Siderophores are a series of important iron chelators secreted by many bacteria that normally have high affinity of iron ions and contain hydroxamate, catecholate and carboxylate and other ligand groups. These organic ligands play significant roles in bacterial metabolism: solubilising iron (III) from environments, enabling iron uptake and acting as a cell-signalling molecule to control gene expression. Recent observations of initial stages of Pseudomonas aeriginosa biofilm formation on metal oxides surfaces indicate that siderophores may also facilitate bacterial adhesion to metals. However, details of how siderophores interact with metal surfaces and the relationship of their chemical nature with bacterial adhesion were not fully understood. To test the generality of bacteria attachment to metals via siderophores, the adsorption behaviour of siderophores and their functional ligands groups on particle films of metal oxides were investigated with in-situ ATR-IR spectroscopy. In this study, nanoparticle films of titanium oxide, boehmite, iron oxide and chromium oxyhydroxide were prepared as substrates to simulate titanium, alumnium, stainless steel surface and more detailed work were carried out on titanium dioxide. Monohydroxamic acids (acetohydroxamic acid, N-methylformohydroxamic acid, N-methyl-acetohydroxamic acid and 1-hydroxy, 2-piperidone) and catechol and catechol-like (L-dopa and esculetin) ligands were selected as modelling compounds for the most frequently occured functional groups in natural siderophores. IR spectra of these ligands in aqueous solution and adsorbed on TiO₂ were obtained with a flowing cell system fit to a horizontal accessory by in situ ATR-IR spectroscopy and interpreted based on vibrational mode analysis with density function theory. Results show that all these ligands can form surface complexes with metal surfaces and possible adsorption modes of these molecules were discussed. The pH dependence of absorbance of IR absorption of these adsorbed ligands showed that most of the ligands exhibited maximium adsorption to TiO₂ at about pH 8, only N-methylformohydroxamic acid, 1-hydroxy, 2-piperidone groups having maximum absorption at pH~3 and pH~6. Infrared spectroscopic studies of adsorbed siderophores (desferroximme B, enterobactin and pyoverdine) were also carried out in variation of concentration and pH. Possible adsorption modes of these iron scavenger ligands on TiO₂ and other metal oxides were discussed. Results showed that all these ligands adsorbed on metal oxide surfaces and form surface complex via hydroxamate or catecholate lignd groups which confirm the generality of siderphore-metal bond formation. Siderophore based-bacterial adhesion to metals of was conducted with Pesudomonas aeruginosa and E. coli strains on titanium oxide and iron oxide films. These observations support that siderophore play a significant role in bacterial adhesion to metals. Further work needs to be carried out on the wider involvement of siderophores in bacterial adhesion initiation to metals and siderophore-mediated iron transport.

Thesis (D. Min.)--Southwestern Baptist Theological Seminary, 1999. / Includes bibliographical references (leaves 361-380).

No description available.

Norethynodrel, a common progestin in oral contraceptives, produces in female rats several significant physiological, cytological and biochemical changes at dose levels of 1 mg and 20 mg per kg: 1) a relative increase in liver mass 2) modification of appearance and extent of the endoplasmic reticulum 3) augmentation of the protein content of the liver 4) increase of the level of cytochrome P- 450 in the liver as determined by : a) difference spectroscopy b) increases in biotransformation of aniline and aminopyrine in vitro and c) reduction of sleeping times of rats dosed with phenobarbital The significance of these findings becomes evident when it is realized that norethynodrel affects and is affected by the same enzyme system which oxidizes medicaments in general in the body: induction of cytochrome P-450 by administration of norethynodrel may interfere with the action of other drugs . Ethinyl estradiol alone showed none of the inductive effects. At high dose levels (20 mg per kg) both norethynodrel and ethinyl estradiol caused a marked inhibition of growth of the animals, producing a net loss of body mass over the 30- day experimental period. Electron micrographic evidence implies that there is also a lowering of glycogen content and a chemical change in the lipids of adrenocortical and liver cells accompanying the use of these agents.

