Anthranilate Hydroxylase from Aspergillus niger: New Type of NADPH-Linked Nonheme Iron Monooxygenase

Anthranilate hydroxylase from Aspergillus niger catalyzes the oxidative deamination and dihydroxylation of anthranilic acid to 2,3-dihydroxybenzoic acid. This enzyme has been purified to homogeneity and has a molecular weight of 89,000. The enzyme is composed of two subunits of 42,000 with 2 gram-atoms of nonheme iron per mol. Fe2+-chelators like alpha,alpha'-dipyridyl and o-phenanthroline are potent inhibitors of the enzyme activity. Absorption and fluorescence spectra of the enzyme offer no evidence for the presence of other cofactors like flavin. Flavins and flavin-specific inhibitors like atebrin have no effect on the activity of the enzyme. The enzyme incorporates one atom of oxygen each from 18O2 and H218O into the product 2,3-dihydroxybenzoic acid. Based on these studies, it is concluded that anthranilate hydroxylase from A. niger is a new type of NADPH-linked nonheme iron monooxygenase.

Mössbauer studies of the corrosion products of iron formed in aqueous ammonium nitrate solution

The products of corrosion reaction of electrolytic iron in 45% ammonium nitrate solution formed under various conditions of time, temperature and pH have been analysed mainly by Mössbauer spectroscopy, in combination with X-ray diffraction, infrared absorption and electron microscopy techniques. γ-Fe00H is found to be the major product of hydrolytic precipitation at pH > 5.6 while only α-FeOOH is formed at pH < 3.0. In the pH range 3.0 < pH < 5.0, α-Fe00H and ferrihydrite are both formed. However, once the nuclei of α-Fe00H are formed under low pH conditions, their growth is favoured even in the otherwise unfavourable slightly acidic medium, resulting in a hydrous α-Fe00H which has two distinct hyperfine fields at the 57Fe nucleus. Magnetite is always formed in the vicinity of the metal and its rate of formation on the surface increases with temperature. α-Fe203 is the major product of hydrolytic precipitation at temperatures >80C. The possible mechanisms for the formation of each of the corrosion products are discussed.

From Iron Horse to Rauta-airot - a Semiotic View on the Domestication of Metaphors in Literary Translation

The thesis concentrates on two questions: the translation of metaphors in literary texts, and the use of semiotic models and tools in translation studies. The aim of the thesis is to present a semiotic, text based model designed to ease the translation of metaphors and to analyze translated metaphors. In the translation of metaphors I will concentrate on the central problem of metaphor translations: in addition to its denotation and connotation, a single metaphor may contain numerous culture or genre specific meanings. How can a translator ensure the translation of all meanings relevant to the text as a whole? I will approach the question from two directions. Umberto Eco's holistic text analysis model provides an opportunity to concentrate on the problematic nature of metaphor translation from the level of a text as a specific entity, while George Lakoff's and Mark Johnson's metaphor research makes it possible to approach the question from the level of individual metaphors. On the semiotic side, the model utilizes Eero Tarasti's existential semiotics supported by Algirdas Greimas' actant model and Yuri Lotman's theory of cultural semiotics. In the model introduced in the thesis, individual texts are deconstructed through Eco's model into elements. The textual roles and features of these elements are distilled further through Tarasti's model into their coexistent meaning levels. The priorization and analysis of these meaning levels provide an opportunity to consider the contents and significance of specific metaphors in relation to the needs of the text as a whole. As example texts, I will use Motörhead's hard rock classic Iron Horse/Born to Lose and its translation into Rauta-airot by Viikate. I will use the introduced model to analyze the metaphors in the source and target texts, and to consider the transfer of culture specific elements between the languages and cultural borders. In addition, I will use the analysis process to examine the validity of the model introduced in the thesis.

Mossbauer-Effect Study Of The Thermal-Decomposition In Hydrogen Of Homogeneously Mixed Ferrous Nickel Oxalates With Different Iron To Nickel Ratios

