Thèses sur le sujet « Extended Synthesis of Evolution »

O objetivo desta pesquisa histórica é inicialmente descrever um importante evento (A Síntese moderna) que ocorreu na biologia no período entre guerras. Os biólogos evolutivos chegaram a um acordo sob vários aspectos tais como: o gradualismo do processo evolutivo, o conceito de população e fatores ecológicos, dentre outros. Em segundo lugar, introduzir a chamada Síntese expandida analisando um de seus pressupostos a plasticidade fenotípica e seus antecedentes históricos. Procurará elucidar se algumas ideias relacionadas à plasticidade fenotípica já estavam presentes no início do século XX como alegam alguns autores. Além disso, se essas ideias estavam presentes em trabalhos publicados durante o período da Síntese. Esta tese compreende uma Introdução e seis capítulos. A Introdução apresenta o escopo, metodologia e objetivos da pesquisa. O Capítulo 1 apresenta a Síntese evolutiva e suas relações com a Síntese expandida, introduzindo a plasticidade fenotípica. O Capítulo 2 discute os antecedentes históricos da plasticidade fenotípica. O Capítulo 3 descreve alguns experimentos relacionados à plasticidade fenotípica realizados no início do século XX, focalizando as contribuições de Richard Woltereck. O Capítulo 4 analisa as pesquisas relacionadas ao assunto, desenvolvidas nas décadas de 1940 e 1950 por Ivan I. Schmalhausen e Conrad Waddington. O Capítulo 5 lida principalmente com as pesquisas voltadas à plasticidade fenotípica desenvolvidas na década de 1960 por Anthony D. Bradshaw. O Capítulo 6 esboça um panorama das pesquisas relacionadas ao assunto desenvolvidas após a década de 1960. O Capítulo 7 apresenta algumas considerações sobre o que foi discutido nesta tese. Esta pesquisa leva à conclusão de que algumas ideias que podem ser relacionadas à concepção de plasticidade fenotípica já estavam presentes no final do século XIX. A partir daí, houve mudanças em relação à sua abrangência e terminologia. Concepções relacionadas à plasticidade fenotípica também podem ser encontradas durante o período da Síntese em alguns autores como Schmalhausen, por exemplo. Talvez devido a razões de ordem política elas não foram propagadas. Além disso, é possível que não tenham sido compreendidas completamente pela comunidade científica da época.
The aim of this historical research is firstly to describe an important event (The Modern synthesis) that took place in biology in the inter-war-years. The evolutionary biologists reached agreement to several respects such as the gradualism of the evolutionary process, the concept of population and ecological factors, among others. Secondly, to introduce the so-called extended synthesis analyzing one of its features - the phenotypic plasticity - and its historical antecedents. It will try to elucidate whether some ideas that could be related to phenotypic plasticity were already present in the beginning of the 20th century as it was claimed by some authors. Besides that, whether such ideas were not present in the works published during the Synthesis period. This thesis comprises an Introduction and six chapters. The Introduction presents the scope of the research, the research method and the aim of the research. Chapter 1 presents the Evolutionary synthesis and its relationship with the Extended synthesis, introducing the phenotypic plasticity. Chapter 2 discusses the historical antecedents of the phenotypic plasticity. Chapter 3 describes some experiments related to phenotypic plasticity performed in the beginning of the 20th century, focusing Richard Woltereck contributions. Chapter 4 analyzes the researches related to the subject performed in the 1940s and 1950s by Ivan I. Schmalhausen and Conrad Waddington. Chapter 5 mainly focuses the inquiries related to phenotypic plasticity made by Anthony D. Bradshaw during the 1960s. Chapter 6 presents an outlook of the researches concerning the subject performed after 1960s. Chapter 7 presents the final remarks concerning the subject of this thesis. This research leads to the conclusion that some ideas that could be related to the conception of phenotypic plasticity were already present in the end of 19th century. From this time onwards there were been made changes mainly related to its scope and terminology. Conceptions related to phenotypic plasticity can also be found during the Synthesis period in some authors such as Schmalhausen. In this case, perhaps due to political reasons they were not propagated. Besides that, it is possibly that they were not completely understood by the scientific community of that time.

This dissertation brings a contribution to the philosophical debate on adaptive landscapes, an influent "model" or "metaphor" in evolutionary biology. Some elements of innovation are: the distinction between native and migrant metaphor; a processual and communicational idea on what the Modern Synthesis was, and on what role a metaphor could have played in it; a view (taken by Richard Lewontin) of the disunity and theoretical structure of population genetics; the distinction between “adaptive surfaces” (mainly metaphors) and “combination spaces”, two terms normally conflated in the word “landscape”; an analysis of what bridges (including heuristics) may be cast between equations of gene frequency and the genotype space that, due to its huge dimensionality, cannot be handled by mathematics; a specified vocabulary to be used to clear the adaptive landscapes debate, accompanied by a plea in favor of a pragmatic approach - for example, the plurality of available notions of model forces us to choose one notion and see where it brings, otherwise we get stuck in confused, endless debates; an updated analytical comment of recent landscapes - Dobzhansky, Simpson, Dawkins but also the proliferation of combination spaces used in evolutionary biology to address a great variety of problems; the vision (got by Sergey Gavrilets) of a patchwork of tools finally making Mendelian population suitable model also for speciation; the exact position of holey landscapes in this patchwork, and the idea that scientists’s questions - like “how possibly” questions - matter in accessing this patchwork and in deciding “what explains” and “what describes” what in the world; the direct response to some mistakes Massimo Pigliucci made, I think, in his assessment of the adaptive landscape; an analysis of the Extended Evolutionary Synthesis project at its present stage, and some reflections on the conditions that will allow such a project to give a fair treatment and a good position to tools from the past, like the adaptive landscapes.

The thesis here presented establishes a triple parallelism between biology and psychology. First, through Haeckel's recapitulation theory as the source of freudian and jungian psychology. Second, from the reductionist view of science to the new phenomenology of evolutionary developmental biology. Third, by overcoming the reductionist paradigm in biology through the Extended Synthesis and in psychology though the revisited archetype theory. By establishing these parallelisms, the thesis faces the nature vs. nurture debate on three epistemological levels, in which the external and internal levels are being mediatied by a middle one. This turns the dualistic debate into a heuristic paradigm aimed to resolve any irreducible dualism inherent in the reductionist view

