Evaluation of an eLearning pilot course based on user experiences: corporate case study

Diplomityön tavoitteena oli arvioida sähköisen oppimisen soveltuvuutta kohdeyrityksessä ja selvittää, voidaanko luokkahuonekoulutusta korvata sähköisen oppimisen kursseilla. Tietojärjestelmän raportoinnista tehtiin sähköisen oppimisen kurssi, joka oli koekäytössä. Koekäytön jälkeen tehtiin käyttäjäkysely, kerättiin käyttötietoja kurssista ja tehtiin haastatteluja. Koekäyttäjien kokemuksista tehdyn arvioinnin perusteella sähköinen oppiminen soveltuu käytettäväksi selkeiden asioiden koulutukseen kohdeyrityksessä, mutta se ei voi kokonaan korvata luokkahuonekoulutusta. Luokkahuonekoulutuksessa tulisi keskittyä monimutkaisempiin asioihin ja ongelmanratkaisuun. Positiivisten tulosten perusteella sähköisen oppimisen kehittämistä päätettiin jatkaa yrityksessä. Sähköisen oppimisen kurssin avulla saadaan kustannussäästöjä kohdeyrityksessä, kun käyttäjämäärä on suurempi kuin 66. Jos koko koekäytössä olleen kurssin kohdeyleisö suorittaa kurssin sähköisesti, ovat kustannukset vain noin 15% vastaavista kustannuksista luokkahuoneessa järjestettynä. Lisäksi sähköisen oppimisen tehokkuutta tutkittiin ja koekäytössä olleen kurssin arvioitiin olevan positiivinen työssä kehitetyn Consensus-mallin mukaan.

Quantum Hall Phases of two-component bosons

The recent production of synthetic magnetic fields acting on electroneutral particles, such as atoms or photons, has boosted interest in the quantum Hall physics of bosons. Adding pseudospin 1/2 to the bosons greatly enriches the scenario, as it allows them to form an interacting integer quantum Hall (IQH) phase with no fermionic counterpart. Here we show that, for a small two-component Bose gas on a disk, the complete strongly correlated regime, extending from the integer phase at filling factor ν = 2 to the Halperin phase at filling factor ν = 2 / 3, is well described by composite fermionization of the bosons. Moreover we study the edge excitations of the IQH state, which, in agreement with expectations from topological field theory, are found to consist of forward-moving charge excitations and backward-moving spin excitations. Finally, we demonstrate how pair-correlation functions allow one to experimentally distinguish the IQH state from competing states, such as non-Abelian spin singlet (NASS) states.

A thematic analysis of delusion with religious content in schizophrenia: open, closed, and mixed dynamics

The aim of the present study was to elicit how patients with delusions with religious contents conceptualized or experienced their spirituality and religiousness. Sixty-two patients with present or past religious delusions went through semistructured interviews, which were analyzed using the three coding steps described in the grounded theory. Three major themes were found in religious delusions: ''spiritual identity,'' ''meaning of illness,'' and ''spiritual figures.'' One higher-order concept was found: ''structure of beliefs.'' We identified dynamics that put these personal beliefs into a constant reconstruction through interaction with the world and others (i.e., open dynamics) and conversely structural dynamics that created a complete rupture with the surrounding world and others (i.e., closed structural dynamics); those dynamics may coexist. These analyses may help to identify psychological functions of delusions with religious content and, therefore, to better conceptualize interventions when dealing with it in psychotherapy.

Role of an LRR receptor-like kinase in the establishment of a functional root endodermal barrier

