Universiẗat, Diss., 1998--Konstanz.

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Στην παρούσα μεταπτυχιακή διπλωματική εργασία η κυματιδιακή ανάλυση (wavelet analysis) εφαρμόζεται σε ηλεκτροεγκεφαλικές καταγραφές μαρτύρων με επιληψία με σκοπό τη μελέτη των δυναμικών αλλαγών της ηλεκτρικής δραστηριότητας στο πεδίο του χρόνου και της συχνότητας. Συγκεκριμένα, χρησιμοποιείται ο Διακριτός Μετασχηματισμός Κυματιδίου (ΔΜΚ) το συγκριτικό πλεονέκτημα του οποίου συνίσταται στην ικανότητά του να επεξεργάζεται μη στάσιμα σήματα, όπως αυτά των ηλεκτροεγκεφαλικών καταγραφών, με βέλτιστη διακριτική ικανότητα στο πεδίο συχνότητας-χρόνου. Ο ΔΜΚ ενός σήματος αποτελεί τη δισδιάστατη αναπαράστασή του (χρόνος-συχνότητα), πάνω στην οποία μπορεί να βασιστεί ο υπολογισμός ποσοτικών δεικτών δυναμικών αλλαγών. Για το σκοπό αυτό χρησιμοποιήθηκαν δυο διαφορετικές προσεγγίσεις: α) ο καθορισμός του χρόνου και η διερεύνηση του συχνοτικού περιεχομένου οδήγησε στον προσδιορισμό μεγεθών εντροπίας και στατιστικής πολυπλοκότητας χαρακτηρίζοντας σφαιρικά το σήμα και β) ο καθορισμός του συχνοτικού περιεχομένου και, ξεχωριστά για κάθε εύρος συχνοτήτων, η διερεύνηση στο χρόνο επέτρεψε τον υπολογισμό ενός στατιστικού μεγέθους απόστασης, της απόκλισης κατά Jensen-Shannon (JSD) χαρακτηρίζοντας τοπικά το σήμα. Η αντιπαραβολή των αποτελεσμάτων αποκαλύπτει μείωση της εντροπίας με σύγχρονη αύξηση της πολυπλοκότητας συνηγορώντας υπέρ μιας κατάστασης υψηλής τάξης και οργάνωσης κατά τη διάρκεια της επιληπτικής κρίσης. Επιπλέον, το μέτρο απόστασης JSD αναδεικνύει μορφολογικές διαφοροποιήσεις, χαρακτηριστικές των διαφόρων σταδίων της κρίσης για τους φυσιολογικούς ρυθμούς του εγκεφάλου δ, θ, α, β και γ. / In this project wavelet analysis is applied to EEG signals of epileptic subjects for the estimation of dynamical changes of the electrical activity in time and frequency. To this end, the discrete wavelet transform (DWT) was used. The DWT of 1D-signal provides a 2D- representation (time-frequency plane), which can be used to define useful quantifiers for characterization of dynamical changes. In particular, two different approaches were used: a) fixing the time and scanning the plane on the frequency-coordinate. Wavelet coefficients at all considered frequency bands were used for definition of entropy and statistical complexity quantifiers. They provide a global description of the signal dynamical changes taken into account the interrelation of all the frequency bands contained in the signal and b) fixing the frequency and scanning in the time-coordinates. Wavelet coefficients corresponding to a given time interval were used to define the Jensen-Shannon divergence JSD, a statistical distance measure. They, in turn, provide a local description of the frequency band dynamical changes. In the first case, the decrease of entropy in association to the increase of complexity during seizure reflected the presence of brain states that are characterized by both order and maximal complexity during the epileptic seizures. Furthermore, the study of JSD in each frequency band separately revealed morphological and dynamical changes (brain rhythms δ, θ, α, β and γ) that can be matched to time instants typical of the transitions between the different stages of the epileptic seizure.

Made available in DSpace on 2014-10-09T12:23:38Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:02Z (GMT). No. of bitstreams: 1 01035.pdf: 2590190 bytes, checksum: 1d1815b8298ea5a3e4f29d7bf0ea2239 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

The expansion of [¹⁸F]-radiolabelling methodologies is vital for the advancement of Positron Emission Tomography (PET) as a medical imaging tool. Novel protocols will simplify access to current PET tracers and allow development of original tracers, potentially enhancing the imaging quality or permit imaging of a wider range of clinical problems. A general introduction is presented in <b>Chapter 1</b>, covering PET, application of fluorine-19 in the pharmaceutical industry, the production of fluorine-18 and the current state-of -art for [¹⁸F]-radiolabelling. The results chapters are divided in to two parts; <b>Part 1</b> (<b>Chapters 2 - 4</b>) concern the synthesis of [18F]fluoroarenes and <b>Part II</b> (<b>Chapters 5</b> and <b>6</b>) discuss diversity oriented radiofluorination techniques, targeting novel [¹⁸F]motifs. In <b>Part I</b>, Chapter 2 describes the use of hypervalent iodine reagents to meditate an umpolung approach for fluorination and radiofluorination of N-arylsulfonamides and anilides. <b>Chapter 3</b> again utilises hypervalent iodine reagents, but as spirocyclic iodonium(III) ylide precursors, being applied to semi-automated and automated microfluidic conditions. <b>Chapter 4</b> discusses the development of conditions for the production and isolation of radiopharmaceuticals employing Cu(II)-mediated radiofluorination of aryl boronic pinacol esters. In <b>Part II, Chapter 5</b> discusses the applicability of halogen exchange reactions to reach polyfluorinated motfis and <b>Chapter 6</b> focuses on the application of a single diazo precursor to access three polyfluorinated motifs with single-step reactions. Finally, <b>Chapter 7</b> provides experimental data for compounds discussed in this thesis.