The aim and the structure of this work are twofold: a general analysis of the current status of the evolutionary research programme will serve as a general framework for an inquiry in specific aspects of a much debated field-study: the evolution of language. This case-study will do as a sort of testing arena to put at work the explanatory tools of the evolutionary research programme, in order to show what conceptual framework can better deal with the unsolved issues associated to the chosen case-study. Hence this work will be characterized by a continuous interplay between specific issues pertaining to the level of evolutionary biology (evolutionary processes at work, morphological, behavioral and cognitive adaptations) and theoretical analysis pertaining to the meta-level of philosophy of science (like conceptual and terminological analysis, causation mechanisms in play, research programmes' evolution). In the Preface we try to delimit the scope of this work, as the chosen case-study is characterized by a strong interdisciplinarity. In the Introduction we provide an essential historical reconstruction of the language evolution debate, starting from Darwin and Wallace's times, identifying some key concepts that will serve to navigate the contemporary debate. We then move forward identifying the common structure of some language evolution hypotheses that have been proposed across the years and highlight some limitations. We also discuss the necessity of providing a proper definition of the language faculty in order to display the evolutionary inquiry accordingly; we take into account the FLB – FLN distinction and highlight some limitations as well. In particular we show the difficulty by the Standard Evolutionary Theory (SET) conceptual framework in integrating the cultural dimension in language evolutionary explanations. We then stress the importance and the necessity of operating such an integration and we argue that the Extended Evolutionary Synthesis (EES) conceptual framework provides an explanatory toolkit that is better equipped to solve such a task. We then present an abstract model (the assimilate-stretch principle) that is able to provide in principle this integration, exploiting some of the key concepts of the EES conceptual framework. We then show that a co-evolutionary model between language and cumulative culture might be a promising path to integrate biological and cultural evolutionary processes, trying to rely our argument on results from co-evolutionary comparative studies (the cultural drive hypothesis). The three central chapters of this work consist of independent papers that were written at different stages. Each one of them deepens a specific aspect but all three of them share the common intent to show how the EES conceptual framework can be properly put at use. The first chapter is dedicated to an exploration of the Self-domestication hypothesis in human evolution through the analysis of a selection of critical examples concerning genus Homo evolution, relevant for the evolution of language, such as the evolution of hominin life-history traits, the enlargement of the social group, increased cooperation among individuals, behavioral change and innovations (the use of fire), heterochronic modifications leading to increased synaptic plasticity. It is argued that a relaxation of selective pressures caused by niche construction activity might have played a role both in human and language evolution. In the second chapter, the selected critical examples presented in chapter one are explicitly analyzed through the lenses of the EES conceptual framework. The evolution of language is treated as an open problem in the evolutionary research programme and it is shown how four factors (niche construction, inclusive inheritance, phenotypic plasticity, developmental bias) and two concepts (reciprocal causation, constructive development) can be usefully exploited to gain a better understanding of human and language evolution. The third chapter explores a specific theoretical issue linked to the EES debate, that is the need to revisit the distinction between proximate and ultimate causes of evolution. In fact, cultural transmission, operating at an intermediate level between the ontogenetic and the phylogenetic one, can be assumed to be both a proximate and an ultimate mechanism, with associated different predictions. We argue that assuming one or the other position leads to two different perspectives of how biological and cultural evolution interact. We argue in favor of an integrative perspective, that is acknowledging culture as an ultimate cause, in agreement with an EES-inclined conceptual framework. We also discuss the consequences of this theoretical shift and show how this can shed light on the evolutionary rate of language evolution (punctuationism and gradualism) debate. In the Conclusions we advance some further proposals, two in particular: first, we treat language as a form of teaching, specifically verbal teaching, and re-examine the hypothesis, presented in the previous chapters, that language could have evolved as a form of high-fidelity transmission mechanism; second, we discuss the proposal according to which language can be intended as a major transition in evolution and in particular we propose to split this transition in two steps: the first concerns the evolution of cumulative cultural capacities, the second the evolution of language; these two steps could share a common evolutionary process at their bases and we suggest this could be identified in an expanded version of the assimilate-stretch principle, which we propose in the conclusions, discussing also possible future directions. Finally, we conclude that gene-culture co-evolutionary models are proving their fruitfulness not only to shed light on human evolution, but also on other social species, and that the EES conceptual framework provides a set of explanatory tools that results appropriate to deal with these issues.
Lo scopo e la struttura di questo lavoro sono duplici: un'analisi generale dello stato attuale del programma di ricerca evoluzionistico servirà come cornice concettuale per un'indagine in alcuni aspetti specifici di un campo di studi molto dibattuto: l'evoluzione del linguaggio. Questo caso di studio fungerà da arena di prova per testare gli strumenti esplicativi del programma di ricerca evoluzionistico per mostrare quale cornice concettuale sia più adatta a trattare alcuni problemi irrisolti associati al caso di studio selezionato. Questo lavoro sarà caratterizzato da un continuo rimbalzo tra tematiche specifiche riguardanti il livello esplicativo della biologia evoluzionistica (quali processi evolutivi sono all'opera, quali adattamenti morfologici, comportamentali e cognitivi) e un'analisi teorica di pertinenza del meta-livello d'analisi della filosofia della scienza (analisi terminologica e concettuale, meccanismi causali in gioco, evoluzione del programma di ricerca). Nella Prefazione tentiamo di delimitare la portata del lavoro, poiché il caso di studio scelto è caratterizzato da una forte interdisciplinarità. Nell'Introduzione forniamo una basilare ricostruzione storica del dibattito intorno all'evoluzione del linguaggio, partendo dai tempi di Darwin e Wallace e identificando alcuni concetti chiave che risulteranno utili nell'esplorazione del dibattito contemporaneo. Dopodiché ci spostiamo a identificare la struttura esplicativa comune di alcune ipotesi sull'evoluzione del linguaggio che sono state proposte nel corso degli anni mettendo in luce alcune limitazioni. Discutiamo anche la necessità di fornire una definizione adeguata dela facoltà del linguaggio, per potervi associare un'adeguata analisi evolutiva; prendiamo in considerazione la distinzione FLB – FLN e pure ne mettiamo in evidenza alcune limitazioni. In particolare mostriamo la difficoltà della cornice concettuale della Teoria Evoluzionistica Standard (TES) nell'integrare la dimensione culturale nelle spiegazioni per l'evoluzione del linguaggio. Sottolineiamo quindi l'importanza e la necessità di operare questo tipo di integrazione e sosteniamo che la cornice concettuale della Sintesi Evoluzionistica Estesa (SEE) fornisce una serie di strumenti esplicativi che sono meglio equipaggiati per affrontare questa problematica. Mostriamo quindi che un modello coevolutivo tra linguaggio e cultura cumulativa può risultare un percorso di ricerca promettente per integrare processi evolutivi biologici e culturali, cercando di appoggiare la nostra argomentazione a risultati di studi coevolutivi comparativi (l'ipotesi della spinta culturale). I tre capitoli centrali di questo lavoro sono costituiti da articoli indipendenti tra loro che sono stati scritti in stadi differenti. Ognuno di essi approfondisce uno specifico aspetto ma tutti e tre condividono l'intento comune di mostrare come la cornice concettuale della Sintesi Estesa possa venire messa all'opera adeguatamente. Il primo capitolo è dedicato a un'esplorazione dell'ipotesi dell'Auto-addomesticazione nell'evoluzione umana attraverso un'analisi di una selezione di esempi chiave che risultino rilevanti per l'evoluzione del linguaggio, avvenuti ne corso dell'evoluzione del genere Homo, come l'evoluzione dei tratti relativi ai tempi di sviluppo, l'allargamento delle dimensioni del gruppo sociale, un aumento della cooperazione tra individui, modifiche comportamentali e innovazioni (come l'uso del fuoco), modifiche eterocroniche che hanno condotto a un aumento della plasticità sinaptica. Viene sostenuto che un rilassamento delle pressioni selettive causato da attività di costruzione di nicchia può aver giocato un ruolo fondamentale sia nell'evoluzione umana sia nell'evoluzione del linguaggio. Nel secondo capitolo, gli esempi chiave presentati nel primo capitolo vengono analizzati attraverso le lenti della cornice concettuale della Sintesi Estesa. L'evoluzione del linguaggio è trattata come un problema aperto nel programma di ricerca evoluzionistico e viene mostrato come quattro fattori (costruzione di nicchia, ereditarietà inclusiva, plasticità fenotipica, bias di sviluppo) e due concetti (causalità reciproca, sviluppo costruzionista) possono venire sfruttati per ottenere una migliore comprensione dell'evoluzione umana e del linguaggio. Il terzo capitolo esplora uno specifico problema teorico associato al dibattito intorno alla SEE, ovvero la necessità di riconsiderare la distinzione tra cause prossime e cause remote nell'evoluzione. Infatti, si può alternativamente assumere che la trasmissione culturale, che opera al livello intermedio tra il livello ontogenetico e il livello filogenetico, possa essere o un meccanismo prossimo o un meccanismo remoto, ottenendo predizioni diverse con assunzioni diverse. Noi sosteniamo che assumere l'una o l'altra posizione conduce a due differenti prospettive su come l'evoluzione biologica e l'evoluzione culturale interagiscono. Sosteniamo una prospettiva integrazionista che permette di riconoscere il ruolo di causa ultima della cultura, in accordo con la cornice concettuale della SEE. Discutiamo anche le conseguenze di questo cambiamento concettuale e mostriamo come ciò possa gettar luce sul dibattito intorno ai ritmi dell'evoluzione del linguaggio (puntuazionismo e gradualismo). Nelle Conclusioni avanziamo qualche ulteriore proposta, due in particolare: prima trattiamo il linguaggio come una forma di insegnamento verbale e riesaminiamo l'ipotesi, presentata nei capitoli precedenti, secondo cui il linguaggio potrebbe essersi evoluto come forma di trasmissione culturale di alta precisione; poi discutiamo la proposta secondo cui il linguaggio può venire inteso come una transizione fondamentale dell'evoluzione e in particolare proponiamo di dividere questa transizione in due parti: la prima riguarda l'evoluzione delle capacità per la cultura cumulativa, la seconda riguarda l'evoluzione del linguaggio; queste due parti potrebbero condividere un comune processo evolutivo alla loro base e suggeriamo che questo possa venire identificato nella versione estesa del principio di “assimilazione-allungamento”, che presentiamo nelle conclusioni, discutendone anche possibili future direzioni. Infine, concludiamo sostenendo che i modelli di coevoluzione geni-culutra stanno rivelando la loro fecondità non solo nel gettare luce sull'evoluzione umana, ma anche su altre specie sociali, e la cornice concettuale della SEE fornisce un insieme di strumenti esplicativi che risultano appropriati per trattare queste problematiche.