The endodermis is a highly conserved cell layer present in the root of all vascular plants, except Lycophytes. This tissue layer establishes a protective diffusion barrier surrounding the vasculature and is expected to prevent passive, uncontrolled flow of nutrients through the root. This barrier property is achieved by the production of Casparian strips (CS), a localized cell wall impregnation of lignin in the anticlinal walls of each endodermal cell, forming a belt-like structure sealing the extracellular space. The CS act as a selective barrier between the external cell layers and the vascular cylinder and are thought to be important in many aspects of root function. For instance, selective nutrient uptake and sequestration from the soil, resistance to different abiotic and biotic stresses are expected to involve functional CS. Although discovered 150 years ago, nothing was known about the genes involved in CS establishment until recently. The use of the model plant Arabidopsis thaliana together with both reverse and forward genetic approaches led to the discovery of an increasing number of genes involved in different steps of CS formation during the last few years. One of these genes encodes SCHENGEN3 (SGN3), a leucine-rich repeat receptor-like kinase (LRR-RLK). SGN3 was discovered first by reverse genetic due to its endodermis-enriched expression, and the corresponding mutant displays strong endodermal permeability of the apoplastic tracer Propidium Iodide (PI) indicative of defective CS. One aim of this thesis is to study the role of SGN3 at the molecular level in order to understand its involvement in establishing an impermeable CS. The endodermal permeability of sgn3 is shown to be the result of incorrect localization of key proteins involved in CS establishment (the "Casparian strip domain proteins", CASPs), leading to non-functional CS interrupted by discontinuities. CASPs localize in the plasma membrane domain subjacent to the CS, named the Casparian Strip membrane Domain (CSD). The CSD discontinuities in sgn3 together with SGN3 localization in close proximity to the CASPs lead to the assumption that SGN3 is involved in the formation of a continuous CSD. In addition, SGN3 might have a second role, acting as a kinase reporting CSD integrity leading to lignin and suberin production in CSD/CS defective plants. Up to now, sgn3 is the strongest and most specific CS mutant available, displaying tracer penetration along the whole length of the seedling root. For this reason, this mutant is well suited in order to characterize the physiological behaviour of CS affected plants. Due to the lack of such mutants in the past, it was not possible to test the presumed functions of CS by using plants lacking this structure. We decided to use sgn3 for this purpose. Surprisingly, sgn3 overall growth is only slightly affected. Nevertheless, processes expected to rely on functional CS, such as water transport through the root, nutrient homeostasis, salt tolerance and resistance to an excess of some nutrients are altered in this mutant. On the other hand, homeostasis for most elements and drought tolerance are not affected in sgn3. It is surprising to observe that homeostatic defects are specific, with a decrease in potassium and an increase in magnesium levels. It indicates a backup system, set up by the plant in order to counteract free diffusion of nutrients into the stele. For instance, potassium shortage in sgn3 upregulates the transcription of potassium influx transport proteins and genes known to be induced by potassium starvation. Moreover, sgn3 mutant is hypersensitive to low potassium conditions. Hopefully, these results about SGN3 will help our understanding of CS establishment at the molecular level. In addition, physiological experiments using sgn3 should give us a framework for future experiments and help us to understand the different roles of CS and their involvement during nutrient radial transport through the root. -- L'endoderme est un tissu présent dans les racines de toutes les plantes vasculaires à l'exception des Lycophytes. Ce tissu établit une barrière protectrice entourant les tissus vasculaires dans le but d'éviter la diffusion passive et incontrôlée des nutriments au travers de la racine. Cette propriété de barrière provient de la production des cadres de Caspary, une imprégnation localisée de lignine des parties anticlinales de la paroi de chaque cellule d'endoderme. Cela donne naissance à un anneau/cadre qui rend étanche l'espace extracellulaire. Les cadres de Caspary agissent comme une barrière sélective entre les couches externes de la racine et le cylindre central et sont supposés être importants dans beaucoup d'aspects du fonctionnement de la racine. Par exemple, l'absorption sélective de nutriments et leur séquestration à partir du sol ainsi que la résistance contre différents stress abiotiques et biotiques sont supposés impliquer des cadres de Caspary fonctionnels. Bien que découverts il y a 150 ans, rien n'était connu concernant les gènes impliqués dans Ja formation des cadres de Caspary jusqu'à récemment. Durant ces dernière années, l'utilisation de la plante modèle Arabidopsis thaliana ainsi que des approches de génétique inverse et classique ont permis la découverte d'un nombre croissant de gènes impliqués à différentes