data System (ADS)

    Kleinman, L.; Kuang, C.; Sedlacek, A.; Senum, G.; Springston, S.; Wang, J.; Zhang, Q.; Jayne, J.; Fast, J.; Hubbe, J.; Shilling, J.; Zaveri, R.

    2015-09-01

    During the Carbonaceous Aerosols and Radiative Effects Study (CARES) the DOE G-1 aircraft was used to sample aerosol and gas phase compounds in the Sacramento, CA plume and surrounding region. We present data from 66 plume transects obtained during 13 flights in which southwesterly winds transported the plume towards the foothills of the Sierra Nevada Mountains. Plume transport occurred partly over land with high isoprene emission rates. Our objective is to empirically determine whether organic aerosol (OA) can be attributed to anthropogenic or biogenic sources, and to determine whether there is a synergistic effect whereby OA concentrations are enhanced by the simultaneous presence of high concentrations of CO and either isoprene, MVK+MACR (sum of methyl vinyl ketone and methacrolein) or methanol, which are taken as tracers of anthropogenic and biogenic emissions, respectively. Linear and bilinear correlations between OA, CO, and each of three biogenic tracers, "Bio", for individual plume transects indicate that most of the variance in OA over short time and distance scales can be explained by CO. For each transect and species a plume perturbation, (i.e., ΔOA, defined as the difference between 90th and 10th percentiles) was defined and regressions done amongst Δ values in order to probe day to day and location dependent variability. Species that predicted the largest fraction of the variance in ΔOA were ΔO3 and ΔCO. Background OA was highly correlated with background methanol and poorly correlated with other tracers. Because background OA was ~ 60 % of peak OA in the urban plume, peak OA should be primarily biogenic and therefore non-fossil. Transects were split into subsets according to the percentile rankings of ΔCO and ΔBio, similar to an approach used by Setyan et al. (2012) and Shilling et al. (2013) to determine if anthropogenic-biogenic interactions enhance OA production. As found earlier, ΔOA in the data subset having high ΔCO and high ΔBio was

  19. Distribution of planktonic biogenic carbonate organisms in the Southern Ocean south of Australia: a baseline for ocean acidification impact assessment

    NASA Astrophysics Data System (ADS)

    Trull, Thomas W.; Passmore, Abraham; Davies, Diana M.; Smit, Tim; Berry, Kate; Tilbrook, Bronte

    2018-01-01

    The Southern Ocean provides a vital service by absorbing about one-sixth of humankind's annual emissions of CO2. This comes with a cost - an increase in ocean acidity that is expected to have negative impacts on ocean ecosystems. The reduced ability of phytoplankton and zooplankton to precipitate carbonate shells is a clearly identified risk. The impact depends on the significance of these organisms in Southern Ocean ecosystems, but there is very little information on their abundance or distribution. To quantify their presence, we used coulometric measurement of particulate inorganic carbonate (PIC) on particles filtered from surface seawater into two size fractions: 50-1000 µm to capture foraminifera (the most important biogenic carbonate-forming zooplankton) and 1-50 µm to capture coccolithophores (the most important biogenic carbonate-forming phytoplankton). Ancillary measurements of biogenic silica (BSi) and particulate organic carbon (POC) provided context, as estimates of the biomass of diatoms (the highest biomass phytoplankton in polar waters) and total microbial biomass, respectively. Results for nine transects from Australia to Antarctica in 2008-2015 showed low levels of PIC compared to Northern Hemisphere polar waters. Coccolithophores slightly exceeded the biomass of diatoms in subantarctic waters, but their abundance decreased more than 30-fold poleward, while diatom abundances increased, so that on a molar basis PIC was only 1 % of BSi in Antarctic waters. This limited importance of coccolithophores in the Southern Ocean is further emphasized in terms of their associated POC, representing less than 1 % of total POC in Antarctic waters and less than 10 % in subantarctic waters. NASA satellite ocean-colour-based PIC estimates were in reasonable agreement with the shipboard results in subantarctic waters but greatly overestimated PIC in Antarctic waters. Contrastingly, the NASA Ocean Biogeochemical Model (NOBM) shows coccolithophores as overly

  20. Transformation and crystallization energetics of synthetic and biogenic amorphous calcium carbonate

    PubMed Central

    Radha, A. V.; Forbes, Tori Z.; Killian, Christopher E.; Gilbert, P. U. P. A.; Navrotsky, Alexandra

    2010-01-01

    Amorphous calcium carbonate (ACC) is a metastable phase often observed during low temperature inorganic synthesis and biomineralization. ACC transforms with aging or heating into a less hydrated form, and with time crystallizes to calcite or aragonite. The energetics of transformation and crystallization of synthetic and biogenic (extracted from California purple sea urchin larval spicules, Strongylocentrotus purpuratus) ACC were studied using isothermal acid solution calorimetry and differential scanning calorimetry. Transformation and crystallization of ACC can follow an energetically downhill sequence: more metastable hydrated ACC → less metastable hydrated ACC⇒anhydrous ACC ∼ biogenic anhydrous ACC⇒vaterite → aragonite → calcite. In a given reaction sequence, not all these phases need to occur. The transformations involve a series of ordering, dehydration, and crystallization processes, each lowering the enthalpy (and free energy) of the system, with crystallization of the dehydrated amorphous material lowering the enthalpy the most. ACC is much more metastable with respect to calcite than the crystalline polymorphs vaterite or aragonite. The anhydrous ACC is less metastable than the hydrated, implying that the structural reorganization during dehydration is exothermic and irreversible. Dehydrated synthetic and anhydrous biogenic ACC are similar in enthalpy. The transformation sequence observed in biomineralization could be mainly energetically driven; the first phase deposited is hydrated ACC, which then converts to anhydrous ACC, and finally crystallizes to calcite. The initial formation of ACC may be a first step in the precipitation of calcite under a wide variety of conditions, including geological CO2 sequestration. PMID:20810918

  1. Iron

    MedlinePlus

    ... too little iron, you may develop iron deficiency anemia. Causes of low iron levels include blood loss, poor diet, or an inability to absorb enough iron from foods. People at higher risk of having too little iron are young children and women who are pregnant or have periods. ...

  2. Iron and alloys of iron. [lunar resources

    NASA Technical Reports Server (NTRS)

    Sastri, Sankar

    1992-01-01

    All lunar soil contains iron in the metallic form, mostly as an iron-nickel alloy in concentrations of a few tenths of 1 percent. Some of this free iron can be easily separated by magnetic means. It is estimated that the magnetic separation of 100,000 tons of lunar soil would yield 150-200 tons of iron. Agglutinates contain metallic iron which could be extracted by melting and made into powder metallurgy products. The characteristics and potential uses of the pure-iron and iron-alloy lunar products are discussed. Processes for working iron that might be used in a nonterrestrial facility are also addressed.

  3. Supercritical Fluid Extraction of Biogenic SOA in Northern Michigan

    NASA Astrophysics Data System (ADS)

    Flores, R. M.; Doskey, P. V.; Perlinger, J. A.

    2010-12-01

    Secondary organic aerosols (SOA) are formed by photooxidation of volatile organic compounds (VOCs) and nucleation and condensation of the oxygenated products. On a global scale, monoaromatic hydrocarbons of anthropogenic origin are estimated to be the source of 12% of the SOA while biogenic emissions of isoprene (C5H8), monoterpenes (C10H16), and sesquiterpenes (C15H24) are estimated to be the source of 46, 29 and 7% of SOA, respectively. The functional groups of organic substances comprising SOA (i.e., hydroxyl, carbonyl, carboxylic acid, sulfate, and nitrate) complicate sample processing, analysis, and identification of the characteristic aerosol products of VOC oxidation pathways. Only a very small fraction of the organic molecular species in SOA have been identified due to the complexity of precursor oxidation reactions and the need for (1) methodologies that are less labor intensive and suitable for thermally labile compounds and (2) analytic instrumentation that provides more complete resolution of complex mixtures for sensitive detection of molecular species. Extraction techniques commonly used include solvent extraction, which requires large amounts of solvent and is labor intensive and thermal desorption, which evolves organic substances from aerosol at temperatures not suitable for thermally labile compounds. A promising technique that does not involve sample processing with solvents or high temperatures is supercritical fluid extraction (SFE). In this work, the composition of biogenic SOA was studied in Northern Michigan. Aerosol samples were collected on quartz fiber filters with a high-volume air sampler and extracted with supercritical CO2. Carboxylic and hydroxyl compounds were derivatized during static extraction conditions and identified by comprehensive two dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOFMS). The overall goal of the research is to couple the post-collection analytic scheme developed here

  4. Influence of the modulated two-step synthesis of biogenic hydroxyapatite on biomimetic products' surface

    NASA Astrophysics Data System (ADS)

    Miculescu, Florin; Mocanu, Aura Cătălina; Stan, George E.; Miculescu, Marian; Maidaniuc, Andreea; Cîmpean, Anisoara; Mitran, Valentina; Voicu, Stefan Ioan; Machedon-Pisu, Teodor; Ciocan, Lucian Toma

    2018-04-01

    Processing calcium-rich natural resources, such as marble and mussel seashells, into biomimetic products could constitute an environmentally-friendly and economically sustainable alternative given their geographical widespread. Hitherto, their value for biomedicine was demonstrated only for seashells, with the technological exploitation approaches still facing challenges with respect to the identification of generic synthesis parameters capable to allow the reproducible and designed synthesis of calcium phosphate at an industrial-ready level. In this study was targeted the optimization of Rathje synthesis method for the fabrication of biogenic calcium phosphates, by conveniently adjusting the chemical composition of employed reagents. It was shown that post-synthesis heat-treatment of compacted powders is the key step for inducing structural transformations suitable to attain biomimetic products for reconstructive orthopedic applications. The sintered materials have been multi-parametricallyevaluated from morpho-compositional, structural, wettability, mechanical and cytocompatibility points of view and the results have been cross-examined and discussed. Convenient and efficient preparation routes to produce biogenic hydroxyapatite have been identified. The functional performances of the as-prepared biogenic ceramics endorse their use as a solid and inexpensive alternative source material for the fabrication of various bone regenerative products and implant coatings.

  5. The occurrence of N-nitrosamines, residual nitrite and biogenic amines in commercial dry fermented sausages and evaluation of their occasional relation.

    PubMed

    De Mey, Eveline; De Klerck, Katrijn; De Maere, Hannelore; Dewulf, Lore; Derdelinckx, Guy; Peeters, Marie-Christine; Fraeye, Ilse; Vander Heyden, Yvan; Paelinck, Hubert

    2014-02-01

    Regarding food borne intoxications, the accumulation of biogenic amines must be avoided in all kinds of food products. Moreover, biogenic amines can function as precursors for the formation of carcinogenic N-nitrosamines when nitrite is present. To estimate the food safety of the dry fermented sausages available on the Belgian market, a screening of the residual sodium nitrite and nitrate contents, biogenic amines and volatile N-nitrosamine concentrations was performed on 101 samples. The median concentrations of residual NaNO2 and NaNO3 were each individually lower than 20mg/kg. In general, the biogenic amine accumulation remained low at the end of shelf life. Only in one product the amounts of cadaverine and putrescine reached intoxicating levels. Concerning the occurrence of N-nitrosamines, only N-nitrosopiperidine and N-nitrosomorpholine were detected in a high number of samples (resp. 22% and 28%). No correlation between the presence of N-nitrosamines and the biogenic amines content was observed. Although the N-nitrosamines could not been linked to specific product categories, the occurrence of N-nitrosopiperidine could probably be attributed to the use of pepper. © 2013.

  6. Influence of Pore Structure on the Effectiveness of a Biogenic Carbonate Surface Treatment for Limestone Conservation ▿

    PubMed Central

    De Muynck, Willem; Leuridan, Stijn; Van Loo, Denis; Verbeken, Kim; Cnudde, Veerle; De Belie, Nele; Verstraete, Willy

    2011-01-01

    A ureolytic biodeposition treatment was applied to five types of limestone in order to investigate the effect of pore structure on the protective performance of a biogenic carbonate surface treatment. Protective performance was assessed by means of transport and degradation processes, and the penetration depth of the treatment was visualized by microtomography. Pore size governs bacterial adsorption and hence the location and amount of carbonate precipitated. This study indicated that in macroporous stone, biogenic carbonate formation occurred to a larger extent and at greater depths than in microporous stone. As a consequence, the biodeposition treatment exhibited the greatest protective performance on macroporous stone. While precipitation was limited to the outer surface of microporous stone, biogenic carbonate formation occurred at depths of greater than 2 mm for Savonnières and Euville. For Savonnières, the presence of biogenic carbonate resulted in a 20-fold decreased rate of water absorption, which resulted in increased resistance to sodium sulfate attack and to freezing and thawing. While untreated samples were completely degraded after 15 cycles of salt attack, no damage was observed in biodeposition-treated Savonnières. From this study, it is clear that biodeposition is very effective and more feasible for macroporous stones than for microporous stones. PMID:21821746

  7. Biogenic amines in Zamorano cheese: factors involved in their accumulation.

    PubMed

    Combarros-Fuertes, Patricia; Fernández, Domingo; Arenas, Ricardo; Diezhandino, Isabel; Tornadijo, Maria Eugenia; Fresno, José María

    2016-01-15

    Ripened cheese is among fermented food the most often associated with food poisoning from biogenic amines. The influence of ripening time, heat treatment of milk and the effect of using milk from a different ewe breed on the biogenic amine (BA) content of Zamorano cheese was studied by high-performance liquid chromatography. Physicochemical, proteolytic and microbiological parameters were also studied. BA content increased significantly during ripening and their final values were around 400 mg kg(-1). Cheeses elaborated with raw milk duplicated the concentration of BA relative to those elaborated with pasteurized milk (72 °C for 20 s). The average levels of putrescine, spermine and tyramine were higher in cheeses made with a greater proportion of milk from Churra breed. Significant differences in microbial counts and nitrogen soluble in 5% phosphotungstic acid were observed between the different batches. Ripening time and heat treatment applied to milk were the factors that exercised the greatest influence upon the concentration of BA in Zamorano cheese. © 2015 Society of Chemical Industry.

  8. Analysis of biogenic amines using corona discharge ion mobility spectrometry.

    PubMed

    Hashemian, Z; Mardihallaj, A; Khayamian, T

    2010-05-15

    A new method based on corona discharge ion mobility spectrometry (CD-IMS) was developed for the analysis of biogenic amines including spermidine, spermine, putrescine, and cadaverine. The ion mobility spectra of the compounds were obtained with and without n-Nonylamine used as the reagent gas. The high proton affinity of n-Nonylamine prevented ion formation from compounds with a proton affinity lower than that of n-Nonylamine and, therefore, enhanced its selectivity. It was also realized that the ion mobility spectrum of n-Nonylamine varied with its concentration. A sample injection port of a gas chromatograph was modified and used as the sample introduction system into the CD-IMS. The detection limits, dynamic ranges, and analytical parameters of the compounds with and without using the reagent gas were obtained. The detection limits and dynamic ranges of the compounds were about 2ng and 2 orders of magnitude, respectively. The wide dynamic range of CD-IMS originates from the high current of the corona discharge. The results revealed the high capability of the CD-IMS for the analysis of biogenic amines.

  9. Assignment of polarization-dependent peaks in carbon K-edge spectra from biogenic and geologic aragonite.

    PubMed

    Zhou, Dong; Metzler, Rebecca A; Tyliszczak, Tolek; Guo, Jinghua; Abrecht, Mike; Coppersmith, Susan N; Gilbert, P U P A

    2008-10-16

    Many biominerals, including mollusk and echinoderm shells, avian eggshells, modern and fossil bacterial sediments, planktonic coccolithophores, and foraminifera, contain carbonates in the form of biogenic aragonite or calcite. Here we analyze biogenic and geologic aragonite using different kinds of surface- and bulk-sensitive X-ray absorption near-edge structure (XANES) spectroscopy at the carbon K-edge, as well as high-resolution scanning transmission X-ray microscopy (STXM). Besides the well-known main pi* and sigma* carbonate peaks, we observed and fully characterized four minor peaks, at energies between the main pi* and sigma* peaks. As expected, the main peaks are similar in geologic and biogenic aragonite, while the minor peaks differ in relative intensity. In this and previous work, the minor peaks appear to be the ones most affected in biomineralization processes, hence the interest in characterizing them. Peak assignment was achieved by correlation of polarization-dependent behavior of the minor peaks with that of the main pi* and sigma* peaks. The present characterization provides the background for future studies of aragonitic biominerals.

  10. Iron excretion in iron dextran-overloaded mice

    PubMed Central

    Musumeci, Marco; Maccari, Sonia; Massimi, Alessia; Stati, Tonino; Sestili, Paola; Corritore, Elisa; Pastorelli, Augusto; Stacchini, Paolo; Marano, Giuseppe; Catalano, Liviana

    2014-01-01

    Background Iron homeostasis in humans is tightly regulated by mechanisms aimed to conserve iron for reutilisation, with a negligible role played by excretory mechanisms. In a previous study we found that mice have an astonishing ability to tolerate very high doses of parenterally administered iron dextran. Whether this ability is linked to the existence of an excretory pathway remains to be ascertained. Materials and methods Iron overload was generated by intraperitoneal injections of iron dextran (1 g/kg) administered once a week for 8 weeks in two different mouse strains (C57bl/6 and B6D2F1). Urinary and faecal iron excretion was assessed by inductively coupling plasma-mass spectrometry, whereas cardiac and liver architecture was evaluated by echocardiography and histological methods. For both strains, 24-hour faeces and urine samples were collected and iron concentration was determined on days 0, 1 and 2 after iron administration. Results In iron-overloaded C57bl/6 mice, the faecal iron concentration increased by 218% and 157% on days 1 and 2, respectively (p<0.01). The iron excreted represented a loss of 14% of total iron administered. Similar but smaller changes was also found in B6D2F1 mice. Conversely, we found no significant changes in the concentration of iron in the urine in either of the strains of mice. In both strains, histological examination showed accumulation of iron in the liver and heart which tended to decrease over time. Conclusions This study indicates that mice have a mechanism for removal of excess body iron and provides insights into the possible mechanisms of excretion. PMID:24960657

  11. Analytical electron microscopy of biogenic and inorganic carbonates

    NASA Technical Reports Server (NTRS)

    Blake, David F.

    1989-01-01

    In the terrestrial sedimentary environment, the mineralogically predominant carbonates are calcite-type minerals (rhombohedral carbonates) and aragonite-type minerals (orthorhombic carbonates). Most common minerals precipitating either inorganically or biogenically are high magnesium calcite and aragonite. High magnesium calcite (with magnesium carbonate substituting for more than 7 mole percent of the calcium carbonate) is stable only at temperatures greater than 700 C or thereabouts, and aragonite is stable only at pressures exceeding several kilobars of confining pressure. Therefore, these carbonates are expected to undergo chemical stabilization in the diagenetic environment to ultimately form stable calcite and dolomite. Because of the strong organic control of carbonate deposition in organisms during biomineralization, the microchemistry and microstructure of invertebrate skeletal material is much different than that present in inorganic carbonate cements. The style of preservation of microstructural features in skeletal material is therefore often quite distinctive when compared to that of inorganic carbonate even though wholesale recrystallization of the sediment has taken place. Microstructural and microchemical comparisons are made between high magnesium calcite echinoderm skeletal material and modern inorganic high magnesium calcite inorganic cements, using analytical electron microscopy and related techniques. Similar comparisons are made between analogous materials which have undergone stabilization in the diagenetic environment. Similar analysis schemes may prove useful in distinguishing between biogenic and inorganic carbonates in returned Martian carbonate samples.

  12. Non-transferrin bound iron: a key role in iron overload and iron toxicity.

    PubMed

    Brissot, Pierre; Ropert, Martine; Le Lan, Caroline; Loréal, Olivier

    2012-03-01

    Besides transferrin iron, which represents the normal form of circulating iron, non-transferrin bound iron (NTBI) has been identified in the plasma of patients with various pathological conditions in which transferrin saturation is significantly elevated. To show that: i) NTBI is present not only during chronic iron overload disorders (hemochromatosis, transfusional iron overload) but also in miscellaneous diseases which are not primarily iron overloaded conditions; ii) this iron species represents a potentially toxic iron form due to its high propensity to induce reactive oxygen species and is responsible for cellular damage not only at the plasma membrane level but also towards different intracellular organelles; iii) the NTBI concept may be expanded to include intracytosolic iron forms which are not linked to ferritin, the major storage protein which exerts, at the cellular level, the same type of protective effect towards the intracellular environment as transferrin in the plasma. Plasma NTBI and especially labile plasma iron determinations represent a new important biological tool since elimination of this toxic iron species is a major therapeutic goal. The NTBI approach represents an important mechanistic concept for explaining cellular iron excess and toxicity and provides new important biochemical diagnostic tools. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. A potential link among biogenic amines-based pesticides, learning and memory, and colony collapse disorder: a unique hypothesis.

    PubMed

    Farooqui, Tahira

    2013-01-01

    Pesticides are substances that have been widely used throughout the world to kill, repel, or control organisms such as certain forms of plants or animals considered as pests. Depending on their type, dose, and persistence in the environment, they can have impact even on non-target species such as beneficial insects (honeybees) in different ways, including reduction in their survival rate and interference with their reproduction process. Honeybee Apis mellifera is a major pollinator and has substantial economical and ecological values. Colony collapse disorder (CCD) is a mysterious phenomenon in which adult honeybee workers suddenly abandon from their hives, leaving behind food, brood, and queen. It is lately drawing a lot of attention due to pollination crisis as well as global agriculture and medical demands. If the problem of CCD is not resolved soon enough, this could have a major impact on food industry affecting world's economy a big time. Causes of CCD are not known. In this overview, I discuss CCD, biogenic amines-based-pesticides (neonicotinoids and formamidines), and their disruptive effects on biogenic amine signaling causing olfactory dysfunction in honeybees. According to my hypothesis, chronic exposure of biogenic amines-based-pesticides to honeybee foragers in hives and agricultural fields can disrupt neural cholinergic and octopaminergic signaling. Abnormality in biogenic amines-mediated neuronal signaling impairs their olfactory learning and memory, therefore foragers do not return to their hive - a possible cause of CCD. This overview is an attempt to discuss a hypothetical link among biogenic amines-based pesticides, olfactory learning and memory, and CCD. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. On biogenicity criteria for endolithic microborings on early Earth and beyond.

    PubMed

    McLoughlin, Nicola; Brasier, Martin D; Wacey, David; Green, Owen R; Perry, Randall S

    2007-02-01

    Micron-sized cavities created by the actions of rock-etching microorganisms known as euendoliths are explored as a biosignature for life on early Earth and perhaps Mars. Rock-dwelling organisms can tolerate extreme environmental stresses and are excellent candidates for the colonization of early Earth and planetary surfaces. Here, we give a brief overview of the fossil record of euendoliths in both sedimentary and volcanic rocks. We then review the current understanding of the controls upon the distribution of euendolithic microborings and use these to propose three lines of approach for testing their biogenicity: first, a geological setting that demonstrates a syngenetic origin for the euendolithic microborings; second, microboring morphologies and distributions that are suggestive of biogenic behavior and distinct from ambient inclusion trails; and third, elemental and isotopic evidence suggestive of biological processing. We use these criteria and the fossil record of terrestrial euendoliths to outline potential environments and techniques to search for endolithic microborings on Mars.

  15. Arsenite and Ferrous Iron Oxidation Linked to Chemolithotrophic Denitrification for the Immobilization of Arsenic in Anoxic Environments

    PubMed Central

    Sun, Wenjie; Sierra-Alvarez, Reyes; Milner, Lily; Oremland, Ron; Field, Jim A.

    2014-01-01

    The objective of this study was to explore a bioremediation strategy based on injecting NO3− to support the anoxic oxidation of ferrous iron (Fe(II)) and arsenite (As(III)) in the subsurface as a means to immobilize As in the form of arsenate (As(V)) adsorbed onto biogenic ferric (Fe(III)) (hydr)oxides. Continuous flow sand filled columns were used to simulate a natural anaerobic groundwater and sediment system with co-occurring As(III) and Fe(II) in the presence (SF1) or absence (SF2) of nitrate, respectively. During operation for 250 days, the average influent arsenic concentration of 567 µg l−1 was reduced to 10.6 (±9.6) µg l−1 in the effluent of column SF1. The cumulative removal of Fe(II) and As(III) in SF1 was 6.5–10-fold higher than that in SF2. Extraction and measurement of the mass of iron and arsenic immobilized on the sand packing of the columns was close to the iron and arsenic removed from the aqueous phase during column operation. The dominant speciation of the immobilized iron and arsenic was Fe(III) and As(V) in SF1, compared with Fe(II) and As(III) in SF2. The speciation was confirmed by XRD and XPS. The results indicate that microbial oxidation of As(III) and Fe(II) linked to denitrification resulted in the enhanced immobilization of aqueous arsenic in anaerobic environments by forming Fe(III) (hydr)oxides coated sands with adsorbed As(V). PMID:19764221

  16. [Atmospheric depositions of biogenic elements and their ecological effects on marine ecosystem of Jiaozhou Bay: A review].

    PubMed

    Xing, Jian Wei; Song, Jin Ming; Yuan, Hua Mao; Li, Xue Gang; Li, Ning; Duan, Li Qin; Qu, Bao Xiao; Kang, Xu Ming

    2017-01-01

    As a typical semi-closed bay, Jiaozhou Bay, is remarkably affected by human activities. Biogenic elements transported into the oceans by the atmospheric deposition of anthropogenic particles can lead to profound impacts on the ecosystem of Jiaozhou Bay. In this paper, the researches of atmospheric dry and wet depositions in the Jiaozhou Bay were systematically summarized from the following three aspects: study methods, variation characteristics of the fluxes and their influencing factors and the ecological effects of atmospheric deposition. The concentrations and fluxes of nitrogen species in atmospheric dry and wet depositions were very high in the Jiaozhou Bay compared with other bays, estuaries and marginal seas around the world. The dissolved inorganic nitrogen (DIN) was the main component of the total dissolved nitrogen (TDN) and the dissolved organic nitrogen (DON) accounted for 22%-31% of TDN. However, the concentrations and fluxes of phosphate and silicate species were very low. The atmospheric deposition fluxes of (NO 3 - -N+NO 2 - -N) were slightly higher than terrestrial inputs, while the fluxes of NH 4 + -N, PO 4 3- -P and SiO 3 2- -Si were very low compared with terrestrial inputs. The concentration of total suspended particulates (TSP) in the air, the intensity of the emission sources, precipitation amount and meteorological conditions are the major factors influencing the atmospheric depositions of biogenic elements, which can increase the primary productivity, change the structure of nutrients and the structure of phytoplankton communities in surface seawater and further promote the succession of phytoplankton dominant species from diatom to dinoflagellate in the Jiaozhou Bay. On that basis, the future research should be focused on constructing the monitoring network for atmospheric dry and wet depositions, accurately quantifying the deposition rates of aerosol particles of different forms and sizes, recognizing the ecological effects and

  17. EPA Response to Petition from Biogenic CO2 Coalition (December 21, 2016)

    EPA Pesticide Factsheets

    This page is a response to the Biogenic CO2 Coalition’s petition for reconsideration of the final finding that greenhouse gas emissions from aircraft cause or contribute to air pollution that may reasonably be anticipated to endanger public health.

  18. Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

    EPA Science Inventory

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 d...

  19. Measurements of Primary Biogenic Aerosol Particles with an Ultraviolet Aerodynamic Particle Sizer (UVAPS) During AMAZE-08

    NASA Astrophysics Data System (ADS)

    Wollny, A. G.; Garland, R.; Pöschl, U.

    2008-12-01

    Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the AMazonian Aerosol CharacteriZation Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. The presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 μm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as 'viable aerosols' or 'fluorescent bioparticles' (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. First data analyses show a pronounced peak of FBAP at diameters around 2-3 μm. In this size range the biogenic particle fraction was

  20. Autocorrelation analysis of the infrared spectra of synthetic and biogenic carbonates along the calcite-dolomite join

    NASA Astrophysics Data System (ADS)

    Jenkins, David M.; Holmes, Zachary F.; Ishida, Kiyotaka; Manuel, Phillip D.

    2018-01-01

    Autocorrelation analysis of infrared spectra can provide insights on the strain energy associated with cation substitutions along a solid-solution compositional join which to date has been applied primarily to silicate minerals. In this study, the method is applied to carbonates synthesized at 10 mol% increments along the calcite-dolomite (CaCO3-CaMg(CO3)2) join in the range of 1000-1150 °C and 0.6-2.5 GPa for the purpose of determining how the band broadening in both the far- and mid-infrared ranges, as represented by the autocorrelation parameter δΔCorr, compares with the existing enthalpy of mixing data for this join. It was found that the carbonate internal vibration ν2 (out-of-plane bending) in the mid-infrared range, and the sum of the three internal vibration modes ν4 + ν2 + ν3 most closely matched the enthalpy of mixing data for the synthetic carbonates. Autocorrelation analysis of a series of biogenic carbonates in the mid-infrared range showed only a systematic variation for the ν2 band. Using the biogenic carbonate with the lowest Mg content for reference, the trend in δΔCorr for biogenic carbonates shows a steady increase with increasing Mg content suggesting a steady increase in solubility with Mg content. The results from this study indicate that autocorrelation analysis of carbonates in the mid-infrared range provides an independent and reliable assessment of the crystallographic strain energy of carbonates. In particular, inorganic carbonates in the range of 0-17 mol% MgCO3 experience a minimum in strain energy and a corresponding minimum in the enthalpy of mixing, whereas biogenic carbonates show a steady increase in strain energy with increasing MgCO3 content. In the event of increasing ocean acidification, biogenic carbonates in the range of 0-17 mol% MgCO3 will dissolve more readily than the compositionally equivalent inorganic carbonates.

  1. Autocorrelation analysis of the infrared spectra of synthetic and biogenic carbonates along the calcite-dolomite join

    NASA Astrophysics Data System (ADS)

    Jenkins, David M.; Holmes, Zachary F.; Ishida, Kiyotaka; Manuel, Phillip D.

    2018-06-01

    Autocorrelation analysis of infrared spectra can provide insights on the strain energy associated with cation substitutions along a solid-solution compositional join which to date has been applied primarily to silicate minerals. In this study, the method is applied to carbonates synthesized at 10 mol% increments along the calcite-dolomite (CaCO3-CaMg(CO3)2) join in the range of 1000-1150 °C and 0.6-2.5 GPa for the purpose of determining how the band broadening in both the far- and mid-infrared ranges, as represented by the autocorrelation parameter δΔCorr, compares with the existing enthalpy of mixing data for this join. It was found that the carbonate internal vibration ν2 (out-of-plane bending) in the mid-infrared range, and the sum of the three internal vibration modes ν4 + ν2 + ν3 most closely matched the enthalpy of mixing data for the synthetic carbonates. Autocorrelation analysis of a series of biogenic carbonates in the mid-infrared range showed only a systematic variation for the ν2 band. Using the biogenic carbonate with the lowest Mg content for reference, the trend in δΔCorr for biogenic carbonates shows a steady increase with increasing Mg content suggesting a steady increase in solubility with Mg content. The results from this study indicate that autocorrelation analysis of carbonates in the mid-infrared range provides an independent and reliable assessment of the crystallographic strain energy of carbonates. In particular, inorganic carbonates in the range of 0-17 mol% MgCO3 experience a minimum in strain energy and a corresponding minimum in the enthalpy of mixing, whereas biogenic carbonates show a steady increase in strain energy with increasing MgCO3 content. In the event of increasing ocean acidification, biogenic carbonates in the range of 0-17 mol% MgCO3 will dissolve more readily than the compositionally equivalent inorganic carbonates.

  2. Diurnally resolved particulate and VOC measurements at a rural site: indication of significant biogenic secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Sjostedt, S. J.; Slowik, J. G.; Brook, J. R.; Chang, R. Y.-W.; Mihele, C.; Stroud, C. A.; Vlasenko, A.; Abbatt, J. P. D.

    2010-11-01

    We report simultaneous measurements of volatile organic compound (VOC) mixing ratios including C6 to C8 aromatics, isoprene, monoterpenes, acetone and organic aerosol mass loadings at a rural location in Southwestern Ontario, Canada by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) and Aerosol Mass Spectrometry (AMS), respectively. During the three-week-long Border Air Quality and Meteorology Study in June-July 2007, air was sampled from a range of sources, including aged air from the polluted US Midwest, direct outflow from Detroit 50 km away, and clean air with higher biogenic input. After normalization to the diurnal profile of CO, a long-lived tracer, diurnal analyses show clear photochemical loss of reactive aromatics and production of oxygenated VOCs and secondary organic aerosol (SOA) during the daytime. Biogenic VOC mixing ratios increase during the daytime in accord with their light- and temperature-dependent sources. Long-lived species, such as hydrocarbon-like organic aerosol and benzene show little to no photochemical reactivity on this timescale. From the normalized diurnal profiles of VOCs, an estimate of OH concentrations during the daytime, measured O3 concentrations, and laboratory SOA yields, we calculate integrated organic aerosol production amounts associated with each measured SOA precursor. Depending on whether the SOA formation is occurring in a low- or high-NOx regime, we estimate that the biogenic gases contribute between 10 to 36 times as much SOA as do the aromatic precursors, making this a highly biogenically dominated region for SOA formation. The conclusion that biogenic SOA formation is of significance to air quality in this region is supported by detailed air quality modeling during this period (Stroud et al., 2010).

  3. A Hierarchical System for Evaluating the Biogenicity of Metavolcanic- and Ultramafic-Hosted Microalteration Textures in the Search for Extraterrestrial Life.

    PubMed

    McLoughlin, Nicola; Grosch, Eugene G

    2015-10-01

    The low-temperature alteration of submarine volcanic glasses has been argued to involve the activity of microorganisms, and analogous fluid-rock-microbial-mediated alteration has also been postulated on Mars. However, establishing the extent to which microbes are involved in volcanic glass alteration has proven to be difficult, and the reliability of resulting textural biosignatures is debated, particularly in the early rock record. We therefore propose a hierarchical scheme to evaluate the biogenicity of candidate textural biosignatures found in altered terrestrial and extraterrestrial basaltic glasses and serpentinized ultramafic rocks. The hierarchical scheme is formulated to give increasing confidence of a biogenic origin and involves (i) investigation of the textural context and syngenicity of the candidate biosignature; (ii) characterization of the morphology and size range of the microtextures; (iii) mapping of the geological and physicochemical variables controlling the occurrence and preservation of the microtextures; (iv) in situ investigation of chemical signatures that are syngenetic to the microtexture; and (v) identification of growth patterns suggestive of biological behavior and redox variations in the host minerals. The scheme results in five categories of candidate biosignature as follows: Category 1 indicates preservation of very weak evidence for biogenicity, Categories 2 through 4 indicate evidence for increasing confidence of a biogenic origin, and Category 5 indicates that biogenic origin is most likely. We apply this hierarchical approach to examine the evidence for a biogenic origin of several examples, including candidate bacterial encrustations in altered pillow lavas, granular and tubular microtextures in volcanic glass from the subseafloor and a Phanerozoic ophiolite, mineralized microtextures in Archean metavolcanic glass, and alteration textures in olivines of the martian meteorite Yamato 000593. The aim of this hierarchical approach

  4. Detection of biogenic CO production above vascular cell cultures using a near-room-temperature QC-DFB laser

    NASA Technical Reports Server (NTRS)

    Kosterev, A. A.; Tittel, F. K.; Durante, W.; Allen, M.; Kohler, R.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Cho, A. Y.

    2002-01-01

    We report the first application of pulsed, near-room-temperature quantum cascade laser technology to the continuous detection of biogenic CO production rates above viable cultures of vascular smooth muscle cells. A computer-controlled sequence of measurements over a 9-h period was obtained, resulting in a minimum detectable CO production of 20 ppb in a 1-m optical path above a standard cell-culture flask. Data-processing procedures for real-time monitoring of both biogenic and ambient atmospheric CO concentrations are described.

  5. Nature and origin of the resistant carbonaceous polymorphs involved the fossilization of biogenic soil-aggregates

    NASA Astrophysics Data System (ADS)

    Courty, M.-A.

    2012-04-01

    The rare occurrence of organic-rich surface horizons in soil archives is widely accepted to resulting from their rapid degradation. We intend here to further elucidate how pedogenic signatures that initially formed at the soil surface could resist over long timescales to burial processes. We focus on the structural evolution of the biogenic soil aggregates that is controlled by the complex interaction of bioturbation, root colonization, microbial decomposition, chemical weathering and physical processes. The nature and origin of carbonaceous components that could possibly contribute to the long term preservation of biogenic soil-aggregates is particularly examined. The study is based on the comparison of pedogenic aggregated microfacies from present-day situations and the ones encountered in soil archives from contrasting edaphic conditions: Arctic Holocene soils from Spitsbergen, hyper-arid soils from the Moche valley (Peru), Holocene semi-arid Mediterranean soils from Northern Syria, late Pleistocene paleosols from lake Mungo (South Wales Australia) and late Pleistocene paleosols from the Ardeche valley (France). The assemblage and composition of biogenic soil-aggregated horizons has been characterized under the binocular microscope and in thin sections. The basic components have been separated by water sieving. A typology of carbonaceous polymorphs and associated composite materials has been established under the binocular. They have been characterized by SEM-EDS, Raman spectrometry, X-ray diffraction and TEM. The comparative study shows that all the biogenic soil-aggregates from the soil archives contain a high amount of similar exotic components that contrast from the parent materials by their fresh aspect and their hydrophobic properties. This exotic assemblage comprises various types of aliphatic carbonaceous polymorphs (filaments, agglutinates, spherules) and aromatic ones (vitrous char, graphite), carbon cenospheres, fine grained sandstones and rock clasts

  6. Nanophase iron phosphate, iron arsenate, iron vanadate, and iron molybdate minerals synthesized within the protein cage of ferritin.

    PubMed

    Polanams, Jup; Ray, Alisha D; Watt, Richard K

    2005-05-02

    Nanoparticles of iron phosphate, iron arsenate, iron molybdate, and iron vanadate were synthesized within the 8 nm interior of ferritin. The synthesis involved reacting Fe(II) with ferritin in a buffered solution at pH 7.4 in the presence of phosphate, arsenate, vanadate, or molybdate. O2 was used as the oxidant to deposit the Fe(III) mineral inside ferritin. The rate of iron incorporation into ferritin was stimulated when oxo-anions were present. The simultaneous deposition of both iron and the oxo-anion was confirmed by elemental analysis and energy-dispersive X-ray analysis. The ferritin samples containing iron and one of the oxo-anions possessed different UV/vis spectra depending on the anion used during mineral formation. TEM analysis showed mineral cores with approximately 8 nm mineral particles consistent with the formation of mineral phases inside ferritin.

  7. Intravenous iron-dextran: studies on unsaturated iron-binding capacity

    PubMed Central

    Cox, J. S. G.; Moss, G. F.; Bremner, I.; Reason, Janet

    1968-01-01

    A method is described for measuring the plasma unsaturated iron-binding capacity in the presence of very high concentrations of iron as iron-dextran. The procedure utilizes 59Fe to label the apotransferrin with subsequent separation of ionic iron from transferrin-bound iron on an ion exchange or Sephadex G.25 column. The unsaturated iron-binding capacity has been measured in rabbits and dogs after intravenous injection of iron-dextran and in human subjects after total dose infusion of iron-dextran. No evidence of saturation of the unsaturated iron-binding capacity was found even when the plasma iron values were greater than 40,000 μg Fe/100 ml. PMID:5697365

  8. Content of biogenic amines in Lemna minor (common duckweed) growing in medium contaminated with tetracycline.

    PubMed

    Baciak, Michał; Sikorski, Łukasz; Piotrowicz-Cieślak, Agnieszka I; Adomas, Barbara

    2016-11-01

    Aquatic plants are continuously exposed to a variety of stress factors. No data on the impact of antibiotics on the biogenic amines in duckweed (Lemna minor) have been available so far, and such data could be significant, considering the ecological role of this plant in animal food chains. In the tissues of control (non-stressed) nine-day-old duckweed, the following biogenic amines were identified: tyramine, putrescine, cadaverine, spermidine and spermine. Based on the tetracycline contents and the computed EC values, the predicted toxicity units have been calculated. The obtained results demonstrated phytoxicity caused by tetracycline in relation to duckweed growth rate, yield and the contents of chlorophylls a and b. The carotenoid content was not modified by tetracycline. It was found that tetracycline as a water pollutant was a stress factor triggering an increase in the synthesis of amines. Tetracycline at 19, 39 and 78μM concentrations increased biogenic amine synthesis by 3.5 times. Although the content of tyramine increased fourteen times with the highest concentration of the drug (and of spermidine - only three-fold) the increase of spermidine was numerically the highest. Among the biogenic amines the most responsive to tetracycline were spermine and tyramine, while the least affected were putrescine and spermidine. Despite putrescine and spermidine being the least sensitive, their sum of contents increased five-fold compared to the control. These studies suggest that tetracycline in water reservoirs is taken up by L. minor as the antibiotic clearly modifies the metabolism of this plant and it may likely pose a risk. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Analysis of Biogenic VOCs Emissions During the MAPS-Seoul Aircraft Field Campaign

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Woo, J. H.; Kim, Y.; Bu, C.; Kim, J.; Kim, H. K.; Lee, M. H.; Eo, Y.