En esta Tesis Doctoral hemos identificado los componentes de la amígdala extendida (EA) de aves, en base a su posición topológica, perfil genético y origen embrionario. En EA central de pollo y pinzón, identificamos las masas intercaladas y amígdala central, con células de origen estriatal dorsal y/o ventral, pero con subpoblaciones menores de otros orígenes. Además, el núcleo lateral de la estria terminal, de origen palidal, contiene subpoblaciones de células inmigrantes de origen estriatal, preóptico o eminencial. En EA medial del pinzón, hemos identificado distintas subpoblaciones celulares en la amígdala medial y el núcleo medial de la estria terminal con origen palidal, preóptico, hipotalámico o eminencial. Nuestros datos indican que EA está formada por múltiples corredores celulares con distinto origen y perfil genético, lo que supone un cambio de paradigma para entender la conectividad y función de cada tipo celular en el control de las emociones, motivación y comportamiento social.
In this Ph.D. Dissertation, we have identified the components of the avian extended amygdala (EA), based on their topological position, genetic profile and embryonic origin. In central EA of chicken and zebra finch, we identified the intercalated masses and the central amygdala, with cells derived from the dorsal and/or ventral striatal domains, but with minor subpopulations from other origins. Moreover, the lateral bed nucleus of the stria terminalis, with pallidal origin, contains subpopulations of immigrant cells with striatal, preoptic or eminential origins. In medial EA of zebra finch, we identified different cell subpopulations with pallidal, preoptic, hypothalamic or eminential origins. Our data indicate that EA is formed by multiple cell corridors with different origin and genetic profile, which opens new venues for investigating the connections and function of each neuron subtype in the control of emotions, motivation and social behavior.
En aquesta Tesi Doctoral hem identificat els components de l'amígdala estesa (EA) d'aus, en base a la seva posició topològica, perfil genètic i origen embrionari. En EA central de pollastre i pinsà, hem identificat les masses intercalades i l'amígdala central, amb cèl·lules estriatals dorsal i/o ventral, però amb subpoblacions menors d'altres orígens. A més, el nucli lateral de l’estria terminal, d'origen palidal, conté subpoblacions de cèl·lules immigrants d'origen estriatal, preòptic o eminèncial. En EA medial del pinsà, hem identificat diferents subpoblacions cel·lulars en l'amígdala medial i el nucli medial de l’estria terminal amb origen palidal, preòptic, hipotalàmic o eminèncial. Les nostres dades indiquen que EA està formada per múltiples corredors cel·lulars amb diferent origen i perfil genètic, la qual cosa suposa un canvi de paradigma per entendre la connectivitat i funció de cada tipus cel·lular en el control de les emocions, motivació i comportament social.

Thesis advisor: Larry W. McLaughlin
Nucleic acids are essential biological molecules that encode and transfer genetic information from generation to generation. Intensive efforts have been made by scientists to study the properties of nucleic acids, looking for opportunities that could help diagnose, prevent, and cure disease, and/or gain a greater insight into the wonder of nature. Chapter 2 presents our synthetic attempts towards the rigidified nucleosides 2'-deoxy-6,3'-propanouridine and 2'-deoxy-6,3'-butanouridine. These nucleosides are constrained so that they mimic the native conformation in DNA duplex and are postulated to increase duplex stability, as well as increase the affinity of the nucleobase for its complementary partner. Chapter 3 presents work towards the synthesis of backbone extended nucleosides. These molecules have the potential to form a new type of helical structure when incorporated into a double helix. Through the investigation of these novel nucleic acids, we would like to gain a greater understanding of the properties that contribute to duplex stability
Thesis (MS) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Porphyrins offer a very synthetically flexible template which can be modified in numerous ways to synthesize molecules with very useful properties applicable in areas such as non-linear optical properties, photodynamic therapy, dye-sensitized solar cells, chemical sensors and organic electronic devices. β-Substituted π-extended porphyrins offer unique capabilities in tuning the properties of the molecule towards practical applications. Increased π-conjugation allows the HOMO-LUMO gap to decrease and hence to redshift the absorption into the near-IR region. β-Fused benzoporphyrins offer additional benefits in which the benzene ring itself can be further modified using electron donating substituents and electron donating substituents to electronically tune these porphyrins for various uses. The goal of the research pursued in this dissertation was to develop new methods for the development of β-Substituted π-extended porphyrins and to study their optical and electronic properties. To accomplish this goal, we developed new method to synthesize A2B2 type tetrabenzoporphyrins and we studied the electron transfer in such systems. We also studied the effectiveness of such systems in dye sensitized solar cells. A new method to synthesize functionalized naphthalene fused porphyrins was also developed and we were also able to use this method to synthesize a push-pull naphthalene fused porphyrin.