étapes de la formation de cette structure. Un des ces gènes code pour SCHENGEN3 (SGN3), un récepteur kinase "leucine-rich repeat receptor-like kinase" (LRR-RLK). SGN3 a été découvert en premier par génétique inverse grâce à son expression enrichie dans l'endoderme. Les cadres de Caspary ne sont pas fonctionnels dans le mutant correspondant, ce qui est visible à cause de la perméabilité de l'endoderme au traceur apoplastique Propidium Iodide (PI). Un des objectifs de cette thèse est d'étudier la fonction de SGN3 au niveau moléculaire dans le but de comprendre son rôle dans la formation des cadres de Caspary. J'ai pu démontrer que la perméabilité de l'endoderme du mutant sgn3 est le résultat de la localisation incorrecte de protéines impliquées dans la formation des cadres de Caspary, les "Casparian strip domain proteins" (CASPs). Cela induit des cadres de Caspary non fonctionnels, contenant de nombreuses interruptions. Les CASPs sont localisés à la membrane plasmique dans un domaine sous-jacent les cadres de Caspary appelé Casparian Strip membrane Domain (CSD). Les interruptions du CSD dans le mutant sgn3, ainsi que la localisation de SGN3 à proximité des CASPs nous font penser à un rôle de SGN3 dans l'élaboration d'un CSD ininterrompu. De plus, SGN3 pourrait avoir un second rôle, agissant en tant que kinase reportant l'intégrité du CSD et induisant la production de lignine et de subérine dans des plantes contenant des cadres de Caspary non fonctionnels. Jusqu'à ce jour, sgn3 est le mutant en notre possession le plus fort et le plus spécifique, ayant un endoderme perméable tout le long de la racine. Pour cette raison, ce mutant est adéquat dans le but de caractériser la physiologie de plantes ayant des cadres de Caspary affectés. De manière surprenante, la croissance de sgn3 est seulement peu affectée. Néanmoins, des processus censés nécessiter des cadres de Caspary fonctionnels, comme le transport de l'eau au travers de la racine, l'homéostasie des nutriments, la tolérance au sel et la résistance à l'excès de certains nutriments sont altérés dans ce mutant. Malgré tout, l'homéostasie de la plupart des nutriments ainsi que la résistance au stress hydrique ne sont pas affectés dans sgn3. De manière surprenante, les altérations de l'ionome de sgn3 sont spécifiques, avec une diminution de potassium et un excès de magnésium. Cela implique un système de compensation établi par la plante dans le but d'éviter la diffusion passive des nutriments en direction du cylindre central. Par exemple, le manque de potassium dans sgn3 augmente la transcription de transporteurs permettant l'absorption de cet élément. De plus, des gènes connus pour être induits en cas de carence en potassium sont surexprimés dans sgn3 et la croissance de ce mutant est sévèrement affectée dans un substrat pauvre en potassium. Ces résultats concernant SGN3 vont, espérons-le, aider à la compréhension du processus de formation des cadres de Caspary au niveau moléculaire. De plus, les expériences de physiologie utilisant sgn3 présentées dans cette thèse devraient nous donner une base pour des expériences futures et nous permettre de comprendre mieux le rôle des cadres de Caspary, et plus particulièrement leur implication dans le transport radial des nutriments au travers de la racine. -- Les plantes terrestres sont des organismes puisant l'eau et les nutriments dont elles ont besoin pour leur croissance dans le sol grâce à leurs racines. De par leur immobilité, elles doivent s'adapter à des sols contenant des quantités variables de nutriments et il leur est crucial de sélectionner ce dont elles ont besoin afin de ne pas s'intoxiquer. Cette sélection est faite grâce à un filtre formé d'un tissu racinaire interne appelé endoderme. L'endoderme fabrique une barrière imperméable entourant chaque cellule appelée "cadre de Caspary". Ces cadres de Caspary empêchent le libre passage des nutriments, permettant un contrôle précis de leur passage. De plus, ils sont censés permettre de résister contre différents stress environnementaux comme la sécheresse, la salinité du sol ou l'excès de nutriments. Bien que découverts il y a 150 ans, rien n'était connu concernant les gènes impliqués dans la formation des cadres de Caspary jusqu'à récemment. Durant ces dernière années, l'utilisation de la plante modèle Arabidopsis thaliana a permis la découverte d'un nombre croissant de gènes impliqués à différentes étapes de la formation de cette structure. Un de ces gènes code pour SCHENGEN3 (SGN3), un récepteur kinase "leucine-rich repeat receptor-like kinase" (LRR- RLK). Nous montrons dans cette étude que le gène SGN3 est impliqué dans la formation des cadres de Caspary, et que le mutant correspondant sgn3 a des cadres de Caspary interrompus. Ces interruptions rendent l'endoderme perméable, l'empêchant de bloquer le passage des molécules depuis le sol vers le centre de la racine. En utilisant ce mutant, nous avons pu caractériser la physiologie de plantes ayant des cadres de Caspary affectés. Cela a permis de découvrir que le transport de l'eau au travers de la racine était affecté dans le mutant sgn3. De plus, l'accumulation de certains éléments dans les feuilles de ce mutant est altérée. Nous avons également pu montrer une sensibilité de ce mutant à un excès de sel ou de certains nutriments comme le fer et le manganèse.

