Contamination events at Oak Creek, which runs through Oregon State University Research lands, prompted investigations into alternate transport mechanisms for moving liquid effluent from OSU Diary lands to Oak Creek. Magnetometer surveys conducted at the Diary identified magnetic signatures spatially associated with sub-surface locations of drain tiles, a 12-inch pipe, and other features. These pipes may provide alternate methods of transporting effluent to Oak Creek. Magnetometer surveys in support of the contamination study identified an interesting variability in the Earth's local magnetic field. Magnetic signatures spatially associated with drain tiles appear strong in the western portion of the site, but fade out in the eastern part of the site. The cause of this variability was investigated by examining soil iron distributions. The Field-scale soil iron distribution was determined using a colorimetric analysis of extractions obtained from soil core samples. This study shows larger concentrations of iron in the western portion of the site where the magnetic signal is strong and lower concentrations of iron where the magnetic signal is lower. Tile-scale iron distribution over the drain tiles and in control units were analyzed using the same colorimetric technique. This study identified a disturbance to the natural iron distribution over the tile in the western part of the site due to soil mixing in the back-filled tile trench resulting in a contrast in the magnetic data. In the eastern part of the site, where there is no magnetic signature associated with the tile, the iron distribution over the tile looks similar to the control unit results. Analysis of the soils determined that excavating during tile installation disturbed soil horizons, but the iron has redistributed itself to the pre-tile configuration effectively erasing the magnetic contrast that existed shortly after tile installation. This project has shown that iron redistribution can adversely affect the ability of magnetometer surveys to identify drain tiles. This project also demonstrates that soils must be looked at as dynamic systems rather than the more common static system approach when evaluating the success of magnetometer surveys. Applying a dynamic view of soils can help ground-based remote sensing surveyors avoid costly, unproductive surveys. / Graduation date: 2003

No description available.

This project aimed to characterise the organic speciation of iron in various oceanic waters associated with the New Zealand marine environment, and to examine the possible production of natural organic Fe-binding ligands by the Southern Ocean phytoplankton Phaeocystis antarctica. The location of New Zealand at the edge of the Southern Ocean provides a natural laboratory for studying ocean processes in a variety of oceanic conditions. A time series of a surface transect across the Otago Continental Shelf was undertaken between April 2002 and January 2005 to measure the organic complexation of iron, hydrographic parameters and macronutrient concentrations. The study area contains three distinct water masses: 1) neritic water; 2) the Southland Current, derived from the Subtropical Surface Water (STW); 3) Subantarctic Surface Water (SASW). Hydrological measurements outlined the positions of the three water masses as being fixed within predictable boundaries. Variations in nutrient concentrations in the study area indicated that SASW is the predominant source of nitrate and phosphate to the shelf. Dissolved iron concentrations dropped sharply seaward from several nanomolar to sub-nanomolar levels. The dissolved iron was fully complexed with strong organic ligands in all three water masses, and the ligand concentrations also showed a slightly seaward decreasing trend. Trends in dissolved iron and the iron-binding ligand concentrations related to season were only obvious in neritic waters. Concentration maxima occurred during late spring and summer months, and concentration minima occurred in the middle of each year (winter months). Dissolved iron concentration was low (~0.1 nM) in SASW year round. Data from the present study are in support of that the SASW as a whole is classified as a high nitrate low chlorophyll (HNLC) water body and has an iron-limited phytoplankton population. East of the New Zealand landmass, the Subtropical Convergence (STC) is topographically locked to the Chatham Rise. This is a dynamic region of enhanced primary production (Bradford-Grieve et al., 1997), which separates macronutrient-depleted STW from macronutrient-replete SASW. Dissolved iron concentrations were low (~0.1-0.2 nM) in SASW, while elevated dissolved iron concentrations were observed at the north flank of the Chatham Rise. The iron data imply that the regional currents may be an important vehicle for transporting the elevated iron across the front. Total dissolved iron-binding ligand concentrations were consistently higher (~0.5 nM) in the STW and STC waters than in SASW. The discrepancy in the ligand concentrations between STW and SASW may reflect a different contribution to the ligand pool from the local planktonic community. The organic complexation of iron in the oligotrophic subtropical water columns in the Tasman Sea was also studied and comparison of waters to the north and south of the Tasman front were reported. The iron speciation data imply the potential biological origin for the iron-binding ligands, and the difference in ligand concentrations across the Tasman Front may represent slight differences in algal biomass. A limited investigation to examine the production of natural organic iron-binding ligands by the Southern Ocean phytoplankton Phaeocystis antarctica was undertaken in laboratory culture experiments. Release of nanomolar levels of a strong iron-binding ligand was detected by cathodic stripping voltammetry (CSV) even under relatively high iron concentrations (> 1nM). The estimated iron binding strength for the ligands was similar to those observed in the open ocean. Moreover, the kinetic data suggested the presence of another weaker ligand class, which had a higher Fe concentration (>2 nM) and was not detectable by the CSV ligand titration technique. Our field observations and culture experiment results suggest that the Fe-binding ligands are biologically produced. It appears algae engineer their environment to make Fe more available/accessible for longer by producing these ligands. Therefore, the organic speciation of Fe plays a very important role in the sustained nutrition of ocean primary productivity and must be accounted for in geochemical modelling.