The electronic and magnetic properties of nanographenes strongly depend on their size, shape and topology. While many nanographenes present a closedshell electronic structure, certain molecular topologies may lead to an open-shell structure. Triangular-shaped nanographenes with zigzag edges, which exist as neutral radicals, are of considerable interest both in fundamental science and for future technologies aimed at harnessing their intrinsic high-spin magnetic ground states for spinbased operations and information storage. Their synthesis, however, is extremely challenging owing to the presence of unpaired electrons, which confers them with enhanced reactivity. We report a combined in-solution and onsurface synthesis of π-extended triangulene, a non-Kekulé nanographene with the structural formula C33H15, consisting of ten benzene rings fused in a triangular fashion. The distinctive topology of the molecule entails the presence of three unpaired electrons that couple to form a spin quartet ground state. The structure of individual molecules adsorbed on an inert gold surface is confirmed through ultrahigh-resolution scanning tunneling microscopy. The electronic properties are studied via scanning tunneling spectroscopy, wherein unambiguous spectroscopic signatures of the spin-split singly occupied molecular orbitals are found. Detailed insight into its properties is obtained through tight-binding, density functional and many-body perturbation theory calculations, with the latter providing evidence that π-extended triangulene retains its open-shell quartet ground state on the surface. Our work provides unprecedented access to open-shell nanographenes with high-spin ground states, potentially useful in carbon-based spintronics.

Thesis advisor: Larry W. McLaughlin
Nucleic acids are responsible for maintaining the biological information responsible for the activities of all known living organisms. Research of nucleic acids provides opportunities to help understand, prevent, and cure disease in addition to allowing us to gain a greater appreciation for the wonders of nature. This work presents the synthesis and properties of several modified nucleosides. Chapter 2 presents an improved synthesis of R and S 6,5'-cyclouridine, which are rigidified nucleosides locked in the anti conformation. This work helps to understand the properties of these interesting molecules and will allow scientists to synthesize large quantities of these monomers for future research. Chapter 3 presents the synthesis of novel 6,6'-(S)-cyclo-2'-deoxyuridine. This work is highlighted by a zinc mediated cyclization to form a seven-membered ring; the first published reaction of its kind. The compound itself is a mimic of thymidine that also has the base locked in the anti position. Lastly, Chapter 4 presents work on 6' extended backbone nucleosides. These molecules have the potential to form a new type of helical structure and will help us to gain a greater understanding of the properties and dynamics that contribute to duplex stability in DNA
Thesis (PhD) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Porphyrins with extended π-electronic networks are promising candidates for a wide range of applications from medicine to nanotechnology owing to their unique optical and electronic properties. This dissertation is focused on synthesis, characterization and application of β-functionalized π-extended porphyrins. This dissertation is comprised of seven chapters. Chapter 1 focuses on the importance and objective of this work. Chapter 2 gives brief introduction to porphyrins and π-extended porphyrins. In chapter 3, a class of β-functionalized linear push-pull zinc dibenzoporphyrins YH1-YH3 were designed, synthesized, and utilized as light harvesters for DSSCs. In chapter 4, in order to further enhance the photovoltaic performance of β-functionalized benzoporphyrin dyes based DSSCs, a new class of push-pull dibenzoporphyrins YH4-YH7 bearing the phenylethynyl bridge was designed, synthesized and utilized as light harvesters for DSSCs. In chapter 5, in order to solve the photodegradation problem associated with YH7, a new series of push-pull dibenzoporphyrins YH8-YH10 bearing different diarylamino push groups was designed and synthesized. This class of push-pull porphyrins shows improved photostability and enhanced DSSC performance. In chapter 6, a new pentacene-fused diporphyrin with high stability and solubility was prepared and characterized. Chapter 7 includes the summary of this dissertation and describes possible future work.

This thesis describes studies directed towards the preparation of new conjugatively extended p-xylylenes through in situ 1,6- or 1,8-Hoffmann elimination reactions of trimethylammonium salts. The polymers arising from these highly reactive compounds were analysed in order to determine whether or not the extra conjugation had been involved in the polymerisation process. A number of fascinating by-products were also isolated which were useful in determining the structural unit orientation in the related polymer chains. Chapter 1 highlights the areas of p-xylylene chemistry of relevance to the general theme of this thesis. Chapter 2 describes the in situ synthesis and consequent polymerisation of vinyl-extended p-xylylene from two different trimethylammonium salts. An in-depth analysis of the polymers and the two cyclic dimers produced is also included. Chapter 3 describes the in situ synthesis and polymerisation of phenyl-extended p-xylylene from two different trimethylammonium salts. Once again, an analysis of die polymer structures and the identification of the two cyclic trimers is also included. Chapter 4 describes attempts to extend the polymerisation reactions of Chapters' 2 and 3 to produce water-soluble precursor polymers from bis-sulphonium salts. Chapter 5 describes attempts to synthesise novel polymeric materials from fluorinated monomers. Chapter 6 gives experimental details for Chapters 2-5.

The importance of conducting efficient product development is growing steadily as traditional market boundaries diminish and are replaced by global market conditions. Digital product development builds on the foundation that digital mock-ups replace physical mock-ups, and this has the potential for strongly improving the efficiency of the product development process. This is a rather drastic change compared to the conventional way of conducting product development, and it cannot be implemented overnight. It requires the extended enterprise to rely on geometry based product models. Business excellence is therefore partially synonymous with managing these models and making them available, and relevant, to different activities throughout the product development process. This thesis deals with the establishment of two key expressions, Geometry Management Process and Geometry Based Product Information. The objective is to improve the utilisation of Geometry Based Product Information by supporting the product development process with adequate methods, tools and processes for managing this type of information. This objective is partly realised by the elimination of rework in the downstream activities of traditional design departments. There are numerous influencing factors and the research approach has been to collect these factors into four separate but correlating domains. The consistency in the approach stems from the fact that all research work is conducted with a geometrical perspective on all types of activity, requirement and process. The methodology is elaborated through participation and surveys of real cases in ongoing projects and activities when developing heavy-duty trucks.

Godkänd; 2001; 20070313 (ysko)