Clinical utility of a molecular test in adjuvant treatment decision making in women with endocrine-sensitive early stage breast cancer: a retrospective, single center one year experience

Background. Molecular tests for breast cancer (BC) risk assessment are reimbursed by health insurances in Switzerland since the beginning of year 2015. The main current role of these tests is to help oncologists to decide about the usefulness of adjuvant chemotherapy in patients with early stage endocrine-sensitive and human epidermal growth factor receptor 2 (HER2)-negative BC. These gene expression signatures aim at predicting the risk of recurrence in this subgroup. One of them (OncotypeDx/OT) also predicts distant metastases rate with or without the addition of cytotoxic chemotherapy to endocrine therapy. The clinical utility of these tests -in addition to existing so-called "clinico-pathological" prognostic and predictive criteria (e.g. stage, grade, biomarkers status)-is still debated. We report a single center one year experience of the use of one molecular test (OT) in clinical decision making. Methods. We extracted from the CHUV Breast Cancer Center data base the total number of BC cases with estrogen-receptor positive (ER+), HER2-negative early breast cancer (node negative (pN0) disease or micrometastases in up to 3 lymph nodes) operated between September 2014 and August 2015. For the cases from this group in which a molecular test had been decided by the tumor board, we collected the clinicopathologic parameters, the initial tumor board decision, and the final adjuvant systemic therapy decision. Results. A molecular test (OT) was done in 12.2% of patients with ER + HER2 negative early BC. The median age was 57.4 years and the median invasive tumor size was 1.7 cm. These patients were classified by ODX testing (Recurrence Score) into low-, intermediate-, and high risk groups, respectively in 27.2%, 63.6% and 9% of cases. Treatment recommendations changed in 18.2%, predominantly from chemotherapyendocrine therapy to endocrine treatment alone. Of 8 patients originally recommended chemotherapy, 25% were recommended endocrine treatment alone after receiving the Recurrence Score result. Conclusions. Though reimbursed by health insurances since January 2015, molecular tests are used moderately in our institution as per the decision of the multidisciplinary tumor board. It's mainly used to obtain a complementary confirmation supporting the decision of no chemotherapy. The OncotypeDx Recurrence Score results were in the intermediate group in 66% of the 9 tested cases but contributed to avoid chemotherapy in 2 patients during the last 12 months.

A nonparametric method for the measurement of size diversity with emphasis on data standardization

