The Eastern Mediterranean marks the site of the Southern Neotethys Ocean that was created, then largely destroyed near the northern margin of Gondwana. Sedimentary and structural evidence is well preserved in the Girne (Kyrenia) Range, a several hundred kilometrelong, narrow, E – W-trending, broadly arcuate lineament that encompasses northern Cyprus and a submarine ridge that links southeastern Turkey (Misis–Andırın Complex). This study focuses on the Oligocene-Miocene sequence exposed on both flanks of the Girne (Kyrenia) Range, based on sedimentology, microfacies, Sr-isotope dating and structural analysis. Two related sedimentary basins are today separated by an E – W-trending high-angle, fault zone, the Değirmenlik (Kythrea) Fault. The northern basin encompasses the Range, whereas the southern basin is located between the Değirmenlik (Kythrea) Fault and an E – W trending fault lineament (Dar dere (Ovgos) Fault Zone), to the south of which is the Troodos Ophiolitic Massif. The Değirmenlik (Kythrea) Fault is interpreted as a convergence-related thrust fault that was active during the Mid-Late Miocene creating an E – W submarine ridge that separated subbasins to the north and south. The sedimentary sequence in the northern basin unconformably overlies Mesozoic platform carbonates and latest Cretaceous-Palaeogene pelagic carbonates with interbedded volcanics. Above basal conglomerates (probably derived from underlying Eocene debris flows based on chemical evidence), there is a fining-upward siliciclastic turbidite sequence (Late Oligocene), then biogenic calciturbidites and marls (Aquitanian-Langhian). The northerly basin is characterised by thin-, to medium-bedded, pale hemipelagic calciturbidites and marls (Serravallian; ~400 m thick), overlain by thick-bedded, medium- to coarse-grained lithic sandstones with carbonate concretions (Tortonian; ~250 m thick). The succession in the southern basin, which is more deformed by thrusting, begins with poorly dated pelagic marls (Early Miocene?), followed by regularly bedded siliciclastic turbidites (~1000 m thick), with abundant sole structures (Serravallian-Tortonian). Palaeocurrent evidence shows mainly E to W flow for the southern basin, and locally a generally E to W flow for the northerly basin, at least for the Late Miocene. Gypsum accumulated in local depocentres during the Messinian salinity crisis and was locally deformed by contemporaneous southward thrusting. Petrographic studies of the Serravallian – Tortonian sandstones indicate that the northern basin is richer in recrystallised limestone grains compared to the southern basin, which contains more abundant siliciclastic and ophiolite-derived material; this trend is also present in results from XRD analysis of clays. The likely source area was the Eurasian-African suture zone in the Tauride Mountains to the northeast. The greater detrital limestone abundance in the south may record relatively deep-level erosion of the source area, through ophiolites to an underlying Mesozoic carbonate platform. Two phases of clastic input are recognised from SE Turkey, the first related to Early Miocene continental collision, and the second reflecting Late Miocene suture tightening, both to the east of Cyprus within the Tauride Suture Zone. Based on the measurement and kinematic analysis of a large number (>1290) of faults, combined with a knowledge of the tectono-stratigraphy, the timing and nature of faulting is inferred. The majority of the faults are south-verging, high-angle reverse faults, while sinistral strike-slip faults dominate several areas of the Girne (Kyrenia) Range and the Dar dere (Ovgos) Fault Zone of the south. Most of the faults in the Girne (Kyrenia) Range are attributed to Mid – Late Eocene and Late Miocene – Early Pliocene phase of thrusting, followed by relative quiescence until Pleistocene uplift of the Girne (Kyrenia) Range. The Dar dere (Ovgos) Fault Zone is interpreted as a long-lived terrane boundary that accommodated sinistral movement during Late Miocene to Recent. In summary, the Girne (Kyrenia) Range reflects the diachronous closure of the Mesozoic Southern Neotethys Ocean, culminating in westward tectonic escape from continent-continent collision zone to the east, coupled with thick-skinned uplift that was triggered by collision with a crustal block to the south, the Eratosthenes Seamount.

