Understanding interactions among words is fundamental for natural language applications. However, many statistical NLP methods still ignore this important characteristic of language. For example, information retrieval models still assume word independence. This work focuses on the creation of lexical affinity models and their applications to natural language problems. The thesis develops two approaches for computing lexical affinity. In the first, the co-occurrence frequency is the calculated by point estimation. The second uses parametric models for co-occurrence distances. For the point estimation approach, we study several alternative methods for computing the degree of affinity by making use of point estimates for co-occurrence frequency. We propose two new point estimators for co-occurrence and evaluate the measures and the estimation procedures with synonym questions. In our evaluation, synonyms are checked directly by their co-occurrence and also by comparing them indirectly, using other lexical units as supporting evidence. For the parametric approach, we address the creation of lexical affinity models by using two parametric models for distance co-occurrence: an independence model and an affinity model. The independence model is based on the geometric distribution; the affinity model is based on the gamma distribution. Both fit the data by maximizing likelihood. Two measures of affinity are derived from these parametric models and applied to the synonym questions, resulting in the best absolute performance on these questions by a method not trained to the task. We also explore the use of lexical affinity in information retrieval tasks. A new method to score missing terms by using lexical affinities is proposed. In particular, we adapt two probabilistic scoring functions for information retrieval to allow all query terms to be scored. One is a document retrieval method and the other is a passage retrieval method. Our new method, using replacement terms, shows significant improvement over the original methods.

The recovery of the selected biological material in affinity-based separations relies on reversing the biological interaction responsible for the binding. General elution methods which are independent of the bioaffinity interaction have attracted increasing attention. The first three chapters of this thesis describe the development of a novel “click” functionalised azobenzene-based linker for affinity-independent elution protocols and the preliminary affinity studies using this linker. Ligands functionalised with a bioorthogonal propargyl label were readily attached to the terminal azide of the linker using the copper(I) catalysed Huisgen cycloaddition (or "click" reaction). Following separation, the linker was cleaved under mild non-denaturing conditions using Na2S2O4. In the last three chapters a novel approach towards the synthesis of the 4-methyl proline fragment of the cytotoxic natural product bisebromoamide (a potential affinity target) is proposed. For the pyrrolidine ring construction an enamide-olefin ring-closing metathesis (RCM) approach has been attempted. The installation of the required absolute stereochemistry has been achieved using a phase-transfer catalyst for the enantioselective alkylation of Schiff bases derived from glycine esters.

Organic cation transporters (OCTs) play a pivotal role in the absorption, tissue distribution, and excretion of a diverse array of substances, and currently the nature of the biochemical interactions between substrate and OCTs are unknown. Therefore, identifying which amino acid residues are critical for OCT-substrate interactions is of central importance to understanding and predicting interactions between drugs and OCTs. A three-dimensional (3-D) homology model of human OCT3 was generated using the crystal structure of a high affinity phosphate transporter from Piriformospora indica (PiPT) as template, and putative binding pocket for the prototypical hOCT3 ligand 1-methyl-4-phenylpyridinium (MPP+) was identified through docking studies. Five residues, Phe36, Val40, Trp358, Glu451 and Asp478, were identified as potentially mediating hOCT3-MPP+ interactions, and confirmed through in vitro studies. Additionally, 3-D homology modeling of the functional hOCT3 mutant Val40Leu, and all non-functional hOCT3 mutants, indicated changes in binding pocket architecture consistent with weakening of ligand-transporter interactions. Docking of structurally divergent hOCT3 substrates indicated binding interactions in the same general region as that identified for MPP+, albeit with mostly unique residues. Interspecies differences were explored by generating 3-D homology models for rat and murine Oct3. Results from docking studies using compounds exhibiting vastly different binding affinities (Km or IC50) towards the OCT3/Oct3 orthologs were consistent with varying strength in ligand-transporter binding pocket interactions. Finally, a series of novel compounds exhibiting anti-depressant-like activity was screened for OCT interaction in vitro, and demonstrated significant inhibitory effects on OCTs for many of the compounds.