The most suitable method for estimation of size diversity is investigated. Size diversity is computed on the basis of the Shannon diversity expression adapted for continuous variables, such as size. It takes the form of an integral involving the probability density function (pdf) of the size of the individuals. Different approaches for the estimation of pdf are compared: parametric methods, assuming that data come from a determinate family of pdfs, and nonparametric methods, where pdf is estimated using some kind of local evaluation. Exponential, generalized Pareto, normal, and log-normal distributions have been used to generate simulated samples using estimated parameters from real samples. Nonparametric methods include discrete computation of data histograms based on size intervals and continuous kernel estimation of pdf. Kernel approach gives accurate estimation of size diversity, whilst parametric methods are only useful when the reference distribution have similar shape to the real one. Special attention is given for data standardization. The division of data by the sample geometric mean is proposedas the most suitable standardization method, which shows additional advantages: the same size diversity value is obtained when using original size or log-transformed data, and size measurements with different dimensionality (longitudes, areas, volumes or biomasses) may be immediately compared with the simple addition of ln k where kis the dimensionality (1, 2, or 3, respectively). Thus, the kernel estimation, after data standardization by division of sample geometric mean, arises as the most reliable and generalizable method of size diversity evaluation

Negative Regulation of Receptor Tyrosine Kinases by T-cell Protein Tyrosine Phosphatase

Protein tyrosine phosphorylation controls a wide array of cellular responses such as growth, migration, proliferation, differentiation, metabolism and cytoskeletal organisation. Tyrosine phosphorylation is a dynamic process involving the competing activities of protein tyrosine kinases and protein tyrosine phosphatases. The protein tyrosine kinases are further divided into non-receptor- and receptor tyrosine kinases. The latter are transmembrane glycoproteins activated by the binding of specific ligands, mostly growth factors, to their extracellular domain, transmitting different signals to the cell. Growth factor receptors such as the epidermal growth factor receptor, vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor β, belong to the receptor tyrosine kinases, the signalling of which is often disturbed in various diseases, including cancer. This has led to the development of receptor tyrosine kinase antagonists for use as anti-cancer drugs. As the receptor tyrosine kinases, also the protein tyrosine phosphatases can be divided into receptor- and non-receptor types. The protein tyrosine phosphatases have attained much less attention than the receptor tyrosine kinases partly because they were identified later. However, accumulating evidence shows that the protein tyrosine phosphatases have important roles as specific and active regulators of tyrosine phosphorylation in cells and of physiological processes. Consequently, the protein tyrosine phosphatases are receiving arising interest as novel drug targets. The aim of this work was to elucidate the negative regulation of receptor tyrosine kinases by one non-receptor protein tyrosine phosphatase, T-cell protein tyrosine phosphatase TCPTP. The results show that TCPTP activated by cell adhesion receptor integrin α1 functions as a negative regulator of the epidermal growth factor receptor. It was also found that TCPTP affects vascular endothelial growth factor receptor 2 signalling and angiogenesis. Lastly, a High-throughput screen with 64,280 compounds was performed to identify novel TCPTP activators, resulting in identification of one small molecule compound capable of exerting similar effects on TCPTP signalling as integrin α1. This compound is shown to downregulate signalling of epidermal growth factor receptor and platelet-derived growth factor receptor β, as well as to inhibit cell proliferation and angiogenesis. Our results suggest that a suitable small-molecule TCPTP activator could be utilized in the development of novel anti-cancer drugs.

On the Connectivity of the Julia sets of meromorphic functions

We prove that every transcendental meromorphic map $f$ with disconnected Julia set has a weakly repelling fixed point. This implies that the Julia set of Newton's method for finding zeroes of an entire map is connected. Moreover, extending a result of Cowen for holomorphic self-maps of the disc, we show the existence of absorbing domains for holomorphic self-maps of hyperbolic regions, whose iterates tend to a boundary point. In particular, the results imply that periodic Baker domains of Newton's method for entire maps are simply connected, which solves a well-known open question.

Minimization of the experimental workload for the prediction of pollutants propagation in rivers. Mathematical modelling and knowledge re-use