This thesis covers different topics in the field of synthetic organic chemistry combined with the field of surface science and glycobiology. First, the text presents a series of orthogonally protected oligosaccharides (tri-, penta-, and heptasaccharides) of varying length and structures, which are synthesized with the aim of developing novel heterobifunctional biocompatible cross-linkers. Successful conjugation with different chemical handles is also described and used to illustrate the potential implementation of defined carbohydrate based compounds have potential use in biosensing applications. The results of incubation experiments using living cells indicate that the linker is incorporated into cell surfaces and enriched in microdomains. Second, synthesis of various saccharide-terminated alkane thiols immobilized on gold surfaces is reported. The protein adsorption and antifouling characteristics of these surfaces were investigated using model proteins and the common fouling organisms, Ulva linza and Balanus amphitrite. Further, oligo(lactose)-based thiols (di-, tetra-, and hexasaccharides) were synthesized and immobilized on gold nanoparticles to investigate how well these rigid, rod-like oligosaccharides can stabilize such nanoparticles for future use in constructing hybrid nanoparticles. Finally, the thesis describes synthesis of a systematic series of oligo(ethylene) glycols possessing either hydrogen- or methyl-terminated groups. Investigation of the fundamental characteristics of self-assembled monolayers, will give important insights into the design of protein repellant surfaces.

This dissertation can be divided into two parts project goals. The first one is the synthesis of rhenium (Re) complexes which are potential reverse saturable absorber (RSA) materials. The second one is the polymerization of ruthenium (Ru) polypyridyl monomers to have an oligomer ensemble for solar light harvesting purposes. THE FIRST part starts with an introduction to optical limiting materials (OLM) (chapter 1). The main discussion in chapter 4 is about the photophysical properties and energy-transfer reactions for three series of facial Re(I) tri-carbonyl complexes. The complexes are of the general type fac-[Re(CO)3(N-N)Cl], where Cl is the chloride and N-N are novel mono functionalized aryl-oligo(p-phenylene-vinylene) bipyridine (bpy) ligands. These series is as a result of changing the aryl group of the ligands to either anthracene or pyrene, and di-alkoxy attachments of phenyl ring in anthracene bipyridine ligands. The synthesis of the bpy ligands involved attaching various aryls by utilizing successive multi-step Wittig-Horner reactions (chapter 2). The ligands were later reacted with Re pentacarbonyl chloride to obtain the complexes. Chromium complexes synthesis is also included (chapter 3). The characterization involved 1H NMR, ESI-MS and elemental analysis. There is also another set of ligands where the aryl group is di-methylaminophenyl where the solvatochromic emission properties of the ligands were studied but were not coordinated to metals. The excited-state properties using both the nanosecond (ns) and picosecond (ps) time resolved transient absorption (TA) of Re(I) complexes shows strong positive excited-state absorption signals in 500-800 nm range. From the TA (ps) and time-resolved infrared of the carbonyl region, the excited state forms instantaneously after excitation. Their observed lifetimes are relatively long (2 μs-40 μs range) and they increase as the phenylene-vinylene linker increases. The excited state triplet energies values for the complexes were obtained experimentally using energy transfer method from the simple Sandros relation. They decreases as the π-conjugated phenylene-vinylene linker decreases, this is because the extended backbone bridge serves to lower the energy of the triplet excited state. Lastly, the Re(I) complexes triplet-triplet molar extinction coefficients(δex) were measured by energy transfer to a standard method and their ratios to the ground state molar absorptivity(δg ) are all (δex/δg ≥40) at 530nm which make them potential candidates for RSA. THE SECOND part involves RAFT polymerization of two new acrylamide functionalized Ru(II) polypyridyl monomers. Photoinduced electron transfer reactions for the obtained Ru oligomers and complexes were done using 10-methylphenothiazine (MPT) quencher (chapter 8). The synthesized acrylamide functionalized bipyridine ligand (chapter 6) was reacted with complex precursors cis-[Ru(L)2Cl2] where the ligand (L) is either 2,2’- bipyridine or biquinoline (chapter 7). The obtained Ru(II) photosensitizers acts as energy donating and accepting respectively. The attachment of these Ru complexes to oligomer backbone as side chains is by a C11 alkyl linker. 