Vibrio cholerae, the causative agent of the diarrheal disease cholera, must acquire iron to survive. Although iron is relatively abundant, it forms insoluble ferric complexes in the presence of oxygen. The more soluble ferrous iron is limited to anaerobic or reducing environments. To meet the nutritional needs of the cell, V. cholerae encodes many different ferric iron transport systems but only one characterized ferrous iron transporter, Feo. Feo is widely distributed in bacteria and archaea, but the mechanism for transport is not known. In this study, basic characterization of the V. cholerae feoABC operon was performed to gain further understanding about a critical iron transport system. Each gene in the operon, feoA, feoB, and feoC, was found to be required for ferrous iron uptake. FeoB, an inner membrane protein, is considered to be the ferrous permease but functions for FeoA and FeoC are not known. These studies show that neither FeoA nor FeoC is required for expression of feoB, suggesting that these proteins are required for Feo function. Analysis of the composition of the Feo transporter using a bacterial adenylate cyclase two-hybrid system indicated interactions between Feo proteins, specifically, between FeoC and the cytoplasmic portion of FeoB. This result indicates that feoC encodes a protein that interacts with FeoB and is necessary for ferrous iron transport. / text

No ano de 2008, a partir das curiosidades, e ideias trazidas pelas crianças para a sala de aula, e a partir de diferentes produções culturais, como imagens das histórias infantis de bruxas, fadas, princesas, de filmes, me vi envolvida num novo desafio: Pesquisar como as crianças, em suas interações com a cultura e com o universo visual estão se apropriando e expressando as noções do belo e do feio. Para tanto, elaborei esta investigação apoiada nos Estudos da Cultura Visual, Estudos da Infância e discussões e reflexões contemporâneas sobre o Belo e o Feio. Para desenvolvê-la, criei um plano de trabalho com diferentes propostas tendo como objetivo incentivar variadas formas de expressão das crianças. No ano de 2008, com minha turma do primeiro Ano do Ensino Fundamental, na cidade de Lajeado, em uma escola privada, surgiu o desafio de realizar propostas investigativas com o intuito de estudar como as crianças se apropriam das noções do belo e do feio nas mediações culturais. Com diferentes propostas realizadas foi possível contribuir para a ampliação e desnaturalização das noções do belo e do feio presente em diferentes artefatos culturais endereçados à infância. Foi possível perceber o quanto as discussões sobre pobres, ricos, belo, feio, negros, brancos despertavam interesse nas crianças e traziam discussões no que diz respeito a aprender a relativizar o conceito de beleza e aprender a lidar com o outro, com o diferente. / En el año 2008, a partir de las curiosidades, e ideas traídas por los niños al aula y a partir de diferentes producciones culturales, como imágenes de las historias infantiles de brujas, hadas, princesas, de películas, me vi cercada por un nuevo reto: Investigar como los niños, en sus interacciones con la cultura y con el universo visual se están apropiando y expresando las nociones de bello y feo. Para tal, elaboré esta investigación apoyada en los Estudios de la Cultura Visual, Estudios de la Infancia y discusiones y reflexiones contemporáneas sobre lo Bello y lo Feo. Para desarrollarla, crié un plan de trabajo con distintas propuestas cuyo objetivo era el de estimular formas variadas de expresión de los niños. En año de 2008, con mi grupo de alumnos del Primer año de la Enseñanza Primaria, en la ciudad de Lajeado, en una escuela privada, surgió el reto de realizar propuestas investigativas con la intención de estudiar como los niños se apropian de las nociones de bello y feo en el medio cultural. A través de diferentes propuestas realizadas fue posible contribuir para la amplitud y desnaturalización de las nociones de bello y feo presentes en diversos artefactos culturales dirigidos a la infancia. Fue posible percibir lo cuanto las discusiones sobre pobres, ricos, bello, feo, negros, blancos despertaban el interés en los niños y generaban discusiones en lo que se refiere a relativizar el concepto de belleza y aprender a convivir con el otro, con lo diferente.