Memetics is a Darwinian approach to evolution of culture proposed in late 1970s. This thesis proposes an approach to Memetics, which is an effort to overcome some of the problems involved. It is argued in this thesis that units of cultural evolution are functional abstraction of physical reality and are realized within the boundaries of our cognitive processes. The boundaries of human cognitive processes are defined by Clark and Chalmers (1998) in their extended cognition hypothesis according to which, human cognition is understood as a part of the cultural environment. Therefore human cognition and cultural environment can best be understood by studying them together. As for identifying these units, an extended functionalist approach has been proposed and an empirical cultural transmission study has been conducted and explored in the thesis.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.
Vita.
Includes bibliographical references.
A series of pure iron jarosites (formula AFe₃(OH)₆(TO₄)₂) possessing the paradigmatic kagomé lattice has been prepared stoichiometrically pure through the use of a redox-based hydlrothermal synthetic strategy. This synthetic method allows us grow single crystals from which we fully characterize the structure and magnetic properties. Iron jarosites show signature spin frustrated behavior, indicated by a large Curie-Weiss constant, [theta] [approx.] -800 K, with a transition temperature, ... narrowly ranging from 56 - 65 K. Long-range antiferromagnetic order is due to a canted spin structure developed from the Dzyaloshinsky-Moriya (DM) interaction. Although the DM interaction energy is only 1.2 cm⁻¹, this is large enough to give rise to a 3-D magnetic structure, precluding the ability to study the ground state physics of a purely 2-D frustrated spin system. Copper hydroxy-bridged triangular species have been prepared and characterized both structurally and magnetically. Overall, the nearest-neighbor exchange interaction is found to be antiferromagnetic in each compound, with [Theta] ranging from -18 to -300 K, although the 1-D material lindgrenite, Cu₃(OH)₂)(MoO₄)₂, and the kagomé-lattice-containing material clinoatacamite, Cu₂(OH)₃Cl, show 3-D long-range ferromagnetic order. The compound zinc paratacamite presents the hallmark of an S = 1/2 Cu²⁺ compound possessing the kagomé lattice. This compound has magnetically isolated layers, and we find no evidence for magnetic ordering to temperatures down to 2 K, despite strong nearest-neighbor antiferromagnetic coupling, indicated by [Theta] [approx.] -300 K.
by Bart M. Bartlett.
Ph.D.

Aquesta tesi doctoral descriu el disseny i la síntesi d’una sèrie de receptors supramoleculars que presenten cavitats aromàtiques polars. Els receptors preparats inclouen receptors organometàl·lics, contenidors moleculars solubles en aigua, caixes moleculars basades en enllaços de coordinació i metal·lo-cavitands. S’han seleccionat unitats de calix[4]pirrole aril i super-aril estesos (AEC[4]P i SAE-C[4]P) com a components principals. S’han estudiat les propietats de reconeixement molecular dels receptors sintètics amb sals de clorur de tetraalquilamoni, així com de molècules polars neutres, en dissolvents orgànics i en aigua. Concretament, s’ha preparat un calix[4]pirrole super aril estès substituït amb una fosfina mono-Au(I) i s’han estudiat les seves propietats de reconeixement davant diferents sals de clorur de tetraalquilamoni en diclorometà i acetona. Els complexos organometàl·lics d'inclusió amb aquestes sals presenten una estabilitat termodinàmica reduïda respecte al seu anàleg no organometàlic simètric "de dues parets". Molt probablement això és degut a que les interaccions repulsives anió-π són més fortes al complex de clorur del receptor organometàl·lic. S’ha explorat l'aplicació d'un receptor SAE-C[4]P soluble en aigua en la hidròlisi de bis-isonitrils alifàtics catalitzada per àcids. El receptor SAE-C[4]P forma complexos 1:1 termodinàmicament estables amb els bis-isonitrils, mono-isonitrils-mono-formamides i bis-formamides. Els compostos mono reaccionats units presenten el grup formamida exclusivament en la conformació cis. Aquesta disposició protegeix el grup isonitril i provoca millores en el rendiment dels compostos mono-reaccionats. També s’ha dut a terme l’auto assemblatge d’una caixa metàl·lica soluble en aigua amb dos llocs d’unió polar endoèdrics. S’ha demostrat que l’assemblatge eficient de la caixa metàl·lica requereix l’encapsulació de molècules polars mono i ditòpiques neutres. La caixa metàl·lica mostra selectivitat conformacional per la unió de bis-formamides alifàtiques amb diferents longituds del espaiadors (grups metilè). Finalment, es descriu la síntesi d'un lligand tetra-oxazolo [4,5-b]pirazinil SAE-C[4]P sense precedents. Es descriu l’auto assemblatge d’un bis-metal·lo-cavitand basat en el lligand SAE-C[4]P i Pt(II) com a precursors. De la mateixa manera, es demostra que la inc
Esta tesis doctoral describe el diseño y la síntesis de una serie de receptores supramoleculares que presentan cavidades aromáticas polares. Los receptores preparados incluyen receptores organometálicos, contenedores moleculares solubles en agua, cajas moleculares basadas en enlaces de coordinación y metalo-cavitandos. Se han seleccionado unidades de calix[4]pirrol aril- y super-aril extendidos (AEC[4]P y SAE-C[4]P) como componentes principales. Se han estudiado las propiedades de reconocimiento molecular de los receptores sintéticos con sales de cloruro de tetraalquilamoni, así como de moléculas polares neutras, en disolventes orgánicos y en agua. Concretamente, se ha preparado un calix[4]pirrol super-aril extendido sustituido con una fosfina mono-Au(I) y se han estudiado sus propiedades de reconocimiento molecular ante diferentes sales de cloruro de tetraalquilamonio en diclorometano y acetona. Los complejos organometálicos de inclusión con estas sales presentan una estabilidad termodinámica reducida respecto a su análogo no organometálico simétrico "de dos paredes". Muy probablemente esto se debe a que las interacciones repulsivas anión-π son más fuertes en el complejo de cloruro del receptor organometálico. Se ha explorado la aplicación de un receptor SAE-C[4]P soluble en agua en la hidrólisis de bis-isonitrilos alifáticos catalizada por ácidos. El receptor SAE-C[4]P forma complejos 1: 1 termodinámicamente estables con los bis-isonitrilos, mono-isonitrilos-mono-formamida y bis-formamida. Los compuestos mono-reaccionados unidos presentan el grupo formamida exclusivamente en la conformación cis. Esta disposición protege el grupo isonitrilo y produce mejoras en el rendimiento de los compuestos mono-reaccionados. También se ha llevado a cabo el auto ensamblaje de una caja metálica soluble en agua con dos sitios de unión polar endoèdricos. Se ha demostrado que el ensamblaje eficiente de la caja metálica requiere la encapsulación de moléculas polares mono y di-tópicas neutras. La caja metálica muestra selectividad conformacional para la unión de bis-formamida alifáticas con diferentes longitudes de espaciadores (número de grupos metileno). Finalmente, se describe la síntesis de un ligando tetra-oxazolo [4,5-b] pirazinil SAE-C[4]P sin precedentes. Se describe el auto ensamblaje de un bis-metalo-cavitando basado
This PhD Thesis describes the design and synthesis of a series of supramolecular receptors featuring polar aromatic clefts and cavities. The prepared receptors include organometallic receptors, water-soluble containers, metallocages and metallocavitands. We selected aryl and super aryl-extended calix[4]pyrrole scaffolds (AE-C[4]P and SAE-C[4]P) as their main building blocks. We studied the molecular recognition properties of the synthetic receptors with tetraalkylammonium chloride salts, as well as neutral polar guests, in organic solvents and in water. Specifically, we prepared a mono-gold(I) phosphine substituted AE-C[4]P and studied its binding properties towards tetraalkylammonium chloride salts in dichloromethane and acetone solutions. The inclusion organometallic complexes featured a reduced thermodynamic stability with respect to its parent symmetrical “two-wall” counterpart. These results were explained considering the stronger repulsive anion-π interactions present in the chloride complex of the organometallic receptor. Next, we explored the application of a water-soluble SAE-C[4]P in the acid-catalyzed hydrolysis of aliphatic bis-isonitriles. The SAE-C[4]P receptor formed thermodynamically stable 1:1 complexes with the bis-isonitriles, mono-isonitrile-mono-formamides and bis-formamides. The bound mono-reacted compounds featured the formamide group in exclusive cis-conformation. This arrangement protected the unreacted isonitrile group from water solvation and induced yield enhancements for the mono-reacted compounds. We also reported the self-assembly of water-soluble metallocage featuring two endohedral polar binding sites. We showed that the efficient assembly of the metallcage requires the encapsulation of neutral mono-and ditopic polar guests. The assembled metallocage displayed conformational selectivity in the binding of aliphatic bis-formamides having different methylene spacers. Finally, we described the synthesis of an unprecedented tetra-oxazolo[4,5-b]pyrazinyl SAE-C[4]P ligand. We reported the self-assembly of a bis-metallocavitand based on the SAE-C[4]P ligand and Pt(II) precursors. Similarly, we showed that the inclusion of suitable polar guest was mandatory for the metallocavitand formation. The SAE-C[4]P ligand chelated only two Pt(II) metals between its adjacent substituents affordin