1H NMR, UV-Vis spectroscopy, and differential pulse voltammetry (DPV) were used to characterize the ligand, monomers and oligomers. The excited state REDOX potentials were determined using the cyclic voltammetry (CV) values and steady state emission values converted to electron volt (eV). Lastly, the TAs (ns) obtained in the presence of MPT electron donating quencher was in agreement with the ones calculated/ predicted from spectroelectrochemistry. These efforts are toward the goal of making a panchromatic solar light collector in the visible region (chapter 5). / acase@tulane.edu

La paléohydrologie permet l'estimation des paramètres hydrologiques allant de la géométrie du chenal à celle du bassin versant, en passant par la dynamique des écoulements et le climat. Bien que les systèmes fluviatiles soient connus pour évoluer sous contrôle de paramètres allo- et auto-cycliques, leur influence n'a que peu été prise en compte dans les études antérieures. Nos travaux exposent une méthode originale de restitution paléohydrologique, basée sur la hauteur des barres de méandre (hauteur d'eau) et contrainte par le climat. Des équations originales exprimant les différents paramètres hydrologiques en fonction de la hauteur d'eau sont développées à partir de données hydrologiques actuelles appartenant à deux domaines climatiques différents. Ces lois sont validées à travers une application à deux cas d'étude géologiques bien contraints : les systèmes méandriformes Oligo-Miocène subtropical semi-humide d'avant-pays alpin (SE France) et subtropical à saisons sèches d'avant-pays ibérique (Centre Espagne). Les restitutions paléohydrologiques sont en parfait accord avec les zones source et les vitesses d'écoulement fournies par les données de terrain. Les influences respectives du climat, de la tectonique et du niveau de base sont quantifiées et discutées à travers les résultats paléohydrologiques. Les restitutions paléo-hydro-climatiques montrent la mise en place à l'Aquitanien inférieur d'un gradient climatique entre l'Espagne et la France et l'enregistrement de l'épisode froid du Mi1. L'analyse des changements de tailles des systèmes met en évidence le passage de régime méandriforme à anabranché en réponse à des déformations tectoniques liées à la création des Alpes.

Deficiencies of selenium (Se) and iodine (I) are widespread in livestock all over Europe. They have an impact on the animals health. Since the clinical signs of the deficiencies are rarely pathognomic, auxiliary exams, based on blood and milk samples are needed for the confirmation of the diagnosis. To evaluate the Se and I status, the plasmatic Se content, the erythrocytic glutathione peroxydase activity (GPX), and the inorganic plasmatic I (IIP) content are measured routinely. Other analyses, like e.g. the dosage of tri-iodothyronine (T3) or thyrotropine (bTSH) can be used. Once the deficiency is diagnosed, it can be corrected by several methods. The first aim of the study was to evaluate the zinc, copper, Se, and I status of Wallonian dairy and beef herds and to correlate their trace element status to their health. The trace element status of the herds with pathologies was less good than that of healthy herds. Further, more herds with pathologies had deficiencies when compared to healthy ones. Dairy herds had a better trace element status than beef herds. Se and I deficiencies are among the most important ones and have the most severe sequels. Therefore, the subsequent parts of the study focussed on these two trace elements. The second aim was the establishment of a technique for the dosage of bTSH and of reference values in healthy cattle. Reference ranges for bTSH and for thyroxine (T4) have been determined in healthy adult cows and in healthy calves. Thereafter, the next aim was to compare the concentration of bTSH in newborn calves with goitre to those obtained in healthy calves, in order to validate a diagnostic test for this pathology. The bTSH allowed the discrimination of the two groups and to approve the diagnosis of hypothyroidism in some of the calves. The threshold value of bTSH for the diagnosis of hypothyroidism in the newborn