No description available.

Dans cette thèse, nous cherchons à développer de nouvelles techniques pour écrire plus simplement des programmes formellement vérifiés. Nous procédons en étudiant l'utilisation de Coq en tant que langage de programmation dans différents environnements. Coq étant un langage purement fonctionnel, nous nous concentrons surtout sur la représentation et la spécification d'effets impurs, tel que les exceptions, les références mutables, les entrées-sorties et la concurrence.Nous travaillons premièrement sur deux projets préliminaires qui nous aident à comprendre les défis existants dans la programmation en Coq. Le premier projet, Cybele, est un plugin Coq pour écrire des preuves par réflexion efficaces avec effets. Nous compilons et nous exécutons les effets impurs en OCaml pour générer une prophétie, une forme de certificat, et interprétons les effets dans Coq en utilisant cette prophétie. Le second projet, le compilateur CoqOfOCaml, importe des programmes OCaml avec effets dans Coq en utilisant un système d'inférence d'effets.Puis nous décrivons différentes représentations génériques et composables d'effets impurs en Coq. Les calculs avec pause combinent les effets d'exceptions et de références mutables avec un mécanisme de pause. Ce mécanisme de pause permet de rendre explicite les étapes d'évaluation dans le but de représenter l'évaluation concurrente de deux termes. En implémentant le serveur web Pluto en Coq, nous réalisons que les entrées-sorties asynchrones sont l'effet le plus utile : cet effet est présent dans la plupart des programmes et ne peux être encodé de façon purement fonctionnelle. Nous concevons alors les "calculs asynchrones" comme moyen pour représenter et compiler des programmes avec événements en Coq.Finalement, nous étudions des techniques pour prouver des propriétés à propos de programmes avec effets. Nous commençons avec la vérification du système de blog ChickBlog écrit dans le langage des "calculs interactifs". Ce blog lance un fil d'exécution par client. Nous vérifions notre blog en utilisant une méthode de spécification par cas d'utilisation. Nous adaptons cette technique à la théorie des types en exprimant un cas d'utilisation comme un co-programme bien typé. Grâce à ce formalisme, nous pouvons présenter un cas d'utilisation comme un programme de test symbolique et le déboguer symboliquement, étape par étape, en utilisant le mode interactif de Coq. À notre connaissance, ceci représente la première telle adaptation de la spécification par cas d'utilisation en théorie des types. Nous pensons que la spécification formelle par cas d'utilisation est l'une des clés pour vérifier des programmes avec effets, sachant que la méthode des cas d'utilisation s'est avérée utile dans l'industrie pour exprimer des spécifications informelles. Nous étendons notre formalisme aux programmes concurrents et potentiellement non-terminants, avec le langage des "calculs concurrents". Nous concevons également un vérificateur de modèles pour vérifier l'absence d'interblocage dans un programme concurrent, en compilant la composition parallèle vers l'opérateur de choix non-déterministe. / In this thesis, we develop new techniques to conveniently write formally verified programs. To proceed, we study the use of Coq as a programming language in different settings. Coq being a purely functional language, we mainly focus on the representation and on the specification of impure effects, like exceptions, mutable references, inputs-outputs, and concurrency.First, we work on two preliminary projects helping us to understand the challenges of programming in Coq. The first project, Cybele, is a Coq plugin to write efficient proofs by reflection with effects. We compile and execute the impure effects in OCaml to generate a prophecy, a kind of certificate, and then interpret the effects in Coq using the prophecy. The second project, the compiler CoqOfOCaml, imports OCaml programs with effects into Coq, using an effect inference system.Next, we describe different generic and composable representations of impure effects in Coq. The breakable computations combine the standard exceptions and mutable references effects, with a pause mechanism to make explicit the evaluation steps in order to represent the concurrent evaluation of two terms. By implementing the Pluto web server in Coq, we realize that the most important effects to program are the asynchronous inputs-outputs. Indeed, these effects are ubiquitous and cannot be encoded in a purely functional manner. Thus, we design the asynchronous computations as a first way to represent and compile programs with events and handlers in Coq.Then, we study techniques to prove properties about programs with effects. We start with the verification of the blog system ChickBlog written in the language of the interactive computations. This blog runs one worker with synchronous inputs-outputs per client. We verify our blog using the method of specification by use cases. We adapt this technique to type theory by expressing a use case as a well-typed co-program over the program we verify. Thanks to this formalism, we can present a use case as a symbolic test program and symbolically debug it, step by step, using the interactive proof mode of Coq. To our knowledge, this is the first such adaptation of the use case specifications in type theory. We believe that the formal specification by use cases is one of the keys to verify effectful programs, as the method of use cases proved to be convenient to express (informal) specifications in the software industry. We extend our formalism to concurrent and potentially non-terminating programs with the language of concurrent computations. Apart from the use case method, we design a model-checker to verify the deadlock freedom of concurrent computations, by compiling the parallel composition to the non-deterministic choice operator using the language of blocking computations

