Obsidian has been a center of interest both for geologists and archaeologists. Geologists have studied on physical and chemical properties of obsidian where archaeologists have worked on this material as a common artifact found in excavations. In this study, obsidian samples from &Ccedil / atalh&ouml / y&uuml / k excavations are examined using their rare earth element (REE) concentrations. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) have been used for this purpose. A mixture (4:1) of lithium metaborate and lithium tetraborate was used for fusion of samples. Because of the low concentrations of REEs, a preconcentration step is needed. Successful recovery results have been achieved with Amberlite IR-120. The developed method is tested using the standard reference material SARM-1.

Idarubicin (IDA) and mitomycin C (MC) are clinically effective quinone-containing anticancer agents used in the treatment of several human cancers. Quinone-containing anticancer drugs have the potential to undergo bioreduction by oxidoreductases to reactive species, and thereby exert their cytotoxic effects. In the present study, we investigated, for the first time, the potential of IDA, in comparison to MC, to undergo reductive activation by NADPH-cytochrome P450 reductase (P450R), NADH-cytochrome b5 reductase (b5R) and P450R-cytochrome P4502B4 (CYP2B4) system by performing both in vitro plasmid DNA damage experiments and enzyme assays. In addition, we examined the potential protective effects of some antioxidants against DNA-damaging effects of IDA and MC resulting from their reductive activation. To achieve these goals, we obtained P450R from sheep lung, beef liver and PB-treated rabbit liver microsomes, b5R from beef liver microsomes and CYP2B4 from PB-treated rabbit liver microsomes in highly purified forms. The plasmid DNA damage experiments demonstrated that P450R is capable of effectively reducing IDA to DNA-damaging species. The effective protections provided by antioxidant enzymes, SOD and catalase, as well as scavengers of hydroxyl radical, DMSO and thiourea, revealed that the mechanism of DNA damage by IDA involves the generation of ROS by redox cycling of IDA with P450R under aerobic conditions. The extent of DNA damages by both IDA and MC were found to increase with increasing concentrations of the drug or the enzyme as well as with increasing incubation time. IDA was found to have a greater ability to induce DNA damage at high drug concentrations than MC. The plasmid DNA experiments using b5R, on the other hand, showed that, unlike P450R, b5R was not able to reduce IDA to DNA-damaging reactive species. It was also found that in the presence of b5R and cofactor NADH, MC barely induced DNA strand breaks. All the purified P450Rs reduced IDA at about two-fold higher rate than that of MC as shown by the measurement of drug-induced cofactor consumption. This indicates that IDA may be a more potent cytotoxic drug than MC in terms of the generation of reactive metabolites. The results obtained from enzyme assays confirmed the finding obtained from plasmid DNA experiments that while MC is a very poor substrate for b5R, IDA is not a suitable substrate for this enzyme unlike P450R. The reconstitution experiments carried out under both aerobic and anaerobic conditions using various amounts of CYP2B4, P450R and lipid DLPC revealed that reconstituted CYP2B4 produced about 1.5-fold and 1.4-fold rate enhancements in IDA and MC reduction catalyzed by P450R alone, respectively. The present results also showed that among the tested dietary antioxidants, quercetin, rutin, naringenin, resveratrol and trolox, only quercetin was found to be highly potent in preventing DNA damage by IDA. These results may have some practical implications concerning the potential use of P450R as therapeutic agent on their own in cancer treatment strategies. Selective targeting of tumor cells with purified P450R by newly developed delivery systems such as using polymers, liposomes or antibodies may produce greater reductive activation of bioreductive drugs in tumor cells. Consequently, this strategy has a high potential to increase the efficacy and selectivity of cancer chemotherapy.

Kitchen waste, which is collected in large amounts from cafeterias, restaurants, dining halls, food processing plants, and household kitchens, have become a valuable material for bioprocess engineering. Due to the high carbohydrate fraction, kitchen waste has great potential to be used as a potential substrate for ethanol production. Utilization of it as a raw material in ethanol fermentation would also contribute to reduction of costs. In the first part of this study, the effect of pretreatment method and enzymatic hydrolysis on glucose production was evaluated. Dry baker&rsquo / s yeast, Saccharomyces cerevisiae, was used in fermentation experiments conducted with and without fermentation medium at pH 4.5 and 30oC for 48 hours. Close values of glucose concentration were obtained from no pretreated and hot water treated samples. The fermentation results indicated that ethanol can be produced at similar concentrations in bioreactors with and without fermentation medium addition (p &gt / 0.05). Thus, it is concluded that use of kitchen wastes as is disposed and without fermentation medium in ethanol fermentation could lower the cost to a large extent. In the second part of this study, the effects of solid load, which is proportional to the glucose concentration (10% to 20% (w/w)), inoculum level of Saccharomyces cerevisiae (5% to 15% (v/v)), and fermentation time (48 to 96 h) on production of bioethanol from kitchen waste were studied using Response Surface Methodology (RSM). A three-factor Box Behnken design was used. Ethanol concentration was used as a response in the resulting experimental design. High Pressure Liquid Chromatography (HPLC) method was used to determine ethanol and glucose concentrations. The statistical analysis of the constructed model developed by RSM suggested that linear effects of solid load, inoculum level, and fermentation time and quadratic effects of inoculum level and fermentation time were all significant (p &lt / 0.05) on bioethanol production. The model was verified by additional runs, which were not present in the design matrix. It was found that the constructed model could be used to determine successfully the bioethanol concentration with &gt / 90% precision. An optimum ethanol concentration of 32.16 g/L was suggested by the model with 20% (w/w) solid load, 8.85% (v/v) inoculum level and 58.8 hours of fermentation. Further study is needed to evaluate the optimal fermentation conditions in a large scale fermentation

No description available.