calf has been fixed at 35 µU/ml. The fourth aim was to compare the I (IIP) and Se (plasmatic Se, GPX) status as well as the thyroid status (bTSH, T4, T3, rT3) in dried pregnant cows and their calves and in non-pregnant cows, that received normal diet and a diet enriched in Se and I. In those receiving a Se and I enriched diet, the T4 and the bTSH decreased while the IIP, the T3, and the GPX activity increased. In the group that received a diet with normal Se and I contents, only the GPX activity increased. At birth, calves from mothers receiving the Se and I enriched diet, had a higher IPP content and GPX activity, and a lower bTSH concentration than calves from the other group. The last aim was to compare the effects of two different forms of Se (sodium selenite versus seleno-methionine) and two different doses of Se (0.1 versus 0.5 ppm) on the health and the Se status of Se deficient Belgian Blue cows and their calves. The first two groups of cows received a ration with 0.1 and 0.5 ppm, respectively, of Se in the form of sodium selenite (Na-Se 0.1 and Na-Se 0.5), while the third group received 0.5 ppm of Se in the form of seleno-methionine (Y-Se 0.5). The Se content of plasma, colostrum, and milk was higher in the cows of group Y-Se 0.5 when compared to the two other groups. The Se content of the plasma was higher in calves from group Y-Se 0.5 when compared to the two other groups. The daily weight gain of the Y-Se 0.5 group was higher than those of the group Na-Se 0.1. The incidence of diarrhoea among calves in group Na-Se 0.1 was higher than in group Y-Se 0.5. In conclusion, trace elements deficiencies are common in Wallonia and often they are multiple. They play a major role in the aetiology of multifactorial diseases diagnosed in the cattle herds. Deficiencies in Se and in I are most commonly implicated in clinical problems. The diagnosis of these deficiencies is determined by blood analyses. Therefore, the tests need to be differentiated according to their capacity to test the nutritional or the thyroid status. A simultaneous supplementation with I and Se, as well as the form of the supplemented Se, may modify the interpretation of the nutritional and the thyroid status. Better reproduction performances and a better health have been observed in herds with a normal trace element status. Furthermore, the advantage of the supplementation with Se in the form of seleno-methionine has been demonstrated in comparison to sodium selenite in deficient Belgian Blue cattle. This study opened numerous perspectives. The measurement of bTSH should be implemented in laboratories in order to offer it as a routine analysis to the practitioning veterinarian, who could use this tool in the framework of many diseases other than goitre. From a fundamental point of view, the dosage of deiodinases would allow the understanding of the regulation and of the synthesis of the thyroid hormones in bovines, and identifying the role of Se and I in this process. Finally, following the discoveries concerning the seleno-methionine, the effect of organic forms of other trace elements in bovine supplementation should be investigated. / Les carences en sélénium (Se) et en iode (I) sont répandues en Europe chez le bétail et ont des répercussions sur leur santé. Les signes cliniques de carence sont rarement pathognomoniques, ce qui nécessite le recours à des examens de sang ou de lait afin de confirmer le diagnostic. Pour évaluer le statut en Se et en I des bovins, le dosage du Se plasmatique, de lactivité de la glutathion peroxydase érythrocytaire (GPX) et de lI inorganique plasmatique (IIP) est réalisé en routine. Lévaluation du statut thyroïdien se fait principalement via la détermination de la thyroxine (T4) dans le plasma. Dautres analyses sont utilisables à cette fin, telles que la tri-iodothyronine (T3) ou la thyrotropine (bTSH). Une fois le diagnostic de carence posé, la carence peut être corrigée de diverses façons. Le 1er objectif de ce travail a été dévaluer les statuts en zinc, cuivre, Se et I dans les exploitations bovines laitières et viandeuses en Wallonie et de mettre en corrélation ces statuts avec létat de santé des troupeaux étudiés. Le statut en oligo-éléments (O-E) dans les troupeaux avec pathologies était moins bon que celui des troupeaux sains. De même, davantage de troupeaux avec pathologies étaient carencés par rapport aux troupeaux sains. Les troupeaux laitiers bénéficiaient de meilleurs statuts par rapport aux