    2016-12-01

    The MAPS-Seoul (Megacity Air Pollution Studies-Seoul) aircraft mission was conducted in May - June 2016 to understand atmospheric environment over the South Korea. BVOCs emissions forecasting, along with other components, were conducted daily in support of the aircraft mission planning. The biogenic emissions as well as anthropogenic ones were very important factor to model and analyze atmospheric environment since more than 80% of global VOCs emission comes from biogenic sources. This also could be true for South Korea, since more than 70% of its land area are vegetated such as forest, cropland. For modeling-based BVOC emission estimation, geographical distribution of PFT (plant functional type) and LAI (Leaf Area Index) are considered as very important driving variables. Most of cases, PFTs and LAI were derived from the low-resolution satellite-based information which are not quite ideal for relatively small area like South Korea. In this study, we developed the more reliable Korean PFT and LAI cover derived from Korean landcover maps and modeled satellite images. The WRF-MEGAN modeling framework over South Korea for the period of May to June 2016 was used to estimate re-analysis BVOCs emission field. Analysis of different PFT and LAI inputs affected local and national biogenic emission estimations will be presented at site. Acknowledgements : This subject is supported by Korea Ministry of Environment as "Climate Change Correspondence Program". This work was supported by a grant from the National Institute of Environment Research (NIER), funded by the Ministry of Environment (MOE) of the Republic of Korea.

  10. Competitive fluorescent pseudo-immunoassay exploiting molecularly imprinted polymers for the detection of biogenic amines in fish matrix.

    PubMed

    Mattsson, Leena; Xu, Jingjing; Preininger, Claudia; Tse Sum Bui, Bernadette; Haupt, Karsten

    2018-05-01

    We developed a competitive fluorescent molecularly imprinted polymer (MIP) assay to detect biogenic amines in fish samples. MIPs synthesized by precipitation polymerization using histamine as template were used in a batch binding assay analogous to competitive fluoroimmunoassays. Introducing a complex sample matrix, such as fish extract, into the assay changes the environment and the binding conditions, therefore the importance of the sample preparation is extensively discussed. Several extraction and purification methods for fish were comprehensively studied, and an optimal clean-up procedure for fish samples using liquid-liquid extraction was developed. The feasibility of the competitive MIP assay was shown in the purified fish extract over a broad histamine range (1 - 430µM). The MIP had the highest affinity towards histamine, but recognized also the structurally similar biogenic amines tyramine and tryptamine, as well as spermine and spermidine, providing simultaneous analysis and assessment of the total amount of biogenic amines. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Application of biogenic carbon dioxide produced by yeast with different carbon sources for attraction of mosquitoes towards adult mosquito traps.

    PubMed

    Sukumaran, D; Ponmariappan, S; Sharma, Atul K; Jha, Hemendra K; Wasu, Yogesh H; Sharma, Ajay K

    2016-04-01

    Surveillance is a prime requisite for controlling arthropod vectors like mosquitoes that transmit diseases such as malaria, dengue and chikungunya. Carbon dioxide (CO2) is one of the main cues from vertebrate breath that attracts mosquitoes towards the host. Hence, CO2 is used as an attractant during surveillance of mosquitoes either from commercial cylinders or dry ice for mosquito traps. In the present study, the biogenic carbon dioxide production was optimized with different carbon sources such as glucose, simple sugar and jaggery with and without yeast peptone dextrose (YPD) media using commercial baker's yeast. The results showed that yeast produced more biogenic CO2 with simple sugar as compared to other carbon sources. Further substrate concentration was optimized for the continuous production of biogenic CO2 for a minimum of 12 h by using 10 g of baker's yeast with 50 g of simple sugar added to 1.5 l distilled water (without YPD media) in a 2-l plastic bottle. This setup was applied in field condition along with two different mosquito traps namely Mosquito Killing System (MKS) and Biogents Sentinel (BGS) trap. Biogenic CO2 from this setup has increased the trapping efficiency of MKS by 6.48-fold for Culex quinquefasciatus, 2.62-fold for Aedes albopictus and 1.5-fold for Anopheles stephensi. In the case of BGS, the efficiency was found to be increased by 3.54-fold for Ae. albopictus, 4.33-fold for An. stephensi and 1.3-fold for Armigeres subalbatus mosquitoes. On the whole, plastic bottle setup releasing biogenic CO2 from sugar and yeast has increased the efficiency of MKS traps by 6.38-fold and 2.74-fold for BGS traps as compared to traps without biogenic CO2. The present study reveals that, among different carbon sources used, simple sugar as a substance (which is economical and readily available across the world) yielded maximum biogenic CO2 with yeast. This setup can be used as an alternative to CO2 cylinder and dry ice in any adult mosquito traps to

  12. Ferritin accumulation under iron scarcity in Drosophila iron cells.

    PubMed

    Mehta, A; Deshpande, A; Bettedi, L; Missirlis, F

    2009-10-01

    Ferritins are highly stable, multi-subunit protein complexes with iron-binding capacities that reach 4500 iron atoms per ferritin molecule. The strict dependence of cellular physiology on an adequate supply of iron cofactors has likely been a key driving force in the evolution of ferritins as iron storage molecules. The insect intestine has long been known to contain cells that are responsive to dietary iron levels and a specialized group of "iron cells" that always accumulate iron-loaded ferritin, even when no supplementary iron is added to the diet. Here, we further characterize ferritin localization in Drosophila melanogaster larvae raised under iron-enriched and iron-depleted conditions. High dietary iron intake results in ferritin accumulation in the anterior midgut, but also in garland (wreath) cells and in pericardial cells, which together filter the circulating hemolymph. Ferritin is also abundant in the brain, where levels remain unaltered following dietary iron chelation, a treatment that depletes ferritin from the aforementioned tissues. We attribute the stability of ferritin levels in the brain to the function of the blood-brain barrier that may shield this organ from systemic iron fluctuations. Most intriguingly, our dietary manipulations demonstrably iron-depleted the iron cells without a concomitant reduction in their production of ferritin. Therefore, insect iron cells may constitute an exception from the evolutionary norm with respect to iron-dependent ferritin regulation. It will be of interest to decipher both the physiological purpose served and the mechanism employed to untie ferritin regulation from cellular iron levels in this cell type.

  13. A novel, colorimetric method for biogenic amine detection based on arylalkylamine N-acetyltransferase.

    PubMed

    Leng, Pei-Qiang; Zhao, Feng-Lan; Yin, Bin-Cheng; Ye, Bang-Ce

    2015-05-21

    We developed a novel colorimetric method for rapid detection of biogenic amines based on arylalkylamine N-acetyltransferase (aaNAT). The proposed method offers distinct advantages including simple handling, high speed, low cost, good sensitivity and selectivity.

  14. Characterization of biogenic ferrihydrite nanoparticles by means of SAXS, SRD and IBA methods

    NASA Astrophysics Data System (ADS)

    Balasoiu, M.; Kichanov, S.; Pantelica, A.; Pantelica, D.; Stolyar, S.; Iskhakov, R.; Aranghel, D.; Ionescu, P.; Badita, C. R.; Kurkin, S.; Orelovich, O.; Tiutiunikov, S.

    2018-03-01

    Investigations of biogenic ferrihydrite nanoparticles produced by bacteria Klebsiella oxytoca by applying small angle X-ray scattering, synchrotron radiation diffraction and ion beam analysis methods are reviewed. Different experimental data processing methods are used and analyzed.

  15. Extracellular proteins limit the dispersal of biogenic nanoparticles

    USGS Publications Warehouse

    Moreau, J.W.; Weber, P.K.; Martin, M.C.; Gilbert, B.; Hutcheon, I.D.; Banfield, J.F.

    2007-01-01

    High-spatial-resolution secondary ion microprobe spectrometry, synchrotron radiation-based Fourier-transform infrared spectroscopy, and polyacrylamide gel analysis demonstrated the intimate association of proteins with spheroidal aggregates of biogenic zinc sulfide nanocrystals, an example of extracellular biomineralization. Experiments involving synthetic zinc sulfide nanoparticles and representative amino acids indicated a driving role for cysteine in rapid nanoparticle aggregation. These findings suggest that microbially derived extracellular proteins can limit the dispersal of nanoparticulate metal-bearing phases, such as the mineral products of bioremediation, that may otherwise be transported away from their source by subsurface fluid flow.

  16. Biogenic and biomass burning organic aerosol in a boreal forest at Hyytiälä, Finland, during HUMPPA-COPEC 2010

    NASA Astrophysics Data System (ADS)

    Corrigan, A. L.; Russell, L. M.; Takahama, S.; Äijälä, M.; Ehn, M.; Junninen, H.; Rinne, J.; Petäjä, T.; Kulmala, M.; Vogel, A. L.; Hoffmann, T.; Ebben, C. J.; Geiger, F. M.; Chhabra, P.; Seinfeld, J. H.; Worsnop, D. R.; Song, W.; Auld, J.; Williams, J.

    2013-06-01

    Submicron aerosol particles were collected during July and August 2010 in Hyytiälä, Finland, to determine the composition and sources of aerosol at that Boreal forest site. Submicron particles were collected on Teflon filters and analyzed by Fourier transform infrared (FTIR) spectroscopy for organic functional groups (OFG). Positive matrix factorization (PMF) was applied to aerosol mass spectrometry (AMS) measurements and FTIR spectra to identify summertime sources of submicron aerosol mass at the sampling site. The two largest sources of organic mass (OM) in particles identified at Hyytiälä were (1) biogenic aerosol from surrounding local forest and (2) biomass burning aerosol, transported 4-5 days from large wildfires burning near Moscow, Russia, and northern Ukraine. The robustness of this apportionment is supported by the agreement of two independent analytical methods for organic measurements with three statistical techniques. FTIR factor analysis was more sensitive to the chemical differences between biogenic and biomass burning organic components, while AMS factor analysis had a higher time resolution that more clearly linked the temporal behavior of separate OM factors to that of different source tracers even though their fragment mass spectrum were similar. The greater chemical sensitivity of the FTIR is attributed to the nondestructive preparation and the functional group specificity of spectroscopy. The FTIR spectra show strong similarities among biogenic and biomass burning factors from different regions as well as with reference OM (namely olive tree burning BBOA and α-pinene chamber secondary organic aerosol (SOA)). The biogenic factor correlated strongly with temperature and oxidation products of biogenic volatile organic compounds (BVOCs), included more than half oxygenated OFGs (carbonyl groups at 29% and carboxylic acid groups at 22%), and represented 35% of the submicron OM. Compared to previous studies at Hyytiälä, the summertime biogenic

  17. Biogenic and biomass burning organic aerosol in a boreal forest at Hyytiälä, Finland, during HUMPPA-COPEC 2010

    NASA Astrophysics Data System (ADS)

    Corrigan, A. L.; Russell, L. M.; Takahama, S.; Äijälä, M.; Ehn, M.; Junninen, H.; Rinne, J.; Petäjä, T.; Kulmala, M.; Vogel, A. L.; Hoffmann, T.; Ebben, C. J.; Geiger, F. M.; Chhabra, P.; Seinfeld, J. H.; Worsnop, D. R.; Song, W.; Auld, J.; Williams, J.

    2013-12-01

    Submicron aerosol particles were collected during July and August 2010 in Hyytiälä, Finland, to determine the composition and sources of aerosol at that boreal forest site. Submicron particles were collected on Teflon filters and analyzed by Fourier transform infrared (FTIR) spectroscopy for organic functional groups (OFGs). Positive matrix factorization (PMF) was applied to aerosol mass spectrometry (AMS) measurements and FTIR spectra to identify summertime sources of submicron aerosol mass at the sampling site. The two largest sources of organic mass (OM) in particles identified at Hyytiälä were (1) biogenic aerosol from surrounding local forest and (2) biomass burning aerosol, transported 4-5 days from large wildfires burning near Moscow, Russia, and northern Ukraine. The robustness of this apportionment is supported by the agreement of two independent analytical methods for organic measurements with three statistical techniques. FTIR factor analysis was more sensitive to the chemical differences between biogenic and biomass burning organic components, while AMS factor analysis had a higher time resolution that more clearly linked the temporal behavior of separate OM factors to that of different source tracers even though their fragment mass spectrum were similar. The greater chemical sensitivity of the FTIR is attributed to the nondestructive preparation and the functional group specificity of spectroscopy. The FTIR spectra show strong similarities among biogenic and biomass burning factors from different regions as well as with reference OM (namely olive tree burning organic aerosol and α-pinene chamber secondary organic aerosol (SOA)). The biogenic factor correlated strongly with temperature and oxidation products of biogenic volatile organic compounds (BVOCs), included more than half of the oxygenated OFGs (carbonyl groups at 29% and carboxylic acid groups at 22%), and represented 35% of the submicron OM. Compared to previous studies at Hyytiälä, the

  18. Production of Biogenic Mn Oxides by Leptothrix discophora SS-1 in a Chemically Defined Growth Medium and Evaluation of Their Pb Adsorption Characteristics

    PubMed Central

    Nelson, Yarrow M.; Lion, Leonard W.; Ghiorse, William C.; Shuler, Michael L.

    1999-01-01

    Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the addition of ≥0.1 μM FeSO4. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and exopolymer alone, as well as to abiotic Mn oxides. The Pb adsorption to cells and exopolymer with biogenic Mn oxides (0.8 mmol of Mn per g) at pH 6.0 and 25°C was 2 orders of magnitude greater than the Pb adsorption to cells and exopolymer alone (on a dry weight basis). The Pb adsorption to the biogenic Mn oxide was two to five times greater than the Pb adsorption to a chemically precipitated abiotic Mn oxide and several orders of magnitude greater than the Pb adsorption to two commercially available crystalline MnO2 minerals. The N2 Brunauer-Emmet-Teller specific surface areas of the biogenic Mn oxide and fresh Mn oxide precipitate (224 and 58 m2/g, respectively) were significantly greater than those of the commercial Mn oxide minerals (0.048 and 4.7 m2/g). The Pb adsorption capacity of the biogenic Mn oxide also exceeded that of a chemically precipitated colloidal hydrous Fe oxide under similar solution conditions. These results show that amorphous biogenic Mn oxides similar to those produced by SS-1 may play a significant role in the control of trace metal phase distribution in aquatic systems. PMID:9872777

  19. Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)

    NASA Astrophysics Data System (ADS)

    Koppmann, R.; Hoffmann, T.; Kesselmeier, J.; Schatzmann, M.

    Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

  20. From the ocean to a salt marsh: towards understanding iron reduction processes with FORC-PCA.

    NASA Astrophysics Data System (ADS)

    Muraszko, J. R.; Lascu, I.; Collins, S. M.; Harrison, R. J.

    2017-12-01

    Biogenic magnetic minerals are a high fidelity recorder of climate change. Their sensitivity to sedimentary redox conditions and bottom water ventilation have the potential to provide useful insights into past diagenetic conditions. However, the mechanisms controlling preservation and dissolution of magnetosomes are not fully understood, thus undermining the reliability of the paleomagnetic records in marine environments. Recovering information about the diagenetic past of the sediment is a crucial challenge; specifically, the biogenic components need to be identified and unmixed from the bulk magnetic signal. We address the issue in this study by applying Principal Component Analysis on First Order Reversal Curve diagrams (FORC-PCA) in case studies of cores obtained from the Iberian Margin and the sedimentologically active coastal salt marshes of Norfolk. We demonstrate the applicability of FORC-PCA as a new environmental proxy, yielding a high resolution temporal marine record of environmental changes reflected in magnetic composition over the last 194 kyr. The strongest variations are observed in the microbially derived components, the bulk properties of the sediment being controlled by a low coercivity SP-SD component which is generally anticorrelated with the magnetosome signal. Supported by TEM studies, we suggest the prevalence of clusters of nano-particles of magnetite associated with iron reduction. To further investigate the mechanisms controlling these processes, the active sedimentary environment of Norfolk was chosen as a case study of early diagenesis controlled by strong vertical geochemical gradients.

  1. A32A-0126: A BIOGENIC ROLE IN EXPOSURE TO TWO TOXIC COMPOUNDS

    EPA Science Inventory

    Biogenic sources play an important role in ozone and particulate concentrations through emissions of volatile organic compounds. The same emissions also contribute to chronic toxic exposures from formaldehyde and acetaldehyde because each compound arises through primary and sec...

  2. Iron deficiency and iron deficiency anaemia in women.

    PubMed

    Percy, Laura; Mansour, Diana; Fraser, Ian

    2017-04-01

    Iron deficiency (ID) is the most common micronutrient deficiency worldwide with >20% of women experiencing it during their reproductive lives. Hepcidin, a peptide hormone mostly produced by the liver, controls the absorption and regulation of iron. Understanding iron metabolism is pivotal in the successful management of ID and iron deficiency anaemia (IDA) using oral preparations, parenteral iron or blood transfusion. Oral preparations vary in their iron content and can result in gastrointestinal side effects. Parenteral iron is indicated when there are compliance/tolerance issues with oral iron, comorbidities which may affect absorption or ongoing iron losses that exceed absorptive capacity. It may also be the preferred option when rapid iron repletion is required to prevent physiological decompensation or given preoperatively for non-deferrable surgery. As gynaecologists, we focus on managing women's heavy menstrual bleeding (HMB) and assume that primary care clinicians are treating the associated ID/IDA. We now need to take the lead in diagnosing, managing and initiating treatment for ID/IDA and treating HMB simultaneously. This dual management will significantly improve their quality of life. In this chapter we will summarise the importance of iron in cellular functioning, describe how to diagnose ID/IDA and help clinicians choose between the available treatment options. Copyright © 2016. Published by Elsevier Ltd.

  3. Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

    PubMed

    Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

    2015-04-21

    The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ∼67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden.

  4. Development and Characterization of Sr-Containing Glass-Ceramic Composites Based on Biogenic Hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Kuda, Oleksii; Pinchuk, Nataliia; Bykov, Oleksandr; Tomila, Tamara; Olifan, Olena; Golovkova, Maryna

    2018-05-01

    Composite materials based on hydroxyapatite are widely used for bone tissue engineering. There is evidence of a positive effect of the presence of strontium in osteoplastic materials in the case of a Ca/Sr certain ratio. To examine the effect of the addition of Sr2+, a study was made by introducing it into the material composition based on biogenic hydroxyapatite and sodium borosilicate glass (50/50% wt.). The strontium was introduced into the composition in an amount of 1% wt. Composite materials were obtained at final sintering temperatures of 780 °C and a sintering time of 1 h. The effect of additions of glass phase and strontium affect changes in the crystal lattice of biogenic hydroxyapatite was investigated with the help of X-ray phase analysis, IR spectroscopy. Also the behavior of composites in vitro in physiological solution was studied.

  5. Radiorespirometric assays for the detection of biogenic sulfides from sulfate-reducing bacteria.

    PubMed

    de Queiroz, J C; de Melo Ferreira, A C; da Costa, A C A

    2013-04-01

    The detection of trace concentrations of biogenic sulfides can be carried out through radiorespirometric assays. The objective of this work was to improve the methodology for detection of H2 S in trace concentrations, to correlate with sulfate-reducing bacterial activity. Serial dilutions of synthetic sea water with a pure culture of Desulfovibrio alaskensis, a mixed anaerobic microbial culture and a natural saline sample from a petroleum offshore platform indicated that dilutions were followed, accordingly, by sulfate reduction. Tests performed indicated that increasing the time of incubation of a mixed anaerobic microbial culture contributed to an increase in the sulfate reduction rates, as well as the amount of carbon source and inoculum. The technique here developed proved to be a rapid test for the detection of biogenic sulfides, particularly those associated with corrosion products, being an useful tool for monitoring and controlling oil/water storage tanks, petroleum continental platforms and several types of reservoirs. © 2013 The Society for Applied Microbiology.

  6. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and... avoided. Cast iron and malleable iron components shall not be used at temperatures above 450 °F. Cast iron...

  7. Spatial learning, monoamines and oxidative stress in rats exposed to 900 MHz electromagnetic field in combination with iron overload.

    PubMed

    Maaroufi, Karima; Had-Aissouni, Laurence; Melon, Christophe; Sakly, Mohsen; Abdelmelek, Hafedh; Poucet, Bruno; Save, Etienne

    2014-01-01

    The increasing use of mobile phone technology over the last decade raises concerns about the impact of high frequency electromagnetic fields (EMF) on health. More recently, a link between EMF, iron overload in the brain and neurodegenerative disorders including Parkinson's and Alzheimer's diseases has been suggested. Co-exposure to EMF and brain iron overload may have a greater impact on brain tissues and cognitive processes than each treatment by itself. To examine this hypothesis, Long-Evans rats submitted to 900 MHz exposure or combined 900 MHz EMF and iron overload treatments were tested in various spatial learning tasks (navigation task in the Morris water maze, working memory task in the radial-arm maze, and object exploration task involving spatial and non spatial processing). Biogenic monoamines and metabolites (dopamine, serotonin) and oxidative stress were measured. Rats exposed to EMF were impaired in the object exploration task but not in the navigation and working memory tasks. They also showed alterations of monoamine content in several brain areas but mainly in the hippocampus. Rats that received combined treatment did not show greater behavioral and neurochemical deficits than EMF-exposed rats. None of the two treatments produced global oxidative stress. These results show that there is an impact of EMF on the brain and cognitive processes but this impact is revealed only in a task exploiting spontaneous exploratory activity. In contrast, there are no synergistic effects between EMF and a high content of iron in the brain. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. The impacts of temperature, alcoholic degree and amino acids content on biogenic amines and their precursor amino acids content in red wine.

    PubMed

    Lorenzo, C; Bordiga, M; Pérez-Álvarez, E P; Travaglia, F; Arlorio, M; Salinas, M R; Coïsson, J D; Garde-Cerdán, T

    2017-09-01

    The aim was to study how factors such as temperature, alcoholic degree, and amino acids supplementation are able to influence the content of tyramine, histamine, 2-phenylethylamine, tryptamine and their precursor amino acids in winemaking process. Biogenic amines and amino acids were quantified at the beginning, middle and end of alcoholic fermentation, and at the end of malolactic fermentation. In general, samples produced with amino acid supplementation did not show the highest concentrations of biogenic amines, except for histamine, which content increased with the addition of the four amino acids. The synthesis of tyramine was mainly affected by the temperature and alcoholic degree, the formation of phenylethylamine was largely influenced by alcoholic degree, and tryptamine synthesis principally depended on temperature. Interestingly, there was interaction between these three factors for the biogenic amines studied. In conclusion, winemaking conditions should be established depending on the biogenic amine which synthesis is required to be controlled. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Higher iron bioavailability of a human-like collagen iron complex.

    PubMed

    Zhu, Chenhui; Yang, Fan; Fan, Daidi; Wang, Ya; Yu, Yuanyuan

    2017-07-01

    Iron deficiency remains a public health problem around the world due to low iron intake and/or bioavailability. FeSO 4 , ferrous succinate, and ferrous glycinate chelate are rich in iron but have poor bioavailability. To solve the problem of iron deficiency, following previous research studies, a thiolated human-like collagen-ironcomplex supplement with a high iron content was prepared in an anaerobic workstation. In addition, cell viability tests were evaluated after conducting an MTT assay, and a quantitative analysis of the thiolated human-like collagen-iron digesta samples was performed using the SDS-PAGE method coupled with gel filtration chromatography. The iron bioavailability was assessed using Caco-2 cell monolayers and iron-deficiency anemia mice models. The results showed that (1) one mole of thiolated human-like collagen-iron possessed approximately 35.34 moles of iron; (2) thiolated human-like collagen-iron did not exhibit cytotoxity and (3) thiolated human-like collagen- iron digesta samples had higher bioavailability than other iron supplements, including FeSO 4 , ferrous succinate, ferrous glycine chelate and thiolated human-like collagen-Fe iron. Finally, the iron bioavailability was significantly enhanced by vitamin C. These results indicated that thiolated human-like collagen-iron is a promising iron supplement for use in the future.

  10. Arsenite and ferrous iron oxidation linked to chemolithotrophic denitrification for the immobilization of arsenic in anoxic environments

    USGS Publications Warehouse

    Sun, W.; Sierra-Alvarez, R.; Milner, L.; Oremland, R.; Field, J.A.

    2009-01-01

    The objective of this study was to explore a bioremediation strategy based on injecting NO3- to support the anoxic oxidation of ferrous iron (Fe(II)) and arsenite (As(III)) in the subsurface as a means to immobilize As in the form of arsenate (As(V)) adsorbed onto biogenic ferric (Fe(III)) (hydr)oxides. Continuous flows and filled columns were used to simulate a natural anaerobic groundwater and sediment system with co-occurring As(III) and Fe(II) in the presence (column SF1) or absence (column SF2) of nitrate, respectively. During operation for 250 days, the average influent arsenic concentration of 567 ??g L-1 was reduced to 10.6 (??9.6) ??g L-1 in the effluent of column SF1. The cumulative removal of Fe(II) and As(III) in SF1 was 6.5 to 10-fold higher than that in SF2. Extraction and measurement of the mass of iron and arsenic immobilized on the sand packing of the columns were close to the iron and arsenic removed from the aqueous phase during column operation. The dominant speciation of the immobilized iron and arsenic was Fe(III) and As(V) in SF1, compared with Fe(II) and As(III) in SF2. The speciation was confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results indicate that microbial oxidation of As(III) and Fe(II) linked to denitrification resulted in the enhanced immobilization of aqueous arsenic in anaerobic environments by forming Fe(III) (hydr)oxide coated sands with adsorbed As(V). ?? 2009 American Chemical Society.

  11. Biogenic Amines in Italian Pecorino Cheese

    PubMed Central

    Schirone, Maria; Tofalo, Rosanna; Visciano, Pierina; Corsetti, Aldo; Suzzi, Giovanna

    2012-01-01

    The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations, and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (∼62.000t of production in 2010). Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes’ milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or pasteurized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA). Bacterial amino acid decarboxylase activity and BA content have to be investigated within the complex microbial community of raw milk cheese for different cheese technologies. The results emphasize the necessity of controlling the indigenous bacterial population responsible for high production of BA and the use of competitive adjunct cultures could be suggested. Several factors can contribute to the qualitative and quantitative profiles of BA’s in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, water activity, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge), and the presence of cofactor (pyridoxal phosphate, availability of aminases and deaminases). In fact physico-chemical parameters seem to favor biogenic amine-positive microbiota; both of these environmental factors can easily be modulated, in order to control growth of undesirable microorganisms. Generally, the total content of BA’s in Pecorino cheeses can range from about 100

  12. Biogenic amines in italian pecorino cheese.

    PubMed

    Schirone, Maria; Tofalo, Rosanna; Visciano, Pierina; Corsetti, Aldo; Suzzi, Giovanna

    2012-01-01

    The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations, and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (∼62.000t of production in 2010). Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or pasteurized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA). Bacterial amino acid decarboxylase activity and BA content have to be investigated within the complex microbial community of raw milk cheese for different cheese technologies. The results emphasize the necessity of controlling the indigenous bacterial population responsible for high production of BA and the use of competitive adjunct cultures could be suggested. Several factors can contribute to the qualitative and quantitative profiles of BA's in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, water activity, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge), and the presence of cofactor (pyridoxal phosphate, availability of aminases and deaminases). In fact physico-chemical parameters seem to favor biogenic amine-positive microbiota; both of these environmental factors can easily be modulated, in order to control growth of undesirable microorganisms. Generally, the total content of BA's in Pecorino cheeses can range from about 100-2400

  13. Potential of Cupriavidus metallidurans CH34 for in situ resource utilization from basalt by determining the molecular micro-mineral interactions

    NASA Astrophysics Data System (ADS)

    Byloos, Bo; Van Houdt, Rob; Boon, Nico; Leys, Natalie

    In order to maintain a persistent human presence in space, materials must either be provided from Earth or generated from material already present in space, in a process referred to as 'in situ resource utilization (ISRU)'. Microorganisms can biomine useful elements from extra-terrestrial materials for use as nutrients in a life support system or to aid in the creation of soil. To effectively use bacteria in an ISRU process more needs to be known about the molecular mechanisms behind microbe-mineral interaction and the influence of microgravity and radiation that affect bioleaching. The aim of this research project is to define the microbe-mineral interactions on basalt, which is a major constituent of Lunar or Martian regolith, the mechanisms that are important in bioleaching and how this process will be altered by space flight conditions. In particular, the research will be focussed on the determination of the genes and proteins involved in the biosynthesis of metallophores and exopolysaccharides (EPS), and biofilm formation. Iron, copper and phosphate uptake mechanisms are investigated in detail because these have been shown to be essential for life and bacteria are faced with limitation of these nutrients in the environment. In this study the bacterium Cupriavidus metallidurans CH34 is used to study these interactions. C. metallidurans CH34 is a soil bacterium which is resistant to up to 20 different heavy metal ions. Its behaviour in space has already been determined with earlier flight experiments to the ISS. It was recently discovered that C. metallidurans forms a biofilm and is capable of leaching calcium, magnesium and iron from basalt to sustain its growth First, C. metallidurans was grown in conditions with and without basalt, iron, copper and phosphate and the production of EPS and metallophores was examined. The iron, copper and phosphate concentrations which are limiting and optimal to allow C. metallidurans cell proliferation could be determined as

  14. Enhanced biogenic emissions of nitric oxide and nitrous oxide following surface biomass burning

    Treesearch

    Iris C. Anderson; Joel S. Levine; Mark A. Poth; Philip J. Riggan

    1988-01-01

    Recent measurements indicate significantly enhanced biogenic soil emissions of both nitric oxide (NO) and nitrous oxide (N2O) following surface burning. These enhanced fluxes persisted for at least 6 months following the burn. Simultaneous measurements indicate enhanced levels of...

  15. Mössbauer study of iron minerals transformations by Fuchsiella ferrireducens

    NASA Astrophysics Data System (ADS)

    Gracheva, M. A.; Chistyakova, N. I.; Antonova, A. V.; Rusakov, V. S.; Zhilina, T. N.; Zavarzina, D. G.

    2017-11-01

    Biogenic transformations of iron-containing minerals synthesized ferrihydrite, magnetite and hydrothermal siderite by anaerobic alkaliphilic bacterium Fuchsiella ferrireducens (strain Z-7101T) were studied by 57Fe Mössbauer spectroscopy. Mössbauer investigations of solid phase samples obtained after microbial transformation were carried out at room temperature and at 82 K. It was found that all tested minerals transformed during bacterial growth. In the presence of synthesized ferrihydrite, added as an electron acceptor, a mixture of large (more than 100 nm) and small (˜5 nm) particles of magnetically ordered phase and siderite was formed. Synthesized magnetite that contains both Fe3+ and Fe2+ forms could serve as electron acceptor as well as an electron donor for F.ferrireducens growth. As a result of its biotransformation, no siderite formation was observed while small particles of magnetite were formed. In the case of the addition of siderite as an electron donor formation of a small amount of a new phase containing Fe2+ caused by recrystallization of siderite during bacterial growth was detected.

  16. Evidence that stainable bone marrow iron following parenteral iron therapy does not correlate with serum iron studies and may not represent readily available storage iron.

    PubMed

    Thomason, Ronald W; Almiski, Muhamad S

    2009-04-01

    We recently reported that parenteral iron therapy is associated with a characteristic pattern of iron staining on bone marrow aspirate smears. We now present clinical information from 6 patients who received parenteral iron and, at one or more points in follow-up, were found to have low or borderline low serum ferritin levels and/or serum iron levels, even though marrow aspirate smears revealed abundant stainable iron in the pattern characteristic of prior parenteral iron therapy. We conclude that stainable iron seen in this pattern does not correlate with serum iron studies and may not represent functionally available storage iron. This pattern of iron staining should not be used as evidence to withhold further iron therapy in patients who otherwise continue to have features of iron deficiency anemia.

  17. Magnetic Dinner Salads: The Role of Biogenic Magnetite in Cryopreservation for Common Food Plants

    NASA Astrophysics Data System (ADS)

    Chaffee, T. M.; Kirschvink, J. L.; Kobayashi, A. K.

    2015-12-01

    Biogenically-precipitated magnetite has been found in organisms ranging from Bacteria, single-celled protists, and many of the animal phyla, where its major function is navigation and magnetoreception. To date there is but a single report of biogenic magnetite in plants (essentially, magnetoferritin), and that is in common grass (Festuca species, from Gajdardziska-Josifovska et. al. doi:10.1127/0935-1221/2001/0013/0863). Recent developments in cryopreservation suggest that ~ 1 mT, ~ 10 Hz oscillating magnetic fields can drastically reduce ice nucleation during freezing, promote supercooling, and minimize cellular damage in living tissues (e.g., Kaku et al., doi: 10.1016/j.cryobiol.2012.02.001). Kobayashi & Kirschvink (2014, doi:10.1016/j.cryobiol.2013.12.002) suggest that biogenic magnetite crystals could be the nucleating site for damaging ice crystals, and that they would be driven magneto-mechanically to rotate in those oscillating fields which could inhibit the ice crystal nucleation process. This prompted our investigation into the magnetite content of ordinary fruit and vegetable food products, as knowledge of the natural levels of biogenic magnetite in the human food supply could guide the selection of which foods might work for this type of cryopreservation. Our study involved a range of common foods including avocados, bananas, garlic, and apples. Samples were prepared in a clean lab environment kept free of contaminant particles, and subjected to a variety of standard rock-magnetic tests including IRM and ARM acquisition, and the corresponding Af demagnetization, on a standard 2G™ SRM. Results are consistent with moderately interacting single-domain magnetite (see figure), with moderate inter-particle interaction effects. Typical magnetite concentrations in these samples are in the range of .1 to 1 ng/g for room temperature samples, increasing to the range of 1-10 ng/g when measured frozen (to inhibit thermal rotation of small particles and clumps). If

  18. Molecular comparison of bacterial communities within iron-containing flocculent mats associated with submarine volcanoes along the Kermadec Arc.

    PubMed

    Hodges, Tyler W; Olson, Julie B

    2009-03-01

    Iron oxide sheaths and filaments are commonly found in hydrothermal environments and have been shown to have a biogenic origin. These structures were seen in the flocculent material associated with two submarine volcanoes along the Kermadec Arc north of New Zealand. Molecular characterization of the bacterial communities associated with the flocculent samples indicated that no known Fe-oxidizing bacteria dominated the recovered clone libraries. However, clones related to the recently described Fe-oxidizing bacterium Mariprofundus ferrooxydans were obtained from both the iron-containing flocculent (Fe-floc) and sediment samples, and peaks corresponding to Mariprofundus ferrooxydans, as well as the related clones, were observed in several of our terminal restriction fragment length polymorphism profiles. A large group of epsilonproteobacterial sequences, for which there is no cultured representative, dominated clones from the Fe-floc libraries and were less prevalent in the sediment sample. Phylogenetic analyses indicated that several operational taxonomic units appeared to be site specific, and statistical analyses of the clone libraries found that all samples were significantly different from each other. Thus, the bacterial communities in the Fe-floc samples were not more closely related to each other than to the sediment communities.

  19. The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates

    NASA Astrophysics Data System (ADS)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2017-04-01

    Rare earth elements (REEs) are commonly used proxies to reconstruct water chemistry and oxygen saturation during the formation of authigenic and biogenic phosphates in marine environments. In the modern ocean REEs exhibit a distinct pattern with enrichment of heavy REEs and strong depletion in cerium (Ce). The wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry has been very different in the Earth's past. However, both early and late diagenesis are known to affect REE signatures in phosphates altering primary marine signals. Herein we present a dataset of REE signatures in 38 grain specific LA-ICP-MS measurements of isolated phosphate and carbonate grains in three discrete rock samples. The phosphates mainly consist of authigenic phosphates and phosphatized microfossils that formed in a microbially mediated micro-milieu. In addition, isolated biogenic and reworked phosphatic grains are also present. The phosphates are emplaced in bioclastic grain- to packstones deposited on a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene Monterey event. The results reveal markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Grain shape and REE patterns together indicate that authigenic, biogenic and reworked phosphates have distinct REE patterns irrespective of the sample. Our study shows that while REE patterns in phosphates do reflect water chemistry during authigenesis, they are often already heavily altered during reworking, a process, which can occur in geologically negligible timespans. REE patterns are therefore more likely to reflect complex enrichment processes after their formation. Similarities in the REE patterns of reworked and biogenic phosphate further suggest that the

  20. Airborne biogenic particles in the snow of the cities of the Russian Far East as potential allergic compounds.

    PubMed

    Golokhvast, Kirill S

    2014-01-01

    This paper presents an analysis of airborne biogenic particles (1 mkm-1 mm) found in the snow in several cities of the Russian Far East during 2010-2013. The most common was vegetational terraneous detritus (fragments of tree and grass leaves) followed by animal hair, small insects and their fragments, microorganisms of aeroplankton, and equivocal biological garbage. Specific components were found in samples from locations close to bodies of water such as fragments of algae and mollusc shells and, marine invertebrates (needles of sea urchins and shell debris of arthropods). In most locations across the Far East (Vladivostok, Khabarovsk, Blagoveshchensk, and Ussuriysk), the content of biogenic particles collected in the winter did not exceed 10% of the total particulate matter, with the exception of Birobidzhan and the nature reserve Bastak, where it made up to 20%. Most of all biogenic compounds should be allergic: hair, fragments of tree and grass leaves, insects, and microorganisms.

  1. Airborne Biogenic Particles in the Snow of the Cities of the Russian Far East as Potential Allergic Compounds

    PubMed Central

    Golokhvast, Kirill S.

    2014-01-01

    This paper presents an analysis of airborne biogenic particles (1 mkm–1 mm) found in the snow in several cities of the Russian Far East during 2010–2013. The most common was vegetational terraneous detritus (fragments of tree and grass leaves) followed by animal hair, small insects and their fragments, microorganisms of aeroplankton, and equivocal biological garbage. Specific components were found in samples from locations close to bodies of water such as fragments of algae and mollusc shells and, marine invertebrates (needles of sea urchins and shell debris of arthropods). In most locations across the Far East (Vladivostok, Khabarovsk, Blagoveshchensk, and Ussuriysk), the content of biogenic particles collected in the winter did not exceed 10% of the total particulate matter, with the exception of Birobidzhan and the nature reserve Bastak, where it made up to 20%. Most of all biogenic compounds should be allergic: hair, fragments of tree and grass leaves, insects, and microorganisms. PMID:25140327

  2. Biogenic opal production changes in the Gulf of Alaska (IODP Expedition 341 Site U1417) during the Pliocene to Miocene

    NASA Astrophysics Data System (ADS)

    Khim, B. K.; Kim, S.; Asahi, H.

    2016-12-01

    IODP Expedition 341 Site U1417 (56o57.59'N, 147o6.59'W, 4200 m) is located in the distal Surveyor Fan in the Gulf of Alaska, Northeast Pacific. In this study, we documented biogenic opal content and its mass accumulation rate using a total of 445 sediments from Hole U1417D (below core 43X, 275 CSF-A m) and from Hole U1417E (below core 14R, 465 CSF-A m) which were assigned to Pliocene-Miocene epoch on the basis of shipboard age model. Biogenic opal content and MAR were generally low (<10% and 0.5 g/cm2/kyr, respectively) throughout the core. A significant offset of biogenic opal contents between Site U1417 and Site 887 (54o21.9'N, 148o26.8'W, 3633 m) is observed; much lower at Site U1417. However, biogenic opal content was distinctively high (20 to 40%) at 23 Ma, 15 Ma, 12 Ma, and 8 Ma, which correspond to the lithologic unit changes. These intervals are also characterized by low NGR, MS, and linear sedimentation rate (LSR), indicating the sediment deposition under warm climate/less glacier influence. Thus, the intervals seem to correspond to climatic optimums during the Miocene. Based on terrigenous MAR at Site 887, terrigenous materials supplied by glacial denudation increased greatly since the Northern Hemisphere Glaciation (NHG; 3.5-2.5 Ma). However, Site U1417 shows that high MS representing the terrestrial input occurred far earlier since 8 Ma. It may imply that the formation of glacier in the Gulf of Alaska began earlier or that terrestrial material input was enhanced by sea-ice or turbidite. Intermittent peaks of biogenic opal content and MAR after 8 Ma coincided with the occurrence of cold water/littoral and neritic diatoms and deep cold water radiolarian species, which is likely related to gradual glaciation. Biogenic opal productivity was high during the early Pliocene (5-3.5 Ma), and then it decreased during the NHG.

  3. A shift in the biogenic silica of sediment in the Larsen B continental shelf, off the Eastern Antarctic Peninsula, resulting from climate change.