Magister Curationis - MCur / There is a growing burden of disease associated with mental disorders especially in low and middle-income countries. This growing burden is accompanied by an increase in psychotic disorders and has increased the demand for antipsychotic medication. The increase in the use of antipsychotic medication has resulted in the increase in side-effects that have a detrimental effect on the health of the mental health care user. Antipsychotic medication side-effects have been classified as the primary indicator for medication non-adherence. There is a relationship between psychiatric nurses’ knowledge and attitudes towards the use and the non-adherence of antipsychotic medication.

Along Sweden’s east coast there are thousands of well-preserved shipwrecks after an extensive shipping that stretches far back in history. The Baltic Sea is a unique sea in the sense that the ship worm Teredo Navalis cannot live here, which means that the ship’s timber is well preserved under water. But we have little knowledge how many these wrecks are and where they are located. No comprehensive underwater inventory like those made on land has even been made. Therefore, these shipwrecks are threatened with destruction by our ignorance of them. By scanning water areas in our immediate environment with Side scan sonar technology, our state of knowledge can be significantly improved. With this method, these relics can be found and preserved as far as possible for future generations. The wrecks can also be used for recreation and experience activities.

>Magister Scientiae - MSc / Non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most commonly used medications globally, as they are highly effective and easily accessible. The NSAIDs are indicated for mild to moderate pain management. The increasing incidence of NSAID related side effects and hospitalisations has raised a concern about these medications’ safety. The prevalence of these side effects has drastic consequences to a challenged South Africanpublic healthcare system. The implications of not treating severe, potentially preventable upper gastrointestinal complications attributed to NSAIDs’ consumption continue to be a significant problem that healthcare professionals (HCP) face.

Dose tolerance and pharmacokinetic studies of pseudoephedrine sustained action capsules were performed in thirty-three adult male subjects who received either 120 mg or 150 mg capsules every twelve hours for seven consecutive days in a double-blind parallel design study. Although only one subject in the 150 mg group was discontinued prematurely from this study, a large number of side effects typical of CNS stimulation were seen. A placebo effect might account for a portion of these complaints, however symtoms evaluated as being due to drug were significantly more severe and persistent in the 150 mg group. Pulse rates showed a persistent and significant increase while systolic and diastolic blood pressure fell from the baseline values in both groups. A pharmacokinetic analysis of the pseudoephedrine plasma concentration-time data provided estimates of half-life and the volume of distribution/availability ratio. The values obtained were in good agreement with values reported by others. Half-life was not influenced by urine pH probably as a result of the narrow range of urine pHs observed in the subjects. Calculations of relative bioavailability suggest that the 120 mg capsule formulation has a 30% greater bioavailability compared to the 150 mg capsule.