troupeaux viandeux. Les carences en Se et en I sont parmi les plus importantes et les plus lourdes de conséquences. La suite du travail sest donc focalisé sur ces 2 oligo-éléments. Le 2ème objectif a consisté à mettre au point un dosage de la bTSH et à établir des valeurs de référence chez des bovins adultes en bonne santé. Un intervalle de référence pour la bTSH et la T4 a été établi pour des vaches adultes saines et des veaux nouveau-nés sains. En corollaire, lobjectif suivant a été de comparer la concentration en bTSH trouvée chez des veaux nouveau-nés atteints dun goitre avec celle obtenue chez des veaux nouveau-nés en bonne santé, afin de valider un test diagnostique pour cette pathologie. La bTSH a permis de discriminer ces 2 groupes de veaux et détablir le diagnostic dhypothyroïdie chez certains veaux goitreux. Une valeur seuil de bTSH pour poser le diagnostic dhypothyroïdie chez des veaux nouveau-nés a été établie à 35 µU/ml. Le 4ème objectif a été de comparer les statuts en I (IIP) et Se (Se plasmatique, GPX) mais également le statut thyroïdien (bTSH, T4, T3, rT3) de vaches taries gestantes ou non et, le cas échéant, de leur veau, qui ont reçu une ration normalement pourvue ou enrichie en I et Se. Chez les vaches recevant une ration enrichie en Se et I, la T4 et la bTSH ont diminué alors que lIIP, la T3 et lactivité de la GPX ont augmenté. Dans le groupe recevant une ration normalement pourvue en Se et I, seule lactivité de la GPX a augmenté. A la naissance, les veaux provenant des mères ayant reçu une ration enrichie en Se et I avaient une concentration en IIP et une activité de la GPX supérieures et une concentration en bTSH inférieure par rapport aux veaux de lautre groupe. Le dernier objectif a été de comparer les effets sur la santé et le statut en Se de vaches BBB carencées et de leur veau de deux formes (sélénite de soude versus séléno-méthionine) et de deux doses différentes de Se (0,1 versus 0,5 ppm). Les deux premiers groupes de vaches ont reçu une ration avec respectivement 0,1 et 0,5 ppm de Se sous forme de sélénite de soude (Na-Se 0,1 et Na-Se 0,5), alors que le troisième groupe de vaches a reçu 0,5 ppm de Se sous forme de séléno-méthionine (Y-Se 0,5). Les concentrations en Se dans le plasma, le colostrum et le lait étaient plus élevées chez les vaches du groupe Y-Se 0,5 par rapport aux 2 autres groupes. La concentration en Se plasmatique était plus importante chez les veaux du groupe Y-Se 0,5 par rapport à celles des autres groupes. Le gain quotidien moyen des veaux du groupe Y-Se 0,5 était plus important par rapport à celui du groupe Na-Se 0,1. La prévalence de diarrhée des veaux du groupe Na-Se 0,1 était plus élevée par rapport à celle du groupe Y-Se 0,5. En conclusion, les carences en oligo-éléments sont fréquentes en Wallonie et souvent multiples. Elles interviennent de manière importante dans létiologie des troubles multifactoriels constatés dans les exploitations bovines. Les carences en Se et en I sont celles qui occasionnent le plus de répercussions cliniques. Le diagnostic de ces carences en particulier repose sur lutilisation de dosages sanguins. Il faut y distinguer ceux qui mesurent le statut nutritionnel en I et Se de ceux qui évaluent plutôt le statut thyroïdien. Une supplémentation simultanée en I et en Se peut modifier linterprétation des statuts nutritionnel et thyroïdien, de même que la forme sous laquelle le Se est apporté aux bovins. De meilleures performances zootechniques et une meilleure santé sont constatées dans les troupeaux supplémentés en O-E qui jouissent de statuts corrects. De plus, de ce point de vue, la supériorité de la supplémentation en Se sous forme de séléno-méthionine a été démontrée par rapport au sélénite de soude chez des bovins BBB carencés. De nombreuses perspectives se dégagent de ce travail. Le dosage de la bTSH est à implémenter dans des laboratoires en vue den faire une analyse de routine à disposition des vétérinaires praticiens qui pourraient ainsi utiliser cet outil dans le cadre de nombreuses autres pathologies que le goitre congénital. Dun point de vue plus fondamental, le dosage des désiodases permettrait daffiner la compréhension de la régulation de la synthèse des hormones thyroïdiennes chez le bovin, en précisant les rôles respectifs de lI et du Se à ce propos. Enfin, à linstar des découvertes concernant la séléno-méthionine, lintérêt annoncé des formes organiques des autres O-E chez les ruminants devrait être investigué plus avant.