No description available.

Call number: LD2668 .T4 1966 G197 / Master of Science

No description available.

Male weanling Wistar rats were fed a low-iron basal diet for 3 weeks. The iron depleted rats were then divided into 9 groups according to a randomized block design based on body weight. During the repletion period of 2 weeks, one group was fed the low-iron basal diet. The other eight groups received either the basal diet to which was added 5, 10, 15, 20 or 25 mg iron per kg diet as ferrous sulfate or test source diets formulated to provide a total of 15 mg iron per kg diet from either freeze-dried ground beef, textured defatted soy flour product or a 2.3:1 (w/w) mixture of beef and soy product. All diets were isocaloric and isonitrogenous. The relative biological value (RBV) of iron in the test source diet was calculated as the ratio of the amounts of iron from the reference source (ferrous sulfate) and the test source diet required to give the same response in hemoglobin or hematocrit. The RBVs ± 95% confidence limits, calculated on the basis of final hemoglobin levels and hematocrit values, were respectively: freeze-dried ground beef, 56 ± 7 % and 62 ± 7 %; fortified textured defatted soy flour product, 81 ± 10 % and 79 ± 10 %; 2.3:1 (w/w) mixture of freeze-dried ground beef and soy flour product, 65 ± 6 % and 68 ± 6 %. The RBVs obtained for the iron in beef and for that in the soy flour product suggest that the anemic rat might not be a suitable model for normal man when screening such foods for their available iron. In normal man, the absorption of the iron in beef is comparable to that of inorganic reference iron, while that in textured soy flour is about one third. / Land and Food Systems, Faculty of / Graduate

Iron (Fe) deficiency affects more than 3 billion of the global population. The objectives of this study were to (1) determine the genetic and environmental variation of seed Fe concentration and food matrix factors that govern Fe bioavailability in field peas (Pisum sativum L.) grown in North Dakota, USA in 2010 and 2011, and (2) determine the genetic variation of Fe uptake by field pea grown under greenhouse conditions with different Fe treatments. Seed Fe concentration in field pea samples from the field study ranged between 46-53 mg/kg with a mean of 51 mg/kg. Mean concentrations of the food matrix factors in those field peas were as follows: phytic acid=5.1 mg/g, xanthophyll=17.3 mg/100 g, canthaxanthin=86.8 mg/100 g, beta-carotene=516.8 μg/100 g, kestose=1697 mg/100g, quercetin=54.3 mg/100 g, and ferulic acid=46.9 mg/100 g. DS Admiral and CDC Golden showed high concentrations of Fe promoter compounds and low concentrations of phytic acid. DS Admiral showed high Fe uptake with increasing Fe fertilizer rates in the greenhouse study. Therefore, DS Admiral and CDC Golden could be potential field pea genotypes for future Fe biofortification efforts.

Der Bericht beinhaltet Ergebnisse von Fleischuntersuchungen auf den Eisengehalt. Untersucht wurden 308 Schweinefleischproben und etwa 300 Fleischproben der Tierarten Rind, Bison, Auerochse, Büffel, Schaf, Ziege, Kaninchen, Wildschwein, Rehwild, Rotwild und Fasan. Die sächsischen Ergebnisse bestätigen Untersuchungen anderer Bundesländer und belegen den starken Rückgang des Eisengehaltes im Schweinefleisch. Er lag im Mittel bei 4,1 mg/kg Frischmasse (FM). Vor 30 Jahren lag der Eisengehalt noch bei 18 mg/kg - 25 mg/kg. Das Fleisch von Tierarten mit sogenanntem rotem Fleisch wie Rind, Schaf, Büffel, Bison, Auerochse, Reh- und Rotwild weist erwartungsgemäß einen hohen Eisengehalt (17 mg/kg FM - 33 mg/kg FM) auf. Farbuntersuchungen zeigten, dass der Eisengehalt eine Abhängigkeit zur Farbhelligkeit und zum Rotton des Fleisches aufweist. Je dunkler bzw. je intensiver der Rotton des Fleisches ist, desto höher der Eisengehalt.

No description available.