This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 27).
Grammatical Evolution (GE) is an evolutionary algorithm that is gaining popularity due to its ability to solve problems where it would be impossible to explore every solution within a realistic time. Structured Grammatical Evolution (SGE) was developed to overcome some of the shortcomings of GE, such as locality issues as well as wrapping around the genotype to complete the phenotype. In this paper, we apply SGE to program synthesis, where the computer must generate code to solve algorithmic problems. SGE was improved upon, because the current definition of SGE does not work. Given that the solution space is very large for possible codes, we aim to improve the efficiency of GE in converging to the correct solution. We present a method in which to remove cycles from a grammar for SGE, to be able to make sure that a genotype matches to a phenotype with reusing parts of the genotype, and analyze results to shed insight on future improvements.
by Andrew H. Zhang.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Cette thèse décrits la synthèse et caractérisations de chaines métalliques étendues (EMACs:extended metal atom chains) construite à partir des ligands dipyridylamine (dpa) etdipyridylformamidinate (DpyF). Le Chapitre I fait une brève introduction sur les liaisons métalmétalet sur les chaines métalliques étendues. Le Chapitre II présente les propriétés de conversionde spin (SCO: spin crossover) d’une série d’EMACs de tris-cobalt de formule générale[Co3(dpa)4X2]. L’influence des ligands axiaux et de la symétrie des molécules a été examinée etcorrélée aux propriétés de conversion de spin. Le Chapitre III porte sur la résolutionénantiomérique et activité RX optique de l’EMAC tris-cobalt [Co3(dpa)4(MeCN)2]2+. Dans lechapitre IV, La chimie de coordination du ligand N,N’-di(2-pyridyl)formamidinate (DpyF), quiconduit à des complexes présentant des propriétés structurales and magnétiques remarquable,est explorée. Finalement, le chapitre V présente nos études préliminaires pour obtenir despolymères unidimensionnelles d’EMAC de tris-cobalt en utilisant des radicaux de type thiazyle
This thesis describes the synthesis and characterizations of extended metal atom chains (EMACs)supported by dipyridylamine (dpa) and dipyridylformamidinate (DpyF) ligands. Chapter Iprovides a brief introduction to metal-metal bonds and extended metal atom chains. In Chapter IIspin crossover properties of series of tricobalt EMACs based on [Co3(dpa)4X2] motifs arepresented. The influence of the axial ligands and the symmetry of the molecule was examined andcorrelated with the SCO properties. Chapter III describes the enantiomeric resolution and X-rayoptical activity of tricobalt EMAC, [Co3(dpa)4(MeCN)2]2+. In chapter IV, the coordination chemistryof N,N’-di(2-pyridyl)formamidinate, (DpyF) is explored, a ligand which gives rise to complexeswith remarkable structural and magnetic properties Finally, chapter V presents our initial effortsto obtain one-dimensional coordination polymers of tricobalt EMAC using thiazyl radicals

Genetic algorithm Synthesis (GaS) is presented in this thesis. GaS is based on a hardware implementation of a genetic algorithm (GA), aimed at evolving the logic circuit of a defined input function, while minimizing the total number of resources utilized on the underlying hardware platform. A GA bases its operation on society itself, attempting to imitate natural selection in computing systems [1]. It has been found that GAs are very good search techniques, to be used when either the search space is vast or the present deterministic techniques are too restrictive. The field of logic synthesis, as well as technology mapping onto a field-programmable gate array (FPGA), contain both of the aforementioned obstacles, and thus a new method must be realized to overcome these obstacles. GaS is the integration of a multitude of technologies, and the realization of a solution for the automated synthesis of combinational logic circuits. The work falls under the evolvable hardware (EHW) [2] domain which is a very novel field of research. The presented system is fully functional, and has been prototyped onto a computing platform, which embeds itself into a personal computer, with the main communications path being the local bus. The front-end of GaS consists of a command-line interface, whence the user inputs both the truth table representation of the Boolean function to be evolved, as well as a few initializing parameters. The system then proceeds to evolve a solution for the user's problem. Experimental results are presented in this thesis. In simple terms, the speedup factors are very promising, and in future versions of the system, the improvements that could be realized will usher in a new computing paradigm: evolvable computing.

CIVINS
Ever since studded tires were flrst introduced, the advantages, disadvantages, and effects of studded tires on vehicles, drivers and pavement systems has been the center of research and controversy for highway and transportation administrators, as well as safety engineers. The primary objective of this synthesis is to assemble, extract, organize and present information pertaining to the history of the studded tire (i.e., how it has evolved over time) in a detailed/descriptive chronological manner. The project also explores the relationship between the wear of pavements and the studded tire developments that have taken place over the past forty years

The hydrothermal synthesis of complex oxides of ruthenium and iridium with potential application as oxygen evolution reaction catalysts in polymer electrolyte membrane fuel cells is reported. The materials M0.15Ru0.85O2, where M = Zn, Mg, Ni, Co or Cu, have been synthesised from peroxide reagents and potassium perruthenate. Structural refinement against powder neutron diffraction data shows these materials adopt the rutile structure with space group P42/mnm with the metals substituting ruthenium and no evidence of oxide vacancies. X-ray absorption near-edge structure spectra recorded at the Ru K-edge show that to compensate for the inclusion of these metals, the ruthenium is oxidised above +4. New oxides based on (Ca0.59Na0.27)2Ir2O6·0.66H2O were produced with substitutions made on both the A and B-site. All materials were shown to adopt the pyrochlore structure with space group Fd m. The level of B-site substitution was found to be dependent on the substituent element (Sb, Ru, Rh, Mn or Zr), with maximum substitution levels ranging from 30-100 %. The zirconium substituted material, (Ca0.58Na0.32Zr0.12)2(Ir0.56Zr0.44)2O6·0.97H2O, shows significant deviation from the average structure at the local scale. The synthesis of the pure iridium material was further investigated and it was found both the A-site composition and particle size could be controlled. Treatment in concentrated H2SO4 at elevated temperature yielded materials with vacant A-sites. The hydrothermal synthesis of a number of other mixed metal oxides is reported. These include the perovskites Na(Ta1-xMx)O3, Na(Nb1-xIrx)O3and SrRuO3, where M = Ir or Ru, and x < 0.15, the hexagonal perovskite 4H-BaRuO3, Sr2.85Ir3O11 a material with a KSbO3-type structure and a barium iridate with an unknown structure. In electrochemical tests, performed in membrane electrode assemblies, all materials outperform the benchmark materials, iridium tantalum oxide and ruthenium iridium oxide under acidic conditions. The substituted rutile materials are highly active, but not as durable or selective towards the oxygen evolution reaction as the iridate materials. In situ studies of catalyst layers using X-ray absorption fine structure spectroscopy at the Ir LIII, Ru K, Rh K and Sb K-edges show that both iridium and ruthenium participate in redox chemistry at oxygen evolution conditions, however antimony and rhodium are redox inactive.