Diagenetic studies of carbonate rocks focused for a long time on photozoan carbonate assemblages deposited in tropical climates. The results of these investigations were taken as models for the diagenetic evolution of many fossil carbonates. Only in recent years the importance of heterozoan carbonates, generally formed out of the tropics or in deeper waters, was realized. Diagenetic studies focusing on this kind of rocks are still scarce, but indicate that the diagenetic evolution of these rocks might be a better model for many fossil carbonate settings ("calcite-sea" carbonates) than the photozoan model used before.<br><br> This study deals with the determination of the diagenetic pathways and environments in such shallow-water heterozoan carbonate assemblages. Special emphasis is put on the identification of early, near-seafloor diagenetic processes and on the evaluation of the amount of constructive diagenesis in form of cementation in this diagenetic environment.<br><br> As study area the Central Mediterranean, the Maltese Islands and Sicily, was chosen. Here two sections were logged in Olio-Miocene shallow-water carbonates consisting of different kinds of heterozoan assemblages. The study area is very suitable for the investigation of constructive early diagenetic processes, as the rocks were never deeply buried and burial diagenetic pressure solution and cementation as cause of lithification could be ruled out. Nevertheless, the carbonate rocks are well lithified and form steep cliffs, implying cementation/lithification in another, shallower diagenetic environment. To determine the diagenetic pathways and environments, detailed transmitted light and cathodoluminescence petrography was carried out on thin sections. Furthermore the stable isotope (δ¹⁸O and δ¹³C) composition of the bulk rock, single biota and single cement phases was determined, as well as the major and trace element composition of the single cement phases.<br><br> Petrographically three (Sicily) to four (Maltese Islands) cementation phases, two phases of fabric selective and one of non-fabric selective dissolution, one phase of neomorphism and one of chemical compaction could be distinguished. The stable isotope measurements of the single cement phases pointed to cement precipitation from marine, marine-derived and meteoric waters. The trace element analysis indicated precipitation under reducing conditions, (A) in an open system with low rock-water interaction on the Maltese Islands and (B) in a closed system with high rock-water interaction on Sicily. For the closed systems case, aragonite as cement source could be concluded because its chemical composition was preserved in the newly formed cements.<br><br> By integrating these results, diagenetic pathways and environments for the investigated locations were established, and the cement source(s) in the different environments were determined. The diagenetic evolution started in the marine environment with the precipitation of fibrous/fibrous-bladed and epitaxial cement I. These cements formed as High Mg Calcite (HMC) directly out of marine waters. The paleoenvironmentally shallowest part of the section on the Maltese Islands was also exposed to meteoric diagenetic fluids. This meteoric influence lead to the dissolution of aragonitic and HMC skeletons, which sourced the cementation by Low Mg Calcitic (LMC) epitaxial cement II in this part of the Maltese section. Entering the burial-marine environment the main part of dissolution, cementation and neomorphism started to take place. The elevated CO2 content in this environment, caused by the decay of organic matter, lead to the dissolution of aragonitic skeletons, which sourced the cementation by LMC epitaxial cement II, bladed and blocky cements. The earlier precipitated HMC cement phases were either partly dissolved (epitaxial cement I) or neomorphosed to LMC (fibrous/fibrous-bladed and epitaxial cement I). In the burial environment weak chemical compaction took place without sourcing significant amounts of cementation. In a last phase the rocks entered the meteoric realm by uplift, which caused non-fabric selective dissolution. This study shows that early diagenetic processes, taking place at or just below the sediment-water-interface, are very important for the mineralogical stabilization of heterozoan carbonate strata. The main amount of constructive diagenesis in form of cementation takes place in this environment, sourced by dissolution of aragonitic and, to a lesser degree, of HMC skeletons.<br><br> The results of this study imply that the primary amount of aragonitic skeletons in heterozoan carbonate sediments must be carefully assessed, as they are the main early diagenetic cement source. In fossil heterozoan carbonate rocks, aragonitic skeletons might be the cement source even when no relict structures like micritic envelops or biomolds are preserved. In general, the diagenetic evolution of heterozoan carbonate rocks is a good model for the diagenesis of "calcite-sea" time carbonate rocks. / Diagenetische Untersuchungen an Karbonatgesteinen beschränkten sich lange Zeit auf photozoische Karbonatvergesellschaftungen der tropischen Breiten. Die Ergebnisse dieser Untersuchungen wurden als modellhaft für den Diageneseverlauf vieler Karbonatgesteine angesehen. Erst in den letzten Jahren wurde die Bedeutung heterozoischer Karbonatvergesellschaften, die sich im Allgemeinen außerhalb der Tropen oder in tieferem Wasser bilden, erkannt. Diagenetische Untersuchungen an dieser Art von Karbonatgesteinen sind immer noch selten, deuten aber an, dass der Diageneseverlauf in diesen Karbonaten ein besseres Model für viele fossile Karbonatgesteine ("Calcit-Meer"-Karbonate) darstellt als das bisher benutzte photozoische Diagenesemodel. Ziel dieser Studie war die Bestimmung des Diageneseverlaufs in solch flachmarinen Karbonaten mit heterozoischer Biogenvergesellschaftung. Die Milieus, in denen die diagenetischen Veränderungen stattfanden, sollten bestimmt werden. Besonderes Augenmerk lag auf der Art und Menge von Veränderungen, die frühdiagenetisch, nahe dem Meeresboden, stattfanden. Dabei war vor allem der Anteil an konstruktiver Diagenese in Form von Zementation von Interesse.