    PubMed

    Sañé, Elisabet; Isla, Enrique; Bárcena, María Ángeles; DeMaster, David J

    2013-01-01

    In 2002, section B of the Larsen ice shelf, off of the Eastern Antarctic Peninsula, collapsed and created the opportunity to study whether the changes at the sea surface left evidence in the sedimentary record. Biogenic silica is major constituent of Antarctic marine sediment, and its presence in the sediment column is associated with diatom production in the euphotic zone. The abundance of diatom valves and the number of sponge spicules in the biogenic silica was analyzed to determine how the origin of the biogenic silica in the upper layers of the sediment column responded to recent environmental changes. Diatom valves were present only in the upper 2 cm of sediment, which roughly corresponds to the period after the collapse of the ice shelf. In contrast, sponge spicules, a more robust form of biogenic silica, were also found below the upper 2 cm layer of the sediment column. Our results indicate that in this region most of the biogenic silica in the sedimentary record originated from sponge spicules rather than diatoms during the time when the sea surface was covered by the Larsen ice shelf. Since the collapse of the ice shelf, the development of phytoplankton blooms and the consequent influx of diatom debris to the seabed have shifted the biogenic silica record to one dominated by diatom debris, as occurs in most of the Antarctic marine sediment. This shift provides further evidence of the anthropogenic changes to the benthic habitats of the Antarctic and will improve the interpretation of the sedimentary record in Polar Regions where these events occur.

  4. Magnesium isotope fractionation in biogenic and abiogenic carbonates: implications for paleoenvironmental proxies

    NASA Astrophysics Data System (ADS)

    Saenger, Casey; Wang, Zhengrong

    2014-04-01

    Geochemical variations in marine biogenic carbonates that are preserved in the geological record serve as proxies of past environmental change. However, interpreting most proxies is complicated by biologically-mediated vital effects, highlighting the need to develop new tools for reconstructing paleoenvironmental change. Recently, magnesium (Mg) isotope variability in carbonates has been explored extensively to determine its utility as a paleoenvironmental proxy. We review the results of these works, which have yielded valuable information on the factors affecting Mg isotope fractionation between carbonates and solution (Δ26Mgcarb-sol) in biogenic and abiogenic carbonate minerals. Strong evidence exists for a mineralogical control on Δ26Mgcarb-sol, with the negative offset from 0‰ following the sequence aragonite < dolomite < magnesite < calcite. Abiogenic carbonates precipitated from solutions with relatively high Mg/Ca ratios (>˜3 mol/mol) and saturation states (Ω >˜3) that are similar to seawater suggest that Δ26Mgcarb-sol has a temperature dependence of ˜0.01‰ °C-1 and is insensitive to precipitation rate. In contrast, a significant precipitation rate dependence is observed in calcites precipitated from solutions with relatively low Mg/Ca ratios (<˜3 mol/mol) and saturation states (Ω <˜3). This difference likely reflects varying mineral growth mechanisms and we discuss the degree to which Δ26Mgcarb-sol may be affected by factors such as fluid inclusions, amorphous calcium carbonate precursors, ion attachment/detachment kinetics, surface entrapment and Mg speciation. High-Mg calcite organisms, which likely precipitate from relatively unmodified seawater, also exhibit a temperature dependence of ˜0.01‰ °C-1, albeit sometimes with a systematic offset toward smaller fractionations. In contrast, strong vital effects in low-Mg calcite organisms, which exclude Mg from their calcifying fluids, lead to Δ26Mgcarb-sol values that exhibit no clear

  5. Oxidative dissolution potential of biogenic and abiogenic TcO 2 in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Fredrickson, James K.; Zachara, John M.; Plymale, Andrew E.; Heald, Steve M.; McKinley, James P.; Kennedy, David W.; Liu, Chongxuan; Nachimuthu, Ponnusamy

    2009-04-01

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O4-] and less mobile in the reduced form [Tc(IV)O 2· nH 2O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site on the Oak Ridge Site. Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Shewanella putrefaciens CN32 reduced Mn(III/IV) oxides and generated Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. After bioreduction and heat-killing, biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO 2-like phase in both sediments. The biogenic redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular scale speciation of Tc compared to RG. X-ray microprobe, electron microprobe, X-ray absorption spectroscopy, and micro X-ray diffraction were applied to the whole sediment and isolated Tc-containing particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 μm-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass

  6. Dietary iron intake, iron status, and gestational diabetes.

    PubMed

    Zhang, Cuilin; Rawal, Shristi

    2017-12-01

    Pregnant women are particularly vulnerable to iron deficiency and related adverse pregnancy outcomes and, as such, are routinely recommended for iron supplementation. Emerging evidence from both animal and population-based studies, however, has raised potential concerns because significant associations have been observed between greater iron stores and disturbances in glucose metabolism, including increased risk of type 2 diabetes among nonpregnant individuals. Yet, the evidence is uncertain regarding the role of iron in the development of gestational diabetes mellitus (GDM), a common pregnancy complication which has short-term and long-term adverse health ramifications for both women and their children. In this review, we critically and systematically evaluate available data examining the risk of GDM associated with dietary iron, iron supplementation, and iron status as measured by blood concentrations of several indicators. We also discuss major methodologic concerns regarding the available epidemiologic studies on iron and GDM. © 2017 American Society for Nutrition.

  7. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.

  8. Reduction of biogenic amines in sufu by ethanol addition during ripening stage

    USDA-ARS?s Scientific Manuscript database

    The aim of this study was to investigate the contents of biogenic amines (BAs) in different types of sufu samples obtained from different producers, and also the possible effect of addition of ethanol on reducing the levels of BAs during sufu ripening. The levels of BAs in sufu samples were analyze...

  9. A web accessible resource for investigating cassava phenomics and genomics information: BIOGEN BASE

    PubMed Central

    Jayakodi, Murukarthick; selvan, Sreedevi Ghokhilamani; Natesan, Senthil; Muthurajan, Raveendran; Duraisamy, Raghu; Ramineni, Jana Jeevan; Rathinasamy, Sakthi Ambothi; Karuppusamy, Nageswari; Lakshmanan, Pugalenthi; Chokkappan, Mohan

    2011-01-01

    The goal of our research is to establish a unique portal to bring out the potential outcome of the research in the Casssava crop. The Biogen base for cassava clearly brings out the variations of different traits of the germplasms, maintained at the Tapioca and Castor Research Station, Tamil Nadu Agricultural University. Phenotypic and genotypic variations of the accessions are clearly depicted, for the users to browse and interpret the variations using the microsatellite markers. Database (BIOGEN BASE ‐ CASSAVA) is designed using PHP and MySQL and is equipped with extensive search options. It is more user-friendly and made publicly available, to improve the research and development of cassava by making a wealth of genetics and genomics data available through open, common, and worldwide forum for all individuals interested in the field. Availability The database is available for free at http://www.tnaugenomics.com/biogenbase/casava.php PMID:21904428

  10. A web accessible resource for investigating cassava phenomics and genomics information: BIOGEN BASE.

    PubMed

    Jayakodi, Murukarthick; Selvan, Sreedevi Ghokhilamani; Natesan, Senthil; Muthurajan, Raveendran; Duraisamy, Raghu; Ramineni, Jana Jeevan; Rathinasamy, Sakthi Ambothi; Karuppusamy, Nageswari; Lakshmanan, Pugalenthi; Chokkappan, Mohan

    2011-01-01

    The goal of our research is to establish a unique portal to bring out the potential outcome of the research in the Casssava crop. The Biogen base for cassava clearly brings out the variations of different traits of the germplasms, maintained at the Tapioca and Castor Research Station, Tamil Nadu Agricultural University. Phenotypic and genotypic variations of the accessions are clearly depicted, for the users to browse and interpret the variations using the microsatellite markers. Database (BIOGEN BASE - CASSAVA) is designed using PHP and MySQL and is equipped with extensive search options. It is more user-friendly and made publicly available, to improve the research and development of cassava by making a wealth of genetics and genomics data available through open, common, and worldwide forum for all individuals interested in the field. The database is available for free at http://www.tnaugenomics.com/biogenbase/casava.php.

  11. Effects of calcium on hepatocyte iron uptake from transferrin, iron-pyrophosphate and iron-ascorbate.

    PubMed

    Nilsen, T

    1991-10-16

    Calcium stimulates hepatocyte iron uptake from transferrin, ferric-iron-pyrophosphate and ferrous-iron-ascorbate. Maximal stimulation of iron uptake is observed at 1-1.5 mM of extra-cellular calcium and the effect is reversible and immediate. Neither the receptor affinity for transferrin, nor the total amounts of transferrin associated with the cells or the rate of transferrin endocytosis are significantly affected by calcium. In the presence of calcium the rate of iron uptake of non-transferrin bound iron increases abruptly at approximate 17 degrees C and 27 degrees C and as assessed by Arrhenius plots, the activation energy is reduced in a calcium dependent manner at approx. 27 degrees C. At a similar temperature, i.e., between 25 degrees C and 28 degrees C, calcium increases the rates of cellular iron uptake from transferrin in a way that is not reflected in the rate of transferrin endocytosis. By the results of this study it is concluded that calcium increases iron transport across the plasma membrane by a mechanism dependent on membrane fluidity.

  12. Response to parenteral iron therapy distinguish unexplained refractory iron deficiency anemia from iron-refractory iron deficiency anemia.

    PubMed

    Akin, M; Sarbay, H; Guler, S; Balci, Y I; Polat, A

    2016-04-01

    We evaluated that response to parenteral iron therapy could be helpful in distinguishing the types of iron deficiency anemia. This study analyzed responses to IV iron sucrose therapy of 15 children with unexplained refractory iron deficiency anemia (URIDA). We compared the results at diagnosis, 6 weeks and 6 months after the therapy. Results were compared with responses of 11 patients' results with iron-refractory iron deficiency anemia (IRIDA) from our previous study. Six weeks after the start of treatment, ferritin, MCV, MCH and Hb values were in normal range in 10 patients. The increase in Hb, MCH, MCV, and ferritin values ranged 2.6-3.5 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. In five patients, Hb, MCH, and MCV mean (range) values [11.2 g/dL (11-12.2), 24.5 pg (24-25.6), and 67 fL (65-70)] were nearly normal but ferritin mean (range) values [9.8 ng/mL (8-11)] were below normal. Six weeks after the start of treatment, Hb, MCH, MCV and ferritin values of patients with IRIDA were increased. The increase in Hb, MCH, MCV, and ferritin values ranged 0.8-2.7 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. IRIDA is only partially responsive to parenteral iron supplementation. In conclusion, this study demonstrated that the response to intravenous iron therapy for the URIDA cases improved blood parameters more effectively than hereditary IRIDA. Response to parenteral iron therapy would be helpful to distinguish unexplained refractory IDA from hereditary IRIDA for clinicians who do not have access to hepcidin or TMPRS6 mutation analysis. © 2016 John Wiley & Sons Ltd.

  13. Offline identification and characterization of biogenic primary emissions

    NASA Astrophysics Data System (ADS)

    Bozzetti, Carlo; El-Haddad, Imad; Dällenbach, Kaspar Rudolf; Sciare, Jean; Kasper-Giebl, Anne; Hueglin, Christoph; Canonaco, Francesco; Flasch, Mira; Wolf, Robert; Krepelova, Adela; Gates Slowik, Jay; Baltensperger, Urs; Prévôt, André Stéphan Henry

    2014-05-01

    Primary biological particles (e.g. pollen, spores) are known to have adverse influence on human health. Several studies illustrated also their ice-nuclei activity (Vali et al., 1976) showing their potential role in the climate changes. Nevertheless, the contribution and the chemical characterization of the biogenic emissions are poorly understood. The Aerodyne aerosol mass spectrometer (AMS, Aerodyne) has significantly advanced real-time PM1 monitoring. The AMS provides both quantitative measurements of the non-refractory (NR) components (organic aerosol (OA), Cl-, NO3-, NH4+, SO42-) and organic fraction mass spectra of the submicron fraction. Application of the positive matrix factorization (PMF) and other statistical tools such as ME-2 (Paatero, 1999; Canonaco et al., 2013) demonstrated that OA AMS mass spectra contain enough information to differentiate several factors subsequently associated with different aerosol sources (Jimenez et al., 2009). However, AMS measurements are restricted to the PM1 fraction and the AMS deployment remains complex and expensive, limiting long-term sampling and the spatial coverage. We explored a novel offline AMS application (Dällenbach et al., 2014) including a water extraction of the particulate matter from quartz filters by sonication. The resulting liquid extracts are nebulized generating an aerosol analyzed by High-Resolution-Time-of-Flight-AMS. The approach allows registering mass spectra and monitoring different particle size fractions not available by normal online AMS measurement (e.g. PM10). Moreover it broadens the sampling coverage since the filters are relatively easy and inexpensive to be collected and stored, furthermore filter samples are already routinely collected at many air quality stations worldwide. PM1, PM2.5, and PM10 filter samples from Payerne (a rural site on the Swiss Plateau)were collected both in summer and in winter. We clearly identified using PMF the contribution of biogenic primary emissions in

  14. Hydropower's Biogenic Carbon Footprint.

    PubMed

    Scherer, Laura; Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations.

  15. Hydropower's Biogenic Carbon Footprint

    PubMed Central

    Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations. PMID:27626943

  16. The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

    NASA Astrophysics Data System (ADS)

    Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

    2018-03-01

    The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

  17. Molecular control of vertebrate iron homeostasis by iron regulatory proteins

    PubMed Central

    Wallander, Michelle L.; Leibold, Elizabeth A.; Eisenstein, Richard S.

    2008-01-01

    Both deficiencies and excesses of iron represent major public health problems throughout the world. Understanding the cellular and organismal processes controlling iron homeostasis is critical for identifying iron-related diseases and in advancing the clinical treatments for such disorders of iron metabolism. Iron regulatory proteins (IRPs) 1 and 2 are key regulators of vertebrate iron metabolism. These RNA binding proteins post-transcriptionally control the stability or translation of mRNAs encoding proteins involved in iron homeostasis thereby controlling the uptake, utilization, storage or export of iron. Recent evidence provides insight into how IRPs selectively control the translation or stability of target mRNAs, how IRP RNA binding activity is controlled by iron-dependent and iron-independent effectors, and the pathological consequences of dysregulation of the IRP system. PMID:16872694

  18. Effects of groundwater flow on the distribution of biogenic gas in parts of the northern Great Plains of Canada and United States

    USGS Publications Warehouse

    Anna, Lawrence O.

    2011-01-01

    Parts of the northern Great Plains in eastern Montana and western North Dakota and southeastern Alberta and southwestern Saskatchewan, Canada, were studied as part of an assessment of shallow biogenic gas in Upper Cretaceous rocks.Parts of the northern Great Plains in eastern Montana and western North Dakota and southeastern Alberta and southwestern Saskatchewan, Canada, were studied as part of an assessment of shallow biogenic gas in Upper Cretaceous rocks. Large quantities of shallow biogenic gas are produced from low-permeability, Upper Cretaceous reservoirs in southeastern Alberta and southwestern Saskatchewan, Canada. Rocks of similar types and age produce sparingly in the United States except on large structures, such as Bowdoin dome and Cedar Creek anticline. Significant production also occurs in the Tiger Ridge area, where uplift of the Bearpaw Mountains created stratigraphic traps. The resource in Canada is thought to be a continuous, biogenic-gas-type accumulation with economic production in a variety of subtle structures and stratigraphic settings. The United States northern Great Plains area has similar conditions but only broad structural closures or stratigraphic traps associated with local structure have produced economically to date. Numerical flow modeling was used to help determine that biogenic gas in low-permeability reservoirs is held in place by high hydraulic head that overrides buoyancy forces of the gas. Modeling also showed where hydraulic head is greater under Tertiary capped topographic remnants rather than near adjacent topographic lows. The high head can override the capillary pressure of the rock and force gas to migrate to low head in topographically low areas. Most current biogenic gas production is confined to areas between mapped lineaments in the northern Great Plains. The lineaments may reflect structural zones in the Upper Cretaceous that help compartmentalize reservoirs and confine gas accumulations.

  19. Iron regulatory proteins and their role in controlling iron metabolism.

    PubMed

    Kühn, Lukas C

    2015-02-01

    Cellular iron homeostasis is regulated by post-transcriptional feedback mechanisms, which control the expression of proteins involved in iron uptake, release and storage. Two cytoplasmic proteins with mRNA-binding properties, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a central role in this regulation. Foremost, IRPs regulate ferritin H and ferritin L translation and thus iron storage, as well as transferrin receptor 1 (TfR1) mRNA stability, thereby adjusting receptor expression and iron uptake via receptor-mediated endocytosis of iron-loaded transferrin. In addition splice variants of iron transporters for import and export at the plasma-membrane, divalent metal transporter 1 (DMT1) and ferroportin are regulated by IRPs. These mechanisms have probably evolved to maintain the cytoplasmic labile iron pool (LIP) at an appropriate level. In certain tissues, the regulation exerted by IRPs influences iron homeostasis and utilization of the entire organism. In intestine, the control of ferritin expression limits intestinal iron absorption and, thus, whole body iron levels. In bone marrow, erythroid heme biosynthesis is coordinated with iron availability through IRP-mediated translational control of erythroid 5-aminolevulinate synthase mRNA. Moreover, the translational control of HIF2α mRNA in kidney by IRP1 coordinates erythropoietin synthesis with iron and oxygen supply. Besides IRPs, body iron absorption is negatively regulated by hepcidin. This peptide hormone, synthesized and secreted by the liver in response to high serum iron, downregulates ferroportin at the protein level and thereby limits iron absorption from the diet. Hepcidin will not be discussed in further detail here.

  20. Production of extremely low volatile organic compounds from biogenic emissions: Measured yields and atmospheric implications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jokinen, Tuija; Berndt, Torsten; Makkonen, Risto

    2015-06-09

    Extremely low volatility organic compounds (ELVOC) are suggested to promote aerosol particle formation and cloud condensation nuclei (CCN) production in the atmosphere. We show that the capability of biogenic VOC (BVOC) to produce ELVOC depends strongly on their chemical structure and relative oxidant levels. BVOC with an endocyclic double bond, representative emissions from, e.g., boreal forests, efficiently produce ELVOC from ozonolysis. Compounds with exocyclic double bonds or acyclic compounds including isoprene, emission representative of the tropics, produce minor quantities of ELVOC, and the role of OH radical oxidation is relatively larger. Implementing these findings into a global modeling framework showsmore » that detailed assessment of ELVOC production pathways is crucial for understanding biogenic secondary organic aerosol and atmospheric CCN formation.« less

  1. Biogenic magnetite, detrital hematite, and relative paleointensity in Quaternary sediments from the Southwest Iberian Margin

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.; Hodell, D. A.; Margari, V.; Skinner, L. C.; Tzedakis, P. C.; Kesler, M. S.

    2013-08-01

    Magnetic properties of late Quaternary sediments on the SW Iberian Margin are dominated by bacterial magnetite, observed by transmission electron microscopy (TEM), with contributions from detrital titanomagnetite and hematite. Reactive hematite, together with low organic matter concentrations and the lack of sulfate reduction, lead to dissimilatory iron reduction and availability of Fe(II) for abundant magnetotactic bacteria. Magnetite grain-size proxies (κARM/κ and ARM/IRM) and S-ratios (sensitive to hematite) vary on stadial/interstadial timescales, contain orbital power, and mimic planktic δ18O. The detrital/biogenic magnetite ratio and hematite concentration are greater during stadials and glacial isotopic stages, reflecting increased detrital (magnetite) input during times of lowered sea level, coinciding with atmospheric conditions favoring hematitic dust supply. Magnetic susceptibility, on the other hand, has a very different response being sensitive to coarse detrital multidomain (MD) magnetite associated with ice-rafted debris (IRD). High susceptibility and/or magnetic grain-size coarsening, mark Heinrich stadials (HS), particularly HS2, HS3, HS4, HS5, HS6 and HS7, as well as older Heinrich-like detrital layers, indicating the sensitivity of this region to fluctuations in the position of the polar front. Relative paleointensity (RPI) records have well-constrained age models based on planktic δ18O correlation to ice-core chronologies, however, they differ from reference records (e.g. PISO) particularly in the vicinity of glacial maxima, mainly due to inefficient normalization of RPI records in intervals of enhanced hematite input.

  2. DETERMINATION OF FERRITIN AND HEMOSIDERIN IRON IN PATIENTS WITH NORMAL IRON STORES AND IRON OVERLOAD BY SERUM FERRITIN KINETICS

    PubMed Central

    SAITO, HIROSHI; TOMITA, AKIHIRO; OHASHI, HARUHIKO; MAEDA, HIDEAKI; HAYASHI, HISAO; NAOE, TOMOKI

    2012-01-01

    ABSTRACT We attempted to clarify the storage iron metabolism from the change in the serum ferritin level. We assumed that the nonlinear decrease in serum ferritin was caused by serum ferritin increase in iron mobilization. Under this assumption, we determined both ferritin and hemosiderin iron levels by computer-assisted simulation of the row of decreasing assay-dots of serum ferritin in 11 patients with normal iron stores free of both iron deficiency and iron overload; chronic hepatitis C (CHC) and iron deficiency anemia after treatment, and 11 patients with iron overload; hereditary hemochromatosis (HH) and transfusion-dependent anemias (TD). We determined the iron removal rates of 20 and 17 mg/day by administering mean doses of deferasirox at 631 and 616 mg/day in 2 TD during the period of balance of iron addition and removal as indicated by the serum ferritin returned to the previous level. The ferritin-per-hemosiderin ratio was almost the same in both HH and CHC. This matched the localized hepatic hemosiderin deposition in CHC with normal iron stores. We detected the ferritin increased by utilizing the hemosiderin iron in iron removal and the ferritin reduced by transforming ferritin into hemosiderin in iron additions. The iron storing capacity of hemosiderin was limitless, while that of ferritin was suppressed when ferritin iron exceeded around 5 grams. We confirmed the pathway of iron from hemosiderin to ferritin in iron mobilization, and that from ferritin to hemosiderin in iron deposition. Thus, serum ferritin kinetics enabled us to be the first to clinically clarify storage iron metabolism. PMID:22515110

  3. MR characterization of hepatic storage iron in transfusional iron overload.

    PubMed

    Tang, Haiying; Jensen, Jens H; Sammet, Christina L; Sheth, Sujit; Swaminathan, Srirama V; Hultman, Kristi; Kim, Daniel; Wu, Ed X; Brown, Truman R; Brittenham, Gary M

    2014-02-01

    To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload. Six healthy volunteers and 20 patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the "reduced" transverse relaxation rate, RR2 , and the "aggregation index," A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were used for validation. Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2 , A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater. This method provides a new means for noninvasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders. Copyright © 2013 Wiley Periodicals, Inc.

  4. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron.

    PubMed

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A

    2016-05-05

    This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Quantification of body iron and iron absorption in the REDS-II Donor Iron Status Evaluation (RISE) study.

    PubMed

    Kiss, Joseph E; Birch, Rebecca J; Steele, Whitney R; Wright, David J; Cable, Ritchard G

    2017-07-01

    Repeated blood donation alters the iron balance of blood donors. We quantified these effects by analyzing changes in body iron as well as calculating iron absorbed per day for donors enrolled in a prospective study. For 1308 donors who completed a final study visit, we calculated total body iron at the enrollment and final visits and the change in total body iron over the course of the study. Taking into account iron lost from blood donations during the study and obligate losses, we also calculated the average amount of iron absorbed per day. First-time/reactivated donors at enrollment had iron stores comparable to previous general population estimates. Repeat donors had greater donation intensity and greater mean iron losses than first-time/reactivated donors, yet they had little change in total body iron over the study period, whereas first-time/reactivated donors had an average 35% drop. There was higher estimated iron absorption in the repeat donors (men: 4.49 mg/day [95% confidence interval [CI], 4.41-4.58 mg/day]; women: 3.75 mg/day [95% CI, 3.67-3.84 mg/day]) compared with estimated iron absorption in first-time/reactivated donors (men: 2.89 mg/day [95% CI, 2.75-3.04 mg/day]; women: 2.76 mg/day [95% CI, 2.64-2.87 mg/day]). The threshold for negative estimated iron stores (below "0" mg/kg stores) was correlated with the development of anemia at a plasma ferritin value of 10 ng/mL. These analyses provide quantitative data on changes in estimated total body iron for a broad spectrum of blood donors. In contrast to using ferritin alone, this model allows assessment of the iron content of red blood cells and the degree of both iron surplus and depletion over time. © 2017 AABB.

  6. Incremental Reactivity Effects on Secondary Organic Aerosol Formation in Urban Atmospheres with and without Biogenic Influence

    NASA Astrophysics Data System (ADS)

    Kacarab, Mary; Li, Lijie; Carter, William P. L.; Cocker, David R., III

    2016-04-01

    Two different surrogate mixtures of anthropogenic and biogenic volatile organic compounds (VOCs) were developed to study secondary organic aerosol (SOA) formation at atmospheric reactivities similar to urban regions with varying biogenic influence levels. Environmental chamber simulations were designed to enable the study of the incremental aerosol formation from select anthropogenic (m-Xylene, 1,2,4-Trimethylbenzene, and 1-Methylnaphthalene) and biogenic (α-pinene) precursors under the chemical reactivity set by the two different surrogate mixtures. The surrogate reactive organic gas (ROG) mixtures were based on that used to develop the maximum incremental reactivity (MIR) factors for evaluation of O3 forming potential. Multiple incremental aerosol formation experiments were performed in the University of California Riverside (UCR) College of Engineering Center for Environmental Research and Technology (CE-CERT) dual 90m3 environmental chambers. Incremental aerosol yields were determined for each of the VOCs studied and compared to yields found from single precursor studies. Aerosol physical properties of density, volatility, and hygroscopicity were monitored throughout experiments. Bulk elemental chemical composition from high-resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) data will also be presented. Incremental yields and SOA chemical and physical characteristics will be compared with data from previous single VOC studies conducted for these aerosol precursors following traditional VOC/NOx chamber experiments. Evaluation of the incremental effects of VOCs on SOA formation and properties are paramount in evaluating how to best extrapolate environmental chamber observations to the ambient atmosphere and provides useful insights into current SOA formation models. Further, the comparison of incremental SOA from VOCs in varying surrogate urban atmospheres (with and without strong biogenic influence) allows for a unique perspective on the impacts

  7. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

    EPA Science Inventory

    Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg−1 ...

  8. Photocatalytic activity of biogenic silver nanoparticles synthesized using potato (Solanum tuberosum) infusion.

    PubMed

    Roy, Kaushik; Sarkar, C K; Ghosh, C K

    2015-07-05

    In this study, we have reported a fast and eco-benign procedure to synthesis silver nanoparticle at room temperature using potato (Solanum tuberosum) infusion along with the study of its photocatalytic activity on methyl orange dye. After addition of potato infusion to silver nitrate solution, the color of the mixture changed indicating formation of silver nanoparticles. Time dependent UV-Vis spectra were obtained to study the rate of nanoparticle formation with time. Purity and crystallinity of the biogenic silver nanoparticles were examined by X-ray diffraction (XRD). Average size and morphology of the nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infra-red spectroscopy (FTIR) was employed to detect functional bio-molecules responsible that contribute to the reduction and capping of biosynthesized Ag nanoparticles. Further, these synthesized nanoparticles were used to investigate their ability to degrade methyl orange dye under sunlight irradiation and the results showed effective photocatalytic property of these biogenic silver nanoparticles. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Effects of packaging, mineral oil coating, and storage time on biogenic amine levels and internal quality of eggs.

    PubMed

    Figueiredo, T C; Assis, D C S; Menezes, L D M; Oliveira, D D; Lima, A L; Souza, M R; Heneine, L G D; Cançado, S V

    2014-12-01

    This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 10(7) cfu/g) and psychrotrophic (6.7 × 10(7) cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health. ©2014 Poultry Science Association Inc.

  10. Implementation of the MEGAN (v2.1) biogenic emission model in the ECHAM6-HAMMOZ chemistry climate model

    NASA Astrophysics Data System (ADS)

    Henrot, Alexandra-Jane; Stanelle, Tanja; Schröder, Sabine; Siegenthaler, Colombe; Taraborrelli, Domenico; Schultz, Martin G.

    2017-02-01

    A biogenic emission scheme based on the Model of Emissions of Gases and Aerosols from Nature (MEGAN) version 2.1 (Guenther et al., 2012) has been integrated into the ECHAM6-HAMMOZ chemistry climate model in order to calculate the emissions from terrestrial vegetation of 32 compounds. The estimated annual global total for the reference simulation is 634 Tg C yr-1 (simulation period 2000-2012). Isoprene is the main contributor to the average emission total, accounting for 66 % (417 Tg C yr-1), followed by several monoterpenes (12 %), methanol (7 %), acetone (3.6 %), and ethene (3.6 %). Regionally, most of the high annual emissions are found to be associated with tropical regions and tropical vegetation types. In order to evaluate the implementation of the biogenic model in ECHAM-HAMMOZ, global and regional biogenic volatile organic compound (BVOC) emissions of the reference simulation were compared to previous published experiment results with MEGAN. Several sensitivity simulations were performed to study the impact of different model input and parameters related to the vegetation cover and the ECHAM6 climate. BVOC emissions obtained here are within the range of previous published estimates. The large range of emission estimates can be attributed to the use of different input data and empirical coefficients within different setups of MEGAN. The biogenic model shows a high sensitivity to the changes in plant functional type (PFT) distributions and associated emission factors for most of the compounds. The global emission impact for isoprene is about -9 %, but reaches +75 % for α-pinene when switching from global emission factor maps to PFT-specific emission factor distributions. The highest sensitivity of isoprene emissions is calculated when considering soil moisture impact, with a global decrease of 12.5 % when the soil moisture activity factor is included in the model parameterization. Nudging ECHAM6 climate towards ERA-Interim reanalysis has an impact on the

  11. [Iron concentration and acceptation of yoghurt prepared in casting iron pots (iron migration and acceptation of yogurt)].

    PubMed

    Quintaes, Késia Diego; Almeyda Haj-Isa, Niurka M; Morgano, Marcelo Antônio

    2005-12-01

    Food fortification is an interesting strategy to treat and prevent iron anemia. This study aims to quantify the iron in yoghurt, with gelatin and sugar and without, prepared in iron and glass containers. Sensorial test was use to evaluate the acceptance and preference of the both products. The yoghurt was prepared in containers of iron and glass with UHT milk, powder milk and natural industrialized yoghurt. After fermentation, half of the product received addition of sugar and strawberry flavor gelatin. The collected samples get the total iron quantified by ICP OES. Sensorial analysis involving 105 consumers was use to determine the acceptance and preference of the products. 0,018 and 0,882mg of iron per 100g added in the natural yoghurt prepared in the glass and in the iron pots, respectively. The yoghurt with gelatin presented 0,037 and 1,302mg of iron per 100g when prepared in the glass and in the iron pots, respectively. The preference was low for the yoghurt prepared in the iron pot (29,5%), but when added strawberry gelatin it was about 51,5%. The yoghurt prepared in iron pots, is easily home made and adds important amount of iron. Add gelatin and sugar can favored its consumption.

  12. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the service...

  13. EVALUATION OF SOLID ADSORBENTS FOR THE COLLECTION AND ANALYSES OF AMBIENT BIOGENIC VOLATILE ORGANICS

    EPA Science Inventory

    Micrometeorological flux measurements of biogenic volatile organic compounds (BVOCs) usually require that large volumes of air be collected (whole air samples) or focused during the sampling process (cryogenic trapping or gas-solid partitioning on adsorbents) in order to achiev...

  14. Biogenic disturbance determines invasion success in a subtidal soft-sediment system.

    PubMed

    Lohrer, Andrew M; Chiaroni, Luca D; Hewitt, Judi E; Thrush, Simon F

    2008-05-01

    Theoretically, disturbance and diversity can influence the success of invasive colonists if (1) resource limitation is a prime determinant of invasion success and (2) disturbance and diversity affect the availability of required resources. However, resource limitation is not of overriding importance in all systems, as exemplified by marine soft sediments, one of Earth's most widespread habitat types. Here, we tested the disturbance-invasion hypothesis in a marine soft-sediment system by altering rates of biogenic disturbance and tracking the natural colonization of plots by invasive species. Levels of sediment disturbance were controlled by manipulating densities of burrowing spatangoid urchins, the dominant biogenic sediment mixers in the system. Colonization success by two invasive species (a gobiid fish and a semelid bivalve) was greatest in plots with sediment disturbance rates < 500 cm(3) x m(-2) x d(-1), at the low end of the experimental disturbance gradient (0 to > 9000 cm(3) x m(-2) x d(-1)). Invasive colonization declined with increasing levels of sediment disturbance, counter to the disturbance-invasion hypothesis. Increased sediment disturbance by the urchins also reduced the richness and diversity of native macrofauna (particularly small, sedentary, surface feeders), though there was no evidence of increased availability of resources with increased disturbance that would have facilitated invasive colonization: sediment food resources (chlorophyll a and organic matter content) did not increase, and space and access to overlying water were not limited (low invertebrate abundance). Thus, our study revealed the importance of biogenic disturbance in promoting invasion resistance in a marine soft-sediment community, providing further evidence of the valuable role of bioturbation in soft-sediment systems (bioturbation also affects carbon processing, nutrient recycling, oxygen dynamics, benthic community structure, and so on.). Bioturbation rates are

  15. Diclofenac and 2‐anilinophenylacetate degradation by combined activity of biogenic manganese oxides and silver

    PubMed Central

    Meerburg, Francis; Hennebel, Tom; Vanhaecke, Lynn; Verstraete, Willy; Boon, Nico

    2012-01-01

    Summary The occurrence of a range of recalcitrant organic micropollutants in our aquatic environment has led to the development of various tertiary wastewater treatment methods. In this study, biogenic manganese oxides (Bio‐MnOx), biogenic silver nanoparticles (Bio‐Ag0) and ionic silver were used for the oxidative removal of the frequently encountered drug diclofenac and its dechlorinated form, 2‐anilinophenylacetate (APA). Diclofenac was rapidly degraded during ongoing manganese oxidation by Pseudomonas putida MnB6. Furthermore, whereas preoxidized Bio‐MnOx, Bio‐Ag0 and Ag+ separately did not show any removal capacity for diclofenac, an enhanced removal occurred when Bio‐MnOx and silver species were combined. Similar results were obtained for APA. Finally, a slow removal of diclofenac but more rapid APA degradation was observed when silver was added to manganese‐free P. putida biomass. Combining these results, three mechanisms of diclofenac and APA removal could be distinguished: (i) a co‐metabolic removal during active Mn2+ oxidation by P. putida; (ii) a synergistic interaction between preoxidized Bio‐MnOx and silver species; and (iii) a (bio)chemical process by biomass enriched with silver catalysts. This paper demonstrates the use of P. putida for water treatment purposes and is the first report of the application of silver combined with biogenic manganese for the removal of organic water contaminants. PMID:22221449

  16. BIOGENIC HYDROCARBON EMISSION INVENTORY FOR THE U.S. USING A SIMPLE FOREST CANOPY MODEL

    EPA Science Inventory

    A biogenic hydrocarbon emission inventory system, developed for acid deposition and regional oxidant modeling, is described, and results for a U.S. emission inventory are presented. or deciduous and coniferous forests, scaling relationships are used to account for canopy effects ...

  17. Microbially induced iron precipitation associated with a neutrophilic spring at Borra Caves, Vishakhapatnam, India.

    PubMed

    Baskar, Sushmitha; Baskar, Ramanathan; Thorseth, Ingunn H; Ovreås, Lise; Pedersen, Rolf B

    2012-04-01

    Betaproteobacteria. Four (4%) of the sequences could not be assigned to phylum level but were affiliating with the candidate division TM7 (2%), candidate division OP11 (1%), and candidate division WWE3 (1%). The results allow us to infer a possible relationship of microbial sheaths, EPS, and the iron precipitates to microbial community diversity in the Borra cave springs. Understanding biogenic iron oxides in caves has important astrobiological applications as it provides a potential tool for the detection of extraterrestrial life.

  18. Biogenic amine formation and nitrite reactions in meat batter as affected by high-pressure processing and chilled storage.

    PubMed

    Ruiz-Capillas, C; Aller-Guiote, P; Carballo, J; Colmenero, F Jiménez

    2006-12-27

    Changes in biogenic amine formation and nitrite depletion in meat batters as affected by pressure-temperature combinations (300 MPa/30 min/7, 20, and 40 degrees C), cooking process (70 degrees C/30 min), and storage (54 days/2 degrees C) were studied. Changes in residual nitrite concentration in raw meat batters were conditioned by the temperature and not by the pressure applied. Cooking process decreased (P < 0.05) the residual nitrite concentration in all samples. High-pressure processing and cooking treatment increased (P < 0.05) the nitrate content. Whereas protein-bound nitrite concentration decreased with pressure processing, no effect was observed with the heating process of meat batters. High-pressure processing conditions had no effect on the rate of residual nitrite loss throughout the storage. The application of high pressure decreased (P < 0.05) the concentration of some biogenic amines (tyramine, agmatine, and spermine). Irrespective of the high processing conditions, generally, throughout storage biogenic amine levels did not change or increased, although quantitatively this effect was not very important.

  19. Iron state in iron nanoparticles with and without zirconium

    NASA Astrophysics Data System (ADS)

    Filippov, V. P.; Khasanov, A. M.; Lauer, Yu. A.

    2017-11-01

    Mössbauer and X-ray methods are used for investigations of structure, stability and characteristics of pure-iron grain and two iron-zirconium alloys such as Fe + 5 wt.% Zr and Fe + 10 wt.% Zr. The used powder was ground for 24 h in a SPEX Model 8000 mill shaker. Complex nanoparticles are found, which change their properties under milling. Mössbauer spectral parameters are obtained for investigated materials. Milling results in formation of nanosized particles with two states of iron atoms: one main part is pure α-Fe and another part of iron atoms displaced in grain boundaries or defective zones in which hyperfine magnetic splitting decrease to ˜ 30.0 T. In alloys with Zr three iron states are formed in each alloy, main part of iron is in the form of α-Fe and another two states depend on the concentration of Zr and represent iron in grain boundaries with Zr atoms in nearest neighbor. The changing of iron states is discussed.

  20. Studying Irony Detection Beyond Ironic Criticism: Let's Include Ironic Praise

    PubMed Central

    Bruntsch, Richard; Ruch, Willibald

    2017-01-01

    Studies of irony detection have commonly used ironic criticisms (i.e., mock positive evaluation of negative circumstances) as stimulus materials. Another basic type of verbal irony, ironic praise (i.e., mock negative evaluation of positive circumstances) is largely absent from studies on individuals' aptitude to detect verbal irony. However, it can be argued that ironic praise needs to be considered in order to investigate the detection of irony in the variety of its facets. To explore whether the detection ironic praise has a benefit beyond ironic criticism, three studies were conducted. In Study 1, an instrument (Test of Verbal Irony Detection Aptitude; TOVIDA) was constructed and its factorial structure was tested using N = 311 subjects. The TOVIDA contains 26 scenario-based items and contains two scales for the detection of ironic criticism vs. ironic praise. To validate the measurement method, the two scales of the TOVIDA were experimentally evaluated with N = 154 subjects in Study 2. In Study 3, N = 183 subjects were tested to explore personality and ability correlates of the two TOVIDA scales. Results indicate that the co-variance between the ironic TOVIDA items was organized by two inter-correlated but distinct factors: one representing ironic praise detection aptitude and one representing ironic criticism detection aptitude. Experimental validation showed that the TOVIDA items truly contain irony and that item scores reflect irony detection. Trait bad mood and benevolent humor (as a facet of the sense of humor) were found as joint correlates for both ironic criticism and ironic praise detection scores. In contrast, intelligence, trait cheerfulness, and corrective humor were found as unique correlates of ironic praise detection scores, even when statistically controlling for the aptitude to detect ironic criticism. Our results indicate that the aptitude to detect ironic praise can be seen as distinct from the aptitude to detect ironic criticism. Generating

  1. The adsorption of biogenic amines on carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Sidorenko, I. G.; Markitan, O. V.; Vlasova, N. N.; Zagorovskii, G. M.; Lobanov, V. V.

    2009-06-01

    The adsorption of phenylethylamine, tryptamine, and tyramine on carbon nanotubes from aqueous solutions (pH 7.4) was studied depending on time and sorbate concentration. The suggestion was made that their interaction with electrodes was determined by electrostatic attraction between protonated amino groups and oxygen-containing functional groups of the surface of carbon. An increase in the adsorption of biological amines was caused by the interaction of the π systems of their aromatic rings with carbon surface hexagons. The adsorption of biogenic amines on carbon nanotubes was necessary for their possible electrooxidation and analytic determination by electrochemical methods with the use of carbon electrodes.