People around the world who are working in companies and organisations need to collaborate, and in their collaboration use information managed by different information systems. The requirements of information systems to be interoperable are therefore apparant. While the technical problems, of communicating or sharing information between different information systems, have become less difficult to solve, the attention has turned to other aspects of interoperability. Such aspects concern the bussiness processes, the knowledge, the syntax and the semantics that involves the information managed by information systems. Enterprise modelling is widely used to achieve integration solutions within enterprises and is a research area both for the integration wihin an enterprise (company or organisation) and the integration between several different enterprises. Enterprise modelling takes into account several of the aspects, mentioned as important for interoperability, in the models that are created. This thesis describes a research which has resulted in the connector view concept. The main contribution with this framework comprises a model structure and an approach, for performing the modelling of the collaboration between several partners in an extended enterprise. The purpose of the enterprise models thus created, by using the connector view concept, is to find solutions to interoperability problems, that exist in the collaboration between several enterprises.

Process-based models are used in a diverse array of fields, including environmental engineering to provide supporting information to engineers, policymakers and stakeholdes. Recent advances in remote sensing and data storage technology have provided opportunities for improving the application of process-based models and visualizing data, but also present new challenges. The availability of larger quantities of data may allow models to be constructed and calibrated in a more thorough and precise manner, but depending on the type and volume of data, it is not always clear how to incorporate the information content of these data into a coherent modeling framework. In this context, using process-based models in new ways to provide decision support or to produce more complete and flexible predictive tools is a key task in the modern data-rich engineering world. In standard usage, models can be used for simulating specific scenarios; they can also be used as part of an automated design optimization algorithm to provide decision support or in a data-assimilation framework to incorporate the information content of ongoing measurements. In that vein, this thesis presents and demonstrates extensions and refinements to leverage the best of what process-based models offer using Differential Evolution (DE) the Extended Kalman Filter (EKF). Coupling multi-objective optimization to a process-based model may provide valuable information provided an objective function is constructed appropriately to reflect the multi-objective problem and constraints. That, in turn, requires weighting two or more competing objectives in the early stages of an analysis. The methodology proposed here relaxes that requirement by framing the model optimization as a sensitivity analysis. For demonstration, this is implemented using a surface water model (HEC-RAS) and the impact of floodplain access up and downstream of a fixed bridge on bridge scour is analyzed. DE, an evoutionary global optimization algorithm, is wrapped around a calibrated HEC-RAS model. Multiple objective functions, representing different relative weighting of two objectives, are used; the resulting rank-orders of river reach locations by floodplain access sensitivity are consistent across these multiple functions. To extend the applicability of data assimilation methods, this thesis proposes relaxing the requirement that the model be calibrated (provided the parameters are still within physically defensible ranges) before performing assimilation. The model is then dynamically calibrated to new state estimates, which depend on the behavior of the model. Feasibility is demonstrated using the EKF and a synthetic dataset of pendulum motion. The dynamic calibration method reduces the variance of prediction errors compared to measurement errors using an initially uncalibrated model and produces estimates of calibration parameters that converge to the true values. The potential application of the dynamic calibration method to river sediment transport modeling is proposed in detail, including a method for automated calibration using sediment grain size distribution as a calibration parameter.

When Alberto Ginastera's oeuvre is viewed as a whole, an essential continuity between compositional ideas often appears in different works. This is especially apparent in the three piano sonatas, where each sonata represents an evolution and a condensation of ideas occurring in the previous one. The evolution of ideas throughout the three sonatas takes place through two primary processes. The first is a shift in cultural focus from reliance on Ibero-American material in the first sonata (1952) to Amerindian in the second (1981), to a synthesis of the two cultural elements in the third (1982). The second means of evolution from sonata to sonata is through a process of symmetrization. Along with constructions using symmetrical scales, material in each of the three sonatas is subjected to various symmetrical procedures which correspond musically to basic geometric symmetry types or operations (bilateral, rotational, and translatory, for instance). The decreasing number of movements evidences a negative dilatation of material, moving from four movements in the first sonata to three in the second, to one in the third. In each case, corresponding material from the previous sonata is integrated into the following sonata. Both independently and as a group the three piano sonatas exhibit "invariance under a transformation."

The Pacific margin of South America was predominantly a subduction margin throughout the Mesozoic and Cenozoic. In the mid-Cretaceous, the continental margin arc from southernmost South America to southern Peru changed from a near sea-level, "neutral" arc to a subaerial, compressive arc. Only minor terrane accretion occurred in the central and southern Andes during this subduction episode (Darwinia and Canta terranes), but there was extensive Cretaceous-Tertiary accretion of oceanic terranes in the northern Andes (Villa de Cura, Cordillera de la Costa, Amaime, Cauca-Macuchi, Pinon, and Baudo terranes). These oceanic additions to the continent were primarily by an oblique subduction/strike-slip process. The development of an uplifted continental margin arc in the Eocene, shedding coarse sediments to the east, followed the accretion of the Cretaceous oceanic terranes in the northern Andes. The Paleozoic tectonic evolution of the Andean margin, in contrast to the Mesozoic-Cenozoic subduction-dominated evolution, shows a tectonically varied margin in space and time. In the central to southern Andes, lower Paleozoic continental margin terranes (Puna and Precordillera terranes) accreted against a margin that displays lower Paleozoic magmatic arc, as well as rift assemblages. Outboard of these terranes are continental terranes (Arequipa and Chilenia terranes) characterized by Precambrian or lower Paleozoic basement that were in place by the Carboniferous. In the late Paleozoic, subduction complexes (Chiloe and Magallanes terranes) were accreted during development of the late Carboniferous continental margin arc in the southern Andes. In the northern Andes, terranes of continental character were also emplaced (Zamora, Eastern Cordillera and Merida terranes) inboard of the younger oceanic terranes, but their final accretion was a result of the late Paleozoic collision of Gondwana and Laurentia. Late Ordovician and Devonian-Early Carboniferous orogenies affected substantial parts of the Andean margin. A magmatic arc developed along the southern Andes following these orogenies, and it continued into the Mesozoic-Cenozoic without major interruption. A Mesozoic-Cenozoic arc eventually extended the length of western South America, with the subduction process producing the present Andean Cordillera, primarily as a result of Neogene orogeny.