<br><br> Das Arbeitsgebiet wurde im zentralen Mittelmeerraum gewählt und befindet sich auf den Maltesischen Inseln und Sizilien. Hier wurden zwei Profile in Flachwassserkarbonaten oligo-miozänen Alters aufgenommen, die sich aus unterschiedlichen heterozoischen Biogenvergesellschaftungen zusammensetzen. Dieses Arbeitsgebiet ist für die Untersuchung konstruktiver frühdiagenetischer Prozesse besonders geeignet, da die Gesteinsabfolgen niemals tief versenkt wurden und versenkungsdiagenetisch bedingte Drucklösung und Zementation als Ursache für die Lithifizierung ausgeschlossen werden können. Trotzdem sind die untersuchten Karbonatgesteine gut verfestigt und bilden steile Kliffs, was auf Zementation/Verfestigung in einem anderen, flacheren Diagenesemilieu hinweist. Zur Bestimmung der Diageneseabfolge und der diagenetischen Milieus wurden detaillierte petrographische Untersuchungen im Durchlicht und mit Kathodolumineszenz an Dünnschliffen durchgeführt. Außerdem wurden die Verhältnisse der stabilen Isotope δ¹⁸O und δ¹³C am Gesamtgestein, an einzelnen Biogenen und an einzelnen Zementphasen bestimmt. Die Haupt- und Spurenelement Zusammensetzung (Ca, Mg, Fe, Mn und Sr) wurde an den einzelnen Zementphasen ermittelt.<br><br> Petrographisch lassen sich drei (Sizilien), beziehungsweise vier (Maltesische Inseln) Zementationsphasen, zwei Phasen von materialabhängiger und eine Phase von materialunabhängiger Lösung, sowie eine Phase von Neomorphismus und eine chemische Kompaktionsphase unterscheiden. Die Messungen der stabilen Isotopenverhältnisse an den einzelnen Zementphasen deuten auf Zementausfällung aus marinen und meteorischen Wässern sowie aus Fluiden marinen Ursprungs hin. Die Spurenelementanalyse lässt außerdem auf Zementausfällung unter reduzierenden Bedingungen schließen. Diese fand einerseits, im Falle der Maltesischen Inseln, in einem offenen System mit geringer Gesteins-Wasser-Interaktion, andererseits, im Falle von Sizilien, in einem geschlossenen System mit großer Gesteins-Wasser-Interaktion statt. Bei der Zementation in einem geschlossenen System konnte Aragonit als Zementquelle bestimmt werden, da seine charakteristische chemische Zusammensetzung im neu gebildeten Zement erhalten blieb.<br><br> Durch die Integration aller Ergebnisse konnten für die beiden Lokalitäten die Diageneseabfolgen und die diagenetischen Milieus sowie die Zementquelle(n) in diesen Milieus bestimmt werden. Die diagenetische Entwicklung begann im marinen Milieu mit der Ausfällung von fibrösem bis fibrös-blättrigem und epitaxialem Zement I. Diese Zemente wurden als Hoch Magnesium Calcit (HMC) direkt aus marinem Wasser ausgefällt. Die paläogeographisch flachsten Abschnitte des Profils auf den Maltesischen Inseln gelangten dann unter den Einfluss meteorischer Wässer. Dieser meteorische Einfluss führte zur Lösung von aragonitischen und HMC Schalen, was die Zementation mit Niedrig (Low) Magnesium Calcitischem (LMC) epitaxialem Zement II in diesem Profilabschnitt speiste. Im marinen Versenkungsmilieu fand anschließend der Hauptteil an Lösung, Zementation und Neomorphismus statt. Der erhöhte CO2-Gehalt in diesem Milieu, verursacht durch den Zerfall von organischem Material, führte zur Lösung von aragonitischen Schalen, was die Zementation mit LMC epitaxialem Zement II, blättrigem und blockigem Zement speiste. Die vorher ausgefällten HMC Zementphasen wurden entweder teilweise gelöst (epitaxialer Zement I) oder in LMC umgewandelt (fibrös/fibrös-blättriger und epitaxialer Zement I). Im versenkungsdiagenetischen Milieu fand anschließend geringe chemische Kompaktion statt, ohne aber die Ausfällung von größeren Mengen an Zement zu speisen. In einer letzten Phase gelangten die Gesteine durch Hebung wieder ins meteorische Milieu, was materialunabhängige Lösungserscheinungen verursachte. Diese Untersuchung zeigt, dass frühdiagenetische Prozesse, die an der Sediment-Wasser-Grenzfläche oder knapp darunter stattfinden, sehr wichtig für die mineralogische Stabilisierung von heterozoischen Karbonatabfolgen sind. Der Hauptteil der konstruktiven Diagenese in Form von Zementation findet in diesem Milieu statt, gespeist durch die Lösung von aragonitischen und, zu einem geringern Teil, HMC Schalen.<br><br> Die Ergebnisse dieser Studie implizieren, dass der ursprünglich vorhandene Anteil an aragonitischen Schalen in heterozoischen Karbonatsedimenten sehr sorgfältig bestimmt werden muss, da diese Schalen die wichtigste frühdiagenetische Zementquelle darstellen. In fossilen heterozoischen Karbonatgesteinen können aragonitische Schalen die wichtigste Zementquelle darstellen, auch wenn keine Reliktstrukturen wie mikritische Hüllen oder Biomolds erhalten geblieben sind. Im Allgemeinen stellt der Diageneseablauf in heterozoischen Karbonaten ein gutes Modell für die Diagenese von "Calcit-Meer"-Karbonatgesteinen dar.