  2. METABOLISM OF IRON STORES

    PubMed Central

    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 the pioneering research by Shoden in 1953. However, we recently developed a new method for determining ferritin iron and hemosiderin iron by computer-assisted serum ferritin kinetics. Serum ferritin increase or decrease curves were measured in patients with normal storage iron levels (chronic hepatitis C and iron deficiency anemia treated by intravenous iron injection), and iron overload (hereditary hemochromatosis and transfusion dependent anemia). We thereby confirmed the existence of two iron pathways where iron flows followed the numbered order (1) labile iron, (2) ferritin and (3) hemosiderin in iron deposition and mobilization among many previously proposed but mostly unproven routes. We also demonstrated the increasing and decreasing phases of ferritin iron and hemosiderin iron in iron deposition and mobilization. The author first demonstrated here the change in proportion between pre-existing ferritin iron and new ferritin iron synthesized by removing iron from hemosiderin in the course of iron removal. In addition, the author disclosed the cause of underestimation of storage iron turnover rate which had been reported by previous investigators in estimating storage iron turnover rate of normal subjects. PMID:25741033

  3. Monitoring of biogenic amines and drugs of various therapeutic groups in urine samples with use of HPLC.

    PubMed

    Baranowska, Irena; Płonka, Joanna

    2016-04-01

    A high-performance liquid chromatography method for simultaneous separation and determination of biogenic amines [dopamine, epinephrine, serotonin and its six metabolites (normetanephrine, metanephrine, 3,4-dihydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenylglycol, homovanilic acid and 5-hydroxyindoloacetic acid)] with drugs from different therapeutically groups [analgesics (paracetamol, metamizol), diuretics (furosemide) and antibiotics (cefazolin, fluconazole)] was developed. A chromatographic column with pre-column with octadecylsilane phase (C18e ) and two detectors - diode array serial connected and fluorescence - was used. Gradient elution of mixture of acetate buffer (pH 4.66) and methanol as a mobile phase was applied. The limit of detection (LOD) of 8-10 ng/mL and limit of quantitation (LOQ) of 24-30 ng/mL for biogenic amines, as well as the LOD of 50-100 ng/mL and the LOQ of 150-300 ng/mL for drugs, were determined. The applied sample preparation method allowed recoveries of 93% for the biogenic amines and 92% for the drugs to be achieved. The developed procedure has been applied to simultaneous determination of the examined compounds in urine samples and could be used in clinical analysis. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Microbial consortia controlling biogenic gas formation in the Qaidam Basin of western China

    NASA Astrophysics Data System (ADS)

    Shuai, Yanhua; Zhang, Shuichang; Grasby, Stephen E.; Hou, Weiguo; Chen, Zhuoheng; Huang, Ling; Kui, Mingqing; Xu, Yirui; Wang, Yang

    2016-08-01

    Knowledge of what controls the activity of subsurface microbial communities is critical for assessing and managing biogenic methane resources. In this study, 19 formation waters and five gas samples were collected at depths of 800 to 1900 m from Quaternary biogenic gas fields of the Qaidam Basin, China. The formation waters were brines with chloride (Cl) concentrations from 1200 to 2700 mM. Bacterial 16S rRNA gene copies ranged from 3.75 × 104 to 2.23 × 106 copies mL-1 of water, and those of archaea ranged from 2.44 × 103 to 4.66 × 107 copies mL-1 of water. Both bacterial and archaea 16 s rRNA gene copies were negatively correlated with Cl concentration. The microbial community structure differed significantly depending on Cl concentrations. At high Cl waters (>1800 mM), the microbial community showed a halophilic signature made up of several abundant taxonomic groups within Firmicules, γ-Proteobacteria, and methylotrophic Methanosarcinales. At low Cl, Firmicules and hydrogenotrophic methanogens were dominant members. The proportion of inferred hydrogenotrophic methanogens decreased from 89% to 14% of total archaeal reads with increasing Cl concentration; in contrast, methylotrophic species increased from 11% to 85%. Given that the proportion of hydrogenotrophic species was positively correlated with the archaeal gene abundances, we suggest that Cl concentrations primarily constrain the activity of archaea catalyzing H2 reduction of CO2. Our results show that dilution of formation waters is critical in the process of biogenic gas formation, suggesting that an engineered decrease in Cl concentrations may induce methanogenesis as a potential method to increase gas reserves in such areas in the future.

  5. Genome Sequence of Lactobacillus saerimneri 30a (Formerly Lactobacillus sp. Strain 30a), a Reference Lactic Acid Bacterium Strain Producing Biogenic Amines

    PubMed Central

    Romano, Andrea; Trip, Hein; Campbell-Sills, Hugo; Bouchez, Olivier; Sherman, David; Lolkema, Juke S.

    2013-01-01

    Lactobacillus sp. strain 30a (Lactobacillus saerimneri) produces the biogenic amines histamine, putrescine, and cadaverine by decarboxylating their amino acid precursors. We report its draft genome sequence (1,634,278 bases, 42.6% G+C content) and the principal findings from its annotation, which might shed light onto the enzymatic machineries that are involved in its production of biogenic amines. PMID:23405290

  6. Formation of biogenic sheath-like Fe oxyhydroxides in a near-neutral pH hot spring: Implications for the origin of microfossils in high-temperature, Fe-rich environments

    NASA Astrophysics Data System (ADS)

    Peng, Xiaotong; Chen, Shun; Xu, Hengchao

    2013-12-01

    small hot spring that is informally called "Fe-waterfall spring" and is located in the Rehai geothermal area discharges hot (42 to 73°C), near-neutral (pH = 7.65) Fe-rich water. Submerged reddish precipitates are composed largely of ferrihydrite, goethite, lepidocrocite, opal-A, quartz, and anorthite, as revealed by X-ray diffraction (XRD) and Mössbauer spectroscopy. Molecular phylogenetic analysis demonstrates that the bacterial community in these precipitates is mainly composed of Cyanobacteria, Planctomycetes, β-proteobacteria, Deinococci-Thermus, and Chlorobi. Scanning electron microscopy and high-resolution transmission electron microscopy examinations show that abundant sheath-like Fe oxyhydroxides, which exhibit different morphologies and sizes, are present in Fe-rich precipitates. These sheath-like structures are composed of ferrihydrite rather than more crystalline lepidocrocite or goethite. Energy-dispersive X-ray spectrometer, scanning transmission electron microscopy, and nano secondary ion mass spectrometry reveal that they are mainly composed of Fe, Si, and O, together with some trace elements. Most of the sheath-like structures are not morphologically comparable to biogenic Fe oxyhydroxides produced by known chemolithotrophic Fe oxidizers, which is consistent with the fact that no chemolithotrophic Fe oxidizers were identified by molecular analysis in the precipitates. We suggest that the sheath-like Fe oxyhydroxides are formed through passive Fe sorption and nucleation onto the cell walls of various thermophiles rather than by the direct metabolic activities of chemolithotrophic Fe oxidizers. Biogenic sheath-like Fe oxyhydroxides in Fe-waterfall spring have important implications for geochemical cycles driven by microorganisms, the origin of microfossils, and the formation of banded iron formations (BIFs) in the Archean ocean.

  7. New developments and controversies in iron metabolism and iron chelation therapy

    PubMed Central

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-01-01

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients’ therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  8. Long-term variation of mesopelagic biogenic flux in the central South China Sea: Impact of monsoonal seasonality and mesoscale eddy

    NASA Astrophysics Data System (ADS)

    Li, Hongliang; Wiesner, Martin G.; Chen, Jianfang; Ling, Zheng; Zhang, Jingjing; Ran, Lihua

    2017-08-01

    The East Asian Monsoon and mesoscale eddies are known to regulate primary production in South China Sea (SCS), the largest tropical marginal sea; however, their contributions to the deep biogenic flux are yet to be quantified. Based on 7-year time series sediment trap observations at the depth of 1200 m in the central SCS, we used the monthly average sinking biogenic fluxes to evaluate the impact of the monsoon and mesoscale cyclonic eddies on biogenic fluxes in combination with remote sensing physical parameters. The monthly average particulate organic carbon (POC) and opal fluxes, ranging from 3.0 to 5.2 and 14.8-34.9 mg m-2 d-1, respectively, were higher during the northeastern monsoon period. This corresponded to the deeper mixed layer depth and higher net primary production in this area, due to nutrient replenishment from the subsurface induced by monsoon transition and surface cooling. In contrast, lower POC and opal fluxes occurred during well-stratified inter-monsoon periods. In addition, CaCO3 flux (23.6-37.0 mg m-2 d-1) exhibited less seasonality and was assumed to originate from foraminifera. In terms of the long-term record, the combined effect of cyclonic eddies and mixing in the upper ocean could effectively regulate the temporal variation in the biogenic flux. In particular, the opal and POC fluxes in cyclonic eddies were 116% and 41% higher on average, respectively, than those during the non-cyclonic eddy period. Since the cyclonic eddies mainly occurred during the northeastern monsoon period, their contributions to biogenic flux via diatom blooms might overlap the regular winter flux peak, which could make the biological carbon pump more efficient at CO2 sequestration during this period thus amplifying the impact of seasonal transition.

  9. Anthropogenic impact on biogenic substance distribution and bacterial community in sediment along the Yarlung Tsangpo River on Tibet Plateau, China

    NASA Astrophysics Data System (ADS)

    Wang, C.; Peifang, W.; Wang, X.; Hou, J.; Miao, L.

    2017-12-01

    Lotic river system plays an important part in water-vapor transfer and biogenic substances migration and transformation. Anthropogenic activities, including wastewater discharging and river damming, have altered river ecosystem and continuum. However, as the longest alpine river in China and suffered from increasing anthropogenic activities, the Yarlung Tsangpo River has been rarely studied. Recently, more attention has also been paid to the bacteria in river sediment as they make vital contributions to the biogeochemical nutrient cycling. Here, the distribution of biogenic substances, including nitrogen, phosphorus, silicon and carbon, was explored in both water and sediment of the Yarlung Tsangpo River. By using the next generation 16S rRNA sequencing, the bacterial diversity and structure in river sediment were presented. The results indicated that the nutrient concentrations increased in densely populated sites, revealing that biogenic substance distribution corresponded with the intensity of anthropogenic activity along the river. Nitrogen, phosphorus, silicon and carbon in water and sediment were all retained by the Zangmu Dam which is the only dam in the mainstream of the river. Moreover, the river damming decreased the biomass and diversity of bacteria in sediment, but no significant alteration of community structure was observed upstream and downstream of the dam. The most dominant bacteria all along the river was Proteobacteria. Meanwhile, Verrucomicrobia and Firmicutes also dominated the community composition in upstream and downstream of the river, respectively. In addition, total organic carbon (TOC) was proved to be the most important environmental factor shaping the bacterial community in river sediment. Our study offered the preliminary insights into the biogenic substance distribution and bacterial community in sediment along an alpine river which was affected by anthropogenic activities. In the future, more studies are needed to reveal the

  10. Biogenic porous silica and silicon sourced from Mexican Giant Horsetail (Equisetum myriochaetum) and their application as supports for enzyme immobilization.

    PubMed

    Sola-Rabada, Anna; Sahare, Padma; Hickman, Graham J; Vasquez, Marco; Canham, Leigh T; Perry, Carole C; Agarwal, Vivechana

    2018-06-01

    Porous silica-based materials are attractive for biomedical applications due to their biocompatibility and biodegradable character. In addition, inorganic supports such as porous silicon are being developed due to integrated circuit chip compatibility and tunable properties leading to a wide range of multidisciplinary applications. In this contribution, biosilica extracted from a rarely studied plant material (Equisetum Myriochaetum), its conversion to silicon and the potential for both materials to be used as supports for enzyme immobilization are investigated. E. myriochaetum was subject to conventional acid digestion to extract biogenic silica with a% yield remarkably higher (up to 3 times) than for other Equisetum sp. (i.e. E. Arvense). The surface area of the isolated silica was ∼400 m 2 /g, suitable for biotechnological applications. Biogenic silicon was obtained by magnesiothermic reduction. The materials were characterized by SEM-EDX, XRD, FT-IR, ICP-OES, TGA and BET analysis and did not contain significant levels of class 1 heavy elements (such as Pb, Cd, Hg and As). Two commercial peroxidases, horseradish peroxidase (HRP) and Coprinus cinereus peroxidase (CiP) were immobilized onto the biogenic materials using three different functionalization routes: (A) carbodiimide, (B) amine + glutaraldehyde and (C) amine + carbodiimide. Although both biogenic silica and porous silicon could be used as supports differences in behaviour were observed for the two enzymes. For HRP, loading onto biogenic silica via the glutaraldehyde immobilization technique (route B) was most effective. The loading of CiP showed a much higher peroxidase activity onto porous silicon than silica functionalized by the carbodiimide method (route A). From the properties of the extracted materials obtained from Equisetum Myriochaetum and the immobilization results observed, these materials appear to be promising for industrial and biomedical applications. Copyright © 2018 Elsevier

  11. Chemometric perspectives on plankton community responses to natural iron fertilisation over and downstream of the Kerguelen Plateau in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Trull, T. W.; Davies, D. M.; Dehairs, F.; Cavagna, A.-J.; Lasbleiz, M.; Laurenceau-Cornec, E. C.; d'Ovidio, F.; Planchon, F.; Leblanc, K.; Quéguiner, B.; Blain, S.

    2015-02-01

    We examined phytoplankton community responses to natural iron fertilisation at 32 sites over and downstream from the Kerguelen Plateau in the Southern Ocean during the austral spring bloom in October-November 2011. The community structure was estimated from chemical and isotopic measurements (particulate organic carbon - POC; 13C-POC; particulate nitrogen - PN; 15N-PN; and biogenic silica - BSi) on size-fractionated samples from surface waters (300, 210, 50, 20, 5, and 1 μm fractions). Higher values of 13C-POC (vs. co-located 13C values for dissolved inorganic carbon - DIC) were taken as indicative of faster growth rates and higher values of 15N-PN (vs. co-located 15N-NO3 source values) as indicative of greater nitrate use (rather than ammonium use, i.e. higher f ratios). Community responses varied in relation to both regional circulation and the advance of the bloom. Iron-fertilised waters over the plateau developed dominance by very large diatoms (50-210 μm) with high BSi / POC ratios, high growth rates, and significant ammonium recycling (lower f ratios) as biomass built up. In contrast, downstream polar frontal waters with a similar or higher iron supply were dominated by smaller diatoms (20-50 μm) and exhibited greater ammonium recycling. Stations in a deep-water bathymetrically trapped recirculation south of the polar front with lower iron levels showed the large-cell dominance observed on the plateau but much less biomass. Comparison of these communities to surface water nitrate (and silicate) depletions as a proxy for export shows that the low-biomass recirculation feature had exported similar amounts of nitrogen to the high-biomass blooms over the plateau and north of the polar front. This suggests that early spring trophodynamic and export responses differed between regions with persistent low levels vs. intermittent high levels of iron fertilisation.

  12. Iron deficiency and iron excess damage mitochondria and mitochondrial DNA in rats

    PubMed Central

    Walter, Patrick B.; Knutson, Mitchell D.; Paler-Martinez, Andres; Lee, Sonia; Xu, Yu; Viteri, Fernando E.; Ames, Bruce N.

    2002-01-01

    Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (≤5 μg/day) and iron-normal (800 μg/day) rats and in both groups after daily high-iron supplementation (8,000 μg/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 μg) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 × nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake. PMID:11854522

  13. Spatial and Temporal Variability in Biogenic Gas Accumulation and Release in The Greater Everglades at Multiple Scales of Measurement

    NASA Astrophysics Data System (ADS)

    McClellan, M. D.; Cornett, C.; Schaffer, L.; Comas, X.

    2017-12-01

    Wetlands play a critical role in the carbon (C) cycle by producing and releasing significant amounts of greenhouse biogenic gasses (CO2, CH4) into the atmosphere. Wetlands in tropical and subtropical climates (such as the Florida Everglades) have become of great interest in the past two decades as they account for more than 20% of the global peatland C stock and are located in climates that favor year-round C emissions. Despite the increase in research involving C emission from these types of wetlands, the spatial and temporal variability involving C production, accumulation and release is still highly uncertain, and is the focus of this research at multiple scales of measurement (i.e. lab, field and landscape). Spatial variability in biogenic gas content, build up and release, at both the lab and field scales, was estimated using a series of ground penetrating radar (GPR) surveys constrained with gas traps fitted with time-lapse cameras. Variability in gas content was estimated at the sub-meter scale (lab scale) within two extracted monoliths from different wetland ecosystems at the Disney wilderness Preserve (DWP) and the Blue Cypress Preserve (BCP) using high frequency GPR (1.2 GHz) transects across the monoliths. At the field scale (> 10m) changes in biogenic gas content were estimated using 160 MHz GPR surveys collected within 4 different emergent wetlands at the DWP. Additionally, biogenic gas content from the extracted monoliths was used to developed a landscape comparison of C accumulation and emissions for each different wetland ecosystem. Changes in gas content over time were estimated at the lab scale at high temporal resolution (i.e. sub-hourly) in monoliths from the BCP and Water Conservation Area 1-A. An autonomous rail system was constructed to estimate biogenic gas content variability within the wetland soil matrix using a series of continuous, uninterrupted 1.2 GHz GPR transects along the samples. Measurements were again constrained with an array

  14. Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters, and iron storage proteins.

    PubMed

    Niles, Brad J; Clegg, Michael S; Hanna, Lynn A; Chou, Susan S; Momma, Tony Y; Hong, Heeok; Keen, Carl L

    2008-02-22

    One consequence of zinc deficiency is an elevation in cell and tissue iron concentrations. To examine the mechanism(s) underlying this phenomenon, Swiss 3T3 cells were cultured in zinc-deficient (D, 0.5 microM zinc), zinc-supplemented (S, 50 microM zinc), or control (C, 4 microM zinc) media. After 24 h of culture, cells in the D group were characterized by a 50% decrease in intracellular zinc and a 35% increase in intracellular iron relative to cells in the S and C groups. The increase in cellular iron was associated with increased transferrin receptor 1 protein and mRNA levels and increased ferritin light chain expression. The divalent metal transporter 1(+)iron-responsive element isoform mRNA was decreased during zinc deficiency-induced iron accumulation. Examination of zinc-deficient cells revealed increased binding of iron regulatory protein 2 (IRP2) and decreased binding of IRP1 to a consensus iron-responsive element. The increased IRP2-binding activity in zinc-deficient cells coincided with an increased level of IRP2 protein. The accumulation of IRP2 protein was independent of zinc deficiency-induced intracellular nitric oxide production but was attenuated by the addition of the antioxidant N-acetylcysteine or ascorbate to the D medium. These data support the concept that zinc deficiency can result in alterations in iron transporter, storage, and regulatory proteins, which facilitate iron accumulation.

  15. Out of Balance—Systemic Iron Homeostasis in Iron-Related Disorders

    PubMed Central

    Steinbicker, Andrea U.; Muckenthaler, Martina U.

    2013-01-01

    Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism. PMID:23917168

  16. Mammalian iron metabolism and its control by iron regulatory proteins☆

    PubMed Central

    Anderson, Cole P.; Shen, Lacy; Eisenstein, Richard S.; Leibold, Elizabeth A.

    2013-01-01

    Cellular iron homeostasis is maintained by iron regulatory proteins 1 and 2 (IRP1 and IRP2). IRPs bind to iron-responsive elements (IREs) located in the untranslated regions of mRNAs encoding protein involved in iron uptake, storage, utilization and export. Over the past decade, significant progress has been made in understanding how IRPs are regulated by iron-dependent and iron-independent mechanisms and the pathological consequences of IRP2 deficiency in mice. The identification of novel IREs involved in diverse cellular pathways has revealed that the IRP–IRE network extends to processes other than iron homeostasis. A mechanistic understanding of IRP regulation will likely yield important insights into the basis of disorders of iron metabolism. This article is part of a Special Issue entitled: Cell Biology of Metals. PMID:22610083

  17. Increased iron availability resulting from increased CO2 enhances carbon and nitrogen metabolism in the economical marine red macroalga Pyropia haitanensis (Rhodophyta).

    PubMed

    Chen, Binbin; Zou, Dinghui; Yang, Yufeng

    2017-04-01

    Ocean acidification caused by rising CO 2 is predicted to increase the concentrations of dissolved species of Fe(II) and Fe(III), leading to the enhanced photosynthetic carbon sequestration in some algal species. In this study, the carbon and nitrogen metabolism in responses to increased iron availability under two CO 2 levels (390 μL L -1 and 1000 μL L -1 ), were investigated in the maricultivated macroalga Pyropia haitanensis (Rhodophyta). The results showed that, elevated CO 2 increased soluble carbonhydrate (SC) contents, resulting from enhanced photosynthesis and photosynthetic pigment synthesis in this algae, but declined its soluble protein (SP) contents, resulting in increased ratio of SC/SP. This enhanced photosynthesis performance and carbon accumulation was more significant under iron enrichment condition in seawater, with higher iron uptake rate at high CO 2 level. As a key essential biogenic element for algae, Fe-replete functionally contributed to P. haitanensis photosynthesis. Increased SC fundamentally provided carbon skeletons for nitrogen assimilation. The significant increase of carbon and nitrogen assimilation finally contributed to enhanced growth in this alga. This was also intuitively reflected by respiration that provided energy for cellular metabolism and algal growth. We propose that, in the predicted scenario of rising atmospheric CO 2 , P. haitanensis is capable to adjust its physiology by increasing its carbon and nitrogen metabolism to acclimate the acidified seawater, at the background of global climate change and simultaneously increased iron concentration due to decreased pH levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

    PubMed Central

    Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

    2013-01-01

    Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

  19. Ferritin iron minerals are chelator targets, antioxidants, and coated, dietary iron.

    PubMed

    Theil, Elizabeth C

    2010-08-01

    Cellular ferritin is central for iron balance during transfusions therapies; serum ferritin is a small fraction of body ferritin, albeit a convenient reporter. Iron overload induces extra ferritin protein synthesis but the protein is overfilled with the extra iron that damages ferritin, with conversion to toxic hemosiderin. Three new approaches that manipulate ferritin to address excess iron, hemosiderin, and associated oxidative damage in Cooley's Anemia and other iron overload conditions are faster removal of ferritin iron with chelators guided to ferritin gated pores by peptides; more ferritin protein synthesis using ferritin mRNA activators, by metal complexes that target mRNA 3D structures; and determining if endocytotic absorption of iron from legumes, which is mostly ferritin, is regulated during iron overload to prevent excess iron entry while providing protein. More of a focus on ferritin features, including protein cage structure, iron mineral, regulatable mRNA, and specific gut absorption properties, will achieve the three novel experimental goals for managing iron homeostasis with transfusion therapies.

  20. Siderophore-mediated iron trafficking in humans is regulated by iron

    PubMed Central

    Liu, Zhuoming; Lanford, Robert; Mueller, Sebastian; Gerhard, Glenn S.; Luscieti, Sara; Sanchez, Mayka; Devireddy, L.

    2013-01-01

    Siderophores are best known as small iron binding molecules that facilitate microbial iron transport. In our previous study we identified a siderophore-like molecule in mammalian cells and found that its biogenesis is evolutionarily conserved. A member of the short chain dehydrogenase family of reductases, 3-OH butyrate dehydrogenase (BDH2) catalyzes a rate-limiting step in the biogenesis of the mammalian siderophore. We have shown that depletion of the mammalian siderophore by inhibiting expression of bdh2 results in abnormal accumulation of cellular iron and mitochondrial iron deficiency. These observations suggest that the mammalian siderophore is a critical regulator of cellular iron homeostasis and facilitates mitochondrial iron import. By utilizing bioinformatics, we identified an iron-responsive element (IRE; a stem-loop structure that regulates genes expression post-transcriptionally upon binding to iron regulatory proteins or IRPs) in the 3′-untranslated region (3′-UTR) of the human BDH2 (hBDH2) gene. In cultured cells as well as in patient samples we now demonstrate that the IRE confers iron-dependent regulation on hBDH2 and binds IRPs in RNA electrophoretic mobility shift assays. In addition, we show that the hBDH2 IRE associates with IRPs in cells and that abrogation of IRPs by RNAi eliminates the iron-dependent regulation of hBDH2 mRNA. The key physiologic implication is that iron-mediated post-transcriptional regulation of hBDH2 controls mitochondrial iron homeostasis in human cells. These observations provide a new and an unanticipated mechanism by which iron regulates its intracellular trafficking. PMID:22527885

  1. Iron overdose

    MedlinePlus

    ... 1222) from anywhere in the United States. Poisonous Ingredient Iron can be harmful in large amounts. Where Found Iron is an ingredient in many mineral and vitamin supplements. Iron supplements ...

  2. Additive impairment of the barrier function and irritation by biogenic amines and sodium lauryl sulphate: a controlled in vivo tandem irritation study.

    PubMed

    Fluhr, J W; Kelterer, D; Fuchs, S; Kaatz, M; Grieshaber, R; Kleesz, P; Elsner, P

    2005-01-01

    Biogenic amines are potential irritants e.g. in fish-, meat-, milk- and egg-processing professions like cooks, butchers and bakers. The aim of this study was to test the irritative and barrier-disrupting properties of the biogenic amines ammonium hydroxide (AM), dimethylamine (DMA) and trimethylamine (TMA). A repeated sequential irritation of 30 min twice per day was performed over a total of 4 days (tandem repeated irritation test) on the back of 20 healthy volunteers of both sexes with AM, DMA, TMA and sodium lauryl sulphate (SLS). The epidermal barrier function was assessed with a Tewameter TM 210, stratum corneum surface pH was measured with a Skin-pH-Meter 900, inflammation was assessed with a Chromameter CR-300 on the a* axis for redness and a visual score was recorded. All tested biogenic amines (AM, DMA and TMA) induced a barrier disruption and a pH increase paralleled with a 1-day-delayed onset of inflammatory signs. These effects were further enhanced and accelerated by a sequential application of SLS together with the biogenic amines, and inflammation occurred earlier than with the single compounds. Acetic acid (AA) in contrast did only show mild barrier disruption and no significant inflammatory signs. Our system allowed a ranking of the different compounds in their irritative potential in the tandem irritation with SLS: SLS > NaOH > TMA > AA > AM > DMA. The results are suggestive that in the food-processing industry the simultaneous contact with biogenic amines and harmful detergents like SLS should be minimized. Copyright 2005 S. Karger AG, Basel.

  3. Iron release from the Lucky Iron Fish®: safety considerations.

    PubMed

    Armstrong, Gavin R; Dewey, Cate E; Summerlee, Alastair Js

    2017-01-01

    The principal objective was to explore in greater detail safety issues with regard to the use of the Lucky Iron Fish® (fish) as a treatment for iron deficiency and iron deficiency anaemia in women in rural Cambodia. Experiments were done to determine: (1) purity of the iron in the fish by mass spectroscopy; (2) release of iron and contaminants released during boiling in water using inductive-ly-coupled plasma optical emission spectroscopy; (3) the impact of cooking time, acidity and number of fish in acidified water and two types of Khmer soups; and (4) drinkability of the water after boiling with different num-bers of fish. The fish is composed primarily of ferrous iron with less than 12% non-ferrous iron. Contaminants were either not detectable or levels were below the acceptable standards set by the World Health Organization. The length of time boiling the fish and the acidity of the water increased iron release but even with 5 fish boiled for 60 minutes, iron levels only approached levels where side effects are observed. Boiling one fish in water did not affect the perception of colour, smell or taste of the water but boiling in water with two or more fish resulted in the water being unpalatable which further limits the potential for iron toxicity from using the fish. The results suggest that the Lucky Iron Fish™ may be a safe treatment for iron deficiency.

  4. New insights into iron deficiency and iron deficiency anemia.

    PubMed

    Camaschella, Clara

    2017-07-01

    Recent advances in iron metabolism have stimulated new interest in iron deficiency (ID) and its anemia (IDA), common conditions worldwide. Absolute ID/IDA, i.e. the decrease of total body iron, is easily diagnosed based on decreased levels of serum ferritin and transferrin saturation. Relative lack of iron in specific organs/tissues, and IDA in the context of inflammatory disorders, are diagnosed based on arbitrary cut offs of ferritin and transferrin saturation and/or marker combination (as the soluble transferrin receptor/ferritin index) in an appropriate clinical context. Most ID patients are candidate to traditional treatment with oral iron salts, while high hepcidin levels block their absorption in inflammatory disorders. New iron preparations and new treatment modalities are available: high-dose intravenous iron compounds are becoming popular and indications to their use are increasing, although long-term side effects remain to be evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Reducing iron deficiency anemia in Bolivian school children: calcium and iron combined versus iron supplementation alone.

    PubMed

    Miranda, Melissa; Olivares, Manuel; Brito, Alex; Pizarro, Fernando

    2014-01-01

    The aim of this study was to determine the effect of combined calcium and iron versus single iron supplementation on iron status in Bolivian schoolchildren. Children ages 6 to 10 y old (N = 195), were randomly assigned to receive either 700 mg Ca (as calcium carbonate) plus 30 mg Fe (as ferrous sulfate) (Ca + Fe group) or 30 mg Fe (as ferrous sulfate) (Fe group). The doses were administered daily, from Monday to Friday, between meals at school over 3 mo. Iron status was assessed at baseline and after intervention. Additionally, overall nutritional status was assessed by anthropometry and an estimation of dietary intake. At baseline, the prevalence of anemia in the Ca + Fe group and the Fe group were 15% and 21.5%, respectively. After 3 mo follow-up, the prevalence of iron deficiency anemia dropped significantly (P < 0.001) to 3% in both groups (χ(2) = NS). Iron dietary intake was within recommended levels, but calcium intake only covered 39% of the Recommended Daily Intake. Combined calcium and iron supplementation is equally as effective as single iron supplementation in reducing the prevalence of iron deficiency anemia in Bolivian school children. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism

    PubMed Central

    Horniblow, Richard D.; Dowle, Miriam; Iqbal, Tariq H.; Latunde-Dada, Gladys O.; Palmer, Richard E.

    2015-01-01

    Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease. PMID:26378798

  7. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM A LOWLAND TROPICAL WET FOREST IN COSTA RICA

    EPA Science Inventory

    Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCS) at a lowland tropical wet forest site in Costa Rica. Ten of the species. examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total bas...

  8. [Old and new iron parameters in iron metabolism and diagnostics].

    PubMed

    Graf, Lukas; Herklotz, Roberto; Huber, Andreas R; Korte, Wolfgang

    2008-09-01

    Iron is an element which is essential to life but also potentially toxic. Therefore, clever mechanisms exist in the human body for uptake, transport and storage of iron. Hepcidin, which seems to be the master protein for regulation of intestinal iron absorption, is known for a short time. The expression of hepcidin is not only influenced by iron levels but also by mediators of inflammation and growth factors of erythropoiesis. Hence hepcidin plays also a crucial role in the development of anemia of chronic disease and iron overload due to ineffective erythropoiesis. Serum ferritin is a reliable parameter to estimate the storage iron. It is an acute phase protein which is elevated during infections and inflammations, though. In these situations, measurement of soluble transferrin receptors is a useful tool to differentiate between iron deficiency and anemia of chronic disease. Newer parameters as erythrocyte zink protoporphyrin or percentage of hypochromic erythrocytes (%HYPO) are suited to detect a functional iron deficiency. Early diagnosis of iron overload is essential to prevent organ damage. Serum ferritin and transferrin are useful parameters to screen for iron overload. If no clear reason for a secondary iron overload can be found, the search for a hereditary haemochromatosis is recommended. Most of these hereditary haemochromatoses are a result of mutations in the HFE gene (homozygous state for Cys282Tyr or compound heterozygosity for Cys282Tyr/ His63Asp) which can be detected by PCR technique. Liver biopsy is still the gold standard for quantification of storage iron. However, a method of increasing importance for quantification of iron overload is magnetic resonance imaging with new approaches as for example T2*.

  9. Nitrate-dependent iron oxidation limits iron transport in anoxic ocean regions

    NASA Astrophysics Data System (ADS)

    Scholz, Florian; Löscher, Carolin R.; Fiskal, Annika; Sommer, Stefan; Hensen, Christian; Lomnitz, Ulrike; Wuttig, Kathrin; Göttlicher, Jörg; Kossel, Elke; Steininger, Ralph; Canfield, Donald E.

    2016-11-01

    Iron is an essential element for life on Earth and limits primary production in large parts of the ocean. Oxygen-free continental margin sediments represent an important source of bioavailable iron to the ocean, yet little of the iron released from the seabed reaches the productive sea surface. Even in the anoxic water of oxygen minimum zones, where iron solubility should be enhanced, most of the iron is rapidly re-precipitated. To constrain the mechanism(s) of iron removal in anoxic ocean regions we explored the sediment and water in the oxygen minimum zone off Peru. During our sampling campaign the water column featured two distinct redox boundaries separating oxic from nitrate-reducing (i.e., nitrogenous) water and nitrogenous from weakly sulfidic water. The sulfidic water mass in contact with the shelf sediment contained elevated iron concentrations >300 nM. At the boundary between sulfidic and nitrogenous conditions, iron concentrations dropped sharply to <20 nM coincident with a maximum in particulate iron concentration. Within the iron gradient, we found an increased expression of the key functional marker gene for nitrate reduction (narG). Part of this upregulation was related to the activity of known iron-oxidizing bacteria. Collectively, our data suggest that iron oxidation and removal is induced by nitrate-reducing microbes, either enzymatically through anaerobic iron oxidation or by providing nitrite for an abiotic reaction. Given the important role that iron plays in nitrogen fixation, photosynthesis and respiration, nitrate-dependent iron oxidation likely represents a key-link between the marine biogeochemical cycles of nitrogen, oxygen and carbon.

  10. Iron Chelation

    MedlinePlus

    ... fortified cereals and eggs. What is Iron Chelation Therapy? Drugs called iron chelators remove extra iron from ... form that must be dissolved in juice or water and taken (by mouth) once a day. Most ...

  11. Magnetic Resonance Characterization of Hepatic Storage Iron in Transfusional Iron Overload

    PubMed Central

    Tang, Haiying; Jensen, Jens H.; Sammet, Christina L.; Sheth, Sujit; Swaminathan, Srirama V.; Hultman, Kristi; Kim, Daniel; Wu, Ed X.; Brown, Truman R.; Brittenham, Gary M.

    2013-01-01

    Purpose To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload. Materials and Methods Six healthy volunteers and twenty patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the “reduced” transverse relaxation rate, RR2 and the “aggregation index,” A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were employed for validation. Results Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2, A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater. Conclusion This method provides a new means for non-invasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders. PMID:23720394

  12. Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren

    PubMed Central

    Thi Le, Huong; Brouwer, Inge D; Burema, Jan; Nguyen, Khan Cong; Kok, Frans J

    2006-01-01

    The effect of iron fortification is generally assumed to be less than iron supplementation; however, the magnitude of difference in effects is not known. The present study aims to compare the efficacy of these two strategies on anaemia and iron status. After screening on low Hb, 425 anaemic children in six primary schools in Tam Nong district of Phu Tho province were included in a randomized, placebo-controlled trial comparing two groups receiving iron fortified instant noodles or iron supplementation for 6 months and a control group, with children in all groups having been dewormed. Blood samples were collected before and after intervention for haemoglobin, serum ferritin (SF), serum transferrin receptor (TfR), C-reactive protein (CRP), and haemoglobinopathies analysis. Regression analysis was used to assess the effect of iron fortification and iron supplementation on haemoglobin concentration, SF, TfR, body iron, and anaemic status as outcome variables. The improvement of haemoglobin, SF, and body iron level in the group receiving iron fortification was 42% (2.6 g/L versus 6.2 g/L), 20% (23.5 μg/L versus 117.3 μg/L), and 31.3% (1.4 mg/kg versus 4.4 mg/kg) of that in the iron supplementation group. The prevalence of anaemia dropped to 15.1% in the control group, with an additional reduction of anaemia of 8.5% in the iron supplementation group. The additional reduction due to iron fortification was 5.4%, which amounts to well over 50% of the impact of supplementation. In conclusion, the efficacy of iron fortification based on reduction of prevalence of anaemia, and on the change in haemoglobin level, is about half of the maximum impact of supplementation in case of optimal compliance. Thus, in a population of anaemic children with mild iron deficiency, iron fortification should be the preferred strategy to combat anaemia. PMID:17147795

  13. Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren.

    PubMed

    Thi Le, Huong; Brouwer, Inge D; Burema, Jan; Nguyen, Khan Cong; Kok, Frans J

    2006-12-05

    The effect of iron fortification is generally assumed to be less than iron supplementation; however, the magnitude of difference in effects is not known. The present study aims to compare the efficacy of these two strategies on anaemia and iron status. After screening on low Hb, 425 anaemic children in six primary schools in Tam Nong district of Phu Tho province were included in a randomized, placebo-controlled trial comparing two groups receiving iron fortified instant noodles or iron supplementation for 6 months and a control group, with children in all groups having been dewormed. Blood samples were collected before and after intervention for haemoglobin, serum ferritin (SF), serum transferrin receptor (TfR), C-reactive protein (CRP), and haemoglobinopathies analysis. Regression analysis was used to assess the effect of iron fortification and iron supplementation on haemoglobin concentration, SF, TfR, body iron, and anaemic status as outcome variables. The improvement of haemoglobin, SF, and body iron level in the group receiving iron fortification was 42% (2.6 g/L versus 6.2 g/L), 20% (23.5 microg/L versus 117.3 microg/L), and 31.3% (1.4 mg/kg versus 4.4 mg/kg) of that in the iron supplementation group. The prevalence of anaemia dropped to 15.1% in the control group, with an additional reduction of anaemia of 8.5% in the iron supplementation group. The additional reduction due to iron fortification was 5.4%, which amounts to well over 50% of the impact of supplementation. In conclusion, the efficacy of iron fortification based on reduction of prevalence of anaemia, and on the change in haemoglobin level, is about half of the maximum impact of supplementation in case of optimal compliance. Thus, in a population of anaemic children with mild iron deficiency, iron fortification should be the preferred strategy to combat anaemia.

  14. High efficiency iron electrode and additives for use in rechargeable iron-based batteries

    DOEpatents

    Narayan, Sri R.; Prakash, G. K. Surya; Aniszfeld, Robert; Manohar, Aswin; Malkhandi, Souradip; Yang, Bo

    2017-02-21

    An iron electrode and a method of manufacturing an iron electrode for use in an iron-based rechargeable battery are disclosed. In one embodiment, the iron electrode includes carbonyl iron powder and one of a metal sulfide additive or metal oxide additive selected from the group of metals consisting of bismuth, lead, mercury, indium, gallium, and tin for suppressing hydrogen evolution at the iron electrode during charging of the iron-based rechargeable battery. An iron-air rechargeable battery including an iron electrode comprising carbonyl iron is also disclosed, as is an iron-air battery wherein at least one of the iron electrode and the electrolyte includes an organosulfur additive.

  15. Milankovitch-scale correlations between deeply buried microbial populations and biogenic ooze lithology

    USGS Publications Warehouse

    Aiello, I.W.; Bekins, B.A.

    2010-01-01

    The recent discoveries of large, active populations of microbes in the subseafloor of the world's oceans supports the impact of the deep biosphere biota on global biogeochemical cycles and raises important questions concerning the functioning of these extreme environments for life. These investigations demonstrated that subseafloor microbes are unevenly distributed and that cell abundances and metabolic activities are often independent from sediment depths, with increased prokaryotic activity at geochemical and/or sedimentary interfaces. In this study we demonstrate that microbial populations vary at the scale of individual beds in the biogenic oozes of a drill site in the eastern equatorial Pacific (Ocean Drilling Program Leg 201, Site 1226). We relate bedding-scale changes in biogenic ooze sediment composition to organic carbon (OC) and microbial cell concentrations using high-resolution color reflectance data as proxy for lithology. Our analyses demonstrate that microbial concentrations are an order of magnitude higher in the more organic-rich diatom oozes than in the nannofossil oozes. The variations mimic small-scale variations in diatom abundance and OC, indicating that the modern distribution of microbial biomass is ultimately controlled by Milankovitch-frequency variations in past oceanographic conditions. ?? 2010 Geological Society of America.

  16. Biomimetic synthesis of struvite with biogenic morphology and implication for pathological biomineralization

    NASA Astrophysics Data System (ADS)

    Li, Han; Yao, Qi-Zhi; Wang, Yu-Ying; Li, Yi-Liang; Zhou, Gen-Tao

    2015-01-01

    Recent studies have found that certain urinary proteins can efficiently inhibit stone formation. These discoveries are significant for developing effective therapies for stone disease, but the inhibition mechanism of crystallization remains elusive. In the present study, polyaspartic acid (PASP) was employed as a model peptide to investigate the effect of urinary proteins on the crystallization and morphological evolution of struvite. The results demonstrate that selective adsorption/binding of PASP onto the {010} and {101} faces of struvite crystals results in arrowhead-shaped morphology, which further evolves into X-shaped and unusual tabular structures with time. Noticeably, these morphologies are reminiscent of biogenic struvite morphology. Concentration-dependent experiments show that PASP can inhibit struvite growth and the inhibitory capacity increases with increasing PASP concentration, whereas aspartic acid monomers do not show a significant effect. Considering that PASP is a structural and functional analogue of the subdomains of aspartic acid-rich proteins, our results reveal that aspartic acid-rich proteins play a key role in regulating biogenic struvite morphology, and aspartic acid residues contribute to the inhibitory capacity of urinary proteins. The potential implications of PASP for developing therapeutic agents for urinary stone disease is also discussed.