Clusters constitute an intermediate state of matter between molecules and solids whose properties are size dependent and can be tailored. In recent years, cluster science has become one of the most exciting areas of research since their study can not only bridge our understanding between atoms and their bulk but also between various disciplines. In addition, clusters can serve as a source of new materials with uncommon properties. This dissertation deals with an in-depth study of clusters as a bridge across physics, chemistry, and materials science and provides a fundamental understanding of the structure-property relationships by focusing on three different topics. The first topic deals with superatoms which are clusters that mimic the chemistry of atoms. I show that superhalogens and superalkalis can be designed to mimic the chemistry of halogen and alkali atoms, respectively. An entirely new class of salts can then be synthesized by using these superatoms as the building blocks. I have also explored the possibility of designing highly electronegative species called hyperhalogens by using superhalogens as ligands or superalkalis as core and a combination of both. Another aspect of my work on superatom is to examine if traditional catalysts (namely Pd) can be replaced by clusters composed of earthabundant elements (namely Zr and O). This is accomplished by comparing the electronic structure and reactivity of Pd clusters with isoelectronic ZrO clusters. The second topic deals with a study of the electronic structure of coinage metal (Cu and Ag) clusters and see if they remain unchanged when a metal atom is replaced by an isoelectronic hydrogen atom as is the case with Au-H clusters. The third topic deals with clusters as model of polymeric materials to understand their gas storage and sequestration properties. This is accomplished by studying the trapping of H2, CO2, CH4 and SO2 molecules in borazine-linked polymers (BLPs) and benzimidazole-linked polymers (BILPs). The first two topics provide a bridge between physics and chemistry, while the third topic provides a bridge to materials science.

This work is intended for high school and university students and their teachers who want to learn or improve their knowledge about affine transformations and perspective collineation. In this work the reader acquainted with the ideal elements, dividing ratio and cross ratio. The main part of the work is perspective collineation and affine transformations, their definitions, properties, specificity and finding other elements. This work also deals with the use of affine transformations and perspective collineation in descriptive geometry. The text is supplemented with illustrative images, applets and step-by-step images that are created with GeoGebra software. Keywords: affine transformations, perspective collineation, ideal elements, cuts of solids, dividing ratio, cross ratio

The purpose of this study was to assess parental preference as perceived by Basque adolescents. A questionnaire was administered to adolescents during the summer months of 1977 in Boise, Idaho and Salt Lake City, Utah. The questionnaire included the Parent- Affinity Perception Scale (Miller, 1972) with a Liker~-type scale showing how much the adolescent preferred mother or father and a cover sheet to determine the degree of "Basqueness" of the subjects. The sample included 27 males and 37 females. l'!'e findings indicate a strong preference for "mother" over "father" by both males and females at all flges. Basque adolescent males"• preference for father did increase with age where the females did not show an increased preference for father with the advancement of age. Results from the profile indicate Basque adolescents think of themselves as "Basques" with majo; identifying characteristics of the Basque people being customs, having fun, being proud, and identification with the family. A large majority of the subjects go to Basque centers and are active in religious programs. Unlike the trad itional Basque family, disciplining in this sample population seems to be shared by both parents. The Likert-type scale indicating degree of affinity showed more adolescents definitely chose mother as the preferred parent than did adolescents definitely preferring father . Chi-square tests for males indicated no relation existed between parental preference and the degree of affinity for the chosen parent but for females a strong positive maternal relationship exists.

In this study, 96 children from Thailand were interviewed using the 30-item Parent-Affinity Perception Scale. Children from four age groups (preschool, first graders, third graders, and sixth graders) were asked to choose either "Mother" or " Father" as a response for this questionnaire. Children's perceptions of affinity in relationship with their parents and their parental preference were studied. The children were to select which parent they would prefer in three categories: (1) as a companion in activities that were physical or social, (2) who they would go to for help in personal or moral needs, and (3) for various activity destinations. The results showed a preference for "Mother" over "Father" on a majority of the questions. Boys and girls selected "Mother" for more of the items overall, except for physical activity where "Father" was chosen. When comparing all of the age groups, "Mother" was selected as the preferred parent in all instances except for the sixth-grade boys.

Parental preference of girls and boys was studied in this research. Situations of recreation, personal and moral needs, places and things, and social events constituted the range of choices in the children's selection for one parent or the other as a companion for the activity. Ninety children (30 preschool, 30 third graders, and 30 sixth graders) we r e tested individually by an interview schedule. The Parent-Affinity Perception Scale developed for this research contained 30 items. Children were asked to choose "Mother" or "Father" as a response for each item. The findings indicated a significant difference in preference for "Mother" rather than "Father," with girls consistently choosing the mother. Third-grade boys selected the mother more often than the father ; however, preschool and sixth-grade boys preferred the father for more of the items. In comparison of the three age groups, mother was perceived as the preferred parent in all except the preschool group. The Parent-Affinity Perception Scale scores of the group's 90 subjects were ranked in the high and low quartiles in order to analyze which items were discriminating children's perceptions for parental preference. Analyses by chi square found 26 of the 30 items indicated a significant difference in parental preference at or beyond the . 05 level of confidence.