The present thesis in focused on the minimization of experimental efforts for the prediction of pollutant propagation in rivers by mathematical modelling and knowledge re-use. Mathematical modelling is based on the well known advection-dispersion equation, while the knowledge re-use approach employs the methods of case based reasoning, graphical analysis and text mining. The thesis contribution to the pollutant transport research field consists of: (1) analytical and numerical models for pollutant transport prediction; (2) two novel techniques which enable the use of variable parameters along rivers in analytical models; (3) models for the estimation of pollutant transport characteristic parameters (velocity, dispersion coefficient and nutrient transformation rates) as functions of water flow, channel characteristics and/or seasonality; (4) the graphical analysis method to be used for the identification of pollution sources along rivers; (5) a case based reasoning tool for the identification of crucial information related to the pollutant transport modelling; (6) and the application of a software tool for the reuse of information during pollutants transport modelling research. These support tools are applicable in the water quality research field and in practice as well, as they can be involved in multiple activities. The models are capable of predicting pollutant propagation along rivers in case of both ordinary pollution and accidents. They can also be applied for other similar rivers in modelling of pollutant transport in rivers with low availability of experimental data concerning concentration. This is because models for parameter estimation developed in the present thesis enable the calculation of transport characteristic parameters as functions of river hydraulic parameters and/or seasonality. The similarity between rivers is assessed using case based reasoning tools, and additional necessary information can be identified by using the software for the information reuse. Such systems represent support for users and open up possibilities for new modelling methods, monitoring facilities and for better river water quality management tools. They are useful also for the estimation of environmental impact of possible technological changes and can be applied in the pre-design stage or/and in the practical use of processes as well.

Analysis of patterns in mining time series using Qlucore

Raw measurement data does not always immediately convey useful information, but applying mathematical statistical analysis tools into measurement data can improve the situation. Data analysis can offer benefits like acquiring meaningful insight from the dataset, basing critical decisions on the findings, and ruling out human bias through proper statistical treatment. In this thesis we analyze data from an industrial mineral processing plant with the aim of studying the possibility of forecasting the quality of the final product, given by one variable, with a model based on the other variables. For the study mathematical tools like Qlucore Omics Explorer (QOE) and Sparse Bayesian regression (SB) are used. Later on, linear regression is used to build a model based on a subset of variables that seem to have most significant weights in the SB model. The results obtained from QOE show that the variable representing the desired final product does not correlate with other variables. For SB and linear regression, the results show that both SB and linear regression models built on 1-day averaged data seriously underestimate the variance of true data, whereas the two models built on 1-month averaged data are reliable and able to explain a larger proportion of variability in the available data, making them suitable for prediction purposes. However, it is concluded that no single model can fit well the whole available dataset and therefore, it is proposed for future work to make piecewise non linear regression models if the same available dataset is used, or the plant to provide another dataset that should be collected in a more systematic fashion than the present data for further analysis.

Cuticular and Suberin Polymers of Edible Plants. Analysis by Gas Chromatographic-Mass Spectrometric and Solid State Spectroscopic Methods

Cutin and suberin are structural and protective polymers of plant surfaces. The epidermal cells of the aerial parts of plants are covered with an extracellular cuticular layer, which consists of polyester cutin, highly resistant cutan, cuticular waxes and polysaccharides which link the layer to the epidermal cells. A similar protective layer is formed by a polyaromatic-polyaliphatic biopolymer suberin, which is present particularly in the cell walls of the phellem layer of periderm of the underground parts of plants (e.g. roots and tubers) and the bark of trees. In addition, suberization is also a major factor in wound healing and wound periderm formation regardless of the plants’ tissue. Knowledge of the composition and functions of cuticular and suberin polymers is important for understanding the physiological properties for the plants and for nutritional quality when these plants are consumed as foods. The aims of the practical work were to assess the chemical composition of cuticular polymers of several northern berries and seeds and suberin of two varieties of potatoes. Cutin and suberin were studied as isolated polymers and further after depolymerization as soluble monomers and solid residues. Chemical and enzymatic depolymerization techniques were compared and a new chemical depolymerization method was developed. Gas chromatographic analysis with mass spectrometric detection (GC-MS) was used to assess the monomer compositions. Polymer investigations were conducted with solid state carbon-13 cross polarization magic angle spinning nuclear magnetic resonance spectroscopy (13C CP-MAS NMR), Fourier transform infrared spectroscopy (FTIR) and microscopic analysis. Furthermore, the development of suberin over one year of post-harvest storage was investigated and the cuticular layers from berries grown in the North and South of Finland were compared. The results show that the amounts of isolated cuticular layers and cutin monomers, as well as monomeric compositions vary greatly between the berries. The monomer composition of seeds was found to differ from the corresponding berry peel monomers. The berry cutin monomers were composed mostly of long-chain aliphatic ω-hydroxy acids, with various mid-chain functionalities (double-bonds, epoxy, hydroxy and keto groups). Substituted α,ω-diacids predominated over ω-hydroxy acids in potato suberin monomers and slight differences were found between the varieties. The newly-developed closed tube chemical method was found to be suitable for cutin and suberin analysis and preferred over the solvent-consuming and laborious reflux method. Enzymatic hydrolysis with cutinase was less effective than chemical methanolysis and showed specificity towards α,ω-diacid bonds. According to ₁₃C CP-MAS NMR and FTIR, the depolymerization residues contained significant amounts of aromatic structures, polysaccharides and possible cutan-type aliphatic moieties. Cultivation location seems to have effect on cuticular composition. The materials studied contained significant amounts of different types of biopolymers that could be utilized for several purposes with or without further processing. The importance of the so-called waste material from industrial processes of berries and potatoes as a source of either dietary fiber or specialty chemicals should be further investigated in detail. The evident impact of cuticular and suberin polymers, among other fiber components, on human health should be investigated in clinical trials. These by-product materials may be used as value-added fiber fractions in the food industry and as raw materials for specialty chemicals such as lubricants and emulsifiers, or as building blocks for novel polymers.