  17. Biomimetic synthesis of struvite with biogenic morphology and implication for pathological biomineralization.

    PubMed

    Li, Han; Yao, Qi-Zhi; Wang, Yu-Ying; Li, Yi-Liang; Zhou, Gen-Tao

    2015-01-16

    Recent studies have found that certain urinary proteins can efficiently inhibit stone formation. These discoveries are significant for developing effective therapies for stone disease, but the inhibition mechanism of crystallization remains elusive. In the present study, polyaspartic acid (PASP) was employed as a model peptide to investigate the effect of urinary proteins on the crystallization and morphological evolution of struvite. The results demonstrate that selective adsorption/binding of PASP onto the {010} and {101} faces of struvite crystals results in arrowhead-shaped morphology, which further evolves into X-shaped and unusual tabular structures with time. Noticeably, these morphologies are reminiscent of biogenic struvite morphology. Concentration-dependent experiments show that PASP can inhibit struvite growth and the inhibitory capacity increases with increasing PASP concentration, whereas aspartic acid monomers do not show a significant effect. Considering that PASP is a structural and functional analogue of the subdomains of aspartic acid-rich proteins, our results reveal that aspartic acid-rich proteins play a key role in regulating biogenic struvite morphology, and aspartic acid residues contribute to the inhibitory capacity of urinary proteins. The potential implications of PASP for developing therapeutic agents for urinary stone disease is also discussed.

  18. What do correlations tell us about anthropogenic – biogenic interactions and SOA formation in the Sacramento plume during CARES?

    DOE PAGES

    Kleinman, Lawrence I.; Kuang, Chongai; Sedlacek, Art; ...

    2016-02-15

    During the Carbonaceous Aerosols and Radiative Effects Study (CARES) the DOE G-1 aircraft was used to sample aerosol and gas phase compounds in the Sacramento, CA plume and surrounding region. We present data from 66 plume transects obtained during 13 flights in which southwesterly winds transported the plume towards the foothills of the Sierra Nevada Mountains. Plume transport occurred partly over land with high isoprene emission rates. Our objective is to empirically determine whether organic aerosol (OA) can be attributed to anthropogenic or biogenic sources, and to determine whether there is a synergistic effect whereby OA concentrations are enhanced bymore » the simultaneous presence of high concentrations of CO and either isoprene, MVK+MACR (sum of methyl vinyl ketone and methacrolein) or methanol, which are taken as tracers of anthropogenic and biogenic emissions. Furthermore, linear and bi-linear correlations between OA, CO, and each of three biogenic tracers, “Bio”, for individual plume transects indicate that most of the variance in OA over short time and distance scales can be explained by CO.« less

  19. Oligocene-Miocene magnetic stratigraphy carried by biogenic magnetite at sites U1334 and U1335 (equatorial Pacific Ocean)

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.; Ohneiser, C.; Yamamoto, Y.; Kesler, M. S.