Ligament/tendon tissue engineering has the potential to provide therapies that overcome the limitations of incomplete natural healing responses and inadequate graft materials. While ligament/tendon fibroblasts are an obvious choice of cell type for these applications, difficulties associated with finding a suitable cell source have limited their utility. Mesenchymal stem cells/marrow stromal cells (MSCs) are seen as a viable alternative since they can be harvested through routine medical procedures and can be differentiated toward a ligament/tendon fibroblast lineage. Further study is needed to create an optimal biomaterial/biomechanical environment for ligament/tendon fibroblastic differentiation of MSCs. The overall goal of this dissertation was to improve the understanding of the role that biomechanical stimulation and the biomaterial environment play, both independently and combined, on human MSC (hMSC) differentiation toward a ligament/tendon fibroblast phenotype. Specifically, the effects of cyclic tensile stimuli were studied in a biomaterial environment that provided controlled presentation of biological moieties. The influence of an enzymatically-degradable biomaterial environment on hMSC differentiation was investigated by creating biomaterials containing enzymatically-cleavable moieties. The role that preculture may play in tensile responses of hMSCs was also explored. Together, these studies provided insights into the contributions of the biomaterial and biomechanical environment to hMSC differentiation toward a ligament/tendon fibroblast phenotype.

An iterative protocol is a highly efficient strategy for the generation of large, complex molecules that has been applied in many different subfields of organic synthesis. The use of a tandem or cascade reaction is also an effective approach for the rapid introduction of molecular complexity into a system since the number of steps requiring independent optimization is greatly reduced. With the aim of creating new synthetic strategies to efficiently gain access to stereochemically complex small molecules, we envisioned the use of short iterative protocols to prepare reactive oligomers to which a diverse range of cascade cyclization processes could be applied. In an attempt to minimize reaction optimization and chromatographic purification steps during the development of our small molecule precursors, we first developed an iterative synthesis based on a conjugate addition/reduction sequence that has allowed us to access a diverse series of oligo-vinyl ether intermediates. Significantly, both the addition and reduction steps proceed in near-quantitative yield, and reaction co-products can be removed without column chromatography. At the same time, most of our vinyl ether intermediates are stable to silica gel, and so analytically pure samples can be prepared when desired. Except for when very sterically demanding substrates are employed as electrophiles, the intermediates are isolated as single geometrical isomers. We also developed an improved synthesis of a previously intractable class of alkynoate starting materials (4-aryl-2-butynoates) to ensure a diverse range of easily accessible monomeric building blocks were available for our use. With this effective iterative route in hand, we have several interesting small molecule targets at our disposal. We first applied our iterative route to synthesize oxygen-containing analogues of juvenile hormone III. These mono- and bis-vinyl ethers are currently undergoing biological testing (in collaboration with Dr. Steve Perlman and Dr. Michael Horst), and early results show promise as ecologically degradable insect control agents. We also developed an unprecedented 6-endo/5-exo radical cascade reaction across bis-vinyl ethers which proceeds in good yield, high diastereoselectivity, and excellent regiochemical control. This reaction represents the first cascading radical cyclization ever reported for a bis-vinyl ether system and validates our iterative approach to molecular complexity. / Graduate

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