Biosynthesis of Yersinia enterocolitica serotype O:3 lipopolysaccharide outer core

Lipopolysacharide (LPS) present on the outer leaflet of Gram-negative bacteria is important for the adaptation of the bacteria to the environment. Structurally, LPS can be divided into three parts: lipid A, core and O-polysaccharide (OPS). OPS is the outermost and also the most diverse moiety. When OPS is composed of identical sugar residues it is called homopolymeric and when it is composed of repeating units of oligosaccharides it is called heteropolymeric. Bacteria synthesize LPS at the inner membrane via two separate pathways, Lipid A-core via one and OPS via the other. These are ligated together in the periplasmic space and the completed LPS molecule is translocated to the surface of the bacteria. The genes directing the OPS biosynthesis are often clustered and the clusters directing the biosynthesis of heteropolymeric OPS often contain genes for i) the biosynthesis of required NDP-sugar precursors, ii) glycosyltransferases needed to build up the repeating unit, iii) translocation of the completed O-unit to the periplasmic side of the inner membrane (flippase) and iv) polymerization of the repeating units to complete OPS. The aim of this thesis was to characterize the biosynthesis of the outer core (OC) of Yersinia enterocolitica serotype O:3 (YeO3). Y. enterocolitica is a member of the Gram-negative Yersinia genus and it causes diarrhea followed sometimes by reactive arthritis. The chemical structure of the OC and the nucleotide sequence of the gene cluster directing its biosynthesis were already known; however, no experimental evidence had been provided for the predicted functions of the gene products. The hypothesis was that the OC biosynthesis would follow the pathway described for heteropolymeric OPS, i.e. a Wzy-dependent pathway. In this work the biochemical activities of two enzymes involved in the NDP-sugar biosynthesis was established. Gne was determined to be a UDP-N-acetylglucosamine-4-epimerase catalyzing the conversion of UDP-GlcNAc to UDP-GalNAc and WbcP was shown to be a UDP-GlcNAc- 4,6-dehydratase catalyzing the reaction that converts UDP-GlcNAc to a rare UDP-2-acetamido- 2,6-dideoxy-d-xylo-hex-4-ulopyranose (UDP-Sugp). In this work, the linkage specificities and the order in which the different glycosyltransferases build up the OC onto the lipid carrier were also investigated. In addition, by using a site-directed mutagenesis approach the catalytically important amino acids of Gne and two of the characterized glycosyltranferases were identified. Also evidence to show the enzymes involved in the ligations of OC and OPS to the lipid A inner core was provided. The importance of the OC to the physiology of Y. enterocolitica O:3 was defined by determining the minimum requirements for the OC to be recognized by a bacteriophage, bacteriocin and monoclonal antibody. The biological importance of the rare keto sugar (Sugp) was also shown. As a conclusion this work provides an extensive overview of the biosynthesis of YeO3 OC as it provides a substantial amount of information of the stepwise and coordinated synthesis of the Ye O:3 OC hexasaccharide and detailed information of its properties as a receptor.