Tesis para optar al grado de Magíster en Literatura mención Literatura general / El presente trabajo tiene por objetivo ahondar en la narrativa de Washington Irving, en la obra Cuentos de la Alhambra para observar cómo la narración busca reconstruir una imagen cultural, social e histórica que surge de la contemplación de otra imagen: la Alhambra. Ahora bien, esta imagen socio-cultural e histórica, que emerge del acto de exploración que Irving realiza en la Alhambra, se concretiza como un tejido de imágenes, es decir, como imágenes textuales.

Tesis para optar al grado de Magíster en Historia mención Etnohistoria / La presente investigación surge a partir del estudio comparado de un conjunto de causas por hechicería y brujería – mayoritariamente inéditas– llevadas en Chile por la Justicia Ordinaria contra indígenas durante el S.XVIII. A diferencia de las investigaciones ya señaladas, cuyo énfasis está en el análisis exhaustivo, hemos escogido un análisis basado en un corpus de causas que nos permiten observar procesos y discursividades globales, en lugar de lecturas autoconclusivas y, de alguna manera, aisladas. Nuestro objeto de estudio es el relato surgido de dichos juicios, síntesis narrativa de los intercambios desarrollados durante el proceso. Es justamente a partir de los parámetros de composición de dicho relato que buscamos aproximarnos a los sujetos enunciantes, al universo de conceptos que estos puedan manejar, y a la proyección que estas ideas puedan tener para el estudio general de la heterodoxia en Chile colonial.

GRANJEIRO, Michel Lopes. Contribuição dos Isótopos Ambientais e Hidroquímica para o Conhecimento das Águas Subterrâneas na Bacia de Lavras da Mangabeira. 2008. 109 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2008. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-05-29T19:57:58Z No. of bitstreams: 1 2008_dis_mlgranjeiro.pdf: 1033596 bytes, checksum: ff9c9b90936eafbed029f855d748773c (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-05-29T20:22:22Z (GMT) No. of bitstreams: 1 2008_dis_mlgranjeiro.pdf: 1033596 bytes, checksum: ff9c9b90936eafbed029f855d748773c (MD5) / Made available in DSpace on 2015-05-29T20:22:22Z (GMT). No. of bitstreams: 1 2008_dis_mlgranjeiro.pdf: 1033596 bytes, checksum: ff9c9b90936eafbed029f855d748773c (MD5) Previous issue date: 2008 / Águas subterrâneas nas duas sub-bacias, a do Riacho do Rosário e a do Riacho Meio, na Bacia Sedimentar de Lavras da Mangabeira foram estudadas utilizando medidas de isótopos ambientais, oxigênio-18, deutério e carbono-14, medidas hidroquímicas, e análises bacteriológicas. Os valores de oxigênio-18 estão na faixa de –3,1 a –0,2‰ e os de deutério, de –17,9 a –3,6‰ e mostram que as águas sofreram processo de evaporação indicando provável recarga feita através dos riachos de cada sub-bacia. As águas nas duas sub-bacias são armazenadas na Formação Serrote do Limoeiro e na Formação Iborepi, onde estão as águas menos salinas. Com exceção do poço P01, as águas têm baixa salinidade e são potáveis quanto a hidroquímica. Predominam águas dos tipos bicarbonatadas mistas e bicarbonatadas sódicas. As análises de carbono-14 feitas nas amostras da sub-bacia Riacho do Meio mostraram que as águas não são modernas, possuindo tempos de permanência da ordem de 3900 anos resultantes da mistura de diferentes contribuições de recarga. Análises bacteriológicas mostraram que as águas não são potáveis apresentando, algumas delas, elevada presença de coliformes totais e de E. Coli.

Artemisinin-resistant Plasmodium falciparum parasites have been reported in the Greater Mekong Subregion since 2007. Artemisinin combination therapy (ACT) is the mainstay of antimalarial treatment and is responsible for decreases in malaria-related morbidity and mortality over the past fifteen years. The slowed parasite clearance rates following ACT indicates resistance to artemisinin derivatives. This resistance places increasing selective pressure for variants or traits that confer resistance to the partner drug used in combination and has led to the rapid failure of several partner drugs. While a single nucleotide polymorphism (SNP) in kelch13 has been shown to mediate some resistance phenotypes, the complete mechanism of artemisinin resistance is poorly understood. The known mechanisms of resistance hint at a connection to autophagy, an intracellular pathway that cells use to degrade waste molecules or organelles in response to stress and starvation, which is poorly characterized in Plasmodium. In this doctoral thesis project, I investigated the role of an autophagy-like mechanism in P. falciparum in the mechanism of artemisinin resistance. I found a SNP in autophagy-related gene 18 (atg18) that was associated with clinical delayed parasite clearance half-life following ACT. This gene encodes PfAtg18, a protein that I characterized as being similar to mammalian/yeast homologues in terms of structure, binding abilities, and ability to form puncta in response to stress. In order to investigate the contribution of the mutation in this protein, I edited the atg18 gene using CRISPR/Cas9 and screened the mutant and parent parasites against a drug library of over 6000 unique compounds. I discovered that while the SNP did not change the mutant parasite's susceptibility to any of the antimalarial compounds using a 72-hour drug pulse, it did alter the susceptibility to 227 other compounds. Further, I found that the SNP offers parasites a fitness advantage by allowing them to grow better in nutrient-limited settings. Finally, I determined that neither this atg18 SNP nor several polymorphisms in kelch13 modulate a dormancy phenotype that appears to be involved in the artemisinin-resistance mechanism.

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