Mossbauer effect and X-ray measurements are carried out on product samples of the thermogravimetric analysis (TGA) and isothermal decomposition in hydrogen of homogeneously mixed ferrous nickel oxalates with different iron to nickel ratios. The formation of Fe-Ni alloy is obtained at considerably lower temperatures (z 300 "C) in each case. The Fe-Ni alloys obtained shift from iron-rich to nickel-rich composition as the nickel ratio in the mixed metal oxalates is increased. The formation of Pe-Ni Invar from mixed metal oxalate with Fe:Ni = 1:l is indicated in the early stages but not from those with Fe:Ni = 2: 1 or 64:36. An Produktproben von homogen verteilten Eisen-Nickeloxalaten mit unterschiedlichem Eisen- Nickel-Verhaltnis nach thermogravimetrischer Analyse (TGA) und isothermem Zerfall in Wasserst off werden Mollbauereffekt- und Rontgenmessnngen durchgefuhrt. In allen Fiillen wird die Bildung der Fe-Ni-Legierung bei betriichtlich niedrigeren Temperaturen (= 300 "C) erhalten. Die erhaltenen Fe-Ni-Legierungen verschieben sich von der eisenreichen zur nickelreichen Zusrtmmensetzung, wenn das Nickelverhaltnis in dem BIetall-Mischoxalat erhoht wird. Die Bildung der Fe-Ni-lnvar-Legierung aus dem Metall-Mischoxalat mit Fe:Ni = 1 : 1 wird in fruhen Zu Zustanden beobachtet, iedoch nicht aus Oxalaten mit Fe:Ni = 2:1 oder 64:36.

Death, Destruction and Commemoration : Tracing ritual activities in Finnish Late Iron Age cemeteries (AD 550-1150)

The thesis is connected with death, memory and ancestor commemoration during the Merovingian Period, the Viking Age and the beginning of the Crusade Period (AD 550-1150) in Finland. During this time, cremation was the dominant burial rite. It was not until the end of the Viking Age that inhumation became more common but both cremations and inhumations are performed even at the same sites throughout the time. Three different burial types 1) cremation cemeteries below level ground, 2) inhumation burials and 3) water burials are discussed in five articles. I consider these burial forms from three different viewpoints; collectivity-individuality, visibility-invisibility and cremation-inhumation. The thesis also discusses the topics of memory, memorialisation and monument re-use, which have been neglected subjects in Finnish archaeology until now. Both cremation cemeteries below level ground and inhumation burials have been re-used during their time of usage, and on most occasions are situated in a landscape that is overlaid by other monuments as well. The main questions of the thesis are: What kinds of ritual behaviour can we detect in the burials during the period (AD 550-1150)? How did people perceive the moraine hills that functioned as burial places? What kind of re-use can be detected in the Iron Age cemeteries? Why have ancient sites and artefacts been re-used? This thesis shows that it is possible to claim that both artefact and site re-use is a much more widespread phenomenon than has previously been thought in Finnish archaeology. It is also a conscious and deliberate behaviour that can be related to an ancestor cult and commemoration of the dead. The funerary rituals during this time period show great variation and complex, both regionally and nationally. Not only have the dead been buried using elaborate rituals, they have also been mourned and commemorated in intricate ways that proves that death was not an end product, but the start of something new.

Disruption of iron homeostasis increases phosphine toxicity in caenorhabditis elegans

The aim of this study is to identify the biochemical mechanism of phosphine toxicity and resistance, using Caenorhabditis elegans as a model organism. To date, the precise mode of phosphine action is unclear. In this report, we demonstrate the following dose-dependent actions of phosphine, in vitro: (1) reduction of ferric iron (Fe3+) to ferrous iron (Fe2+), (2) release of iron from horse ferritin, (3) and the peroxidation of lipid as a result of iron release from ferritin. Using in situ hybridization, we show that the ferritin genes of C. elegans, both ferritin-1 and ferritin-2, are expressed along the digestive tract with greatest expression at the proximal and distal ends. Basal expression of the ferritin-2 gene, as determined by quantitative PCR, is approximately 80 times that of ferritin-1. However, transcript levels of ferritin-1 are induced at least 20-fold in response to phosphine, whereas there is no change in the level of ferritin-2. This resembles the reported pattern of ferritin gene regulation by iron, suggesting that phosphine toxicity may be related to an increase in the level of free iron. Indeed, iron overload increases phosphine toxicity in C. elegans at least threefold. Moreover, we demonstrate that suppression of ferritin-2 gene expression by RNAi, significantly increases sensitivity to phosphine. This study identifies similarities between phosphine toxicity and iron overload and demonstrates that phosphine can trigger iron release from storage proteins, increasing lipid peroxidation, leading to cell injury and/or cell death.