Metal-organic frameworks (MOFs) have been intensely researched over the past 20 years. In this dissertation, metal-inorganic frameworks (MIFs), a new class of porous and nonporous materials using inorganic complexes as linkers, in lieu of traditional organic linkers in MOFs is reported. Besides novel MIF regimes, the previously described fluorous MOF "FMOF-1", is re-categorized herein as "F-MIF1". F-MIF-1 is comprised of [Ag4Tz6]2- (Tz = 3,5-bis-trifluoromethyl-1,2,4-triazolate) inorganic clusters connected by 3-coordinate Ag+ metal centers. Chapter 2 describes isosteric heat of adsorption studies of F-MIF1 for CO2 at near ambient temperatures, suggesting promise for carbon capture and storage. We then successfully exchanged some of these Ag(I) centers with Au(I) to form an isostructural Au/F-MIF1. Other, nonporous MIFs have been synthesized using Ag2Tz2 clusters with bridging diamine linkers 4,4'-bipyridine, pyrazine, and a Pt(II) complex containing two oppositely-situated non-coordinating pyridines. This strategy attained luminescent products better-positioned for photonic devices than porous materials due to greater exciton density. Chapter 3 overviews work using an entirely inorganic luminescent complex, [Pt2(P2O5)4]4- (a.k.a. "PtPOP") to form new carbon-free MIFs. PtPOP is highly luminescent in solution, but as a solid shows poor quantum yield (QY ~0.02) and poor stability under ambient conditions. By complexing PtPOP to various metals, we have shown a dramatic enhancement in its solid-state luminescence (by an order of magnitude) and stability (from day to year scale). One embodiment (MIF-1) demonstrates microporous character. Chapter 4 overviews the design and application of new MIF linkers. Pt complexes based upon (pyridyl)azolates, functionalized with carboxylic acid groups, have been synthesized. These complexes, and their esterized precursors, show strong luminescence on their own. They have been used to generate new luminescent MIFs. Such new MIFs may be useful toward future inorganic (LEDs) or organic (OLEDs) light-emitting diodes, respectively. The electronic communication along their infinite coordination structures is desirable for color tuning and enhanced conductivity functions, compared to the small molecules used in such technologies, which rely on intermolecular interactions for these functions.

Resistance to antimicrobials is an increasing problem in the world of today, and develops faster than man can counter. It is therefore of importance to study metabolic pathways in order to develop new antibiotics, but also to understand how resistance spreads and stabilizes in microbial populations.

The commensal flora could be an important factor in the spread of antimicrobial resistance, as drugs aimed at other targets also hit the harmless commensal bacteria. If stable resistance develops in such a population, it could seriously impair a later treatment with the same drug. After a treatment with the macrolide clarithromycin, resistance to this antibiotic increased markedly in the untargeted throat flora, and resistance levels did not recede until at least one year later.

Another example of stable resistance can also be seen in sulfonamide resistant Streptococcus pyogenes. Sequence determinations of the dihydropteroate synthase (dhps) gene conferring this resistance revealed a mosaic organisation implying that the it had been brought there by horizontal transfer. Molecular characterization of this gene showed that the sulfonamide resistance was due to mutations of structurally important amino acids in position 65 and 213.

The folate synthesis pathway has potential for being exploited further as a drug target. One possible new drug target is hydroxymethyl-dihydropterin pyrophosphokinase (hppk). In the malaria parasite Plasmodium falciparum this enzyme is part of a polyfunctional entity, also encoding dhps. The HPPK part can be separated from DHPS, but that the opposite is not possible. The PfHPPK has two insertions: one also present in other plasmodia, and one apparently unique to P. falciparum. Both are crucial for enzyme activity.

To further characterize HPPK, we developed a spectrophotometric activity assay and a method to measure substrate channelling of hydroxymethyl-dihydropterin diphosphate.

A synthetic approach to macromolecules of acetylenic arrays and luminescent properties is proposed and the execution of initial steps is described. Palladium-catalyzed coupling of 1,3,5-triiodobenzene with trimethylsilylbuta-1,3-diyne, trimethylsilylocta-1,3,5,7-tetrayne, and trimethylsilylhexadeca-1,3,5,7,9,11,13,15-octayne to yield the new 1,3,5-tris(trimethylsilylbuta-1,3-diynyl)benzene and the proposed 1,3,5-tris(8-(trimethylsilyl)octa-1,3,5,7-tetraynyl)benzene and 1,3,5-tris(trimethylsilyl)hexadeca-1,3,5,7,9,11,13,15-octaynyl)benzene respectively. The proposed three-coordinate Au (I) complexed macromolecules will be derived from the metallation of the aforementioned alkynylated arenes.

This project was a step forward in electrochemically synthesizing nanomaterials for the water splitting reaction which directly produces hydrogen and oxygen. The thesis investigated the performances of newly developed nanomaterials for the energetically demanding water splitting reaction. In order to understand the reaction mechanism, thorough materials characterization was carried out to identify structure-activity relationships. This study also answers some fundamental questions such as "bifunctionality" in the field of water electrolysis. It also presents the modification of a readily available and cheap material, stainless steel, into an efficient water splitting catalyst that operates under industrial conditions.

We revisit the proposed extended Schmidt law, which posits that the star formation efficiency in galaxies depends on the stellar mass surface density, by investigating spatially resolved star formation rates (SFRs), gas masses, and stellar masses of star formation regions in a vast range of galactic environments, from the outer disks of dwarf galaxies, to spiral disks and to merging galaxies, as well as individual molecular clouds in M33. We find that these regions are distributed in a tight power law as Sigma(SFR) proportional to (Sigma(0.5)(star)Sigma(gas))(1.09), which is also valid for the integrated measurements of disk and merging galaxies at high-z. Interestingly, we show that star formation regions in the outer disks of dwarf galaxies with Sigma(SFR) down to 10(-5) M(circle dot)yr(-1) kpc(-2), which are outliers of both the Kennicutt-Schmidt and Silk-Elmegreen laws, also follow the extended Schmidt law. Other outliers in the Kennicutt-Schmidt law, such as extremely metal-poor star formation regions, also show significantly reduced deviation from the extended Schmidt law. These results suggest an important role for existing stars in helping to regulate star formation through the effect of their gravity on the midplane pressure in a wide range of galactic environments.

Dans cette thèse un système de synthèse sonore imitative sera présenté, applicable à la plupart des instruments de quasi-harmoniques. Le système se base sur les enregistrements d’une note unique qui représentent une version quantifiée de l'espace de timbre possible d'un instrument par rapport à sa hauteur et son intensité. Une méthode de transformation permet alors de générer des signaux sonores de valeurs continues des paramètres de contrôle d'expression qui sont perceptuellement cohérent avec ses équivalents acoustiques. Un modèle paramétrique de l'instrument se présente donc basé sur un modèle de filtre de source étendu avec des manipulations distinctes sur les harmoniques d’un signal et ses composantes résiduelles. Une procédure d'évaluation subjective sera présentée afin d’évaluer une variété de résultats de transformation par une comparaison directe avec des enregistrements non modifiés, afin de comparer la perception entre les résultats synthétiques et leurs équivalents acoustiques
Within this thesis an imitative sound synthesis system will be introduced that is applicable to most quasi-harmonic instruments. The system bases upon single-note recordings that represent a quantized version of an instrument's possible timbre space with respect to its pitch and intensity dimension. A transformation method then allows to render sound signals with continuous values of the expressive control parameters which are perceptually coherent with its acoustic equivalents. A parametric instrument model is therefore presented based on an extended source-filter model with separate manipulations of a signal’s harmonic and residual components. A subjective evaluation procedure will be shown to assess a variety of transformation results by a direct comparison with unmodified recordings to determine how perceptually close the synthesis results are regarding their respective acoustic correlates