    2013-02-01

    AbstractSediments from the equatorial Pacific Ocean, at the Integrated Ocean Drilling Program sites U1334 and U1335, record reliable magnetic polarity stratigraphies back to ~26.5 Ma (late Oligocene) at sedimentation rates usually in the 5-20 m/Myr range. Putative polarity subchrons that do not appear in current polarity timescales occur within Chrons C5ACr, C5ADn, and C5Bn.1r at Site U1335; and within Chrons C6AAr.2r, C6Br, C7Ar, and C8n.1n at Site U1334. Subchron C5Dr.1n (~17.5 Ma) is recorded at both sites, supporting its apparent recording in the South Atlantic Ocean, and has an estimated duration of ~40 kyr. The Oligocene-Miocene calcareous oozes have magnetizations carried by submicron magnetite, as indicated by thermal demagnetization of magnetic remanences, the anhysteretic remanence to susceptibility ratio, and magnetic hysteresis parameters. Transmission electron microscopy of magnetic separates indicates the presence of low-titanium <span class="hlt">iron</span> oxide (magnetite) grains with size (50-100 nm) and shape similar to modern and fossil bacterial magnetite, supporting other evidence that <span class="hlt">biogenic</span> submicron magnetite is the principal remanence carrier in these sediments. In the equatorial Pacific Ocean, low organic-carbon burial arrests microbial pore-water sulfate reduction, thereby aiding preservation of bacterial magnetite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29402517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29402517"><span>Protection alone may not promote natural recovery of <span class="hlt">biogenic</span> habitats of high biodiversity damaged by mobile fishing gears.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fariñas-Franco, Jose M; Allcock, A Louise; Roberts, Dai</p> <p>2018-04-01</p> <p>The horse mussel Modiolus modiolus (L.) is a large marine bivalve that aggregates to create complex habitats of high biodiversity. As a keystone species, M. modiolus is of great importance for the functioning of marine benthic ecosystems, forming <span class="hlt">biogenic</span> habitats used to designate Marine Protected Areas (MPAs). The present study investigates the condition of M. modiolus beds historically subjected to intense scallop fishing using mobile fishing gears. The study, conducted seven years after the introduction of legislation banning all forms of fishing, aimed to establish whether natural habitat recovery occurs after protection measures are put in place. Lower biodiversity and up to 80% decline in densities of M. modiolus were recorded across the current distributional range of the species in Strangford Lough, Northern Ireland. The decline in biodiversity in most areas surveyed was consistent with that observed in <span class="hlt">biogenic</span> reefs impacted by mobile fishing gears elsewhere. Epifauna, including sponges, hydroids and tunicates, experienced the most substantial decline in biodiversity, with up to 64% fewer taxa recorded in 2010 compared with 2003. Higher variability in community composition and a shift towards faunal assemblages dominated by opportunistic infaunal species typical of softer substrata were also detected. Based on these observations we suggest that, for <span class="hlt">biogenic</span> habitats, the designation of MPAs and the introduction of fishing bans alone may not be sufficient to reverse or halt the negative effects caused by past anthropogenic impacts. Direct intervention, including habitat restoration based on translocation of native keystone species, should be considered as part of management strategies for MPAs which host similar <span class="hlt">biogenic</span> reef habitats where condition and natural recovery have been compromised. Copyright © 2018 Elsevier Ltd. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28221938','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28221938"><span>Reduction of <span class="hlt">Biogenic</span> Amines during Miso Fermentation by Lactobacillus plantarum as a Starter Culture.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Yi-Chen; Kung, Hsien-Feng; Huang, Ya-Ling; Wu, Chien-Hui; Huang, Yu-Ru; Tsai, Yung-Hsiang</p> <p>2016-09-01</p> <p>Lactobacillus plantarum D-103 isolated from a miso product that possesses amine-degrading activity was used as a starter culture in miso fermentation (25°C for 120 days) in this study. The salt content in control samples (without starter culture) and inoculated samples (inoculated with L. plantarum D-103) remained constant at 10.4% of the original salt concentration throughout fermentation, whereas the pH value decreased from 6.2 to 4.6 during fermentation. The inoculated samples had significantly lower (P < 0.05) levels of total volatile basic nitrogen than control samples after 40 days of fermentation. After 120 days of fermentation, the histamine and overall <span class="hlt">biogenic</span> amine contents in inoculated samples were reduced by 58 and 27%, respectively, compared with control samples. To our knowledge, this is the first report to demonstrate that application of a starter culture with amine-degrading activity in miso products was effective in reducing the accumulation of <span class="hlt">biogenic</span> amines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1354727-project-final-report-linking-plant-stress-biogenic-soa-ccn-production-new-feedback-climate-system','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1354727-project-final-report-linking-plant-stress-biogenic-soa-ccn-production-new-feedback-climate-system"><span>Project Final Report: Linking Plant Stress, <span class="hlt">Biogenic</span> SOA, and CCN Production - A New Feedback in the Climate System?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>VanReken, Timothy; Balasingam, Muhunthan</p> <p>2017-05-01</p> <p>This project worked toward understanding the role of variable <span class="hlt">biogenic</span> emissions in the formation of secondary organic aerosol (SOA), and in turn the potential for this aerosol to affect cloud droplet formation. It was premised on the idea that a changing climate could impose <span class="hlt">biogenic</span> and abiogenic stresses on plants that would affect the emissions of volatile organic compounds (VOCs). The transformation of these VOCs to SOA and cloud condensation nuclei (CCN) implied the possibility of a feedback mechanism within the biosphere/atmosphere/climate system. The project’s activities centered on laboratory experiments to study the effects of stresses on plants and plant-derivedmore » material under controlled conditions, observing both the VOC emissions and the aerosol that formed from the oxidation of those VOCs. The results highlighted the potentially important contributions of stress and decomposition mechanisms to <span class="hlt">biogenic</span> SOA formation. Related field measurements elucidated the conditions when these factors could be important in the ambient environment. The project also revealed repeated the complexity of the stress/VOC emission relationship, and the difficulty in expressing these relationships in a comprehensive manner.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70048568','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70048568"><span>Processes of zinc attenuation by <span class="hlt">biogenic</span> manganese oxides forming in the hyporheic zone of Pinal Creek, Arizona</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fuller, Christopher C.; Bargar, John R.</p> <p>2014-01-01</p> <p>The distribution and speciation of Zn sorbed to <span class="hlt">biogenic</span> Mn oxides forming in the hyporheic zone of Pinal Creek, AZ, was investigated using extended X-ray absorption fine structure (EXAFS) and microfocused synchrotron X-ray fluorescence (μSXRF) mapping, and chemical extraction. μSXRF and chemical extractions show that contaminant Zn co-varied with Mn in streambed sediment grain coatings. Bulk and microfocused EXAFS spectra of Zn in the <span class="hlt">biogenic</span> Mn oxide coating are indicative of Zn forming triple-corner-sharing inner-sphere complexes over octahedral vacancies in the Mn oxide sheet structure. Zn desorbed in response to the decrease in pH in batch experiments and resulted in near-equal dissolved Zn at each pH over a 10-fold range in the solid/solution ratio. The geometry of sorbed Zn was unchanged after 50% desorption at pH 5, indicating that desorption is not controlled by dissolution of secondary Zn phases. In summary, these findings support the idea that Zn attenuation in Pinal Creek is largely controlled by sorption to microbial Mn oxides forming in the streambed during hyporheic exchange. Sorption to <span class="hlt">biogenic</span> Mn oxides is likely an important process of Zn attenuation in circum-neutral pH reaches of many acid-mine drainage contaminated streams when dissolved Mn is present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19924939','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19924939"><span>Aerosol mass spectrometric features of <span class="hlt">biogenic</span> SOA: observations from a plant chamber and in rural atmospheric environments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kiendler-Scharr, Astrid; Zhang, Qi; Hohaus, Thorsten; Kleist, Einhard; Mensah, Amewu; Mentel, Thomas F; Spindler, Christian; Uerlings, Ricarda; Tillmann, Ralf; Wildt, Jürgen</p> <p>2009-11-01</p> <p>Secondary organic aerosol (SOA) is known to form from a variety of anthropogenic and <span class="hlt">biogenic</span> precursors. Current estimates of global SOA production vary over 2 orders of magnitude. Since no direct measurement technique for SOA exists, quantifying SOA remains a challenge for atmospheric studies. The identification of <span class="hlt">biogenic</span> SOA (BSOA) based on mass spectral signatures offers the possibility to derive source information of organic aerosol (OA) with high time resolution. Here we present data from simulation experiments. The BSOA from tree emissions was characterized with an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS). Collection efficiencies were close to 1, and effective densities of the BSOA were found to be 1.3 +/- 0.1 g/cm(3). The mass spectra of SOA from different trees were found to be highly similar. The average BSOA mass spectrum from tree emissions is compared to a BSOA component spectrum extracted from field data. It is shown that overall the spectra agree well and that the mass spectral features of BSOA are distinctively different from those of OA components related to fresh fossil fuel and biomass combustions. The simulation chamber mass spectrum may potentially be useful for the identification and interpretation of <span class="hlt">biogenic</span> SOA components in ambient data sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol3/pdf/CFR-2011-title49-vol3-sec192-489.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol3/pdf/CFR-2011-title49-vol3-sec192-489.pdf"><span>49 CFR 192.489 - Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span> pipelines.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... for Corrosion Control § 192.489 Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span> pipelines. (a) General graphitization. Each segment of cast <span class="hlt">iron</span> or ductile <span class="hlt">iron</span> pipe on which general graphitization is found to a... 49 Transportation 3 2011-10-01 2011-10-01 false Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol3/pdf/CFR-2010-title49-vol3-sec192-489.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol3/pdf/CFR-2010-title49-vol3-sec192-489.pdf"><span>49 CFR 192.489 - Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span> pipelines.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... for Corrosion Control § 192.489 Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span> pipelines. (a) General graphitization. Each segment of cast <span class="hlt">iron</span> or ductile <span class="hlt">iron</span> pipe on which general graphitization is found to a... 49 Transportation 3 2010-10-01 2010-10-01 false Remedial measures: Cast <span class="hlt">iron</span> and ductile <span class="hlt">iron</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28739199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28739199"><span>Results of the First American Prospective Study of Intravenous <span class="hlt">Iron</span> in Oral <span class="hlt">Iron</span>-Intolerant <span class="hlt">Iron</span>-Deficient Gravidas.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Auerbach, Michael; James, Stephanie E; Nicoletti, Melissa; Lenowitz, Steven; London, Nicola; Bahrain, Huzefa F; Derman, Richard; Smith, Samuel</p> <p>2017-12-01</p> <p>Anemia affects up to 42% of gravidas. Neonatal <span class="hlt">iron</span> deficiency is associated with low birth weight, delayed growth and development, and increased cognitive and behavioral abnormalities. While oral <span class="hlt">iron</span> is convenient, up to 70% report significant gastrointestinal toxicity. Intravenous <span class="hlt">iron</span> formulations allowing replacement in one visit with favorable side-effect profiles decrease rates of anemia with improved hemoglobin responses and maternal fetal outcomes. Seventy-four oral <span class="hlt">iron</span>-intolerant, second- and third-trimester <span class="hlt">iron</span>-deficient gravidas were questioned for oral <span class="hlt">iron</span> intolerance and treated with intravenous <span class="hlt">iron</span>. All received 1000 mg of low-molecular-weight <span class="hlt">iron</span> dextran in 250 mL normal saline. Fifteen minutes after a test dose, the remainder was infused over the balance of 1 hour. Subjects were called at 1, 2, and 7 days to assess delayed reactions. Four weeks postinfusion or postpartum, hemoglobin levels and <span class="hlt">iron</span> parameters were measured. Paired t test was used for hemoglobin and <span class="hlt">iron</span>; 58/73 women were questioned about interval growth and development of their babies. Seventy-three of 74 enrolled subjects completed treatment. Sixty had paired pre- and posttreatment data. The mean pre- and posthemoglobin concentrations were 9.7 and 10.8 g/dL (P < .00001), transferrin saturations 11.7% and 22.6% (P = .0003), and ferritins 14.5 and 126.3 ng/mL, respectively (P < .000001). Six experienced minor infusion reactions. All resolved. Data for 58 infants were available; one was low on its growth charts for 11 months. The remaining 57 were normal. None were diagnosed with <span class="hlt">iron</span> deficiency anemia. Intravenous <span class="hlt">iron</span> has less toxicity and is more effective, supporting moving it closer to frontline therapy. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ACP....10..299S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ACP....10..299S"><span>Slower CCN growth kinetics of anthropogenic aerosol compared to <span class="hlt">biogenic</span> aerosol observed at a rural site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shantz, N. C.; Chang, R. Y.-W.; Slowik, J. G.; Vlasenko, A.; Abbatt, J. P. D.; Leaitch, W. R.</p> <p>2010-01-01</p> <p>Growth rates of water droplets were measured with a static diffusion cloud condensation chamber in May-June 2007 at a rural field site in Southern Ontario, Canada, 70 km north of Toronto. The observations include periods when the winds were from the south and the site was impacted by anthropogenic air from the U.S. and Southern Ontario as well as during a 5-day period of northerly wind flow when the aerosol was dominated by <span class="hlt">biogenic</span> sources. The growth of droplets on anthropogenic size-selected particles centred at 0.1 μm diameter and composed of approximately 40% organic and 60% ammonium sulphate (AS) by mass, was delayed by on the order of 1 s compared to a pure AS aerosol. Simulations of the growth rate on monodisperse particles indicate that a lowering of the water mass accommodation coefficient from αc=1 to an average of αc=0.04 is needed (assuming an insoluble organic with hygroscopicity parameter, κorg, of zero). Simulations of the initial growth rate on polydisperse anthropogenic particles agree best with observations for αc=0.07. In contrast, the growth rate of droplets on size-selected aerosol of <span class="hlt">biogenic</span> character, consisting of >80% organic, was similar to that of pure AS. Simulations of the predominantly <span class="hlt">biogenic</span> polydisperse aerosol show agreement between the observations and simulations when κorg=0.2 (with upper and lower limits of 0.5 and 0.07, respectively) and αc=1. Inhibition of water uptake by the anthropogenic organic applied to an adiabatic cloud parcel model in the form of a constant low αc increases the number of droplets in a cloud compared to pure AS. If the αc is assumed to increase with increasing liquid water on the droplets, then the number of droplets decreases which could diminish the indirect climate forcing effect. The slightly lower κorg in the <span class="hlt">biogenic</span> case decreases the number of droplets in a cloud compared to pure AS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/druginfo/meds/a614033.html','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/druginfo/meds/a614033.html"><span><span class="hlt">Iron</span> Dextran Injection</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p><span class="hlt">Iron</span> dextran injection is used to treat <span class="hlt">iron</span>-deficiency anemia (a lower than normal number of red blood cells ... treated with <span class="hlt">iron</span> supplements taken by mouth. <span class="hlt">Iron</span> dextran injection is in a class of medications called ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611981L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611981L"><span>Ground penetrating radar study of a thickness of <span class="hlt">biogenic</span> sediments in the vicinity of the Czechowskie Lake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamparski, Piotr</p> <p>2014-05-01</p> <p>The paper present results of investigations, which have made on a <span class="hlt">biogenic</span> plain in the north-east part of the vicinity of the Czechowskie Lake. The basin of Lake Czechowskie occupies a deep depression located in the immediate hinterland of the maximum range of the Pomeranian Phase ice sheet in the northern part of Poland (Błaszkiewicz 2005). Drillings carried out within the peat plain in the western part of the lake basin indicate that there are relatively diversified lake sediments of up to 12 m in thickness. The ground penetrating radar profiling method (GPR) was used to determine a thickness of <span class="hlt">biogenic</span> sediments. To tests was used GSS'I SIR SYSTEM-2000™ radar device with two antennae - the high resolution 400 MHz central frequency - for shallow prospecting of the subsurface layers and the low resolution 35 MHz - for determining the shape of the mineral bedrock. Overall, 33 GPR profiles was made all in all more than 3000 meters along and crosswise the longer axis of the <span class="hlt">biogenic</span> plain. The range of radar penetration was set to 200 ns for 400 MHz antenna and 600 ns for the 35 MHz one, what is the equivalent respectively 4 m and 12,5 m in depth of <span class="hlt">biogenic</span> sediments thickness. Horizontal scaling was made by GSSI survey wheel device. The thickness of <span class="hlt">biogenic</span> sediments recognized by GPR reaches 10 meters only using 35 MHz antenna. In the case of the 400 MHz antenna, relatively high conductivity water-saturated peat and gyttia did not allow for the achievement of greater thickness than 3-4 meters testing. In a large part of the profiles was able to see the shape of the mineral bedrock in the form of a former lake basin. Also observed elevations and thresholds in the bedrock. Depth of the mineral deposits forming former lake bottom was confirmed by drillings. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association. References: Błaszkiewicz M, 2005. Późnoglacjalna i</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987PEPI...46..289C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987PEPI...46..289C"><span><span class="hlt">Biogenic</span> magnetite as a primary remanence carrier in limestone deposits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Shih-Bin R.; Kirschvink, Joseph L.; Stolz, John F.</p> <p>1987-06-01</p> <p>Studies on the microbial communities and magnetic phases of samples collected from carbonate oozes at Sugarloaf Key, FL, U.S.A. and calcareous laminated sediments from Laguna Figueroa, Baja California, Mexico have revealed the existence of magnetotactic bacteria and ultrafine-grained single domain magnetite in both environments. Magnetotactic bacteria were identified by light and electron microscopy. The single domain magnetite was detected by coercivity spectra analysis with a SQUID magnetometer and examined under the transmission electron microscope. The similarity, in terms of size and shape, between the single domain magnetite found in these sediments and the magnetite observed in the bacterial magnetosome from enriched cultures indicates the ultrafine-grained magnetite in these two marine environments was biologically formed. These results, combined with the common occurrences of ultrafine-grained magnetite in limestone deposits detected rock magnetically, suggest <span class="hlt">biogenic</span> magnetite may be present and contribute to the magnetic remanence in these rocks. Several Cambrian limestone samples, separately collected from Siberia, China, and Kazakhstan, were examined for the presence of bacterial magnetite. Samples from the Lower Cambrian Sinskian Formation at Siberia Platform were found to contain both a large amount of apparently bacterial magnetite particles and a very stable primary magnetic component. Post-Cambrian diagenesis does not seem to affect the microgranulometry of these apparently bacterial magnetite crystals or the magnetic remanence carried by them. Assessing the potential role of <span class="hlt">biogenic</span> magnetite as a primary remanence carrier in other Phanerozoic limestone deposits ought to be further pursued.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.B21A..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.B21A..03W"><span>Structural Characterization of <span class="hlt">Biogenic</span> Manganese Oxides Produced in Sea Water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Webb, S. M.; Bargar, J. R.; Tebo, B. M.</p> <p>2003-12-01</p> <p>Manganese oxides have been coined as the "scavengers of the sea" and play important roles in both marine and freshwater systems. Natural manganese oxide nanoparticles and grain coatings are ubiquitous in the environment and profoundly impact the quality of sediments via their ability to degrade and sequester contaminants. These oxides are believed to form dominantly via oxidation of Mn(II) by marine and freshwater bacteria and have extremely high sorptive capacities for heavy metals. We have used XANES, EXAFS, and synchrotron (SR)-XRD techniques to study <span class="hlt">biogenic</span> manganese oxides produced by spores of the marine Bacillus sp., strain SG-1 in seawater as a function of reaction time under fully in-situ conditions. The primary <span class="hlt">biogenic</span> solid-phase Mn oxide product is a hexagonal layered phyollomanganate with an oxidation state similar to that in delta-MnO2. XRD data show the biooxides to have a phyllomanganate 10 basal plane spacing, suggesting the interlayer is hydrated and contains calcium. As the experiment continues, the initial biooxide changes to show triclinic symmetry. Fits to these EXAFS spectra suggest the octahedral layers have low Mn octahedral site vacancies in the lattice and the latyers bend to accommodate Jahn-Teller distortions creating the change in symmetry. The oxides observed in this study as models of Mn(II) bio-oxidation may be representative of the most abundant manganese oxide phase suspended in the oxic and sub-oxic zones of the oceanic water column.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28381473','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28381473"><span>Modeling tool for calculating dietary <span class="hlt">iron</span> bioavailability in <span class="hlt">iron</span>-sufficient adults.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fairweather-Tait, Susan J; Jennings, Amy; Harvey, Linda J; Berry, Rachel; Walton, Janette; Dainty, Jack R</p> <p>2017-06-01</p> <p>Background: Values for dietary <span class="hlt">iron</span> bioavailability are required for setting dietary reference values. These are estimated from predictive algorithms, nonheme <span class="hlt">iron</span> absorption from meals, and models of <span class="hlt">iron</span> intake, serum ferritin concentration, and <span class="hlt">iron</span> requirements. Objective: We developed a new interactive tool to predict dietary <span class="hlt">iron</span> bioavailability. Design: <span class="hlt">Iron</span> intake and serum ferritin, a quantitative marker of body <span class="hlt">iron</span> stores, from 2 nationally representative studies of adults in the United Kingdom and Ireland and a trial in elderly people in Norfolk, United Kingdom, were used to develop a model to predict dietary <span class="hlt">iron</span> absorption at different serum ferritin concentrations. Individuals who had raised inflammatory markers or were taking <span class="hlt">iron</span>-containing supplements were excluded. Results: Mean <span class="hlt">iron</span> intakes were 13.6, 10.3, and 10.9 mg/d and mean serum ferritin concentrations were 140.7, 49.4, and 96.7 mg/L in men, premenopausal women, and postmenopausal women, respectively. The model predicted that at serum ferritin concentrations of 15, 30, and 60 mg/L, mean dietary <span class="hlt">iron</span> absorption would be 22.3%, 16.3%, and 11.6%, respectively, in men; 27.2%, 17.2%, and 10.6%, respectively, in premenopausal women; and 18.4%, 12.7%, and 10.5%, respectively, in postmenopausal women. Conclusions: An interactive program for calculating dietary <span class="hlt">iron</span> absorption at any concentration of serum ferritin is presented. Differences in <span class="hlt">iron</span> status are partly explained by age but also by diet, with meat being a key determinant. The effect of the diet is more marked at lower serum ferritin concentrations. The model can be applied to any adult population in whom representative, good-quality data on <span class="hlt">iron</span> intake and <span class="hlt">iron</span> status have been collected. Values for dietary <span class="hlt">iron</span> bioavailability can be derived for any target concentration of serum ferritin, thereby giving risk managers and public health professionals a flexible and transparent basis on which to base their dietary recommendations. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=167743&keyword=computer+AND+tomography&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=167743&keyword=computer+AND+tomography&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>APPLICATION OF COMPUTER-AIDED TOMOGRAPHY TO VISUALIZE AND QUANTIFY <span class="hlt">BIOGENIC</span> STRUCTURES IN MARINE SEDIMENTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>We used computer-aided tomography (CT) for 3D visualization and 2D analysis of<br><br>marine sediment cores from 3 stations (at 10, 75 and 118 m depths) with different environmental<br><br>impact. <span class="hlt">Biogenic</span> structures such as tubes and burrows were quantified and compared among st...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26047483','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26047483"><span><span class="hlt">Iron</span> homeostasis and its disruption in mouse lung in <span class="hlt">iron</span> deficiency and overload.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Giorgi, Gisela; D'Anna, María Cecilia; Roque, Marta Elena</p> <p>2015-10-01</p> <p>What is the central question of this study? The aim was to explore the role and hitherto unclear mechanisms of action of <span class="hlt">iron</span> proteins in protecting the lung against the harmful effects of <span class="hlt">iron</span> accumulation and the ability of pulmonary cells to mobilize <span class="hlt">iron</span> in <span class="hlt">iron</span> deficiency. What is the main finding and its importance? We show that pulmonary hepcidin appears not to modify cellular <span class="hlt">iron</span> mobilization in the lung. We propose pathways for supplying <span class="hlt">iron</span> to the lung in <span class="hlt">iron</span> deficiency and for protecting the lung against <span class="hlt">iron</span> excess in <span class="hlt">iron</span> overload, mediated by the co-ordinated action of <span class="hlt">iron</span> proteins, such as divalent metal transporter 1, ZRT-IRE-like-protein 14, transferrin receptor, ferritin, haemochromatosis-associated protein and ferroportin. <span class="hlt">Iron</span> dyshomeostasis is associated with several forms of chronic lung disease, but its mechanisms of action remain to be elucidated. The aim of the present study was to determine the role of the lung in whole-animal models with <span class="hlt">iron</span> deficiency and <span class="hlt">iron</span> overload, studying the divalent metal transporter 1 (DMT1), ZRT-IRE-like protein 14 (ZIP14), transferrin receptor (TfR), haemochromatosis-associated protein (HFE), hepcidin, ferritin and ferroportin (FPN) expression. In each model, adult CF1 mice were divided into the following groups (six mice per group): (i) <span class="hlt">iron</span>-overload model, <span class="hlt">iron</span> saccharate i.p. and control group (<span class="hlt">iron</span> adequate), 0.9% NaCl i.p.; and (ii) <span class="hlt">iron</span>-deficiency model, induced by repeated bleeding, and control group (sham operated). Proteins were assessed by immunohistochemistry and Western blot. In control mice, DMT1 was localized in the cytoplasm of airway cells, and in <span class="hlt">iron</span> deficiency and overload it was in the apical membrane. Divalent metal transporter 1 and TfR increased in <span class="hlt">iron</span> deficiency, without changes in <span class="hlt">iron</span> overload. ZRT-IRE-like protein 14 decreased in airway cells in <span class="hlt">iron</span> deficiency and increased in <span class="hlt">iron</span> overload. In <span class="hlt">iron</span> deficiency, HFE and FPN were immunolocalized close to the apical membrane</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.V23A2790S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.V23A2790S"><span>Ion microprobe U-Pb dating and strontium isotope analysis of <span class="hlt">biogenic</span> apatite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sano, Y.; Toyoshima, K.; Takahata, N.; Shirai, K.</p> <p>2012-12-01</p> <p>Conodonts are micro-fossils chemically composed of apatite which occurred in the body of one animal. They are guide fossils to show formation ages of sedimentary sequences with the highest resolution [1] and good samples to verify the dating method. We developed the ion microprobe U-Pb dating of apatite [2] and applied the method to a Carboniferous conodont [3] by using a SHRIMP II installed at Department of Earth and Planetary Sciences, Hiroshima University. Recently we have developed the NanoSIMS U-Pb dating method and successfully measured the formation ages of monazite [4] and zircon [5] at Atmosphere and Ocean Research Institute, University of Tokyo. In this work we carried out the NanoSIMS U-Pb dating of <span class="hlt">biogenic</span> apatite such as conodont. Since the spot size of NanoSIMS is smaller than SHRIMP II, it is easier to have multi-spots on the single fragment of <span class="hlt">biogenic</span> apatite. Based on the isochron method of U-Pb system, we have calculated the formation ages. They are consistent with those in literature. In order to study the chemical evolution of ocean during the past 600 Million years, strontium isotopes (87Sr/86Sr) of fossil marine carbonate such as coral skeletons and foraminifera tests were measured and compiled [6]. However they are not robust when the age is older than 500Ma, partly due to post-depositional histories. Apatite is more stable and more resistant to the alteration than carbonate [7]. Recently we have developed the method of NanoSIMS strontium isotopic analysis of a fish otolith, which composed of aragonite [8]. In this work we carried out the strontium isotopic analysis of <span class="hlt">biogenic</span> apatite. The advantage of the ion microprobe technique over the TIMS (thermal ionization mass spectrometer) and MC-ICP-MS (multi-collector inductively coupled argon plasma mass spectrometer) method is preservation of the important textural context and to provide an opportunity for other simultaneous analytical work with high spatial resolution. This is the case for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29576065','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29576065"><span>Facilitated citrate-dependent <span class="hlt">iron</span> translocation increases rice endosperm <span class="hlt">iron</span> and zinc concentrations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Ting-Ying; Gruissem, Wilhelm; Bhullar, Navreet K</p> <p>2018-05-01</p> <p><span class="hlt">Iron</span> deficiency affects one third of the world population. Most <span class="hlt">iron</span> biofortification strategies have focused on genes involved in <span class="hlt">iron</span> uptake and storage but facilitating internal long-distance <span class="hlt">iron</span> translocation has been understudied for increasing grain <span class="hlt">iron</span> concentrations. Citrate is a primary <span class="hlt">iron</span> chelator, and the transporter FERRIC REDUCTASE DEFECTIVE 3 (FRD3) loads citrate into the xylem. We have expressed AtFRD3 in combination with AtNAS1 (NICOTIANAMINE SYNTHASE 1) and PvFER (FERRITIN) or with PvFER alone to facilitate long-distance <span class="hlt">iron</span> transport together with efficient <span class="hlt">iron</span> uptake and storage in the rice endosperm. The citrate and <span class="hlt">iron</span> concentrations in the xylem sap of transgenic plants increased two-fold compared to control plants. <span class="hlt">Iron</span> and zinc levels increased significantly in polished and unpolished rice grains to more than 70% of the recommended estimated average requirement (EAR) for <span class="hlt">iron</span> and 140% of the recommended EAR for zinc in polished rice grains. Furthermore, the transformed lines showed normal phenotypic growth, were tolerant to <span class="hlt">iron</span> deficiency and aluminum toxicity, and had grain cadmium levels similar to control plants. Together, our results demonstrate that deploying FRD for <span class="hlt">iron</span> biofortification has no obvious anti-nutritive effects and should be considered as an effective strategy for reducing human <span class="hlt">iron</span> deficiency anemia. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ACP....16.1729K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ACP....16.1729K"><span>What do correlations tell us about anthropogenic-<span class="hlt">biogenic</span> interactions and SOA formation in the Sacramento plume during CARES?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kleinman, L.; Kuang, C.; Sedlacek, A.; Senum, G.; Springston, S.; Wang, J.; Zhang, Q.; Jayne, J.; Fast, J.; Hubbe, J.; Shilling, J.; Zaveri, R.</p> <p>2016-02-01</p> <p>During the Carbonaceous Aerosols and Radiative Effects Study (CARES) the US Department of Energy (DOE) G-1 aircraft was used to sample aerosol and gas phase compounds in the Sacramento, CA, plume and surrounding region. We present data from 66 plume transects obtained during 13 flights in which southwesterly winds transported the plume towards the foothills of the Sierra Nevada. Plume transport occurred partly over land with high isoprene emission rates. Our objective is to empirically determine whether organic aerosol (OA) can be attributed to anthropogenic or <span class="hlt">biogenic</span> sources, and to determine whether there is a synergistic effect whereby OA concentrations are enhanced by the simultaneous presence of high concentrations of carbon monoxide (CO) and either isoprene, MVK + MACR (sum of methyl vinyl ketone and methacrolein), or methanol, which are taken as tracers of anthropogenic and <span class="hlt">biogenic</span> emissions, respectively. Linear and bilinear correlations between OA, CO, and each of three <span class="hlt">biogenic</span> tracers, "Bio", for individual plume transects indicate that most of the variance in OA over short timescales and distance scales can be explained by CO. For each transect and species a plume perturbation, (i.e., ΔOA, defined as the difference between 90th and 10th percentiles) was defined and regressions done amongst Δ values in order to probe day-to-day and location-dependent variability. Species that predicted the largest fraction of the variance in ΔOA were ΔO3 and ΔCO. Background OA was highly correlated with background methanol and poorly correlated with other tracers. Because background OA was ˜ 60 % of peak OA in the urban plume, peak OA should be primarily <span class="hlt">biogenic</span> and therefore non-fossil, even though the day-to-day and spatial variability of plume OA is best described by an anthropogenic tracer, CO. Transects were split into subsets according to the percentile rankings of ΔCO and ΔBio, similar to an approach used by Setyan et al. (2012) and Shilling et al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999934','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999934"><span><span class="hlt">Iron</span> Homeostasis in Mycobacterium tuberculosis: Mechanistic Insights into Siderophore-Mediated <span class="hlt">Iron</span> Uptake</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>Mycobacterium tuberculosis requires <span class="hlt">iron</span> for normal growth but faces a limitation of the metal ion due to its low solubility at biological pH and the withholding of <span class="hlt">iron</span> by the mammalian host. The pathogen expresses the Fe3+-specific siderophores mycobactin and carboxymycobactin to chelate the metal ion from insoluble <span class="hlt">iron</span> and the host proteins transferrin, lactoferrin, and ferritin. Siderophore-mediated <span class="hlt">iron</span> uptake is essential for the survival of M. tuberculosis, as knockout mutants, which were defective in siderophore synthesis or uptake, failed to survive in low-<span class="hlt">iron</span> medium and inside macrophages. But as excess <span class="hlt">iron</span> is toxic due to its catalytic role in the generation of free radicals, regulation of <span class="hlt">iron</span> uptake is necessary to maintain optimal levels of intracellular <span class="hlt">iron</span>. The focus of this review is to present a comprehensive overview of <span class="hlt">iron</span> homeostasis in M. tuberculosis that is discussed in the context of mycobactin biosynthesis, transport of <span class="hlt">iron</span> across the mycobacterial cell envelope, and storage of excess <span class="hlt">iron</span>. The clinical significance of the serum <span class="hlt">iron</span> status and the expression of the <span class="hlt">iron</span>-regulated protein HupB in tuberculosis (TB) patients is presented here, highlighting the potential of HupB as a marker, notably in extrapulmonary TB cases. PMID:27402628</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1410683-iron-isotope-systematics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1410683-iron-isotope-systematics"><span><span class="hlt">Iron</span> Isotope Systematics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dauphas, Nicolas; John, Seth G.; Rouxel, Olivier</p> <p></p> <p><span class="hlt">Iron</span> is a ubiquitous element with a rich (i.e., complex) chemical behavior. It possesses three oxidation states, metallic <span class="hlt">iron</span> (Fe0), ferrous <span class="hlt">iron</span> (Fe2+) and ferric <span class="hlt">iron</span> (Fe3+). The distribution of these oxidation states is markedly stratified in the Earth.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994JOM....46h..44D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994JOM....46h..44D"><span>Compacted graphite <span class="hlt">iron</span>: Cast <span class="hlt">iron</span> makes a comeback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dawson, S.</p> <p>1994-08-01</p> <p>Although compacted graphite <span class="hlt">iron</span> has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite <span class="hlt">iron</span> relative to conventional gray <span class="hlt">iron</span> allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite <span class="hlt">iron</span> together with its low cost and recyclability reinforce cast <span class="hlt">iron</span> as a prime engineering material for the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1019843-virus-removal-biogenic-cerium','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1019843-virus-removal-biogenic-cerium"><span>Virus Removal by <span class="hlt">Biogenic</span> Cerium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>De Gusseme, B.; Du Laing, G; Hennebel, T</p> <p>2010-01-01</p> <p>The rare earth element cerium has been known to exert antifungal and antibacterial properties in the oxidation states +III and +IV. This study reports on an innovative strategy for virus removal in drinking water by the combination of Ce(III) on a bacterial carrier matrix. The <span class="hlt">biogenic</span> cerium (bio-Ce) was produced by addition of aqueous Ce(III) to actively growing cultures of either freshwater manganese-oxidizing bacteria (MOB) Leptothrix discophora or Pseudomonas putida MnB29. X-ray absorption spectroscopy results indicated that Ce remained in its trivalent state on the bacterial surface. The spectra were consistent with Ce(III) ions associated with the phosphoryl groups ofmore » the bacterial cell wall. In disinfection assays using a bacteriophage as model, it was demonstrated that bio-Ce exhibited antiviral properties. A 4.4 log decrease of the phage was observed after 2 h of contact with 50 mg L{sup -1} bio-Ce. Given the fact that virus removal with 50 mg L{sup -1} Ce(III) as CeNO{sub 3} was lower, the presence of the bacterial carrier matrix in bio-Ce significantly enhanced virus removal.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/000584.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/000584.htm"><span><span class="hlt">Iron</span> deficiency anemia</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Anemia - <span class="hlt">iron</span> deficiency ... <span class="hlt">iron</span> from old red blood cells. <span class="hlt">Iron</span> deficiency anemia develops when your body's <span class="hlt">iron</span> 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 ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29792778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29792778"><span>Does <span class="hlt">Iron</span> Supplementation Improve Performance in <span class="hlt">Iron</span>-Deficient Nonanemic Athletes?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rubeor, Amity; Goojha, Carmen; Manning, Jeffrey; White, Jordan</p> <p>2018-05-01</p> <p>Supplementing <span class="hlt">iron</span>-deficient nonanemic (IDNA) athletes with <span class="hlt">iron</span> to improve performance is a trend in endurance sports. To investigate the benefits of <span class="hlt">iron</span> on performance, identify a ferritin level cutoff in IDNA athletes, and determine which <span class="hlt">iron</span> supplementation regimens are most effective. A search of the PubMed, CINAHL, Embase, ERIC, and Cochrane databases was performed in 2014 including all articles. Citations of pertinent review articles were also searched. In 2017, the search was repeated. Inclusion criteria comprised studies of level 1 to 3 evidence, written in the English language, that researched <span class="hlt">iron</span> supplementation in nonanemic athletes and reported performance outcomes. Systematic review. Level 3. The search terms used included athletic performance, resistance training, athletes, physical endurance, <span class="hlt">iron</span>, <span class="hlt">iron</span> deficiency, supplement, non-anemic, low ferritin, ferritin, ferritin blood level, athletes, and sports. A total of 1884 studies were identified through the initial database search, and 13 were identified through searching references of relevant review articles. A subsequent database search identified 46 studies. Following exclusions, 12 studies with a total of 283 participants were included. Supplementing IDNA athletes with <span class="hlt">iron</span> improved performance in 6 studies (146 participants) and did not improve performance in the other 6 studies (137 participants). In the 6 studies that showed improved performance with <span class="hlt">iron</span> supplementation, all used a ferritin level cutoff of ≤20 μg/L for treatment. Additionally, all studies that showed improved performance used oral <span class="hlt">iron</span> as a supplement. The evidence is equivocal as to whether <span class="hlt">iron</span> supplementation in IDNA athletes improves athletic performance. Supplementing athletes with ferritin levels <20 μg/L may be more beneficial than supplementing athletes with higher baseline ferritin levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26109335','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26109335"><span>Effects of a Tripeptide <span class="hlt">Iron</span> on <span class="hlt">Iron</span>-Deficiency Anemia in Rats.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xiao, Chen; Lei, Xingen; Wang, Qingyu; Du, Zhongyao; Jiang, Lu; Chen, Silu; Zhang, Mingjie; Zhang, Hao; Ren, Fazheng</p> <p>2016-02-01</p> <p>This study aims to investigate the effects of a tripeptide <span class="hlt">iron</span> (REE-Fe) on <span class="hlt">iron</span>-deficiency anemia rats. Sprague-Dawley rats were randomly divided into seven groups: a normal control group, an <span class="hlt">iron</span>-deficiency control group, and <span class="hlt">iron</span>-deficiency groups treated with ferrous sulfate (FeSO4), ferrous glycinate (Fe-Gly), or REE-Fe at low-, medium-, or high-dose groups. The rats in the <span class="hlt">iron</span>-deficiency groups were fed on an <span class="hlt">iron</span>-deficient diet to establish <span class="hlt">iron</span>-deficiency anemia (IDA) model. After the model established, different <span class="hlt">iron</span> supplements were given to the rats once a day by intragastric administration for 21 days. The results showed that REE-Fe had effective restorative action returning body weight, organ coefficients, and hematological parameters in IDA rats to normal level. In addition, comparing with FeSO4 or Fe-Gly, high-dose REE-Fe was more effective on improving the levels of renal coefficient, total <span class="hlt">iron</span>-binding capacity, and transferrin. Furthermore, the liver hepcidin messenger RNA (mRNA) expression in the high-dose group was significantly higher (p < 0.05) than that in the FeSO4 or Fe-Gly group and showed no significant difference (p > 0.05) with the normal control group. The findings suggest that REE-Fe is an effective source of <span class="hlt">iron</span> supplement for IDA rats and might be exploited as a new <span class="hlt">iron</span> fortifier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ods.od.nih.gov/factsheets/Iron-Consumer/','NIH-MEDLINEPLUS'); return false;" href="https://ods.od.nih.gov/factsheets/Iron-Consumer/"><span><span class="hlt">Iron</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... Guidelines for Americans and the U.S. Department of Agriculture's MyPlate . Where can I find out more about ... on food sources of <span class="hlt">iron</span>: U.S. Department of Agriculture's (USDA) National Nutrient Database Nutrient List for <span class="hlt">Iron</span> ( ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2942822','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2942822"><span>Systems analysis of <span class="hlt">iron</span> metabolism: the network of <span class="hlt">iron</span> pools and fluxes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2010-01-01</p> <p>Background Every cell of the mammalian organism needs <span class="hlt">iron</span> as trace element in numerous oxido-reductive processes as well as for transport and storage of oxygen. The very versatility of ionic <span class="hlt">iron</span> makes it a toxic entity which can catalyze the production of radicals that damage vital membranous and macromolecular assemblies in the cell. The mammalian organism maintains therefore a complex regulatory network of <span class="hlt">iron</span> uptake, excretion and intra-body distribution. Intracellular regulation in different cell types is intertwined with a global hormonal signalling structure. <span class="hlt">Iron</span> deficiency as well as excess of <span class="hlt">iron</span> are frequent and serious human disorders. They can affect every cell, but also the organism as a whole. Results Here, we present a kinematic model of the dynamic system of <span class="hlt">iron</span> pools and fluxes. It is based on ferrokinetic data and chemical measurements in C57BL6 wild-type mice maintained on <span class="hlt">iron</span>-deficient, <span class="hlt">iron</span>-adequate, or <span class="hlt">iron</span>-loaded diet. The tracer <span class="hlt">iron</span> levels in major tissues and organs (16 compartment) were followed for 28 days. The evaluation resulted in a whole-body model of fractional clearance rates. The analysis permits calculation of absolute flux rates in the steady-state, of <span class="hlt">iron</span> distribution into different organs, of tracer-accessible pool sizes and of residence times of <span class="hlt">iron</span> in the different compartments in response to three states of <span class="hlt">iron</span>-repletion induced by the dietary regime. Conclusions This mathematical model presents a comprehensive physiological picture of mice under three different diets with varying <span class="hlt">iron</span> contents. The quantitative results reflect systemic properties of <span class="hlt">iron</span> metabolism: dynamic closedness, hierarchy of time scales, switch-over response and dynamics of <span class="hlt">iron</span> storage in parenchymal organs. Therefore, we could assess which parameters will change under dietary perturbations and study in quantitative terms when those changes take place. PMID:20704761</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24130337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24130337"><span>Obesity alters adipose tissue macrophage <span class="hlt">iron</span> content and tissue <span class="hlt">iron</span> distribution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Orr, Jeb S; Kennedy, Arion; Anderson-Baucum, Emily K; Webb, Corey D; Fordahl, Steve C; Erikson, Keith M; Zhang, Yaofang; Etzerodt, Anders; Moestrup, Søren K; Hasty, Alyssa H</p> <p>2014-02-01</p> <p>Adipose tissue (AT) expansion is accompanied by the infiltration and accumulation of AT macrophages (ATMs), as well as a shift in ATM polarization. Several studies have implicated recruited M1 ATMs in the metabolic consequences of obesity; however, little is known regarding the role of alternatively activated resident M2 ATMs in AT homeostasis or how their function is altered in obesity. Herein, we report the discovery of a population of alternatively activated ATMs with elevated cellular <span class="hlt">iron</span> content and an <span class="hlt">iron</span>-recycling gene expression profile. These <span class="hlt">iron</span>-rich ATMs are referred to as MFe(hi), and the remaining ATMs are referred to as MFe(lo). In lean mice, ~25% of the ATMs are MFe(hi); this percentage decreases in obesity owing to the recruitment of MFe(lo) macrophages. Similar to MFe(lo) cells, MFe(hi) ATMs undergo an inflammatory shift in obesity. In vivo, obesity reduces the <span class="hlt">iron</span> content of MFe(hi) ATMs and the gene expression of <span class="hlt">iron</span> importers as well as the <span class="hlt">iron</span> exporter, ferroportin, suggesting an impaired ability to handle <span class="hlt">iron</span>. In vitro, exposure of primary peritoneal macrophages to saturated fatty acids also alters <span class="hlt">iron</span> metabolism gene expression. Finally, the impaired MFe(hi) <span class="hlt">iron</span> handling coincides with adipocyte <span class="hlt">iron</span> overload in obese mice. In conclusion, in obesity, <span class="hlt">iron</span> distribution is altered both at the cellular and tissue levels, with AT playing a predominant role in this change. An increased availability of fatty acids during obesity may contribute to the observed changes in MFe(hi) ATM phenotype and their reduced capacity to handle <span class="hlt">iron</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23712019','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23712019"><span><span class="hlt">Iron</span> status and dietary <span class="hlt">iron</span> intake of vegetarian children from Poland.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gorczyca, Daiva; Prescha, Anna; Szeremeta, Karolina; Jankowski, Adam</p> <p>2013-01-01</p> <p>In Poland, vegetarian diets are becoming more and more popular. The aim of this study was to examine the effect of <span class="hlt">iron</span> intake on <span class="hlt">iron</span> status in vegetarian children. Dietary <span class="hlt">iron</span> intake, <span class="hlt">iron</span> food sources, blood count, serum <span class="hlt">iron</span>, ferritin level and total <span class="hlt">iron</span>-binding capacity were estimated in two groups of children, namely vegetarians (n = 22) and omnivores (n = 18) of both sexes, aged from 2 to 18 years. Seven-day food records were used to assess their diet. Dietary <span class="hlt">iron</span> intake in vegetarians and omnivores was low (up to 65.0 and 60.1% of the recommended dietary allowance). A significantly higher intake of vitamin C was observed in vegetarians compared with omnivores (p = 0.019). The main sources of <span class="hlt">iron</span> in vegetarians were cereal products, followed by vegetables and mushroom products, then fruit. The prevalence of <span class="hlt">iron</span> deficiency (ID) was higher in the vegetarian group (p = 0.023). The serum ferritin level and mean corpuscular volume in the vegetarians were also lower than in the omnivores (p = 0.01 and p = 0.014, respectively). Children who follow a vegetarian diet may suffer from ID in spite of having a high vitamin C intake. This indicates the need to introduce dietary education and <span class="hlt">iron</span> status monitoring. Copyright © 2013 S. Karger AG, Basel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A32A..02E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A32A..02E"><span>Evaluation of <span class="hlt">Biogenic</span> and Fire Emissions in a Global Chemistry Model with NOMADSS, DC3 and SEAC4RS observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emmons, L. K.; Wiedinmyer, C.; Park, M.; Kaser, L.; Apel, E. C.; Guenther, A. B.</p> <p>2014-12-01</p> <p>Numerous measurements of compounds produced by <span class="hlt">biogenic</span> and fire emissions were made during several recent field campaigns in the southeast United States, providing a unique data set for emissions and chemical model evaluation. The NCAR Community Atmosphere Model with Chemistry (CAM-chem) is coupled to the Community Land Model (CLM), which includes the <span class="hlt">biogenic</span> emissions model MEGAN-v2.1, allowing for online calculation of emissions from vegetation for 150 compounds. Simulations of CAM-chem for summers 2012 and 2013 are evaluated with the aircraft and ground-based observations from DC3, NOMADSS and SEAC4RS. Comparison of directly emitted <span class="hlt">biogenic</span> species, such as isoprene, terpenes, methanol and acetone, are used to evaluate the MEGAN emissions. Evaluation of oxidation products, including methyl vinyl ketone (MVK), methacrolein, formaldehyde, and other oxygenated VOCs are used to test the model chemistry mechanism. In addition, several biomass burning inventories are used in the model, including FINN, QFED, and FLAMBE, and are compared for their impact on atmospheric composition and ozone production, and evaluated with the aircraft observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20381313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20381313"><span><span class="hlt">Iron</span> deficiency anemia: pregnancy outcomes with or without <span class="hlt">iron</span> supplementation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bánhidy, Ferenc; Acs, Nándor; Puhó, Erzsébet H; Czeizel, Andrew E</p> <p>2011-01-01</p> <p>To estimate the efficacy of <span class="hlt">iron</span> supplementation in anemic pregnant women on the basis of occurrence of pregnancy complications and birth outcomes. Comparison of the occurrence of medically recorded pregnancy complications and birth outcomes in pregnant women affected with medically recorded <span class="hlt">iron</span> deficiency anemia and <span class="hlt">iron</span> supplementation who had malformed fetuses/newborns (cases) and who delivered healthy babies (controls) in the population-based Hungarian Case-Control Surveillance System of Congenital Abnormalities. Of 22,843 cases with congenital abnormalities, 3242 (14.2%), while of 38,151 controls, 6358 (16.7%) had mothers with anemia. There was no higher rate of preterm births and low birth weight in the newborns of anemic pregnant women supplemented by <span class="hlt">iron</span>. However, anemic pregnant women without <span class="hlt">iron</span> treatment had a significantly shorter gestational age at delivery with a somewhat higher rate of preterm births but these adverse birth outcomes were prevented with <span class="hlt">iron</span> supplementation. The rate of total and some congenital abnormalities was lower than expected and explained mainly by the healthier lifestyle and folic acid supplements. The secondary findings of the study showed a higher risk of constipation-related hemorrhoids and hypotension in anemic pregnant women with <span class="hlt">iron</span> supplementation. A higher rate of preterm birth was found in anemic pregnant women without <span class="hlt">iron</span> treatment but this adverse birth outcome was prevented with <span class="hlt">iron</span> supplementation. There was no higher rate of congenital abnormalities in the offspring of anemic pregnant women supplemented with <span class="hlt">iron</span> and/or folic acid supplements. Copyright © 2011 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29070542','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29070542"><span><span class="hlt">Iron</span> homeostasis during pregnancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fisher, Allison L; Nemeth, Elizabeta</p> <p>2017-12-01</p> <p>During pregnancy, <span class="hlt">iron</span> needs to increase substantially to support fetoplacental development and maternal adaptation to pregnancy. To meet these <span class="hlt">iron</span> requirements, both dietary <span class="hlt">iron</span> absorption and the mobilization of <span class="hlt">iron</span> from stores increase, a mechanism that is in large part dependent on the <span class="hlt">iron</span>-regulatory hormone hepcidin. In healthy human pregnancies, maternal hepcidin concentrations are suppressed in the second and third trimesters, thereby facilitating an increased supply of <span class="hlt">iron</span> into the circulation. The mechanism of maternal hepcidin suppression in pregnancy is unknown, but hepcidin regulation by the known stimuli (i.e., <span class="hlt">iron</span>, erythropoietic activity, and inflammation) appears to be preserved during pregnancy. Inappropriately increased maternal hepcidin during pregnancy can compromise the <span class="hlt">iron</span> availability for placental transfer and impair the efficacy of <span class="hlt">iron</span> supplementation. The role of fetal hepcidin in the regulation of placental <span class="hlt">iron</span> transfer still remains to be characterized. This review summarizes the current understanding and addresses the gaps in knowledge about gestational changes in hematologic and <span class="hlt">iron</span> variables and regulatory aspects of maternal, fetal, and placental <span class="hlt">iron</span> homeostasis. © 2017 American Society for Nutrition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1411898-evolution-multispectral-aerosol-absorption-properties-biogenically-influenced-urban-environment-during-cares-campaign','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1411898-evolution-multispectral-aerosol-absorption-properties-biogenically-influenced-urban-environment-during-cares-campaign"><span>Evolution of Multispectral Aerosol Absorption Properties in a <span class="hlt">Biogenically</span>-Influenced Urban Environment during the CARES Campaign</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gyawali, Madhu; Arnott, W.; Zaveri, Rahul</p> <p></p> <p>We present the evolution of multispectral optical properties as urban aerosols aged and interacted with <span class="hlt">biogenic</span> emissions resulting in stronger short wavelength absorption and formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made during June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area. Data on black carbon and non-refractory aerosol mass and composition were collected at both sites. In addition, photoacoustic (PA) instruments with integrating nephelometers were used to measure spectral absorption and scattering coefficients for wavelengths ranging from 355 to 870more » nm. The daytime absorption Ångström exponent (AAE) indicated a modest wavelength-dependent enhancement of absorption at both sites throughout the study. From the 22nd to the 28th of June, secondary organic aerosol mass increased significantly at both sites due to increased <span class="hlt">biogenic</span> emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the median BC mass-normalized absorption cross-section (MAC) values for 405 nm and 532 nm at T1 increased by ~23% and ~35%, respectively, compared to the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for the 870 nm wavelength were similar for both sites. These results suggest formation of moderately brown secondary organic aerosols in <span class="hlt">biogenically</span>-influenced urban air.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1430721-evolution-multispectral-aerosol-absorption-properties-biogenically-influenced-urban-environment-during-cares-campaign','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1430721-evolution-multispectral-aerosol-absorption-properties-biogenically-influenced-urban-environment-during-cares-campaign"><span>Evolution of Multispectral Aerosol Absorption Properties in a <span class="hlt">Biogenically</span>-Influenced Urban Environment during the CARES Campaign</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gyawali, Madhu; Arnott, W.; Zaveri, Rahul; ...</p> <p>2017-11-13</p> <p>We present the evolution of multispectral optical properties through urban aerosols that have aged and interacted with <span class="hlt">biogenic</span> emissions, resulting in stronger short wavelength absorption and the formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made in June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area. Data on black carbon (BC) and non-refractory aerosol mass and composition were collected at both sites. In addition, photoacoustic (PA) instruments with integrating nephelometers were used to measure spectral absorption and scattering coefficients for wavelengths rangingmore » from 355 to 870 nm. The daytime absorption Ångström exponent (AAE) indicated a modest wavelength-dependent enhancement of absorption at both sites throughout the study. From 22 to 28 June 2010, secondary organic aerosol mass increased significantly at both sites, which was due to increased <span class="hlt">biogenic</span> emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the median BC mass-normalized absorption cross-section (MAC) values for 405 nm and 532 nm at T1 increased by ~23% and ~35%, respectively, compared with the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for the 870 nm wavelength were similar for both sites. These results suggest the formation of moderately brown secondary organic aerosols in <span class="hlt">biogenically</span>-influenced urban air.