No ano de 2008, a partir das curiosidades, e ideias trazidas pelas crianças para a sala de aula, e a partir de diferentes produções culturais, como imagens das histórias infantis de bruxas, fadas, princesas, de filmes, me vi envolvida num novo desafio: Pesquisar como as crianças, em suas interações com a cultura e com o universo visual estão se apropriando e expressando as noções do belo e do feio. Para tanto, elaborei esta investigação apoiada nos Estudos da Cultura Visual, Estudos da Infância e discussões e reflexões contemporâneas sobre o Belo e o Feio. Para desenvolvê-la, criei um plano de trabalho com diferentes propostas tendo como objetivo incentivar variadas formas de expressão das crianças. No ano de 2008, com minha turma do primeiro Ano do Ensino Fundamental, na cidade de Lajeado, em uma escola privada, surgiu o desafio de realizar propostas investigativas com o intuito de estudar como as crianças se apropriam das noções do belo e do feio nas mediações culturais. Com diferentes propostas realizadas foi possível contribuir para a ampliação e desnaturalização das noções do belo e do feio presente em diferentes artefatos culturais endereçados à infância. Foi possível perceber o quanto as discussões sobre pobres, ricos, belo, feio, negros, brancos despertavam interesse nas crianças e traziam discussões no que diz respeito a aprender a relativizar o conceito de beleza e aprender a lidar com o outro, com o diferente. / En el año 2008, a partir de las curiosidades, e ideas traídas por los niños al aula y a partir de diferentes producciones culturales, como imágenes de las historias infantiles de brujas, hadas, princesas, de películas, me vi cercada por un nuevo reto: Investigar como los niños, en sus interacciones con la cultura y con el universo visual se están apropiando y expresando las nociones de bello y feo. Para tal, elaboré esta investigación apoyada en los Estudios de la Cultura Visual, Estudios de la Infancia y discusiones y reflexiones contemporáneas sobre lo Bello y lo Feo. Para desarrollarla, crié un plan de trabajo con distintas propuestas cuyo objetivo era el de estimular formas variadas de expresión de los niños. En año de 2008, con mi grupo de alumnos del Primer año de la Enseñanza Primaria, en la ciudad de Lajeado, en una escuela privada, surgió el reto de realizar propuestas investigativas con la intención de estudiar como los niños se apropian de las nociones de bello y feo en el medio cultural. A través de diferentes propuestas realizadas fue posible contribuir para la amplitud y desnaturalización de las nociones de bello y feo presentes en diversos artefactos culturales dirigidos a la infancia. Fue posible percibir lo cuanto las discusiones sobre pobres, ricos, bello, feo, negros, blancos despertaban el interés en los niños y generaban discusiones en lo que se refiere a relativizar el concepto de belleza y aprender a convivir con el otro, con lo diferente.

No ano de 2008, a partir das curiosidades, e ideias trazidas pelas crianças para a sala de aula, e a partir de diferentes produções culturais, como imagens das histórias infantis de bruxas, fadas, princesas, de filmes, me vi envolvida num novo desafio: Pesquisar como as crianças, em suas interações com a cultura e com o universo visual estão se apropriando e expressando as noções do belo e do feio. Para tanto, elaborei esta investigação apoiada nos Estudos da Cultura Visual, Estudos da Infância e discussões e reflexões contemporâneas sobre o Belo e o Feio. Para desenvolvê-la, criei um plano de trabalho com diferentes propostas tendo como objetivo incentivar variadas formas de expressão das crianças. No ano de 2008, com minha turma do primeiro Ano do Ensino Fundamental, na cidade de Lajeado, em uma escola privada, surgiu o desafio de realizar propostas investigativas com o intuito de estudar como as crianças se apropriam das noções do belo e do feio nas mediações culturais. Com diferentes propostas realizadas foi possível contribuir para a ampliação e desnaturalização das noções do belo e do feio presente em diferentes artefatos culturais endereçados à infância. Foi possível perceber o quanto as discussões sobre pobres, ricos, belo, feio, negros, brancos despertavam interesse nas crianças e traziam discussões no que diz respeito a aprender a relativizar o conceito de beleza e aprender a lidar com o outro, com o diferente. / En el año 2008, a partir de las curiosidades, e ideas traídas por los niños al aula y a partir de diferentes producciones culturales, como imágenes de las historias infantiles de brujas, hadas, princesas, de películas, me vi cercada por un nuevo reto: Investigar como los niños, en sus interacciones con la cultura y con el universo visual se están apropiando y expresando las nociones de bello y feo. Para tal, elaboré esta investigación apoyada en los Estudios de la Cultura Visual, Estudios de la Infancia y discusiones y reflexiones contemporáneas sobre lo Bello y lo Feo. Para desarrollarla, crié un plan de trabajo con distintas propuestas cuyo objetivo era el de estimular formas variadas de expresión de los niños. En año de 2008, con mi grupo de alumnos del Primer año de la Enseñanza Primaria, en la ciudad de Lajeado, en una escuela privada, surgió el reto de realizar propuestas investigativas con la intención de estudiar como los niños se apropian de las nociones de bello y feo en el medio cultural. A través de diferentes propuestas realizadas fue posible contribuir para la amplitud y desnaturalización de las nociones de bello y feo presentes en diversos artefactos culturales dirigidos a la infancia. Fue posible percibir lo cuanto las discusiones sobre pobres, ricos, bello, feo, negros, blancos despertaban el interés en los niños y generaban discusiones en lo que se refiere a relativizar el concepto de belleza y aprender a convivir con el otro, con lo diferente.