Um biossensor de afinidade química baseado no fenômeno da reflexão total interna é apresentado. Nesse, as propriedades particulares apresentadas pelas componentes ortogonais de polarização do campo elétrico da luz permitem que ambas se cancelem na vizinhança do ângulo crítico da reflexão interna, proporcionando um meio para sua determinação unívoca, permitindo monitorar o mesmo como função do índice de refração de uma amostra de interesse. Um estudo acerca dos principais aspectos teóricos envolvidos no fenômeno da reflexão total interna foi realizado, a fim de explorar e justificar os fenômenos observados. A montagem experimental utilizada nos experimentos consiste de um laser de HeNe emitindo em 633 nm, um polarizador, uma lente semicilíndrica de alto índice de refração, produzida com um vidro denso do tipo flint, um filme produzido com um anticorpo, que é depositado sobre essa lente, um analisador paralelamente orientado com relação ao eixo de transmissão do polarizador, um dispositivo transdutor, que converte um sinal luminoso em sinais elétricos, uma solução aquosa do antígeno específico e de um computador, onde as informações coletadas pelo transdutor são tratadas por meio de um programa de aquisição de dados desenvolvido em uma plataforma gráfica de programação. O programa empregado permite o acompanhamento das variações do perfil luminoso, devido à interação do filme de anticorpos com a solução de antígenos, coletado pelo transdutor em tempo real, ou seja, é possível acompanhar toda evolução da reação química entre um par de espécies químicas em tempo real. Para confirmação da efetividade da técnica, foram comparadas medidas obtidas com um refratômetro comercial, onde foi constatado que o sistema possui sensibilidade suficiente para acompanhar mudanças da ordem de 10-5 unidades do índice de refração. / A chemical affinity biosensor based on the phenomenon of total internal reflection is presented. In it, the particular properties exhibited by the orthogonal polarization components of the electric field of light allow them to cancel in the vicinity of the critical angle of the internal reflection, providing means for its univocal determination, allowing its monitoring as a function of the refractive index of a sample of interest. A study about the theoretical aspects involved in the total internal reflection phenomenon was carried out in order to explore and justify the observed phenomena. The experimental set up consists of a HeNe laser emitting at 633 nm; a polarizer; a high refractive index semi-cylindrical lens, produced with a dense flint type glass; a film produced with an antibody, which is deposited over the aforementioned lens; an analyzer oriented parallel to the transmission axis of the polarizer; a transducer device, which converts a light signal into electric signals; an aqueous solution of the specific antigen and a computer, where the information collected by the transducer is treated with a data acquisition software developed in a graphical programming platform. The software allows one to monitor changes in the light profile due to interaction of the antibody with the antigen solution, collected by the transducer in real time, i.e. it’s possible to follow the evolution of the chemical reaction between a couple of chemical species in real time. To confirm the effectiveness of the technique a comparison with measurements obtained with a commercial refractometer was carried out, where it was verified enough sensitivity to follow changes of the order of 10-5 refractive index units.

New Zealand's five endemic mudfish (Neochanna spp.) species have distributions that differ both geographically and by habitat type. Differences in habitat preferences between species have led to the proposal of an evolutionary series within the group. A morphological cline can be observed from the galaxiform Chatham Island and Canterbury species inhabiting lakes and streams, respectively, to the anguilliform Northland and brown mudfishes of ephemeral wetlands. Morphological specializations proposed for wetland dwelling include loss of pelvic fins, reduced eyes, enlarged nostrils, development of caudal flanges, and elongation of dorsal and anal fin bases to become almost confluent with the caudal fin. Another expectation of adaptation to wetland dwelling is specializations in respiratory physiology to obtain oxygen from highly hypoxic or acidic waters, and the ability to cope with seasonal exposure to air during the drought season. Expected respiratory specializations to wetland dwelling include high oxygen affinity haemoglobins, high levels of cooperative oxygen binding, the presence of multiple haemoglobins and the ability to aestivate and survive long periods of emersion. The four mainland Neochanna species were examined to determine if differences in haemoglobin expression as well as differences in haemoglobin oxygen binding correlated with differing habitats and treatments. Whole blood oxygen affinity was determined at several pH levels (6.5, 7.0, 7.5 and 8.0) and temperatures (10'C, 15'C and 20'C), as well as different treatments (aestivating, fasting and control) using a Hemox analyzer. The presence of multiple haemoglobins was determined by isoelectric focusing. All four species displayed high oxygen affinities (p50 = 6.5 to 9.5 mm Hg at pH 7.5 15'C), moderate levels of cooperativity (Hill coefficients = 1.75 to 2.00 at pH 7.5 15'C), pH sensitivity (Bohr coefficients = -0.62 to -0.94 between pH 7.5 and 7.0 at 15'C), temperature sensitivity (ΔH = -2.20 to -15.78 k cal mol-1 between 10'C and 15'C) and the presence of multiple haemoglobins. Black, brown and Northland mudfish were able to survive aestivation for six weeks but there were no changes between air-breathing and water-breathing individuals with respect to oxygen binding characteristics. Although there is evidence of habitat specialization in haemoglobin physiology between mudfish species, differences between species did not correlate with the evolutionary series proposed for specialization to dwelling in ephemeral wetlands and latitudinal distributions of mudfish species appear to strongly dictate oxygen binding properties of mudfish whole blood.