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1430721','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1430721"><span>Evolution of Multispectral Aerosol Absorption Properties in a <span class="hlt">Biogenically</span>-Influenced Urban Environment during the CARES Campaign</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gyawali, Madhu; Arnott, W.; Zaveri, Rahul</p> <p></p> <p>We present the evolution of multispectral optical properties through urban aerosols that have aged and interacted with <span class="hlt">biogenic</span> emissions, resulting in stronger short wavelength absorption and the formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made in June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area. Data on black carbon (BC) and non-refractory aerosol mass and composition were collected at both sites. In addition, photoacoustic (PA) instruments with integrating nephelometers were used to measure spectral absorption and scattering coefficients for wavelengths rangingmore » from 355 to 870 nm. The daytime absorption Ångström exponent (AAE) indicated a modest wavelength-dependent enhancement of absorption at both sites throughout the study. From 22 to 28 June 2010, secondary organic aerosol mass increased significantly at both sites, which was due to increased <span class="hlt">biogenic</span> emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the median BC mass-normalized absorption cross-section (MAC) values for 405 nm and 532 nm at T1 increased by ~23% and ~35%, respectively, compared with the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for the 870 nm wavelength were similar for both sites. These results suggest the formation of moderately brown secondary organic aerosols in <span class="hlt">biogenically</span>-influenced urban air.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29280410','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29280410"><span><span class="hlt">Iron</span> balance and <span class="hlt">iron</span> supplementation for the female athlete: A practical approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pedlar, Charles R; Brugnara, Carlo; Bruinvels, Georgie; Burden, Richard</p> <p>2018-03-01</p> <p>Maintaining a positive <span class="hlt">iron</span> balance is essential for female athletes to avoid the effects of <span class="hlt">iron</span> deficiency and anaemia and to maintain or improve performance. A major function of <span class="hlt">iron</span> is in the production of the oxygen and carbon dioxide carrying molecule, haemoglobin, via erythropoiesis. <span class="hlt">Iron</span> balance is under the control of a number of factors including the peptide hormone hepcidin, dietary <span class="hlt">iron</span> intake and absorption, environmental stressors (e.g. altitude), exercise, menstrual blood loss and genetics. Menstruating females, particularly those with heavy menstrual bleeding are at an elevated risk of <span class="hlt">iron</span> deficiency. Haemoglobin concentration [Hb] and serum ferritin (sFer) are traditionally used to identify <span class="hlt">iron</span> deficiency, however, in isolation these may have limited value in athletes due to: (1) the effects of fluctuations in plasma volume in response to training or the environment on [Hb], (2) the influence of inflammation on sFer and (3) the absence of sport, gender and individually specific normative data. A more detailed and longitudinal examination of haematology, menstrual cycle pattern, biochemistry, exercise physiology, environmental factors and training load can offer a superior characterisation of <span class="hlt">iron</span> status and help to direct appropriate interventions that will avoid <span class="hlt">iron</span> deficiency or <span class="hlt">iron</span> overload. Supplementation is often required in <span class="hlt">iron</span> deficiency; however, nutritional strategies to increase <span class="hlt">iron</span> intake, rest and descent from altitude can also be effective and will help to prevent future <span class="hlt">iron</span> deficient episodes. In severe cases or where there is a time-critical need, such as major championships, <span class="hlt">iron</span> injections may be appropriate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3104019','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3104019"><span>Mutations in TMPRSS6 cause <span class="hlt">iron</span>-refractory <span class="hlt">iron</span> deficiency anemia (IRIDA)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Finberg, Karin E; Heeney, Matthew M; Campagna, Dean R; Aydınok, Yeşim; Pearson, Howard A; Hartman, Kip R; Mayo, Mary M; Samuel, Stewart M; Strouse, John J; Markianos, Kyriacos; Andrews, Nancy C; Fleming, Mark D</p> <p>2011-01-01</p> <p><span class="hlt">Iron</span> deficiency is usually attributed to chronic blood loss or inadequate dietary intake. Here, we show that <span class="hlt">iron</span> deficiency anemia refractory to oral <span class="hlt">iron</span> therapy can be caused by germline mutations in TMPRSS6, which encodes a type II transmembrane serine protease produced by the liver that regulates the expression of the systemic <span class="hlt">iron</span> regulatory hormone hepcidin. These findings demonstrate that TMPRSS6 is essential for normal systemic <span class="hlt">iron</span> homeostasis in humans. PMID:18408718</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26314490','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26314490"><span><span class="hlt">Iron</span> deficiency anaemia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent</p> <p>2016-02-27</p> <p>Anaemia affects roughly a third of the world's population; half the cases are due to <span class="hlt">iron</span> 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 <span class="hlt">iron</span> 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 <span class="hlt">iron</span> deficiency anaemia. In addition to the search for and treatment of the cause of <span class="hlt">iron</span> deficiency, treatment strategies encompass prevention, including food fortification and <span class="hlt">iron</span> supplementation. Oral <span class="hlt">iron</span> is usually recommended as first-line therapy, but the most recent intravenous <span class="hlt">iron</span> formulations, which have been available for nearly a decade, seem to replenish <span class="hlt">iron</span> stores safely and effectively. Hepcidin has a key role in <span class="hlt">iron</span> 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 <span class="hlt">iron</span> deficiency anaemia, and outstanding research questions for treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15189124','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15189124"><span><span class="hlt">Iron</span>, ferritin, and nutrition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Theil, Elizabeth C</p> <p>2004-01-01</p> <p>Ferritin, a major form of endogenous <span class="hlt">iron</span> in food legumes such as soybeans, is a novel and natural alternative for <span class="hlt">iron</span> supplementation strategies where effectiveness is limited by acceptability, cost, or undesirable side effects. A member of the nonheme <span class="hlt">iron</span> group of dietary <span class="hlt">iron</span> sources, ferritin is a complex with Fe3+ <span class="hlt">iron</span> in a mineral (thousands of <span class="hlt">iron</span> atoms inside a protein cage) protected from complexation. Ferritin illustrates the wide range of chemical and biological properties among nonheme <span class="hlt">iron</span> sources. The wide range of nonheme <span class="hlt">iron</span> receptors matched to the structure of the <span class="hlt">iron</span> complexes that occurs in microorganisms may, by analogy, exist in humans. An understanding of the chemistry and biology of each type of dietary <span class="hlt">iron</span> source (ferritin, heme, Fe2+ ion, etc.), and of the interactions dependent on food sources, genes, and gender, is required to design diets that will eradicate global <span class="hlt">iron</span> deficiency in the twenty-first century.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSME51C..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSME51C..02L"><span>Planktonic Marine <span class="hlt">Iron</span>-Oxidizers Drive <span class="hlt">Iron</span>(III) Mineralization Under Low Oxygen Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luther, G. W., III; Field, E.; Findlay, A.; MacDonald, D. J.; Chan, C. S. Y.; Kato, S.</p> <p>2016-02-01</p> <p>Observations of modern microbes have led to several hypotheses on how microbes precipitated the extensive banded <span class="hlt">iron</span> formations in the geologic record, but we have yet to resolve the exact microbial contributions. An initial hypotheses was that cyanobacteria produced oxygen that oxidized <span class="hlt">iron</span>(II) abiotically; however, in modern environments such as microbial mats, where Fe(II) and O2 coexist, we commonly find microaerophilic chemolithotrophic <span class="hlt">iron</span>(II)-oxidizing bacteria producing Fe(III) oxyhydroxides. This suggests that such <span class="hlt">iron</span>-oxidizers could have inhabited niches in ancient coastal oceans where Fe(II) and O2 coexisted, and therefore contributed to <span class="hlt">iron</span> deposits, but there is currently little evidence for planktonic marine <span class="hlt">iron</span>-oxidizers in modern analogs. Here, we demonstrate successful cultivation of planktonic microaerophilic <span class="hlt">iron</span>-oxidizing Zetaproteobacteria from the Chesapeake Bay during seasonal stratification. <span class="hlt">Iron</span>-oxidizers were associated with low oxygen concentrations and active <span class="hlt">iron</span> redox cycling in the oxic-anoxic transition zone (<3 µM O2, <0.2 µM H2S). While cyanobacteria were also detected in this transition zone, oxygen concentrations were too low to support significant rates of abiotic <span class="hlt">iron</span> oxidation. Instead, cyanobacteria may be providing oxygen for microaerophilic <span class="hlt">iron</span>(II) oxidation through a symbiotic relationship that promotes oxygen consumption rather than build-up. Our results suggest that once oxygenic photosynthesis evolved, microaerophilic chemolithotrophic <span class="hlt">iron</span>(II)-oxidizers were likely important drivers of <span class="hlt">iron</span>(III) mineralization in ancient oceans.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23163937','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23163937"><span>Influence of various cooking methods on the concentrations of volatile N-nitrosamines and <span class="hlt">biogenic</span> amines in dry-cured sausages.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Ling; Wang, Peng; Xu, Xinglian; Zhou, Guanghong</p> <p>2012-05-01</p> <p>N-nitrosamines, <span class="hlt">biogenic</span> amines, and residual nitrites are harmful substances and are often present in cured meats. The effects of different cooking methods (boiling, pan-frying, deep-frying, and microwave) were investigated on their contents in dry-cured sausage. The various N-nitrosamines were isolated by a steam distillation method and analyzed by gas chromatography mass spectrometry (GC-MS). The <span class="hlt">biogenic</span> amines were determined after extraction with perchloric acid as dansyl derivatives by high-performance liquid chromatography (HPLC) method. The results showed that initial dry-cured raw sausage contained 5.31 μg/kg of total N-nitrosamines. Cooking by deep-frying or pan-frying resulted in products having the highest (P < 0.05) contents, compared with boiling or microwave treatments, which were not different from the raw. Although frying increased the content of N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and N-nitrosopyrrolidine (NPYR), it decreased the contents of histamine and cadaverine. Boiling and microwave treatments decreased the total <span class="hlt">biogenic</span> amines significantly (P < 0.05). Residual nitrite was significantly reduced by cooking treatments. The results suggest that boiling and microwave treatments were more suitable methods for cured meat. © 2012 Institute of Food Technologists®</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3991428','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3991428"><span>Processes of zinc attenuation by <span class="hlt">biogenic</span> manganese oxides forming in the hyporheic zone of Pinal Creek, Arizona</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fuller, Christopher C.; Bargar, John R.</p> <p>2014-01-01</p> <p>The distribution and speciation of Zn sorbed to <span class="hlt">biogenic</span> Mn oxides forming in the hyporheic zone of Pinal Creek, AZ, was investigated using micro-focused Extended X-ray Absorption Fine Structure (EXAFS) and X-ray fluorescence (μSXRF) mapping , bulk EXAFS, and chemical extraction. μSXRF and chemical extractions show that contaminant Zn co-varied with Mn in streambed sediment grain coatings. Bulk and micro-focused EXAFS spectra of Zn in the <span class="hlt">biogenic</span> Mn oxides coating are indicative of Zn forming triple corner sharing inner-sphere complexes over octahedral vacancies in the Mn oxide sheet structure. Zn desorbed in response to decreasing in pH in batch experiments and resulted in near-equal dissolved Zn at each pH over a 10-fold range in solid to solution ratio. The geometry of sorbed Zn was unchanged after 50% desorption at pH 5, indicating desorption is not controlled by dissolution of secondary Zn phases. In sum, these findings support the idea that Zn attenuation in Pinal Creek is largely controlled by sorption to microbial Mn oxides forming in the streambed during hyporheic exchange. Sorption to <span class="hlt">biogenic</span> Mn oxides is likely an important process in Zn attenuation in circum-neutral pH reaches of many acid-mine drainage contaminated streams when dissolved Mn is present. PMID:24460038</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29459666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29459666"><span>Substantial Seasonal Contribution of Observed <span class="hlt">Biogenic</span> Sulfate Particles to Cloud Condensation Nuclei.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sanchez, Kevin J; Chen, Chia-Li; Russell, Lynn M; Betha, Raghu; Liu, Jun; Price, Derek J; Massoli, Paola; Ziemba, Luke D; Crosbie, Ewan C; Moore, Richard H; Müller, Markus; Schiller, Sven A; Wisthaler, Armin; Lee, Alex K Y; Quinn, Patricia K; Bates, Timothy S; Porter, Jack; Bell, Thomas G; Saltzman, Eric S; Vaillancourt, Robert D; Behrenfeld, Mike J</p> <p>2018-02-19</p> <p><span class="hlt">Biogenic</span> sources contribute to cloud condensation nuclei (CCN) in the clean marine atmosphere, but few measurements exist to constrain climate model simulations of their importance. The chemical composition of individual atmospheric aerosol particles showed two types of sulfate-containing particles in clean marine air masses in addition to mass-based Estimated Salt particles. Both types of sulfate particles lack combustion tracers and correlate, for some conditions, to atmospheric or seawater dimethyl sulfide (DMS) concentrations, which means their source was largely <span class="hlt">biogenic</span>. The first type is identified as New Sulfate because their large sulfate mass fraction (63% sulfate) and association with entrainment conditions means they could have formed by nucleation in the free troposphere. The second type is Added Sulfate particles (38% sulfate), because they are preexisting particles onto which additional sulfate condensed. New Sulfate particles accounted for 31% (7 cm -3 ) and 33% (36 cm -3 ) CCN at 0.1% supersaturation in late-autumn and late-spring, respectively, whereas sea spray provided 55% (13 cm -3 ) in late-autumn but only 4% (4 cm -3 ) in late-spring. Our results show a clear seasonal difference in the marine CCN budget, which illustrates how important phytoplankton-produced DMS emissions are for CCN in the North Atlantic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5622765','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5622765"><span>Dietary Factors Modulate <span class="hlt">Iron</span> Uptake in Caco-2 Cells from an <span class="hlt">Iron</span> Ingot Used as a Home Fortificant to Prevent <span class="hlt">Iron</span> Deficiency</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rodriguez-Ramiro, Ildefonso; Perfecto, Antonio; Fairweather-Tait, Susan J.</p> <p>2017-01-01</p> <p><span class="hlt">Iron</span> deficiency is a major public health concern and nutritional approaches are required to reduce its prevalence. The aim of this study was to examine the <span class="hlt">iron</span> bioavailability of a novel home fortificant, the “Lucky <span class="hlt">Iron</span> Fish™” (LIF) (www.luckyironfish.com/shop, Guelph, Canada) and the impact of dietary factors and a food matrix on <span class="hlt">iron</span> uptake from LIF in Caco-2 cells. LIF released a substantial quantity of <span class="hlt">iron</span> (about 1.2 mM) at pH 2 but this <span class="hlt">iron</span> was only slightly soluble at pH 7 and not taken up by cells. The addition of ascorbic acid (AA) maintained the solubility of <span class="hlt">iron</span> released from LIF (LIF-<span class="hlt">iron</span>) at pH 7 and facilitated <span class="hlt">iron</span> uptake by the cells in a concentration-dependent manner. In vitro digestion of LIF-<span class="hlt">iron</span> in the presence of peas increased <span class="hlt">iron</span> uptake 10-fold. However, the addition of tannic acid to the digestion reduced the cellular <span class="hlt">iron</span> uptake 7.5-fold. Additionally, LIF-<span class="hlt">iron</span> induced an overproduction of reactive oxygen species (ROS), similar to ferrous sulfate, but this effect was counteracted by the addition of AA. Overall, our data illustrate the major influence of dietary factors on <span class="hlt">iron</span> solubility and bioavailability from LIF, and demonstrate that the addition of AA enhances <span class="hlt">iron</span> uptake and reduces ROS in the intestinal lumen. PMID:28895913</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28391437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28391437"><span>Oral sucrosomial <span class="hlt">iron</span> versus intravenous <span class="hlt">iron</span> in anemic cancer patients without <span class="hlt">iron</span> deficiency receiving darbepoetin alfa: a pilot study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mafodda, Antonino; Giuffrida, D; Prestifilippo, A; Azzarello, D; Giannicola, R; Mare, M; Maisano, R</p> <p>2017-09-01</p> <p>Erythropoiesis-stimulating agents (ESAs) are often used in treatment of patients with chemotherapy-induced anemia. Many studies have demonstrated an improved hemoglobin (Hb) response when ESA is combined with intravenous <span class="hlt">iron</span> supplementation and a higher effectiveness of intravenous <span class="hlt">iron</span> over traditional oral <span class="hlt">iron</span> formulations. A new formulation of oral sucrosomial <span class="hlt">iron</span> featuring an increased bioavailability compared to traditional oral formulations has recently become available and could provide a valid alternative to those by intravenous (IV) route. Our study evaluated the performance of sucrosomial <span class="hlt">iron</span> versus intravenous <span class="hlt">iron</span> in increasing hemoglobin in anemic cancer patients receiving chemotherapy and darbepoetin alfa, as well as safety, need of transfusion, and quality of life (QoL). The present study considered a cohort of 64 patients with chemotherapy-related anemia (Hb >8 g/dL <10 g/dL) and no absolute or functional <span class="hlt">iron</span> deficiency, scheduled to receive chemotherapy and darbepoetin. All patients received darbepoetin alfa 500 mcg once every 3 weeks and were randomly assigned to receive 8 weeks of IV ferric gluconate 125 mg weekly or oral sucrosomial <span class="hlt">iron</span> 30 mg daily. The primary endpoint was to demonstrate the performance of oral sucrosomial <span class="hlt">iron</span> in improving Hb response, compared to intravenous <span class="hlt">iron</span>. The Hb response was defined as the Hb increase ≥2 g/dL from baseline or the attainment Hb ≥ 12 g/dL. There was no difference in the Hb response rate between the two treatment arms. Seventy one percent of patients treated with IV <span class="hlt">iron</span> achieved an erythropoietic response, compared to 70% of patients treated with oral <span class="hlt">iron</span>. By conventional criteria, this difference is considered to be not statistically significant. There were also no differences in the proportion of patients requiring red blood cell transfusions and changes in QoL. Sucrosomial oral <span class="hlt">iron</span> was better tolerated. In cancer patients with chemotherapy-related anemia receiving</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915652D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915652D"><span><span class="hlt">Biogenic</span> Volatile Organic Compounds (BVOCs) and their oxidation products at two Mediterranean background sites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Debevec, Cecile; Sauvage, Stephane; Gros, Valerie; Sciare, Jean; Pikridas, Michael; Dusanter, Sebastien; Leonardis, Thierry; Gaudion, Vincent; Depelchin, Laurence; Fronval, Isabelle; Sarda-Esteve, Roland; Baisnee, Dominique; Vasiliadou, Emily; Savvides, Chrysanthos; Kalogridis, Cerise; Michoud, Vincent; Locoge, Nadine</p> <p>2017-04-01</p> <p>In the framework of the ChArMEx (Chemistry Aerosol Mediterranean Experiments) program, this work aims at providing a better characterization of the sources and fate of VOCs impacting the Mediterranean region as well as conducting a parallel between organic aerosol and gas phase composition. To reach these objectives, on-line measurements of a large number of VOCs were conducted by flame ionization detection/gas chromatography and proton transfer reaction mass spectrometry at two Mediterranean receptor sites, Cape Corsica in summer 2013 and the Cyprus Atmospheric Observatory (CAO) in March 2015. Additionally, off-line air samples were collected on cartridges. On-line submicron aerosol chemical composition was performed in parallel with an aerosol mass spectrometer. VOCs Sources were identified using positive matrix factorization (PMF) tool and discussed in previous studies (Michoud et al., submitted, Debevec et al., submitted). This work focuses on BVOCs measured at these sampling sites (especially on their levels, speciation, variability and processes). Different speciation of monoterpenes was noticed at these sites. Even if monoterpenes were mainly composed of β-pinene at both sites (34 % - 38 % of the total monoterpenes mass concentration), α-terpinene was observed in higher proportion at Cape Corsica (21 %) than CAO (2 %) while lower proportion of α-pinene was measured (Cape Corsica: 24 %, CAO: 35 %). <span class="hlt">Biogenic</span> sources were found to be significant contributors to the VOCs concentrations observed at these sampling sites (Cape Corsica: 20%, CAO: 36 %) but have shown different variabilities. At Cape Corsica, a primary and a secondary <span class="hlt">biogenic</span> factor were identified, both correlating with air temperature and exhibiting a clear diurnal profile. At CAO, two different <span class="hlt">biogenic</span> factors were identified with distinct diurnal profiles, the first one driven by isoprene was correlated with air temperature and the second one, driven by monoterpenes, showed maxima during</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.loc.gov/pictures/collection/hh/item/al1087.photos.046810p/','SCIGOV-HHH'); return false;" href="https://www.loc.gov/pictures/collection/hh/item/al1087.photos.046810p/"><span>35. GREY <span class="hlt">IRON</span> TUMBLERS, IN THE GREY <span class="hlt">IRON</span> FOUNDRY ROTATE ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>35. GREY <span class="hlt">IRON</span> TUMBLERS, IN THE GREY <span class="hlt">IRON</span> FOUNDRY ROTATE CASTINGS WITH SHOT TO REMOVE AND SURFACE OXIDES AND REMAINING EXCESS METALS. - Stockham Pipe & Fittings Company, Grey <span class="hlt">Iron</span> Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4518169','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4518169"><span>Intravenous <span class="hlt">Iron</span> Therapy in Patients with <span class="hlt">Iron</span> Deficiency Anemia: Dosing Considerations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Myers, Jennifer; Goodnough, Lawrence Tim</p> <p>2015-01-01</p> <p>Objective. To provide clinicians with evidence-based guidance for <span class="hlt">iron</span> therapy dosing in patients with <span class="hlt">iron</span> deficiency anemia (IDA), we conducted a study examining the benefits of a higher cumulative dose of intravenous (IV) <span class="hlt">iron</span> than what is typically administered. Methods. We first individually analyzed 5 clinical studies, averaging the total <span class="hlt">iron</span> deficit across all patients utilizing a modified Ganzoni formula; we then similarly analyzed 2 larger clinical studies. For the second of the larger studies (Study 7), we also compared the efficacy and retreatment requirements of a cumulative dose of 1500 mg ferric carboxymaltose (FCM) to 1000 mg <span class="hlt">iron</span> sucrose (IS). Results. The average <span class="hlt">iron</span> deficit was calculated to be 1531 mg for patients in Studies 1–5 and 1392 mg for patients in Studies 6-7. The percentage of patients who were retreated with IV <span class="hlt">iron</span> between Days 56 and 90 was significantly (p < 0.001) lower (5.6%) in the 1500 mg group, compared to the 1000 mg group (11.1%). Conclusions. Our data suggests that a total cumulative dose of 1000 mg of IV <span class="hlt">iron</span> may be insufficient for <span class="hlt">iron</span> repletion in a majority of patients with IDA and a dose of 1500 mg is closer to the actual <span class="hlt">iron</span> deficit in these patients. PMID:26257955</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25369923','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25369923"><span><span class="hlt">Iron</span> and vegetarian diets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saunders, Angela V; Craig, Winston J; Baines, Surinder K; Posen, Jennifer S</p> <p>2013-08-19</p> <p>Vegetarians who eat a varied and well balanced diet are not at any greater risk of <span class="hlt">iron</span> deficiency anaemia than non-vegetarians. A diet rich in wholegrains, legumes, nuts, seeds, dried fruits, <span class="hlt">iron</span>-fortified cereals and green leafy vegetables provides an adequate <span class="hlt">iron</span> intake. Vitamin C and other organic acids enhance non-haem <span class="hlt">iron</span> absorption, a process that is carefully regulated by the gut. People with low <span class="hlt">iron</span> stores or higher physiological need for <span class="hlt">iron</span> will tend to absorb more <span class="hlt">iron</span> and excrete less. Research to date on <span class="hlt">iron</span> absorption has not been designed to accurately measure absorption rates in typical Western vegetarians with low ferritin levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.8277C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.8277C"><span>Holocene laminated <span class="hlt">biogenic</span> mud in Wood Bay (western Ross Sea, Antarctica): geochemical data and preliminary paleoclimatic interpretation.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colizza, Ester; Finocchiaro, Furio; Giglio, Federico; Kuhn, Gerhard; Langone, Leonardo; Presti, Massimo</p> <p>2010-05-01</p> <p>The study of LGM and Holocene marine sediments is an important goal in Antarctic research and needs high-resolution sequences to reconstruct paleoclimatic events in detail. Literature reports a large number of data coming from inner-shelf bays and fjords, especially around Antarctic peninsula, but also from western Ross Sea. In this note we discuss compositional data from a gravity core (BAY05-45c; 74° 09.7' S, 165° 57.7' E; water depth: 1058 m; core length: 445.5 cm) collected in 2005 during the Italian PNRA cruise into the inner part of Wood Bay, in front of the Aviator Ice tongue. Wood Bay sea floor morphology is charcterised by a narrow basin, deeper than 1,000 m, oriented WNW-ESE, and transversally connected, by a 800-m deep sill, to the Drygalski basin, streching NE-SW. Core sediment is composed by laminated biosiliecous mud, with a strong hydrogen sulphide odour and black in colour. Within a few days from core sampling, sediment became oxidized: laminae colour ranges from dark (from dark olive grey to black) to light (from olive grey to olive). Some lighter laminae have cotton-like texture. Data set include X-ray images, magnetic susceptibility, AMS 14C dating, organic carbon, <span class="hlt">biogenic</span> silica, XRF-scan of major and minor elements. Discussion of the data will point out inferences about sedimentary processes, paleoproductivity and oceanographic conditions during the Holocene. The most apparent feature is the occurrence, down-core, of at least two intervals of increased productivity, characterised by higher organic carbon and <span class="hlt">biogenic</span> silica. Within such intervals, a few cm-thick levels show peaks of <span class="hlt">biogenic</span> silica, as well as of barium, which correspond to relatively lows in organic carbon contents. Organic carbon content is higher in darker laminae, whereas lighter and fluffy laminae display an increased percentage of <span class="hlt">biogenic</span> silica. Such levels probably mark a rapid and not persistent change in phytoplankton assemblage compositions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP43C1367C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP43C1367C"><span>Silicon Isotopes of Marine Pore Water: Tracking the Destiny of Marine <span class="hlt">Biogenic</span> Opal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cassarino, L.; Hendry, K. R.</p> <p>2017-12-01</p> <p>Silicon isotopes (δ30Si) are a powerful tool for the studying of the past and present silicon cycles, which is closely linked to the carbon cycle. Siliceous phytoplankton, such as diatoms, as one of the major conveyors of carbon to marine sediments. δ30Si from fossil diatoms has been shown to represent past silicic acid (DSi) utilization in the photic zone, since the lighter isotope is preferentially incorporated in their skeleton, the frustule. This assumes that species in the sediments depict past blooms and that frustules are preserved in their initial state during burial. Here we present new silicon isotopes data of sea water and pore water of deep marine sediments from two contrasted environments, the Equatorial Atlantic and West Antarctic Peninsula. δ30Si and DSi concentration, of both sea water and pore water, are negatively correlated. Marine <span class="hlt">biogenic</span> opal dissolution can be tracked using δ30Si signature of pore water as lighter signals and high DSi concentrations are associated with the <span class="hlt">biogenic</span> silica. Our data enhances post depositional and diagenesis processes during burial with a clear highlight on the sediment water interface exchanges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatGe...9..349K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatGe...9..349K"><span>Large increases in Arctic <span class="hlt">biogenic</span> volatile emissions are a direct effect of warming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kramshøj, Magnus; Vedel-Petersen, Ida; Schollert, Michelle; Rinnan, Åsmund; Nymand, Josephine; Ro-Poulsen, Helge; Rinnan, Riikka</p> <p>2016-05-01</p> <p><span class="hlt">Biogenic</span> volatile organic compounds are reactive gases that can contribute to atmospheric aerosol formation. Their emission from vegetation is dependent on temperature and light availability. Increasing temperature, changing cloud cover and shifting composition of vegetation communities can be expected to affect emissions in the Arctic, where the ongoing climate changes are particularly severe. Here we present <span class="hlt">biogenic</span> volatile organic compound emission data from Arctic tundra exposed to six years of experimental warming or reduced sunlight treatment in a randomized block design. By separately assessing the emission response of the whole ecosystem, plant shoots and soil in four measurements covering the growing season, we have identified that warming increased the emissions directly rather than via a change in the plant biomass and species composition. Warming caused a 260% increase in total emission rate for the ecosystem and a 90% increase in emission rates for plants, while having no effect on soil emissions. Compared to the control, reduced sunlight decreased emissions by 69% for the ecosystem, 61-65% for plants and 78% for soil. The detected strong emission response is considerably higher than observed at more southern latitudes, emphasizing the high temperature sensitivity of ecosystem processes in the changing Arctic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64689&keyword=Branches+AND+science&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64689&keyword=Branches+AND+science&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">BIOGENIC</span> VOLATILE ORGANIC COMPOUND EMISSIONS (BVOCS) I. IDENTIFICATIONS FROM THREE CONTINENTAL SITES IN THE U.S.</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Vegetation composition and biomass were surveyed for three specific sites in Atlanta, GA; near Rhinelander, WI; and near Hayden, CO. At each research site, emissions of <span class="hlt">biogenic</span> volatile organic compounds (BVOCs) from the dominant vegetation species were sampled by enclosing bran...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25050519','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25050519"><span>Nitrosative Stress and Apoptosis by Intravenous Ferumoxytol, <span class="hlt">Iron</span> Isomaltoside 1000, <span class="hlt">Iron</span> Dextran, <span class="hlt">Iron</span> Sucrose, and Ferric Carboxymaltose in a Nonclinical Model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toblli, J E; Cao, G; Giani, J F; Dominici, F P; Angerosa, M</p> <p>2015-07-01</p> <p><span class="hlt">Iron</span> is involved in the formation as well as in the scavenging of reactive oxygen and nitrogen species. Thus, <span class="hlt">iron</span> can induce as well as inhibit both oxidative and nitrosative stress. It also has a key role in reactive oxygen and nitrogen species-mediated apoptosis. We assessed the differences in tyrosine nitration and caspase 3 expression in the liver, heart, and kidneys of rats treated weekly with intravenous ferumoxytol, <span class="hlt">iron</span> isomaltoside 1000, <span class="hlt">iron</span> dextran, <span class="hlt">iron</span> sucrose and ferric carboxymaltose (40 mg <span class="hlt">iron</span>/kg body weight) for 5 weeks. Nitrotyrosine was quantified in tissue homogenates by Western blotting and the distribution of nitrotyrosine and caspase 3 was assessed in tissue sections by immunohistochemistry. Ferric carboxymaltose and <span class="hlt">iron</span> sucrose administration did not result in detectable levels of nitrotyrosine or significant levels of caspase 3 vs. control in any of the tissue studied. Nitrotyrosine and caspase 3 levels were significantly (p<0.01) increased in all assessed organs of animals treated with <span class="hlt">iron</span> dextran and <span class="hlt">iron</span> isomaltoside 1000, as well as in the liver and kidneys of ferumoxytol-treated animals compared to isotonic saline solution (control). Nitrotyrosine and caspase 3 levels were shown to correlate positively with the amount of Prussian blue-detectable <span class="hlt">iron</span>(III) deposits in <span class="hlt">iron</span> dextran- and <span class="hlt">iron</span> isomaltoside 1000-treated rats but not in ferumoxytol-treated rats, suggesting that <span class="hlt">iron</span> dextran, <span class="hlt">iron</span> isomaltoside 1000 and ferumoxytol induce nitrosative (and oxidative) stress as well as apoptosis via different mechanism(s). © Georg Thieme Verlag KG Stuttgart · New York.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23043830','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23043830"><span><span class="hlt">Biogenic</span> amine content, histamine-forming bacteria, and adulteration of pork in tuna sausage products.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kung, Hsien-Feng; Tsai, Yung-Hsiang; Chang, Shih-Chih; Hong, Tang-Yao</p> <p>2012-10-01</p> <p>Twenty-five tuna sausage products were purchased from retail markets in Taiwan. The rates of occurrence of <span class="hlt">biogenic</span> amines, histamine-forming bacteria, and adulteration by pork and poultry were determined. The average content of various <span class="hlt">biogenic</span> amines in all tested samples was less than 2.0 mg/100 g (<0.05 to 1.85 mg/100 g). Thirteen histamine-producing bacterial strains isolated from tested samples produced 12.1 to 1,261 ppm of histamine in Trypticase soy broth supplemented with 1.0% L-histidine. Among them, Raoultella ornithinolytica (one strain), Enterobacter aerogenes (one strain), and Staphylococcus pasteuri (two strains) were identified as prolific histamine formers. PCR assay revealed that the adulteration rates were 80% (20 of 25) and 4% (1 of 25) for pork and poultry, respectively, in tuna sausage. The fish species in the tuna sausage samples were identified as Thunnus albacares for 22 samples (88%), Thunnus alalunga for 1 sample (4%), and Thunnus thynnus for 1 sample (4%), whereas the remaining sample was identified as Makaira nigricans (blue marlin).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27795321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27795321"><span>Characterization of a Novel <span class="hlt">Iron</span> Acquisition Activity That Coordinates the <span class="hlt">Iron</span> Response with Population Density under <span class="hlt">Iron</span>-Replete Conditions in Bacillus subtilis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roy, Emily M; Griffith, Kevin L</p> <p>2017-01-01</p> <p><span class="hlt">Iron</span> is an essential micronutrient required for the viability of many organisms. Under oxidizing conditions, ferric <span class="hlt">iron</span> is highly insoluble (∼10 -9 to 10 -18 M), yet bacteria typically require ∼10 -6 M for survival. To overcome this disparity, many bacteria have adopted the use of extracellular <span class="hlt">iron</span>-chelating siderophores coupled with specific <span class="hlt">iron</span>-siderophore uptake systems. In the case of Bacillus subtilis, undomesticated strains produce the siderophore bacillibactin. However, many laboratory strains, e.g., JH642, have lost the ability to produce bacillibactin during the process of domestication. In this work, we identified a novel <span class="hlt">iron</span> acquisition activity from strain JH642 that accumulates in the growth medium and coordinates the <span class="hlt">iron</span> response with population density. The molecule(s) responsible for this activity was named elemental Fe(II/III) (Efe) acquisition factor because efeUOB (ywbLMN) is required for its activity. Unlike most <span class="hlt">iron</span> uptake molecules, including siderophores and <span class="hlt">iron</span> reductases, Efe acquisition factor is present under <span class="hlt">iron</span>-replete conditions and is regulated independently of Fur repressor. Restoring bacillibactin production in strain JH642 inhibits the activity of Efe acquisition factor, presumably by sequestering available <span class="hlt">iron</span>. A similar <span class="hlt">iron</span> acquisition activity is produced from a mutant of Escherichia coli unable to synthesize the siderophore enterobactin. Given the conservation of efeUOB and its regulation by catecholic siderophores in B. subtilis and E. coli, we speculate that Efe acquisition factor is utilized by many bacteria, serves as an alternative to Fur-mediated <span class="hlt">iron</span> acquisition systems, and provides cells with biologically available <span class="hlt">iron</span> that would normally be inaccessible during aerobic growth under <span class="hlt">iron</span>-replete conditions. <span class="hlt">Iron</span> is an essential micronutrient required for a variety of biological processes, yet ferric <span class="hlt">iron</span> is highly insoluble during aerobic growth. In this work, we identified a novel <span class="hlt">iron</span> acquisition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ACPD...1328343G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ACPD...1328343G"><span>Emissions of terpenoids, benzenoids, and other <span class="hlt">biogenic</span> gas-phase organic compounds from agricultural crops and their potential implications for air quality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gentner, D. R.; Ormeño, E.; Fares, S.; Ford, T. B.; Weber, R.; Park, J.-H.; Brioude, J.; Angevine, W. M.; Karlik, J. F.; Goldstein, A. H.</p> <p>2013-11-01</p> <p>Agriculture comprises a substantial fraction of land cover in many regions of the world, including California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone and particulate matter (PM2.5). Emissions from vegetation and other <span class="hlt">biogenic</span> and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of PM2.5. Using data from three measurement campaigns, we examine emissions of reactive gas-phase organic carbon from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions in California's San Joaquin Valley. Emission rates for a suite of <span class="hlt">biogenic</span> terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008, and ambient measurements of terpenoids and other <span class="hlt">biogenic</span> compounds in the volatile and intermediate-volatility organic compound range were made over an orange orchard in a rural area of the San Joaquin Valley during two seasons in 2010: summer and spring flowering. When accounting for both emissions of reactive precursors and the deposition of ozone to an orange orchard, the net effect of the orange trees is a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such <span class="hlt">biogenic</span> emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by an order of magnitude. In regions like the San Joaquin Valley, the mass of <span class="hlt">biogenic</span> emissions from agricultural crops during the summer (without flowering) and the potential ozone and secondary organic aerosol formation from these emissions are on the same order as anthropogenic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29070551','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29070551"><span>Current understanding of <span class="hlt">iron</span> homeostasis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anderson, Gregory J; Frazer, David M</p> <p>2017-12-01</p> <p><span class="hlt">Iron</span> is an essential trace element, but it is also toxic in excess, and thus mammals have developed elegant mechanisms for keeping both cellular and whole-body <span class="hlt">iron</span> concentrations within the optimal physiologic range. In the diet, <span class="hlt">iron</span> is either sequestered within heme or in various nonheme forms. Although the absorption of heme <span class="hlt">iron</span> is poorly understood, nonheme <span class="hlt">iron</span> is transported across the apical membrane of the intestinal enterocyte by divalent metal-ion transporter 1 (DMT1) and is exported into the circulation via ferroportin 1 (FPN1). Newly absorbed <span class="hlt">iron</span> binds to plasma transferrin and is distributed around the body to sites of utilization with the erythroid marrow having particularly high <span class="hlt">iron</span> requirements. <span class="hlt">Iron</span>-loaded transferrin binds to transferrin receptor 1 on the surface of most body cells, and after endocytosis of the complex, <span class="hlt">iron</span> enters the cytoplasm via DMT1 in the endosomal membrane. This <span class="hlt">iron</span> can be used for metabolic functions, stored within cytosolic ferritin, or exported from the cell via FPN1. Cellular <span class="hlt">iron</span> concentrations are modulated by the <span class="hlt">iron</span> regulatory proteins (IRPs) IRP1 and IRP2. At the whole-body level, dietary <span class="hlt">iron</span> absorption and <span class="hlt">iron</span> export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin. When tissue <span class="hlt">iron</span> demands are high, hepcidin concentrations are low and vice versa. Too little or too much <span class="hlt">iron</span> can have important clinical consequences. Most <span class="hlt">iron</span> deficiency reflects an inadequate supply of <span class="hlt">iron</span> in the diet, whereas <span class="hlt">iron</span> excess is usually associated with hereditary disorders. These disorders include various forms of hemochromatosis, which are characterized by inadequate hepcidin production and, thus, increased dietary <span class="hlt">iron</span> intake, and <span class="hlt">iron</span>-loading anemias whereby both increased <span class="hlt">iron</span> absorption and transfusion therapy contribute to the <span class="hlt">iron</span> overload. Despite major recent advances, much remains to be learned about <span class="hlt">iron</span> physiology and pathophysiology. © 2017 American Society for Nutrition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4975278','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4975278"><span>Pathogenic Mechanisms Underlying <span class="hlt">Iron</span> Deficiency and <span class="hlt">Iron</span> Overload: New Insights for Clinical Application</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Velden, DP; van Rensburg, SJ; Erasmus, R</p> <p>2009-01-01</p> <p><span class="hlt">Iron</span> uptake, utilisation, release and storage occur at the gene level. Individuals with variant forms of genes involved in <span class="hlt">iron</span> metabolism may have different requirements for <span class="hlt">iron</span> and are likely to respond differently to the same amount of <span class="hlt">iron</span> in the diet, a concept termed nutrigenetics. <span class="hlt">Iron</span> deficiency, <span class="hlt">iron</span> overload and the anemia of inflammation are the commonest <span class="hlt">iron</span>-related disorders. While at least four types of hereditary <span class="hlt">iron</span> overload have been identified to date, our knowledge of the genetic basis and consequences of inherited <span class="hlt">iron</span> deficiency remain limited. The importance of genetic risk factors in relation to <span class="hlt">iron</span> overload was highlighted with the identification of the HFE gene in 1996. Deleterious mutations in this gene account for 80-90% of inherited <span class="hlt">iron</span> overload and are associated with loss of <span class="hlt">iron</span> homeostasis, alterations in inflammatory responses, oxidative stress and in its most severe form, the disorder hereditary haemochromatosis (HH). Elucidation of the genetic basis of HH has led to rapid clinical benefit through drastic reduction in liver biopsies performed as part of the diagnostic work-up of affected patients. Today, detection of a genetic predisposition in the presence of high serum ferritin and transferrin saturation levels is usually sufficient to diagnose HH, thereby addressing the potential danger of inherited <span class="hlt">iron</span> overload which starts with the same symptoms as <span class="hlt">iron</span> deficiency, namely chronic fatigue. This review provides the scientific back-up for application of pathology supported genetic testing, a new test concept that is well placed for optimizing clinical benefit to patients with regard to <span class="hlt">iron</span> status. PMID:27683335</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311107&Lab=NHEERL&keyword=oncology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=311107&Lab=NHEERL&keyword=oncology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">Iron</span> and <span class="hlt">iron</span>-related proteins in asbestosis.</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>ABSTRACT: We tested the postulate that <span class="hlt">iron</span> homeostasis is altered among patients diagnosed to have asbestosis. Lung tissue from six individuals diagnosed to have had asbestosis at autopsy was stained for <span class="hlt">iron</span>, ferritin, divalent metal transporter 1 (DMT1), and ferroportin 1 (FP...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28537421','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28537421"><span>Glutathione, Glutaredoxins, and <span class="hlt">Iron</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berndt, Carsten; Lillig, Christopher Horst</p> <p>2017-11-20</p> <p>Glutathione (GSH) is the most abundant cellular low-molecular-weight thiol in the majority of organisms in all kingdoms of life. Therefore, functions of GSH and disturbed regulation of its concentration are associated with numerous physiological and pathological situations. Recent Advances: The function of GSH as redox buffer or antioxidant is increasingly being questioned. New functions, especially functions connected to the cellular <span class="hlt">iron</span> homeostasis, were elucidated. Via the formation of <span class="hlt">iron</span> complexes, GSH is an important player in all aspects of <span class="hlt">iron</span> metabolism: sensing and regulation of <span class="hlt">iron</span> levels, <span class="hlt">iron</span> trafficking, and biosynthesis of <span class="hlt">iron</span> cofactors. The variety of GSH coordinated <span class="hlt">iron</span> complexes and their functions with a special focus on FeS-glutaredoxins are summarized in this review. Interestingly, GSH analogues that function as major low-molecular-weight thiols in organisms lacking GSH resemble the functions in <span class="hlt">iron</span> homeostasis. Since these <span class="hlt">iron</span>-related functions are most likely also connected to thiol redox chemistry, it is difficult to distinguish between mechanisms related to either redox or <span class="hlt">iron</span> metabolisms. The ability of GSH to coordinate <span class="hlt">iron</span> in different complexes with or without proteins needs further investigation. The discovery of new Fe-GSH complexes and their physiological functions will significantly advance our understanding of cellular <span class="hlt">iron</span> homeostasis. Antioxid. Redox Signal. 27, 1235-1251.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27927768','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27927768"><span><span class="hlt">Iron</span>-heme-Bach1 axis is involved in erythroblast adaptation to <span class="hlt">iron</span> deficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kobayashi, Masahiro; Kato, Hiroki; Hada, Hiroshi; Itoh-Nakadai, Ari; Fujiwara, Tohru; Muto, Akihiko; Inoguchi, Yukihiro; Ichiyanagi, Kenji; Hojo, Wataru; Tomosugi, Naohisa; Sasaki, Hiroyuki; Harigae, Hideo; Igarashi, Kazuhiko</p> <p>2017-03-01</p> <p><span class="hlt">Iron</span> plays the central role in oxygen transport by erythrocytes as a constituent of heme and hemoglobin. The importance of <span class="hlt">iron</span> and heme is also to be found in their regulatory roles during erythroblast maturation. The transcription factor Bach1 may be involved in their regulatory roles since it is deactivated by direct binding of heme. To address whether Bach1 is involved in the responses of erythroblasts to <span class="hlt">iron</span> status, low <span class="hlt">iron</span> conditions that induced severe <span class="hlt">iron</span> deficiency in mice were established. Under <span class="hlt">iron</span> deficiency, extensive gene expression changes and mitophagy disorder were induced during maturation of erythroblasts. Bach1 -/- mice showed more severe <span class="hlt">iron</span> deficiency anemia in the developmental phase of mice and a retarded recovery once <span class="hlt">iron</span> was replenished when compared with wild-type mice. In the absence of Bach1, the expression of globin genes and Hmox1 (encoding heme oxygenase-1) was de-repressed in erythroblasts under <span class="hlt">iron</span> deficiency, suggesting that Bach1 represses these genes in erythroblasts under <span class="hlt">iron</span> deficiency to balance the levels of heme and globin. Moreover, an increase in genome-wide DNA methylation was observed in erythroblasts of Bach1 -/- mice under <span class="hlt">iron</span> deficiency. These findings reveal the principle role of <span class="hlt">iron</span> as a regulator of gene expression in erythroblast maturation and suggest that the <span class="hlt">iron</span>-heme-Bach1 axis is important for a proper adaptation of erythroblast to <span class="hlt">iron</span> deficiency to avoid toxic aggregates of non-heme globin. Copyright© Ferrata Storti Foundation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27591110','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27591110"><span>Amphotericin B-conjugated <span class="hlt">biogenic</span> silver nanoparticles as an innovative strategy for fungal infections.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ahmad, Aftab; Wei, Yun; Syed, Fatima; Tahir, Kamran; Taj, Raheela; Khan, Arif Ullah; Hameed, Muhammad Usman; Yuan, Qipeng</p> <p>2016-10-01</p> <p>New strategies are required to improve the efficacy of drugs and to treat the emerging microbial resistance. An effective strategy is to combine drugs with metal nanoparticles for the control of microbial infections and resistance. Keeping in view this fact, we developed a facile and eco-friendly protocol for the synthesis of amphotericin B-conjugated silver nanoparticles and their assessment as an antifungal agent. Phytochemicals from the aqueous extract of Maytenus royleanus and amphotericin B were used as capping agents to prepare two types of silver nanoparticles i.e. (i) <span class="hlt">biogenic</span> silver nanoparticles (b-AgNPs) and (ii) amphotericin B-conjugated <span class="hlt">biogenic</span> silver nanoparticles (Amp-bAgNPs). UV-Vis spectroscopy was used to detect the characteristic surface Plasmon resonance peaks (SPR) for the prepared nanoparticles (424-433 nm). High-resolution transmission electron microscopy (HRTEM) study revealed the formation of well dispersed and spherical silver nanoparticles and Amp-bAgNPs with an average particles size of 10 and 15 nm. EDX and FTIR studies confirmed the elemental composition and surface adhered biomolecules in the prepared nanoparticles respectively. <span class="hlt">Biogenic</span> silver nanoparticles revealed low to moderate antifungal activity (4-8 mm ± 0.2), however, the amphotericin B conjugated silver nanoparticles exhibited significant activity against Candida albicans (16 mm ± 1.4) and Candida tropicalis (18 mm ± 1.5). In conclusion, the enhanced antifungal activity of the Amp-AgNPs conjugate system is due to the synergy between the antifungal activity of amphotericin B and the antimicrobial property of silver. The findings of this study suggest that the conjugated nanoparticles could be used as efficient antifungal agents and drug delivery vehicles. Furthermore, this is the first report describing the synthesis of silver nanoparticles using the aqueous extract of Maytenus royleanus and the conjugation of amphotericin B, an antifungal drug, to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5409619','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5409619"><span>Comparison of <span class="hlt">Biogenic</span> Amines and Mycotoxins in Alfalfa and Red Clover Fodder Depending on Additives</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Skladanka, Jiri; Adam, Vojtech; Zitka, Ondrej; Mlejnkova, Veronika; Kalhotka, Libor; Horky, Pavel; Konecna, Klara; Hodulikova, Lucia; Knotova, Daniela; Balabanova, Marie; Slama, Petr; Skarpa, Petr</p> <p>2017-01-01</p> <p>In the production of fermented feed, each crop can be contaminated with a variety of microorganisms that may produce natural pollutants. <span class="hlt">Biogenic</span> amines, mycotoxins, and undesirable organic acids can decrease health feed safety. The aim of this study was to compare the counts of microorganisms, levels of <span class="hlt">biogenic</span> amines, and the mycotoxins in forage legumes, and also to compare the occurrence of microorganisms and levels of mycotoxins in green fodder and subsequently produced silage and the influence of additives on the content of natural harmful substances in silage. The experimental plot was located in Troubsko and Vatín, in the Czech Republic. Two varieties of Medicago sativa and one variety of Trifolium pratense were compared. Green fodder and subsequently produced silage reaching up to 23% of dry matter were evaluated and prepared using a bio-enzymatic additive and a chemical additive. Green fodder of Medicago sativa was more contaminated by Enterococci than Trifolium pratense fodder. The obvious difference was determined by the quality of silage leachate. The silage prepared from Medicago sativa fodder was more contaminated with butyric acid. Fungi were present in higher counts in the anaerobic environment of green fodder and contaminated it with zearalenone and deoxynivalenol. Lower counts of fungi were found in silage, although the zearalenone content did not change. Lower content of deoxynivalenol was detected in silage, compared with green fodder. Silages treated with a chemical additive were found not to contain butyric acid. Lower ethanol content was determined, and the tendency to reduce the risk of <span class="hlt">biogenic</span> amines occurrence was evident. The additives proved to have no influence on the content of mycotoxins. PMID:28420109</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28420109','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28420109"><span>Comparison of <span class="hlt">Biogenic</span> Amines and Mycotoxins in Alfalfa and Red Clover Fodder Depending on Additives.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Skladanka, Jiri; Adam, Vojtech; Zitka, Ondrej; Mlejnkova, Veronika; Kalhotka, Libor; Horky, Pavel; Konecna, Klara; Hodulikova, Lucia; Knotova, Daniela; Balabanova, Marie; Slama, Petr; Skarpa, Petr</p> <p>2017-04-14</p> <p>In the production of fermented feed, each crop can be contaminated with a variety of microorganisms that may produce natural pollutants. <span class="hlt">Biogenic</span> amines, mycotoxins, and undesirable organic acids can decrease health feed safety. The aim of this study was to compare the counts of microorganisms, levels of <span class="hlt">biogenic</span> amines, and the mycotoxins in forage legumes, and also to compare the occurrence of microorganisms and levels of mycotoxins in green fodder and subsequently produced silage and the influence of additives on the content of natural harmful substances in silage. The experimental plot was located in Troubsko and Vatín, in the Czech Republic. Two varieties of Medicago sativa and one variety of Trifolium pratense were compared. Green fodder and subsequently produced silage reaching up to 23% of dry matter were evaluated and prepared using a bio-enzymatic additive and a chemical additive. Green fodder of Medicago sativa was more contaminated by Enterococci than Trifolium pratense fodder. The obvious difference was determined by the quality of silage leachate. The silage prepared from Medicago sativa fodder was more contaminated with butyric acid. Fungi were present in higher counts in the anaerobic environment of green fodder and contaminated it with zearalenone and deoxynivalenol. Lower counts of fungi were found in silage, although the zearalenone content did not change. Lower content of deoxynivalenol was detected in silage, compared with green fodder. Silages treated with a chemical additive were found not to contain butyric acid. Lower ethanol content was determined, and the tendency to reduce the risk of <span class="hlt">biogenic</span> amines occurrence was evident. The additives proved to have no influence on the content of mycotoxins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5218490','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5218490"><span>Differential Roles of <span class="hlt">Iron</span> Storage Proteins in Maintaining the <span class="hlt">Iron</span> Homeostasis in Mycobacterium tuberculosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tyagi, Anil K.</p> <p>2017-01-01</p> <p>Ferritins and bacterioferritins are <span class="hlt">iron</span> storage proteins that represent key players in <span class="hlt">iron</span> homeostasis. Several organisms possess both forms of ferritins, however, their relative physiological roles are less understood. Mycobacterium tuberculosis possesses both ferritin (BfrB) and bacterioferritin (BfrA), playing an essential role in its pathogenesis as reported by us earlier. This study provides insights into the role of these two proteins in <span class="hlt">iron</span> homeostasis by employing M. tuberculosis bfr mutants. Our data suggests that BfrA is required for efficient utilization of stored <span class="hlt">iron</span> under low <span class="hlt">iron</span> conditions while BfrB plays a crucial role as the major defense protein under excessive <span class="hlt">iron</span> conditions. We show that these two proteins provide protection against oxidative stress and hypoxia. <span class="hlt">Iron</span> incorporation study showed that BfrB has higher capacity for storing <span class="hlt">iron</span> than BfrA, which augurs well for efficient <span class="hlt">iron</span> quenching under <span class="hlt">iron</span> excess conditions. Moreover, <span class="hlt">iron</span> release assay demonstrated that BfrA has 3 times superior ability to release stored <span class="hlt">iron</span> emphasizing its requirement for efficient <span class="hlt">iron</span> release under low <span class="hlt">iron</span> conditions, facilitated by the presence of heme. Thus, for the first time, our observations suggest that the importance of BfrA or BfrB separately might vary depending upon the <span class="hlt">iron</span> situation faced by the cell. PMID:28060867</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACPD...1425167F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACPD...1425167F"><span>Chemical characterization of <span class="hlt">biogenic</span> SOA generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faiola, C. L.; Wen, M.; VanReken, T. M.</p> <p>2014-10-01</p> <p>The largest global source of secondary organic aerosol in the atmosphere is derived from the oxidation of <span class="hlt">biogenic</span> emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the <span class="hlt">biogenic</span> VOC profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate, a proxy compound. Experiments were repeated under pre- and post-treatment conditions for six different coniferous plant types. VOCs emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA particle size distribution and chemical composition were measured using a scanning mobility particle sizer (SMPS) and Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS), respectively. The aerosol mass spectra of pre-treatment <span class="hlt">biogenic</span> SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible <span class="hlt">biogenic</span> stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH3O+), m/z 58 (C2H2O2+, C3H6O+) m/z 29 (C2H5+), m/z 57 (C3H5O+), m/z 59 (C2H3O2+, C3H7O+), m/z 71 (C3H3O2+, C4H7O+), and m/z 83 (C5H7O+). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, methyl jasmonate, is also presented. Elemental analysis results demonstrated an O:C range of baseline <span class="hlt">biogenic</span> SOA between 0.3-0.47. The O:C of standard methyl jasmonate SOA was 0.52. Results presented here could be used to help identify a <span class="hlt">biogenic</span> plant stress marker in ambient datasets collected in forest environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25626410','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25626410"><span>Comparison of food habits, <span class="hlt">iron</span> intake and <span class="hlt">iron</span> status in adolescents before and after the withdrawal of the general <span class="hlt">iron</span> fortification in Sweden.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sjöberg, A; Hulthén, L</p> <p>2015-04-01</p> <p>Sifted flour was fortified with carbonyl <span class="hlt">iron</span> for 50 years in Sweden. This study evaluates changes in food habits, intake of <span class="hlt">iron</span>, factors affecting <span class="hlt">iron</span> absorption and <span class="hlt">iron</span> status after the discontinuation of the general <span class="hlt">iron</span> fortification in adolescents with the highest requirements. A total of 2285 15- to 16-year-old students in 1994 (634 girls and 611 boys) and in 2000 (534 girls and 486 boys) in 13 schools in Gothenburg, Sweden, were included in two cross-sectional surveys assessing food habits with diet history interviews and <span class="hlt">iron</span> deficiency defined with serum ferritin stores ⩽ 15 μg/l and no preceding infection. In girls, <span class="hlt">iron</span> deficiency increased from 37 to 45%, while in boys, it was stable at 23%. Total <span class="hlt">iron</span> intake decreased from 15.7 to 9.5 mg/day and 22.5 to 13.9 mg/day in girls and boys, respectively. Cereals were the main <span class="hlt">iron</span> source. Among girls, the increase of fish and decrease of calcium intake may not counteract the effect of decreased intake of fortification <span class="hlt">iron</span>. Among boys, more meat, less calcium and more vitamin C may have favoured the bioavailability of <span class="hlt">iron</span>. The discontinuation of the general <span class="hlt">iron</span> fortification resulted in a 39% decrease in total <span class="hlt">iron</span> intake and <span class="hlt">iron</span> deficiency increased substantially in girls. However, in boys no change in <span class="hlt">iron</span> deficiency was observed. Whether this was a result of changed bioavailability of dietary <span class="hlt">iron</span> or simultaneous changes of non-dietary factors remains to be explored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA499660','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA499660"><span><span class="hlt">Iron</span> and Prochlorococcus</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-06-01</p> <p>greatly influenced by the sources of <span class="hlt">iron</span> to the marine environment, which include riverine input, hydrothermal upwelling, and atmospheric...deposition (Jickells et al, 2005). While the amount of <span class="hlt">iron</span> introduced to the oceans from riverine and hydrothermal sources is high, precipitation occurs...rapidly in both cases and removes <span class="hlt">iron</span> from seawater, minimizing the impact of hydrothermal and riverine sources on the concentration of <span class="hlt">iron</span> in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28149313','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28149313"><span>Effects of digoxin on cardiac <span class="hlt">iron</span> content in rat model of <span class="hlt">iron</span> overload.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nasri, Hamid Reza; Shahouzehi, Beydolah; Masoumi-Ardakani, Yaser; Iranpour, Maryam</p> <p>2016-07-01</p> <p>Plasma <span class="hlt">iron</span> excess can lead to <span class="hlt">iron</span> accumulation in heart, kidney and liver. Heart failure is a clinical widespread syndrome. In thalassemia, <span class="hlt">iron</span> overload cardiomyopathy is caused by <span class="hlt">iron</span> accumulation in the heart that leads to cardiac damage and heart failure. Digoxin increases the intracellular sodium concentration by inhibition of Na+/K+-ATPase that affects Na+/Ca2+ exchanger (NCX), which raises intracellular calcium and thus attenuates heart failure. The mechanism of <span class="hlt">iron</span> uptake into cardiomyocytes is not exactly understood. We assessed the effect of different concentrations of digoxin on cardiac <span class="hlt">iron</span> content in rat model of <span class="hlt">iron</span> overload. Digoxin had been administrated intraperitoneally (IP) for one week before main study began to assure increased digoxin levels. Group 1 received four IP injections of <span class="hlt">iron</span>-dextran (12.5mg/100g body weight) every 5 days evenly distributed over 20 days. Groups 2-4 received 0.5, 1 and 5 mg/kg/day IP digoxin, respectively. Last three groups 5-7 received <span class="hlt">iron</span>-dextran as group 1 and digoxin concentrations 0.5, 1 and 5 mg/kg/day, respectively. Cardiac <span class="hlt">iron</span> contents were significantly higher in <span class="hlt">iron</span> overload groups that received different concentrations (0.5, 1 and 5 mg/kg/day) of digoxin than their counterparts in control groups and this pattern was also observed in pathology assessment. It seems that digoxin plays an important role in <span class="hlt">iron</span> transport into heart in <span class="hlt">iron</span> overload state but exact mechanism of this phenomenon is not clear. L-type Ca2+ channels are good candidates that probably could be involved in <span class="hlt">iron</span> accumulation in cardiomyocytes. Thus it would be better to reconsider digoxin administration in thalassemia and <span class="hlt">iron</span> overload conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29921869','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29921869"><span>Tubular <span class="hlt">iron</span> deposition and <span class="hlt">iron</span> handling proteins in human healthy kidney and chronic kidney disease.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Raaij, Sanne van; Swelm, Rachel van; Bouman, Karlijn; Cliteur, Maaike; Heuvel, Marius van den; Pertijs, Jeanne; Patel, Dominic; Bass, Paul; Goor, Harry van; Unwin, Robert; Srai, Surjit Kaila; Swinkels, Dorine</p> <p>2018-06-19</p> <p><span class="hlt">Iron</span> is suggested to play a detrimental role in the progression of chronic kidney disease (CKD). The kidney recycles <span class="hlt">iron</span> back into the circulation. However, the localization of proteins relevant for physiological tubular <span class="hlt">iron</span> handling and their potential role in CKD remain unclear. We examined associations between <span class="hlt">iron</span> deposition, expression of <span class="hlt">iron</span> handling proteins and tubular injury in kidney biopsies from CKD patients and healthy controls using immunohistochemistry. <span class="hlt">Iron</span> was deposited in proximal (PT) and distal tubules (DT) in 33% of CKD biopsies, predominantly in pathologies with glomerular dysfunction, but absent in controls. In healthy kidney, PT contained proteins required for <span class="hlt">iron</span> recycling including putative <span class="hlt">iron</span> importers ZIP8, ZIP14, DMT1, <span class="hlt">iron</span> storage proteins L- and H-ferritin and <span class="hlt">iron</span> exporter ferroportin, while DT only contained ZIP8, ZIP14, and DMT1. In CKD, <span class="hlt">iron</span> deposition associated with increased intensity of <span class="hlt">iron</span> importers (ZIP14, ZIP8), storage proteins (L-, H-ferritin), and/or decreased ferroportin abundance. This demonstrates that tubular <span class="hlt">iron</span> accumulation may result from increased <span class="hlt">iron</span> uptake and/or inadequate <span class="hlt">iron</span> export. <span class="hlt">Iron</span> deposition associated with oxidative injury as indicated by heme oxygenase-1 abundance. In conclusion, <span class="hlt">iron</span> deposition is relatively common in CKD, and may result from altered molecular <span class="hlt">iron</span> handling and may contribute to renal injury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP14B..08D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP14B..08D"><span>Diagenetic alteration of <span class="hlt">biogenic</span> silica oxygen isotope values: implications for use as a paleoenvironmental proxy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dodd, J. P.; Abbott, T.; Scherer, R. P.</p> <p>2016-12-01</p> <p>Oxygen isotope (δ18O) values of <span class="hlt">biogenic</span> silica have enormous potential as paleoenvironmental proxies in marine and non-marine environments. Isotopic exchange and phase changes (opal-A to opal-CT) can overprint the initial δ18O values, but these diagenetic processes can also provide additional paleoenvironmental information. The timing and magnitude of isotopic exchange reactions are difficult to constrain in natural environments; however, experimental results of diatom aging indicate that changes in the δ18O values of the <span class="hlt">biogenic</span> silca occur coincident with dehydroxylation of the silica prior to opal-CT formation. Diagenetic alteration of <span class="hlt">biogenic</span> silica dramatically changes our interpretation of silica isotope data from sedimentary records. For example, diatom δ18O values from a Pliocene ( 4.68 to 3.44 Ma) age marine sediment core (AND-1B) from the Ross Sea, Antarctica range from +28 to +36‰. The silica-water fractionation relationship for marine diatoms of Juillet-Leclerc and Labeyrie (1987) and a standard marine δ18O water value of 0‰ results in unrealistic sea surface temperatures of >20°C. Conversely, if water temperatures of 0 to 10°C are used, the resulting water δ18O values range from -8 to -16‰. A plausible alternate scenario is that the diatom δ18O values are recording sediment pore-water conditions. Pore waters in the AND-2A core had δ18O values of -11‰, possibly as a result cryogenic brine formation (Frank et al., 2010). These low δ18O values are in close agreement with our calculated δ18O water values. Despite diagenetic overprinting of the diatom δ18O values, there is still good agreement between the measured diatom δ18O values and the stacked benthic δ18O record (Lisiecki and Raymo, 2005); <span class="hlt">biogenic</span> silica δ18O values in the AND-1B core likely record the composition of shallow sediment pore water and cryogenic brine formation. The agreement between our δ18O record and the benthic stack δ18O values suggests that brine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24323949','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24323949"><span>Study of the effect of vintage, maturity degree, and irrigation on the amino acid and <span class="hlt">biogenic</span> amine content of a white wine from the Verdejo variety.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ortega-Heras, Miriam; Pérez-Magariño, Silvia; Del-Villar-Garrachón, Vanesa; González-Huerta, Carlos; Moro Gonzalez, Luis Carlos; Guadarrama Rodríguez, Alberto; Villanueva Sanchez, Sonia; Gallo González, Rubén; Martín de la Helguera, Sara</p> <p>2014-08-01</p> <p>The aim of this study was to determine the effect of three factors directly related to the amino acid content of grapes and their interaction. These three factors were vintage, maturity degree and irrigation. The evolution of amino acid was also assessed during the winemaking along with the effect of maturity and irrigation on the <span class="hlt">biogenic</span> amine formation. The grapes used for this study were of the Verdejo variety. The results indicated that there was a strong vintage effect on amino acid content in grapes, which seemed to be clearly related to climatic conditions. The effect of maturity on amino acid content depended on vintage, irrigation and the amino acid itself although it was observed that irrigation caused the increase of most amino acids present in the berry. Irrigation did not affect the evolution of nitrogen compounds during the alcoholic fermentation process but the maturity degree in some of the amino acids tested did so. No direct relationship could be established between irrigation or maturity degree and <span class="hlt">biogenic</span> amines. However, it should be noted that the <span class="hlt">biogenic</span> amine content was very low. Vintage has a strong effect on the amino acid content in grapes which appears to be related to weather conditions. No direct relationship has been found between irrigation or maturity degree and <span class="hlt">biogenic</span> amines content. Furthermore, it is noted that <span class="hlt">biogenic</span> amine content found in final wines was very low. © 2013 Society of Chemical Industry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.914a2028L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.914a2028L"><span><span class="hlt">Iron</span> deficiency anaemia: with the conclusion of a need for <span class="hlt">iron</span> reader</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lim, Wai Feng; Yap, Boon Kar; Lai, Mei I.; Talik, Noorazrina; Nasser, Ammar Ahmed; Al-Haiqi, Ahmed Mubarak Ahmed; Sankar Krishnan, Prajindra</p> <p>2017-10-01</p> <p>In our bloodstream, there are plenty of red blood cells (RBC), which function as an important oxygen carrier in our bodies. Each RBC consists of millions of haemoglobin (Hb), which is made up from globin and <span class="hlt">iron</span>. If any deficiency/malfunction of any globin, it will lead to anaemia as indicated in low Hb level while <span class="hlt">iron</span> deficiency anaemia (IDA) is anaemic due to the lacking of <span class="hlt">iron</span> as indicated in low Hb and ferritin levels. IDA affects almost two billion people globally while anaemia without <span class="hlt">iron</span> deficiency, such as thalassaemia, affects almost 4.5% in Malaysian population. These anaemic conditions have similar clinical symptoms like fatigue, dizziness, in which disturb their cognitive development and productivity in workplace. In areas without proper medical access, many anaemic individuals were misdiagnosed and treated with <span class="hlt">iron</span> tablets because they were thought to have <span class="hlt">iron</span> deficiency anaemia due to low Hb content. But, excess <span class="hlt">iron</span> is toxic to the body. Misdiagnosis can be avoided by <span class="hlt">iron</span> status assessment. We hereby review the currently available <span class="hlt">iron</span> status parameters in laboratory and field study with the conclusion of demonstrating the importance of a need for <span class="hlt">iron</span> reader, in the effort to reduce the prevalence of IDA globally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PNAS..11312053G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PNAS..11312053G"><span>Reduced anthropogenic aerosol radiative forcing caused by <span class="hlt">biogenic</span> new particle formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gordon, Hamish; Sengupta, Kamalika; Rap, Alexandru; Duplissy, Jonathan; Frege, Carla; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K.; Wagner, Robert; Dunne, Eimear M.; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill S.; Dias, Antonio; Ehrhart, Sebastian; Fischer, Lukas; Flagan, Richard C.; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R.; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Krapf, Manuel; Kürten, Andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Monks, Sarah A.; Onnela, Antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P.; Pringle, Kirsty J.; Richards, Nigel A. D.; Rissanen, Matti P.; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E.; Seinfeld, John H.; Sharma, Sangeeta; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander Lucas; Wagner, Andrea C.; Wagner, Paul E.; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M.; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M.; Worsnop, Douglas R.; Baltensperger, Urs; Kulmala, Markku; Curtius, Joachim; Carslaw, Kenneth S.</p> <p>2016-10-01</p> <p>The magnitude of aerosol radiative forcing caused by anthropogenic emissions depends on the baseline state of the atmosphere under pristine preindustrial conditions. Measurements show that particle formation in atmospheric conditions can occur solely from <span class="hlt">biogenic</span> vapors. Here, we evaluate the potential effect of this source of particles on preindustrial cloud condensation nuclei (CCN) concentrations and aerosol-cloud radiative forcing over the industrial period. Model simulations show that the pure <span class="hlt">biogenic</span> particle formation mechanism has a much larger relative effect on CCN concentrations in the preindustrial atmosphere than in the present atmosphere because of the lower aerosol concentrations. Consequently, preindustrial cloud albedo is increased more than under present day conditions, and therefore the cooling forcing of anthropogenic aerosols is reduced. The mechanism increases CCN concentrations by 20-100% over a large fraction of the preindustrial lower atmosphere, and the magnitude of annual global mean radiative forcing caused by changes of cloud albedo since 1750 is reduced by 0.22 W m-2 (27%) to -0.60 W m-2. Model uncertainties, relatively slow formation rates, and limited available ambient measurements make it difficult to establish the significance of a mechanism that has its dominant effect under preindustrial conditions. Our simulations predict more particle formation in the Amazon than is observed. However, the first observation of pure organic nucleation has now been reported for the free troposphere. Given the potentially significant effect on anthropogenic forcing, effort should be made to better understand such naturally driven aerosol processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/47936','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/47936"><span>An approach for verifying <span class="hlt">biogenic</span> greenhouse gas emissions inventories with atmospheric CO2 concentration data</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Stephen M Ogle; Kenneth Davis; Thomas Lauvaux; Andrew Schuh; Dan Cooley; Tristram O West; Linda S Heath; Natasha L Miles; Scott Richardson; F Jay Breidt; James E Smith; Jessica L McCarty; Kevin R Gurney; Pieter Tans; A Scott Denning</p> <p>2015-01-01</p> <p>Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country's contribution to GHG concentrations in the atmosphere. Furthermore, verifying <span class="hlt">biogenic</span> fluxes provides a check on estimated...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29695046','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29695046"><span>Laser Scribed Graphene Biosensor for Detection of <span class="hlt">Biogenic</span> Amines in Food Samples Using Locally Sourced Materials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vanegas, Diana C; Patiño, Laksmi; Mendez, Connie; Oliveira, Daniela Alves de; Torres, Alba M; Gomes, Carmen L; McLamore, Eric S</p> <p>2018-04-24</p> <p>In foods, high levels of <span class="hlt">biogenic</span> amines (BA) are the result of microbial metabolism that could be affected by temperatures and storage conditions. Thus, the level of BA is commonly used as an indicator of food safety and quality. This manuscript outlines the development of laser scribed graphene electrodes, with locally sourced materials, for reagent-free food safety biosensing. To fabricate the biosensors, the graphene surface was functionalized with copper microparticles and diamine oxidase, purchased from a local supermarket; and then compared to biosensors fabricated with analytical grade materials. The amperometric biosensor exhibits good electrochemical performance, with an average histamine sensitivity of 23.3 µA/mM, a lower detection limit of 11.6 µM, and a response time of 7.3 s, showing similar performance to biosensors constructed from analytical grade materials. We demonstrated the application of the biosensor by testing total BA concentration in fish paste samples subjected to fermentation with lactic acid bacteria. <span class="hlt">Biogenic</span> amines concentrations prior to lactic acid fermentation were below the detection limit of the biosensor, while concentration after fermentation was 19.24 ± 8.21 mg histamine/kg, confirming that the sensor was selective in a complex food matrix. The low-cost, rapid, and accurate device is a promising tool for <span class="hlt">biogenic</span> amine estimation in food samples, particularly in situations where standard laboratory techniques are unavailable, or are cost prohibitive. This biosensor can be used for screening food samples, potentially limiting food waste, while reducing chances of foodborne outbreaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29134651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29134651"><span>Heavy metal contamination, microbiological spoilage and <span class="hlt">biogenic</span> amine content in sushi available on the Polish market.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kulawik, Piotr; Dordevic, Dani; Gambuś, Florian; Szczurowska, Katarzyna; Zając, Marzena</p> <p>2018-05-01</p> <p>The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and <span class="hlt">biogenic</span> amine content in ready-to-eat sushi meals were analysed. All of the nori samples contained high levels of Cd (2.122 mg kg -1 ), Ni (0.715 mg kg -1 ), As (34.56 mg kg -1 ) and Pb (0.659 mg kg -1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg -1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 10 6  cfu g -1 . However, <span class="hlt">biogenic</span> amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg -1 . Sushi is not the source of high levels of <span class="hlt">biogenic</span> amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.171.2425P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.171.2425P"><span>Aerosol Measurements in the Atmospheric Surface Layer at L'Aquila, Italy: Focus on <span class="hlt">Biogenic</span> Primary Particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pitari, Giovanni; Coppari, Eleonora; De Luca, Natalia; Di Carlo, Piero; Pace, Loretta</p> <p>2014-09-01</p> <p>Two year measurements of aerosol concentration and size distribution (0.25 μm < d < 30 μm) in the atmospheric surface layer, collected in L'Aquila (Italy) with an optical particle counter, are reported and analysed for the different modes of the particle size distribution. A different seasonal behaviour is shown for fine mode aerosols (largely produced by anthropogenic combustion), coarse mode and large-sized aerosols, whose abundance is regulated not only by anthropogenic local production, but also by remote natural sources (via large scale atmospheric transport) and by local sources of primary <span class="hlt">biogenic</span> aerosols. The observed total abundance of large particles with diameter larger than 10 μm is compared with a statistical counting of primary <span class="hlt">biogenic</span> particles, made with an independent technique. Results of these two observational approaches are analysed and compared to each other, with the help of a box model driven by observed meteorological parameters and validated with measurements of fine and coarse mode aerosols and of an atmospheric primary pollutant of anthropogenic origin (NOx). Except in winter months, primary <span class="hlt">biogenic</span> particles in the L'Aquila measurement site are shown to dominate the atmospheric boundary layer population of large aerosol particles with diameter larger than 10 μm (about 80 % of the total during summer months), with a pronounced seasonal cycle, contrary to fine mode aerosols of anthropogenic origin. In order to explain these findings, the main mechanisms controlling the abundance and variability of particulate matter tracers in the atmospheric surface layer are analysed with the numerical box-model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018FrEaS...6...22J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018FrEaS...6...22J"><span>Organic matter controls of <span class="hlt">iron</span> incorporation in growing sea ice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janssens, Julie; Meiners, Klaus M.; Townsend, Ashley T.; Lannuzel, Delphine</p> <p>2018-03-01</p> <p>This study presents the first laboratory-controlled sea-ice growth experiment conducted under trace metal clean conditions. The role played by organic matter, in the incorporation of <span class="hlt">iron</span> (Fe) into sea ice was investigated by means of laboratory ice-growth experiments using a titanium cold-finger apparatus. Experiments were also conducted to understand the role of extracellular polymeric substances (EPS) in the enrichment of ammonium in sea ice. Sea ice was grown from several seawater solutions containing different quantities and qualities of particulate Fe (PFe), dissolved Fe (DFe) and organic matter. Sea ice and seawater were analyzed for particulate organic carbon and nitrogen, macro-nutrients, extracellular EPS, PFe and DFe, and particulate aluminium. The experiments showed that <span class="hlt">biogenic</span> PFe is preferentially incorporated into sea ice compared to lithogenic PFe. Furthermore, sea ice grown from ultra-violet (UV) and non-UV treated seawaters exhibits contrasting incorporation rates of organic matter and Fe. Whereas the effects of UV-treatments were not always significant, we do find indications that the type or organic matter controls the enrichment of Fe in forming sea ice.. Specifically, we come to the conclusion that the incorporation of DFe is favored by the presence of organic ligands in the source solution.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22213195','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22213195"><span>Pituitary <span class="hlt">iron</span> and volume predict hypogonadism in transfusional <span class="hlt">iron</span> overload.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noetzli, Leila J; Panigrahy, Ashok; Mittelman, Steven D; Hyderi, Aleya; Dongelyan, Ani; Coates, Thomas D; Wood, John C</p> <p>2012-02-01</p> <p>Hypogonadism is the most common morbidity in patients with transfusion-dependent anemias such as thalassemia major. We used magnetic resonance imaging (MRI) to measure pituitary R2 (<span class="hlt">iron</span>) and volume to determine at what age these patients develop pituitary <span class="hlt">iron</span> overload and volume loss. We recruited 56 patients (47 with thalassemia major, five with chronically transfused thalassemia intermedia and four with Blackfan-Diamond syndrome) to have pituitary MRIs to measure pituitary R2 and volume. Hypogonadism was defined clinically based on the timing of secondary sexual characteristics or the need for sex hormone replacement therapy. Patients with transfusional <span class="hlt">iron</span> overload begin to develop pituitary <span class="hlt">iron</span> overload in the first decade of life; however, clinically significant volume loss was not observed until the second decade of life. Severe pituitary <span class="hlt">iron</span> deposition (Z > 5) and volume loss (Z < -2.5) were independently predictive of hypogonadism. Pituitary R2 correlated significantly with serum ferritin as well as liver, pancreatic, and cardiac <span class="hlt">iron</span> deposition by MRI. Log pancreas R2* was the best single predictor for pituitary <span class="hlt">iron</span>, with an area under the receiving operator characteristic curve of 0.88, but log cardiac R2* and ferritin were retained on multivariate regression with a combined r(2) of 0.71. Pituitary <span class="hlt">iron</span> overload and volume loss were independently predictive of hypogonadism. Many patients with moderate-to-severe pituitary <span class="hlt">iron</span> overload retained normal gland volume and function, representing a potential therapeutic window. The subset of hypogonadal patients having preserved gland volumes may also explain improvements in pituitary function observed following intensive chelation therapy. Copyright © 2011 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23768392','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23768392"><span>Monitoring of <span class="hlt">biogenic</span> amines in cheeses manufactured at small-scale farms and in fermented dairy products in the Czech Republic.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buňková, Leona; Adamcová, Gabriela; Hudcová, Kateřina; Velichová, Helena; Pachlová, Vendula; Lorencová, Eva; Buňka, František</p> <p>2013-11-01</p> <p>The aim of the study was the monitoring of six <span class="hlt">biogenic</span> amines (histamine, tyramine, phenylethylamine, tryptamine, putrescine, and cadaverine) and two polyamines (spermidine and spermine) in 112 samples of dairy products purchased in the Czech Republic, namely in 55 cheeses made in small-scale farms and in 57 fermented dairy products. The products were tested at the end of their shelf-life period. Neither tryptamine nor phenylethylamine was detected in the monitored samples; histamine was found only in four cheese samples containing up to 25mg/kg. The contents of spermine and spermidine were low and did not exceed the values of 35 mg/kg. Significant amounts of tyramine, putrescine, and cadaverine occurred especially in cheeses produced from ewe's milk or in long-term ripened cheeses. In about 10% of the tested cheeses, the total concentration of all the monitored <span class="hlt">biogenic</span> amines and polyamines exceeded the level of 200mg/kg, which can be considered toxicologically significant. In fermented dairy products, the tested <span class="hlt">biogenic</span> amines occurred in relatively low amounts (generally up to 30 mg/kg) that are regarded safe for the consumer's health. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25676047','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25676047"><span>Effects of plant polyphenols and α-tocopherol on lipid oxidation, microbiological characteristics, and <span class="hlt">biogenic</span> amines formation in dry-cured bacons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yongli; Li, Feng; Zhuang, Hong; Li, Lianghao; Chen, Xiao; Zhang, Jianhao</p> <p>2015-03-01</p> <p>Effects of plant polyphenols (tea polyphenol [TP], grape seed extract [GSE], and gingerol) and α-tocopherol on physicochemical parameters, microbiological counts, and <span class="hlt">biogenic</span> amines were determined in dry-cured bacons at the end of ripening. Results showed that plant polyphenols and α-tocopherol significantly decreased pH, thiobarbituric acid reactive substances content, and total volatile basic nitrogen (TVBN) compared with the control (P < 0.05). Microbial counts and <span class="hlt">biogenic</span> amine contents in dry-cured bacons were affected by plant polyphenols or α-tocopherol, with TP being the most effective (P < 0.05) in reducing aerobic plate counts, Enterobacteriaceae, Micrococcaceae, yeast, and molds, as well as in inhibiting formation of putrescine, cadaverine, tyramine, and spermine. Principal component analysis indicated that the first 2 principal components (PC) explained about 85.5% of the total variation. PC1 was related with physicochemical factors, parts of <span class="hlt">biogenic</span> amines, and spoilage microorganisms, whereas PC2 grouped the TVBN, tyramine, 2-phenylethylamine, yeast, and molds. These findings suggest that plant polyphenols, especially TP, could be used to process dry-cured bacons to improve the quality and safety of finished products. © 2015 Institute of Food Technologists®</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23883419','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23883419"><span>Design and synthesis of heterobimetallic Ru(II)-Ln(III) complexes as chemodosimetric ensembles for the detection of <span class="hlt">biogenic</span> amine odorants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chow, Cheuk-Fai; Lam, Michael H W; Wong, Wai-Yeung</p> <p>2013-09-03</p> <p>The detection of neutral <span class="hlt">biogenic</span> amines plays a crucial role in food safety. Three new heterobimetallic Ru(II)-Ln(III) donor-acceptor complexes, KPrRu, KNdRu, and KSmRu, K{[Ru((II))((t)Bubpy)(CN)4]2-Ln((III))(H2O)4} (where (t)Bubpy = 4,4'-di-tert-butyl-2,2'-bipyridine), have been synthesized and characterized. Their photophysical and X-ray crystallographic data were reported in this study. These complexes were found to be selective for <span class="hlt">biogenic</span> amine vapors, such as histamine, putrescine, and spermidine, with a detection limit down to the ppb level. The sensitivities of these complexes to the amines were recorded as ~log K = 3.6-5.0. Submicron rods of the complexes, with a nanoscale diameter and microscale length, were obtained through a simple precipitation process. Free-standing polymeric films with different degrees of porosity were fabricated by blending the submicron rods with polystyrene polymer. The polymer with the highest level of porosity exhibited the strongest luminescence enhancement after amine exposure. Real time monitoring of gaseous <span class="hlt">biogenic</span> amines was applied to real fish samples (Atlantic mackerel) by studying the spectrofluorimetric responses of the Ru(II)-Ln(III) blended polymer film.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3936199','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3936199"><span><span class="hlt">Iron</span> homeostasis in the liver</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Anderson, Erik R; Shah, Yatrik M</p> <p>2014-01-01</p> <p><span class="hlt">Iron</span> is an essential nutrient that is tightly regulated. A principal function of the liver is the regulation of <span class="hlt">iron</span> homeostasis. The liver senses changes in systemic <span class="hlt">iron</span> requirements and can regulate <span class="hlt">iron</span> concentrations in a robust and rapid manner. The last 10 years have led to the discovery of several regulatory mechanisms in the liver which control the production of <span class="hlt">iron</span> regulatory genes, storage capacity, and <span class="hlt">iron</span> mobilization. Dysregulation of these functions leads to an imbalance of <span class="hlt">iron</span>, which is the primary causes of <span class="hlt">iron</span>-related disorders. Anemia and <span class="hlt">iron</span> overload are two of the most prevalent disorders worldwide and affect over a billion people. Several mutations in liver-derived genes have been identified, demonstrating the central role of the liver in <span class="hlt">iron</span> homeostasis. During conditions of excess <span class="hlt">iron</span>, the liver increases <span class="hlt">iron</span> storage and protects other tissues, namely the heart and pancreas from <span class="hlt">iron</span>-induced cellular damage. However, a chronic increase in liver <span class="hlt">iron</span> stores results in excess reactive oxygen species production and liver injury. Excess liver <span class="hlt">iron</span> is one of the major mechanisms leading to increased steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. PMID:23720289</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572738','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3572738"><span>Mechanisms of mammalian <span class="hlt">iron</span> homeostasis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pantopoulos, Kostas; Porwal, Suheel Kumar; Tartakoff, Alan; Devireddy, L.</p> <p>2012-01-01</p> <p><span class="hlt">Iron</span> is vital for almost all organisms because of its ability to donate and accept electrons with relative ease. It serves as a cofactor for many proteins and enzymes necessary for oxygen and energy metabolism, as well as for several other essential processes. Mammalian cells utilize multiple mechanisms to acquire <span class="hlt">iron</span>. Disruption of <span class="hlt">iron</span> homeostasis is associated with various human diseases: <span class="hlt">iron</span> deficiency resulting from defects in acquisition or distribution of the metal causes anemia; whereas <span class="hlt">iron</span> surfeit resulting from excessive <span class="hlt">iron</span> absorption or defective utilization causes abnormal tissue <span class="hlt">iron</span> deposition, leading to oxidative damage. Mammals utilize distinct mechanisms to regulate <span class="hlt">iron</span> homeostasis at the systemic and cellular levels. These involve the hormone hepcidin and <span class="hlt">iron</span> regulatory proteins, which collectively ensure <span class="hlt">iron</span> balance. This review outlines recent advances in <span class="hlt">iron</span> regulatory pathways, as well as in mechanisms underlying intracellular <span class="hlt">iron</span> trafficking, an important but less-studied area of mammalian <span class="hlt">iron</span> homeostasis. PMID:22703180</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3048577','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3048577"><span>Regulation of cellular <span class="hlt">iron</span> metabolism</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Jian; Pantopoulos, Kostas</p> <p>2011-01-01</p> <p><span class="hlt">Iron</span> is an essential but potentially hazardous biometal. Mammalian cells require sufficient amounts of <span class="hlt">iron</span> to satisfy metabolic needs or to accomplish specialized functions. <span class="hlt">Iron</span> is delivered to tissues by circulating transferrin, a transporter that captures <span class="hlt">iron</span> released into the plasma mainly from intestinal enterocytes or reticuloendothelial macrophages. The binding of <span class="hlt">iron</span>-laden transferrin to the cell-surface transferrin receptor 1 results in endocytosis and uptake of the metal cargo. Internalized <span class="hlt">iron</span> is transported to mitochondria for the synthesis of haem or iron–sulfur clusters, which are integral parts of several metalloproteins, and excess <span class="hlt">iron</span> is stored and detoxified in cytosolic ferritin. <span class="hlt">Iron</span> metabolism is controlled at different levels and by diverse mechanisms. The present review summarizes basic concepts of <span class="hlt">iron</span> transport, use and storage and focuses on the IRE (<span class="hlt">iron</span>-responsive element)/IRP (<span class="hlt">iron</span>-regulatory protein) system, a well known post-transcriptional regulatory circuit that not only maintains <span class="hlt">iron</span> homoeostasis in various cell types, but also contributes to systemic <span class="hlt">iron</span> balance. PMID:21348856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5097959-chemical-classification-iron-meteorites-xi-multi-element-studies-new-irons-high-abundance-ungrouped-irons-from-antarctica','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5097959-chemical-classification-iron-meteorites-xi-multi-element-studies-new-irons-high-abundance-ungrouped-irons-from-antarctica"><span>Chemical classification of <span class="hlt">iron</span> meteorites. XI. Multi-element studies of 38 new <span class="hlt">irons</span> and the high abundance of ungrouped <span class="hlt">irons</span> from Antarctica</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wasson, J.T.; Ouyang, Xinwei; Wang, Jianmin</p> <p>1989-03-01</p> <p>The authors report concentrations of 14 elements in the metal of 38 <span class="hlt">iron</span> meteorites and a pallasite. The meteorites are classified based on these data and on structural observations. Three samples are paired with previously classified <span class="hlt">irons</span>; thus, these additional 35 <span class="hlt">irons</span> raise the number of well-classified, independent <span class="hlt">iron</span> meteorites to 598. One Yamato <span class="hlt">iron</span> contains 342 mg/g Ni, the second highest Ni content in an IAB <span class="hlt">iron</span> after Oktibbeha County. Two small <span class="hlt">irons</span> from Western Australia appear to be metal nodules from mesosiderites. Several of the new <span class="hlt">irons</span> are from Antarctica. Of 24 independent <span class="hlt">irons</span> from Antarctica, 8 aremore » ungrouped. The fraction, 0.333, is much higher than the fraction 0.161 among all 598 classified <span class="hlt">irons</span>. Statistical tests show that it is highly improbably ({approximately}2.9% probability) that the Antarctic population is a random sample of the larger population. The difference is probably related to the fact that the median mass of Antarctic <span class="hlt">irons</span> is about two orders of magnitude smaller than that of non-Antarctic <span class="hlt">irons</span>. It is doubtful that the difference results from fragmentation patterns yielding different size distributions favoring smaller masses among ungrouped <span class="hlt">irons</span>. More likely is the possibility that smaller meteoroids tend to sample a larger number of asteroidal source regions, perhaps because small meteoroids tend to have higher ejection velocities or because small meteoroids have random-walked a greater increment of orbital semimajor axis away from that of the parent body.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19344751','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19344751"><span>Cellular <span class="hlt">iron</span> transport.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garrick, Michael D; Garrick, Laura M</p> <p>2009-05-01</p> <p><span class="hlt">Iron</span> 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 <span class="hlt">iron</span> by regulating transport into the blood stream. In developing red blood cells, adaptations in transport manage the body's highest flux of <span class="hlt">iron</span>. Hepatocytes buffer the body's stock of <span class="hlt">iron</span>. Macrophage recycle the <span class="hlt">iron</span> from effete red cells among other <span class="hlt">iron</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=139237&Lab=NERL&keyword=contractor&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=139237&Lab=NERL&keyword=contractor&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>EARTH, WIND AND FIRE: BUILDING METEOROLOGICALLY-SENSITIVE <span class="hlt">BIOGENIC</span> AND WILDLAND FIRE EMISSION ESTIMATES FOR AIR QUALITY MODELS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Emission estimates are important for ensuring the accuracy of atmospheric chemical transport models. Estimates of <span class="hlt">biogenic</span> and wildland fire emissions, because of their sensitivity to meteorological conditions, need to be carefully constructed and closely linked with a meteorolo...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14631488','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14631488"><span>Effect of acute progestational hypoxia on the content of <span class="hlt">biogenic</span> amines in the brain of albino rat pups: Peptide correction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maslova, M V; Graf, A V; Sokolova, N A; Goncharenko, E N; Shestakova, S V; Kudryashova, N Yu; Andreeva, L A</p> <p>2003-08-01</p> <p>We studied the effect of exposure to acute hypobaric hypoxia in the progestational period on the content of <span class="hlt">biogenic</span> amines in the brainstem and cerebral cortex in rat pups of different age. The possibility of correcting hypoxia-induced changes with regulatory peptides was evaluated. We found that early antenatal hypoxia disturbs maturation of catecholaminergic systems in the brain. It should be emphasized that the differences from the control varied depending on the age of rat pups. Single intranasal administration of Semax heptapeptides and beta-casomorphine-7 to pregnant females prevented changes in the content of <span class="hlt">biogenic</span> amines in CNS of the offspring during postnatal ontogeny.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeCoA.192..318R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeCoA.192..318R"><span>Impacts of seawater saturation state (ΩA = 0.4-4.6) and temperature (10, 25 °C) on the dissolution kinetics of whole-shell <span class="hlt">biogenic</span> carbonates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ries, Justin B.; Ghazaleh, Maite N.; Connolly, Brian; Westfield, Isaac; Castillo, Karl D.</p> <p>2016-11-01</p> <p>Anthropogenic increase of atmospheric pCO2 since the Industrial Revolution has caused seawater pH to decrease and seawater temperatures to increase-trends that are expected to continue into the foreseeable future. Myriad experimental studies have investigated the impacts of ocean acidification and warming on marine calcifiers' ability to build protective shells and skeletons. No studies, however, have investigated the combined impacts of ocean acidification and warming on the whole-shell dissolution kinetics of <span class="hlt">biogenic</span> carbonates. Here, we present the results of experiments designed to investigate the effects of seawater saturation state (ΩA = 0.4-4.6) and temperature (10, 25 °C) on gross rates of whole-shell dissolution for ten species of benthic marine calcifiers: the oyster Crassostrea virginica, the ivory barnacle Balanus eburneus, the blue mussel Mytilus edulis, the conch Strombus alatus, the tropical coral Siderastrea siderea, the temperate coral Oculina arbuscula, the hard clam Mercenaria mercenaria, the soft clam Mya arenaria, the branching bryozoan Schizoporella errata, and the coralline red alga Neogoniolithon sp. These experiments confirm that dissolution rates of whole-shell <span class="hlt">biogenic</span> carbonates decrease with calcium carbonate (CaCO3) saturation state, increase with temperature, and vary predictably with respect to the relative solubility of the calcifiers' polymorph mineralogy [high-Mg calcite (mol% Mg > 4) ≥ aragonite > low-Mg calcite (mol% Mg < 4)], consistent with prior studies on sedimentary and inorganic carbonates. Furthermore, the severity of the temperature effects on gross dissolution rates also varied with respect to carbonate polymorph solubility, with warming (10-25 °C) exerting the greatest effect on <span class="hlt">biogenic</span> high-Mg calcite, an intermediate effect on <span class="hlt">biogenic</span> aragonite, and the least effect on <span class="hlt">biogenic</span> low-Mg calcite. These results indicate that both ocean acidification and warming will lead to increased dissolution of <span class="hlt">biogenic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27793204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27793204"><span>High-dose intravenously administered <span class="hlt">iron</span> versus orally administered <span class="hlt">iron</span> in blood donors with <span class="hlt">iron</span> deficiency: study protocol for a randomised, controlled trial.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Macher, Susanne; Drexler, Camilla; Lindenau, Ines; Sareban, Nazanin; Schlenke, Peter; Amrein, Karin</p> <p>2016-10-28</p> <p>About 2-3 % of the population participates in blood donation programmes. Each whole blood donation or ten apheresis donations cause a loss of 200-250 mg of <span class="hlt">iron</span>. As a result, one of the most common risks of regular blood donors is <span class="hlt">iron</span> deficiency. Although this has been known for decades, in most countries, <span class="hlt">iron</span> status is currently not assessed or treated in this population. Premenopausal women are particularly affected, as they have lower <span class="hlt">iron</span> reserves and higher daily requirements. Besides anaemia, <span class="hlt">iron</span> deficiency may lead to fatigue and impaired cognitive and physical performance. Current <span class="hlt">iron</span> preparations for intravenous administration are well tolerated and allow for application of large doses up to 1 g in one visit. Our hypothesis is that in blood donors with <span class="hlt">iron</span> deficiency, intravenously administered <span class="hlt">iron</span> is more efficient and as safe as oral <span class="hlt">iron</span> supplementation. Since anaemia is one of the most frequent reasons for permanent or intermittent donor deferral, maintaining an <span class="hlt">iron</span>-replete donor pool may help to prevent shortages in blood supply and to avoid <span class="hlt">iron</span> deficiency-related comorbidities. In this randomised clinical trial we include male and female blood donors aged ≥18 and ≤65 years with a ferritin value of ≤30 ng/ml. Stratified by gender, participants are randomized with a web-based randomisation tool in a 1:1 ratio to either 1 g of intravenously administered ferric carboxymaltose or 10 g of <span class="hlt">iron</span> fumarate supplements at one to two daily doses of 100 mg each. Eight to 12 weeks after the first visit, <span class="hlt">iron</span> status, blood count and symptoms are assessed in both groups. The primary endpoint is the difference in transferrin saturation (%) following the intervention between both groups. Secondary endpoints include other parameters of <span class="hlt">iron</span> metabolism and red blood cell count, the number of patients with drug-related adverse events, and subjective symptoms including those of the restless legs syndrome, quality of life, and fatigue. <span class="hlt">Iron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMGP43B..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMGP43B..03D"><span>Applications of Magnetic Micro- and Nanoparticles in Biology and Medicine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dobson, J.</p> <p>2005-12-01</p> <p>Magnetic nanoparticles were first proposed for biomedical applications in the 1970s - primarily as targeted drug delivery vehicles and MRI contrast agents. Since that time, such particles have found application in a variety of biomedical techniques. In addition to drug delivery, magnetic nanoparticles are now used routinely as MRI contrast agents as well as for magneto-immunoassay and cell sorting. More recently, magnetic micro- and nanoparticles have been used to investigate and manipulate cellular processes both in vitro and in vivo. In addition, <span class="hlt">biogenic</span> magnetic nanoparticles are also produced in the human body. The <span class="hlt">iron</span> storage protein, ferritin, consists of a superparamagnetic ferrihydrite core and <span class="hlt">biogenic</span> magnetite (a ferrimagnet) has also been found in the brain and other organs. Though the role of ferritin and several other magnetic <span class="hlt">iron</span> oxides in the body is well understood, the origin and role of <span class="hlt">biogenic</span> magnetite is only now coming to light - and this may have profound implications for our understanding of neurodegenerative diseases, such as Alzheimer's, Parkinson's and Huntington's diseases. This talk will review applications related to magnetic particle-mediated activation of cellular processes for tissue engineering applications and novel methods of magnetofection which have the potential to provide enhanced transfection for non-viral therapeutic gene delivery. It will also briefly highlight new techniques recently developed for the mapping and characterization of magnetic <span class="hlt">iron</span> compounds related to neurodegenerative diseases and how rock magnetic techniques have been adapted to study magnetic <span class="hlt">iron</span> compounds in the brain and other organs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21910602','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21910602"><span><span class="hlt">Iron</span> chelation therapy for transfusional <span class="hlt">iron</span> overload: a swift evolution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Musallam, Khaled M; Taher, Ali T</p> <p>2011-01-01</p> <p>Chronic transfusional <span class="hlt">iron</span> overload leads to significant morbidity and mortality. While deferoxamine (DFO) is an effective <span class="hlt">iron</span> chelator with over four decades of experience, it requires tedious subcutaneous infusions that reflect negatively on patient compliance. The novel oral <span class="hlt">iron</span> chelators deferiprone (L1) and deferasirox (DFRA) opened new horizons for the management of transfusional siderosis. A large body of evidence is now available regarding their efficacy and safety in various populations and settings. Nevertheless, experience with both drugs witnessed some drawbacks, and the search for an ideal and cost-effective <span class="hlt">iron</span> chelator continues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16096139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16096139"><span>In vitro evaluation of <span class="hlt">iron</span> solubility and dialyzability of various <span class="hlt">iron</span> fortificants and of <span class="hlt">iron</span>-fortified milk products targeted for infants and toddlers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kapsokefalou, Maria; Alexandropoulou, Isidora; Komaitis, Michail; Politis, Ioannis</p> <p>2005-06-01</p> <p>The objectives of the present study were: to compare the solubility and dialyzability of various <span class="hlt">iron</span> fortificants (<span class="hlt">iron</span> pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of <span class="hlt">iron</span> in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including <span class="hlt">iron</span> and targeted towards infants (6-12 months old) and toddlers. <span class="hlt">Iron</span> solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable <span class="hlt">iron</span> (molecular weight lower than 8000) was used as an index for prediction of <span class="hlt">iron</span> bioavailability. Ferrous dialyzable <span class="hlt">iron</span> in pasteurized milk samples fortified with <span class="hlt">iron</span> pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P < 0.05) than that in milk samples fortified with ferrous sulfate and ferrous gluconate. In commercial liquid pasteurized or UHT milk products, formation of ferrous dialyzable <span class="hlt">iron</span> in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable <span class="hlt">iron</span> in four condensed commercial milk products was higher (P < 0.05) than the corresponding values of the liquid UHT milk samples fortified with the same fortificant (ferrous sulfate). Ferrous dialyzable <span class="hlt">iron</span> was higher (P < 0.05) in products targeted for infants compared with those targeted for toddlers. In conclusion, the type of <span class="hlt">iron</span> source, milk processing and the overall product composition affect formation of ferrous dialyzable <span class="hlt">iron</span> and may determine the success and effectiveness of <span class="hlt">iron</span> fortification of milk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22287873','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22287873"><span>Management of transfusional <span class="hlt">iron</span> overload - differential properties and efficacy of <span class="hlt">iron</span> chelating agents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwiatkowski, Janet L</p> <p>2011-01-01</p> <p>Regular red cell transfusion therapy ameliorates disease-related morbidity and can be lifesaving in patients with various hematological disorders. Transfusion therapy, however, causes progressive <span class="hlt">iron</span> loading, which, if untreated, results in endocrinopathies, cardiac arrhythmias and congestive heart failure, hepatic fibrosis, and premature death. <span class="hlt">Iron</span> chelation therapy is used to prevent <span class="hlt">iron</span> loading, remove excess accumulated <span class="hlt">iron</span>, detoxify <span class="hlt">iron</span>, and reverse some of the <span class="hlt">iron</span>-related complications. Three chelators have undergone extensive testing to date: deferoxamine, deferasirox, and deferiprone (although the latter drug is not currently licensed for use in North America where it is available only through compassionate use programs and research protocols). These chelators differ in their modes of administration, pharmacokinetics, efficacy with regard to organ-specific <span class="hlt">iron</span> removal, and adverse-effect profiles. These differential properties influence acceptability, tolerability and adherence to therapy, and, ultimately, the effectiveness of treatment. Chelation therapy, therefore, must be individualized, taking into account patient preferences, toxicities, ongoing transfusional <span class="hlt">iron</span> intake, and the degree of cardiac and hepatic <span class="hlt">iron</span> loading.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4959083','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4959083"><span>Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates <span class="hlt">Iron</span> Accumulation and Resistance to Elevated <span class="hlt">Iron</span> Concentrations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa</p> <p>2016-01-01</p> <p>ABSTRACT Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as <span class="hlt">iron</span> storage organelles. This work explored how plant ferritin expression influenced baker's yeast <span class="hlt">iron</span> metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular <span class="hlt">iron</span> in vivo and, consequently, induced the activation of the genes expressed during <span class="hlt">iron</span> scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar <span class="hlt">iron</span> detoxification transporter from toxic <span class="hlt">iron</span> levels by reducing cellular oxidation, thus allowing growth at high <span class="hlt">iron</span> concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased <span class="hlt">iron</span> resistance and reduced the oxidative stress produced by excess <span class="hlt">iron</span> compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased <span class="hlt">iron</span> accumulation in both wild-type and ccc1Δ yeast cells at certain environmental <span class="hlt">iron</span> concentrations. IMPORTANCE <span class="hlt">Iron</span> deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat <span class="hlt">iron</span> deficiency consists of dietary supplementation with inorganic <span class="hlt">iron</span> salts, whose bioavailability is very low. <span class="hlt">Iron</span>-enriched yeasts and cereals are alternative strategies to diminish <span class="hlt">iron</span> deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular <span class="hlt">iron</span>. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as <span class="hlt">iron</span> storage organelles. Here, we explored how soybean ferritin expression influenced yeast <span class="hlt">iron</span> metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary <span class="hlt">iron</span> absorption. PMID:26969708</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24867923','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24867923"><span>OPT3 Is a Phloem-Specific <span class="hlt">Iron</span> Transporter That Is Essential for Systemic <span class="hlt">Iron</span> Signaling and Redistribution of <span class="hlt">Iron</span> and Cadmium in Arabidopsis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhai, Zhiyang; Gayomba, Sheena R; Jung, Ha-Il; Vimalakumari, Nanditha K; Piñeros, Miguel; Craft, Eric; Rutzke, Michael A; Danku, John; Lahner, Brett; Punshon, Tracy; Guerinot, Mary Lou; Salt, David E; Kochian, Leon V; Vatamaniuk, Olena K</p> <p>2014-05-01</p> <p><span class="hlt">Iron</span> is essential for both plant growth and human health and nutrition. Knowledge of the signaling mechanisms that communicate <span class="hlt">iron</span> demand from shoots to roots to regulate <span class="hlt">iron</span> uptake as well as the transport systems mediating <span class="hlt">iron</span> partitioning into edible plant tissues is critical for the development of crop biofortification strategies. Here, we report that OPT3, previously classified as an oligopeptide transporter, is a plasma membrane transporter capable of transporting transition ions in vitro. Studies in Arabidopsis thaliana show that OPT3 loads <span class="hlt">iron</span> into the phloem, facilitates <span class="hlt">iron</span> recirculation from the xylem to the phloem, and regulates both shoot-to-root <span class="hlt">iron</span> signaling and <span class="hlt">iron</span> redistribution from mature to developing tissues. We also uncovered an aspect of crosstalk between <span class="hlt">iron</span> homeostasis and cadmium partitioning that is mediated by OPT3. Together, these discoveries provide promising avenues for targeted strategies directed at increasing <span class="hlt">iron</span> while decreasing cadmium density in the edible portions of crops and improving agricultural productivity in <span class="hlt">iron</span> deficient soils. © 2014 American Society of Plant Biologists. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20063743','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20063743"><span>[Growth characteristics and control of <span class="hlt">iron</span> bacteria on cast <span class="hlt">iron</span> in drinking water distribution systems].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yang; Zhang, Xiao-Jian; Chen, Yu-Qiao; Lu, Pin-Pin; Chen, Chao</p> <p>2009-11-01</p> <p>This study investigated the growth characteristics of <span class="hlt">iron</span> bacteria on cast <span class="hlt">iron</span> and relationship between suspended and attached <span class="hlt">iron</span> bacteria. The steady-state growth of <span class="hlt">iron</span> bacteria would need 12 d and <span class="hlt">iron</span> bacteria level in effluents increased 1 lg. Hydraulics influence on <span class="hlt">iron</span> bacteria level and detachment rate of steady-state attached <span class="hlt">iron</span> bacteria was not significant. But it could affect the time of attached <span class="hlt">iron</span> bacteria on cast-<span class="hlt">iron</span> coupons reaching to steady state. When the chlorine residual was 0.3 mg/L, the <span class="hlt">iron</span> bacteria growth could be controlled effectively and suspended and attached <span class="hlt">iron</span> bacteria levels both decreased 1 lg. When the chlorine residual was more than 1.0 mg/L, it could not inactivate the <span class="hlt">iron</span> bacteria of internal corrosion scale yet. There was little effect on inhibiting the <span class="hlt">iron</span> bacteria growth that the chlorine residual was 0.05 mg/L in drinking water quality standard of China. The <span class="hlt">iron</span> bacteria on coupons reached to steady state without disinfectant and then increased the chlorine residual to 1.25 mg/L, the attached <span class="hlt">iron</span> bacteria level could decrease 2 lg to 3 lg. Under steady-state, the suspended <span class="hlt">iron</span> bacteria levels were linearly dependent on the attached <span class="hlt">iron</span> bacteria. The control of <span class="hlt">iron</span> bacteria in drinking water distribution systems was advanced: maintaining the chlorine residual (0.3 mg/L), flushing the pipeline with high dosage disinfectant, adopting corrosion-resistant pipe materials and renovating the old pipe loop.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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