Iron is an essential element for virtually all forms of life. Complicating matters, it is present in the insoluble ferric form in aerobic environments, while the more soluble ferrous form is found in anaerobic or reducing environments. Vibrio cholerae, the causative agent of the disease cholera, requires iron to survive. In order to meet the need for iron, V. cholerae expresses a variety of iron acquisition systems. One of these systems, Feo, is highly conserved among bacterial species as well as archaea and transports ferrous iron. The Feo system consists of three proteins: FeoA, FeoB, and FeoC. Previous work using the bacterial adenylate cyclase two hybrid system has shown that FeoC interacts with the cytoplasmic N-terminal domain of FeoB. However, the significance of this interaction is not known. In this study, V. cholerae Feo system proteins were analyzed for residues important for the interaction between FeoB and FeoC. In addition, FeoA and FeoC were purified for antibody production. It was found that a residue in the G protein domain of FeoB was not necessary for interaction with FeoC. However, a conserved residue in FeoC did abolish the interaction with FeoB. These results indicate that there is at least one residue important in the interaction of FeoB and FeoC, although further characterization will most likely reveal more. Antibodies to FeoA and FeoC were generated to use them for further characterization of the Feo system. / text

This dissertation describes the determination of the equilibrium constant for the reduction of ferrous oxide by manganese to yield manganese oxide and iron. The experimental work was carried out over the temperature range of 1650°C to 1870°C. The results from the present work were combined with reliable published data to give what is considered to be the best relationship between the equilibrium constant and the temperature. The difference between this study and previous work on this topic is the radically new experimental approach. While previous workers used crucible techniques to achieve equilibrium for their system and standard wet chemical analysis, the method used here involved levitation melting and analysis by the electron probe micro-analyser. / Thesis / Master of Engineering (ME)

How would a housing system work in a just society? How do we account for differences in opportunity according to one’s birthplace? These two questions, both a result of our recent housing crisis, can be addressed through inquiries into policy, economics, history, or other forms of social sciences. In this paper I attempt to address these questions instead through a philosophical lens by examining the principles that guide the distribution of goods in our society. It is from such a theory that we can construct the fairest government or economic policies. Theories of distributive justice try to account for the fairest distribution of goods in a society. I take one such theory, John Rawls’ theory of justice as fairness, and apply it to the distribution of housing. I begin by deconstructing the core principles of Rawls’ theory and analyzing how each applies to housing. Then I make an argument about the fairness of these outcomes. My conclusion is, in fact, Rawls theory does not adequately account for the importance of housing in our society. In doing so, I hope to demonstrate the inequalities that face families throughout our society by illustrating the profound impact of housing on one’s well-being as well as one’s opportunity to succeed.

This essay explores the concept of “equivalence” (likvärdighet) and how it can be defined in the context of the Swedish school system. The method that is used is a critical examination of the equivalence theory formulated by Lars Lindblom. The concept of equivalence in his theory can be defined as equal opportunities for education that is designed to provide compensated resources and welfare where the most disadvantaged students, which includes the differently abled, are compensated according to the principle of difference. Further, that the social distribution domain in a fair society must both ensure that the school provides equal opportunities and compensates the disadvantaged and that the school's compensatory mission must therefore become the first priority in equality. In the essay I advance the thesis that Lindblom’s theory does neither function as a framework for allocation of resources to different categories of students or as a tool do model teaching. This is, because it does not provide any practical guidance for how the concept of equivalence should be used when distributing resources among different groups of students, except for the fact that students who receive compensatory should be prioritized. Lindblom's contribution is nevertheless valuable in that the theory provides a new and in-depth insight into the various dimensions contained within the concept of equivalence.