Statistical Optimization of Iron Electrodes for Alkaline Storage Batteries

A pressed-plate Fe electrode for alkalines storage batteries, designed using a statistical method (fractional factorial technique), is described. Parameters such as the configuration of the base grid, electrode compaction temperature and pressure, binder composition, mixing time, etc. have been optimised using this method. The optimised electrodes have a capacity of 300 plus /minus 5 mA h/g of active material (mixture of Fe and magnetite) at 7 h rate to a cut-off voltage of 8.86V vs. Hg/HgO, OH exp 17 ref.

Properties of iron related quenched-in levels in p-silicon

The electrical and optical properties of the thermally induced quenched-in levels in p-silicon which have heen attributed to iron are studied. The two levels, HI and H2, are located at Ev + 0.42 eV and Ev + 0.52 eV, respectively, as determined by TSCAP, DLTS, and transient photocapacitance methods. The photoionization cross sections are well described by Lucovsky's model. The hole capture by H1 is temperature dependent; a barrier of 40 meV is measured. However, multiphonon emission mechanism cannot be invoked to explain this temperature dependence due to the inferred zero lattice relaxation. The source of iron contamination is found to be the ambient conditions, in particular the quartz tube. The conflicting reports regarding the stability and the variation in the reported capture cross section values suggests that the observed Ev + 0.4 eV level must be a complex centre. The inferred near zero lattice relaxation during the electron transition implies weak coupling to the host lattice.

Kinetics of Extraction of Iron(II1) by Bis(2-ethylhexyl Phosphate in a Laminar Liquid-Liquid Jet Reactor

The kinetics of iron(II1) extraction by bis(Zethylhexy1) phosphate (HDEHP, HA) in kerosene from sulfuric acid solutions has been studied in a liquid-liquid laminar jet reactor. The contact time of the interface in this reacting device is of the same order of magnitude as the surface renewal time in dispersion mixing and much less than that obtained in the relatively quiescent condition of the Lewis cell. Yet the analysis of the data in this study suggested a rate-controlling step involving surface saturation quite in conformity with that obtained in the Lewis cell and not with that in dispersion mixing as reported in the literature. Further, the mechanism suggested a weaker dependence of the rate on hydrogen ion concentration which was reported by other workers.

Mossbauer Effect Study of the Thermal Decomposition in Hydrogen of Homogeneously Mixed Ferrous Nickel Oxalates with Different Iron to Nickel Ratios

Mossbauer effect and X-ray measurements are carried out on product samples of the thermogravimetric analysis (TGA) and isothermal decomposition in hydrogen of homogeneously mixed ferrous nickel oxalates with different iron to nickel ratios. The formation of Fe-Ni alloy is obtained at considerably lower temperatures (z 300 "C) in each case. The Fe-Ni alloys obtained shift from iron-rich to nickel-rich composition as the nickel ratio in the mixed metal oxalates is increased. The formation of Pe-Ni Invar from mixed metal oxalate with Fe:Ni = 1:l is indicated in the early stages but not from those with Fe:Ni = 2: 1 or 64:36. An Produktproben von homogen verteilten Eisen-Nickeloxalaten mit unterschiedlichem Eisen- Nickel-Verhaltnis nach thermogravimetrischer Analyse (TGA) und isothermem Zerfall in Wasserstoff werden Mollbauereffekt- und Rontgenmessnngen durchgefuhrt. In allen Fiillen wird die Bildung der Fe-Ni-Legierung bei betriichtlich niedrigeren Temperaturen (= 300 "C) erhalten. Die erhaltenen Fe-Ni-Legierungen verschieben sich von der eisenreichen zur nickelreichen Zusrtmmensetzung, wenn das Nickelverhaltnis in dem BIetall-Mischoxalat erhoht wird. Die Bildung der Fe-Ni-lnvar-Legierung aus dem Metall-Mischoxalat mit Fe:Ni = 1 : 1 wird in fruhen Zustanden beobachtet, iedoch nicht aus Oxalaten mit Fe:Ni = 2:1 oder 64:36.

Role of free volume in strain softening of as-cast and annealed bulk metallic glass

Plasticity in amorphous alloys is associated with strain softening, induced by the creation of additional free volume during deformation. In this paper, the role of free volume, which was a priori in the material, on work softening was investigated. For this, an as-cast Zr-based bulk metallic glass (BMG) was systematically annealed below its glass transition temperature, so as to reduce the free volume content. The bonded-interface indentation technique is used to generate extensively deformed and well defined plastic zones. Nanoindentation was utilized to estimate the hardness of the deformed as well as undeformed regions. The results show that the structural relaxation annealing enhances the hardness and that both the subsurface shear band number density and the plastic zone size decrease with annealing time. The serrations in the nanoindentation load-displacement curves become smoother with structural relaxation. Regardless of the annealing condition, the nanohardness of the deformed regions is similar to 12-15% lower, implying that the prior free volume only changes the yield stress (or hardness) but not the relative flow stress (or the extent of strain softening). Statistical distributions of the nanohardness obtained from deformed and undeformed regions have no overlap, suggesting that shear band number density has no influence on the plastic characteristics of the deformed region.