Boron influence on concentration of polyols and other sugars in Eucalyptus

Although the functions of the element Boron (B) in plants have not been sufficiently clarified, several hypotheses have been raised. Some of the functions attributed to this element are synthesis and transport of carbohydrates. To evaluate the effect of B on the synthesis of some polyols and sugars in Eucalyptus grandis and hybrids "urograndis", these species were submitted to situations of supply and restriction of B. The experiment was carried out in a greenhouse, arranged in a randomized block design in a 2 x 2 factorial scheme, with 5 replicates of each genotype. The B levels were provided in the form of nutrient solution. No significant difference was observed in the content of mannitol, sorbitol, myo-inositol and scyllo-inositol and sugars α-glucose and β-glucose between E. grandis and hybrids. Arabinose was the only one to present a higher content in E. grandis on restriction of B. The effect of the presence of B was very expressive, but regarding B supply, the plants showed significant increase in the synthesis of the compounds evaluated.

Sensibility analysis of the pearl model for pesticide leaching in the State of Mato Grosso do Sul, Brazil

For an accurate use of pesticide leaching models it is necessary to assess the sensitivity of input parameters. The aim of this work was to carry out sensitivity analysis of the pesticide leaching model PEARL for contrasting soil types of Dourados river watershed in the state of Mato Grosso do Sul, Brazil. Sensitivity analysis was done by carrying out many simulations with different input parameters and calculating their influence on the output values. The approach used was called one-at-a-time sensitivity analysis, which consists in varying independently input parameters one at a time and keeping all others constant with the standard scenario. Sensitivity analysis was automated using SESAN tool that was linked to the PEARL model. Results have shown that only soil characteristics influenced the simulated water flux resulting in none variation of this variable for scenarios with different pesticides and same soil. All input parameters that showed the greatest sensitivity with regard to leached pesticide are related to soil and pesticide properties. Sensitivity of all input parameters was scenario dependent, confirming the need of using more than one standard scenario for sensitivity analysis of pesticide leaching models.

Software for design of experiments and response modelling of cake ltration applications

Filtration is a widely used unit operation in chemical engineering. The huge variation in the properties of materials to be ltered makes the study of ltration a challenging task. One of the objectives of this thesis was to show that conventional ltration theories are di cult to use when the system to be modelled contains all of the stages and features that are present in a complete solid/liquid separation process. Furthermore, most of the ltration theories require experimental work to be performed in order to obtain critical parameters required by the theoretical models. Creating a good overall understanding of how the variables a ect the nal product in ltration is somewhat impossible on a purely theoretical basis. The complexity of solid/liquid separation processes require experimental work and when tests are needed, it is advisable to use experimental design techniques so that the goals can be achieved. The statistical design of experiments provides the necessary tools for recognising the e ects of variables. It also helps to perform experimental work more economically. Design of experiments is a prerequisite for creating empirical models that can describe how the measured response is related to the changes in the values of the variable. A software package was developed that provides a ltration practitioner with experimental designs and calculates the parameters for linear regression models, along with the graphical representation of the responses. The developed software consists of two software modules. These modules are LTDoE and LTRead. The LTDoE module is used to create experimental designs for di erent lter types. The lter types considered in the software are automatic vertical pressure lter, double-sided vertical pressure lter, horizontal membrane lter press, vacuum belt lter and ceramic capillary action disc lter. It is also possible to create experimental designs for those cases where the variables are totally user de ned, say for a customized ltration cycle or di erent piece of equipment. The LTRead-module is used to read the experimental data gathered from the experiments, to analyse the data and to create models for each of the measured responses. Introducing the structure of the software more in detail and showing some of the practical applications is the main part of this thesis. This approach to the study of cake ltration processes, as presented in this thesis, has been shown to have good practical value when making ltration tests.