In the present work, the thermodynamic activites of ironoxide, denoted as "FeO" in the slag systems Al2O3-"FeO", CaO-"FeO", "FeO"-SiO2, Al2O3-"FeO"-SiO2, CaO-"FeO"-SiO2and "FeO"-MgO-SiO2were investigated by employing the gasequilibration technique at steelmaking temperatures. Thestrategy was to expose the molten slag mixtures kept inplatinum crucibles for an oxygen potential, determined by aCO/CO2-ratio. A part of the iron reduced from the "FeO"in the slag phase was dissolved into the Pt crucible. In order to obtain the activites of "FeO", chemical analysisof the quenched slag samples together with thermodynamicinformation of the binary metallic system Fe-Pt is required.Careful experimental work was carried out by employing asolid-state galvanic cell technique as well as calorimetricmeasurements in the temperature ranges of 1073-1273 K and300-1988 K respectively. The outcome of these experiments wasincorporated along with previous studies into a CALPHAD-type ofthermodynamic assessment performed with the Thermo-Calc™software. The proposed equilibrium diagram enabledextrapolation to higher temperatures. The experimentally obtained activites of "FeO" in thepresent work, along with earlier investigations were assessedwith the KTH slag model, THERMOSLAG©. New binaryparameters were evolved and incorporated in THERMOSLAG©.The present model calculations are compared with othercommercially available software such as F*A*C*T™andThermo-Calc™. The validity of the modified model wasinvestigated by measurements carried out in case of Al2O3-"FeO"-SiO2, CaO-"FeO"-SiO2and "FeO"-MgO-SiO2ternary slags. The potential of the model tocompute the activities in the case of multicomponent slags wasdemonstrated. A correlation between the activity of a metallic oxide in aternary slag system and the sulphide capacity of the slag wasinvestigated by using the solubility of sulphur in the binarysystems CaO-SiO2and Al2O3-CaO along with the sulphide capacity of the Al2O3-CaO-SiO2system. The estimated values of the activitieswere found to be in good agreement with the measured values.This correlation also gives the possibility to elucidate theapplicability of Henry's law to the activity of a metallicsulphide and to determine the order in the affinity of a cationto sulphur between two metallic oxides in a slag. Model calculations were performed with THERMOSLAG©, by using plant data from the ladle refiningprocess at OVAKO Steel, Hofors, Sweden. It was found thatoxygen estimations in the metal from the "FeO" analyses ofslags, obtained by conventional sampling and analysis methodwere less reliable. Reliable estimation of the oxygen levelsutilising the sulphur partition between the slag and the metalwere carried out using THERMOSLAG© software. <b>Keywords:</b>Thermodynamics, Activity, Galvanic cell,Calorimetry, Gas equilibration technique, Iron-platinum alloys,FeO, Slags, Modelling, Ladle

<p>In the present work, the thermodynamic activites of ironoxide, denoted as "FeO" in the slag systems Al₂O₃-"FeO", CaO-"FeO", "FeO"-SiO₂, Al₂O₃-"FeO"-SiO₂, CaO-"FeO"-SiO₂and "FeO"-MgO-SiO₂were investigated by employing the gasequilibration technique at steelmaking temperatures. Thestrategy was to expose the molten slag mixtures kept inplatinum crucibles for an oxygen potential, determined by aCO/CO₂-ratio. A part of the iron reduced from the "FeO"in the slag phase was dissolved into the Pt crucible.</p><p>In order to obtain the activites of "FeO", chemical analysisof the quenched slag samples together with thermodynamicinformation of the binary metallic system Fe-Pt is required.Careful experimental work was carried out by employing asolid-state galvanic cell technique as well as calorimetricmeasurements in the temperature ranges of 1073-1273 K and300-1988 K respectively. The outcome of these experiments wasincorporated along with previous studies into a CALPHAD-type ofthermodynamic assessment performed with the Thermo-Calc™software. The proposed equilibrium diagram enabledextrapolation to higher temperatures.</p><p>The experimentally obtained activites of "FeO" in thepresent work, along with earlier investigations were assessedwith the KTH slag model, THERMOSLAG©. New binaryparameters were evolved and incorporated in THERMOSLAG©.The present model calculations are compared with othercommercially available software such as F*A*C*T™andThermo-Calc™. The validity of the modified model wasinvestigated by measurements carried out in case of Al₂O₃-"FeO"-SiO₂, CaO-"FeO"-SiO₂and "FeO"-MgO-SiO₂ternary slags. The potential of the model tocompute the activities in the case of multicomponent slags wasdemonstrated.</p><p>A correlation between the activity of a metallic oxide in aternary slag system and the sulphide capacity of the slag wasinvestigated by using the solubility of sulphur in the binarysystems CaO-SiO₂and Al₂O₃-CaO along with the sulphide capacity of the Al₂O₃-CaO-SiO₂system. The estimated values of the activitieswere found to be in good agreement with the measured values.This correlation also gives the possibility to elucidate theapplicability of Henry's law to the activity of a metallicsulphide and to determine the order in the affinity of a cationto sulphur between two metallic oxides in a slag.</p><p>Model calculations were performed with THERMOSLAG^©, by using plant data from the ladle refiningprocess at OVAKO Steel, Hofors, Sweden. It was found thatoxygen estimations in the metal from the "FeO" analyses ofslags, obtained by conventional sampling and analysis methodwere less reliable. Reliable estimation of the oxygen levelsutilising the sulphur partition between the slag and the metalwere carried out using THERMOSLAG© software.</p><p><b>Keywords:</b>Thermodynamics, Activity, Galvanic cell,Calorimetry, Gas equilibration technique, Iron-platinum alloys,FeO, Slags, Modelling, Ladle</p>