A combined XPS-UPS-EELS study of nitrogen adsorbed on clean and barium-promoted iron surfaces: The nature of the precursor to dissociation

For N2 on a clean Fe surface, the adsorbed precursor in a parallel orientation becomes predominant around 110 K, while at lower temperatures it coexists with a weakly adsorbed species. On a Ba-promoted Fe surface, however, N2 is present exclusively in the precursor state in the temperature range 80–150 K following moderate exposure. Besides exhibiting a low N-N stretching frequency of 1530 cm−1, the precursor shows a clear separation between the 5σ and 1π levels in the UPS; the precursor dissociates to give a nitridic species around 160 K.

Growth and carcass characteristics of cast-for-age Merino ewes fed sorghum-based feedlot diets

Grain feeding low bodyweight, cast-for-age (CFA) sheep from pastoral areas of eastern Australia at the end of the growing season can enable critical carcass weight grades to be achieved and thus yield better economic returns. The aim of this work was to compare growth and carcass characteristics for CFA Merino ewes consuming either simple diets based on whole sorghum grain or commercial feed pellets. The experiment also compared various sources of additional nitrogen (N) for inclusion in sorghum diets and evaluated several introductory regimes. Seventeen ewes were killed initially to provide baseline carcass data and the remaining 301 ewes were gradually introduced to the concentrate diets over 14 days before being fed concentrates and wheaten hay ad libitum for 33 or 68 days. Concentrate treatments were: (i) commercial feed pellets, (ii) sorghum mix (SM; whole sorghum grain, limestone, salt and molasses) + urea and ammonium sulfate (SMU), (iii) SMU + whole cottonseed at 286 g/kg of concentrate dry matter (DM), (iv) SM + cottonseed meal at 139 g/kg of concentrate DM, (v) SMU + virginiamycin (20 mg/kg of concentrate) for the first 21 days of feeding, and (vi) whole cottonseed gradually replaced by SMU over the first 14 days of feeding. The target carcass weight of 18 kg was achieved after only 33 days on feed for the pellets and the SM + cottonseed meal diet. All other whole grain sorghum diets required between 33 and 68 days on feed to achieve the target carcass weight. Concentrates based on whole sorghum grain generally produced significantly (P < 0.05) lower carcass weight and fat score than pellets and this may have been linked to the significantly (P < 0.05) higher faecal starch concentrations for ewes consuming sorghum-based diets (270 v. 72 g/kg DM on day 51 of feeding for sorghum-based diets and pellets, respectively). Source of N in whole grain sorghum rations and special introductory regimes had no significant (P > 0.05) effects on carcass weight or fat score of ewes with the exception of carcass weight for SMU + whole cottonseed being significantly lower than SM + cottonseed meal at day 33. Ewes finished on all diets produced acceptable carcasses although muscle pH was high in all ewe carcasses (average 5.8 and 5.7 at 33 and 68 days, respectively). There were no significant (P > 0.05) differences between diets in concentrate DM intake, rumen fluid pH, meat colour score, fat colour score, eye muscle area, meat pH or meat temperature.

Low temperature electrical transport properties of carbon matrix containing iron nanoparticles

We present a comparative study of the low temperature electrical transport properties of the carbon matrix containing iron nanoparticles and the films. The conductivity of the nanoparticles located just below the metal-insulator transition exhibits metallic behavior with a logarithmic temperature dependence over a large temperature interval. The zero-field conductivity and the negative magnetoresistance, showing a characteristic upturn at liquid helium temperature, are consistently explained by incorporating the Kondo relation and the two dimensional electron-electron interaction. The films, in contrast, exhibit a crossover of the conductivity from power-law dependence at high temperatures to an activated hopping law dependence in the low temperature region. The transition is attributed to changes in the energy dependence of the density of states near the Fermi level. The observed magnetoresistance is discussed in terms of quantum interference effect on a three-dimensional variable range hopping mechanism.