Rhizopus oryzae is a filamentous fungi which produces lactic acid and ethanol in fermentations. R. oryzae has numerous advantages for use industrial production of L-(+)-lactic acid but the yield of lactic acid produced on the basis of carbon consumed is low. Metabolic flux analysis of R. oryzae has shown that most of the pyruvate produced at the end of the glycolysis is channelled to ethanol, acetyl-CoA and oxaloacetate production. This study aimed to answer some questions addressed on the regulation of pyruvate branch point in R. oryzae and for this purpose biochemical characterisation of the enzymes acting at this branch point and cloning the genes coding for these enzymes have been done. Pyruvate decarboxylase was purified and characterised for the first time from R. oryzae. The purified enzyme has a Hill coefficient of 1.84 and the Km of the enzyme is 8.6 mM for pyruvate at pH 6.5. The enzyme is inhibited at pyruvate concentrations higher than 30 mM. The optimum pH for enzyme activity shows a broad range from 5.7 and 7.2. The monomer molecular weight was estimated as 59&plusmn / 2 kDa by SDS-PAGE analysis. Pyruvate decarboxylase (pdcA and pdcB) and lactate dehydrogenase (ldhA and ldhB) genes of R. oryzae have been cloned by PCR-cloning approach and the filamentous fungi Aspergillus niger was transformed with these genes. The A. niger transformed with either of the ldh genes of R. oryzae showed enhanced production of lactic acid compared to wild type. Citric acid production was also increased in these transformants while no gluconate production was observed Cloning of hexokinase gene from R. oryzae using degenerate primers was studied by the use of GenomeWalker kit (Clontech). The results of this study were evaluated by using some bioinformatics tools depending on the unassembled clone sequences of R. oryzae genome.

Trotz weit entwickelter Technologien und dem weltweiten Zugang zu Informationen müssen diese immer noch von jedem einzelnen in Wissen umgewandelt werden, um sinnvoll und nützlich zu sein (Rüschoff, 1999). Um die immer wachsenden Sprachausbildung in der Lingua Franca Englisch zu unterstützen, wurde die Chemnitz InternetGrammar (CING) entwickelt. Sie vereint authentische Sprachmaterialien mit Grammatikübungen und Feedback sowie eine Auswahl von deduktivem und/oder induktivem Grammatikmaterial (Dual Approach) in einem einzigen web-basierten Selbstlernmmittel für fortgeschrittene Lerner. Um den Erfolg des besonderen CING Grammatikmaterials (Hypertext, DualApproach, Feedback) CING als Lehrmittel nachhaltig zu sichern, wurde das Programm einer empirischen Usability-Evaluation (im Sinne von Jakobs & Lehnen, 2005) unterzogen. Durch die Untersuchung wurde der Inhaltsrahmen der CING für die Grammatikstrukturen definiert, die in der empirischen Untersuchung verwendet wurden (Simple Past und Present Perfect). Ausserdem wurden die Lernfortschritte von Lernern mit der CING und deren Verhalten in der InternetGrammar beobachtet sowie ihre Erfahrungen mit dem Programm in Kommentaren zu lernrelevanten Aspekten (z.B. Autonomes Lernen, Verständlichkeit des Materials) ermittelt. Dabei werden zentral vor allem die Fragestellung der CING-eigenen Struktur der Grammatikthemen, des Hypertextverhaltens fortgeschrittener deutscher Englischlerner und die des autonomen Lernens mit Hilfe von quantitativen und qualitativen Forschungsmethoden untersucht. Die Ergebnisse der Studie zeigen, dass die InternetGrammar schon ein nützliches Grammatiklerntool ist, doch dass sein Einfluss durch Nutzerunterstützung in den verschiedenen Bereichen weiter verbessert werden kann. Ein Ansatz den die Autorin vorschlägt für einen neuen, verbesserten Einsatz der CING ist ein Lehrerunterstütztes Lernszenario wie Blended Learning (Kapitel 6), wo Lerner nur in Phasen mit Instruktoren zusammen arbeiten und sonst autonom lernen. Damit wird nicht nur fachliche (z.B. in der Fremdsprache) sondern auch die Ausbildung des Lerners zu einem autonomen, fähigen Nutzer moderner Lernmethoden ermöglicht. Nur unter diesen Voraussetzungen werden wir aktive Mitglieder einer modernen Wissensgesellschaft werden und uns ihre Vorzüge erfolgreich zu Nutzen machen können.

Le travail de cette thèse se situe dans le domaine de la sémantique nominale et porte sur un échantillon de noms dénotant les humains (NH) pendant les différentes phases de vie : bébé, enfant, adolescent, adulte, vieillard (N-[âge]). Elle poursuit un triple objectif. D’abord, il s’agit d’offrir une description linguistique fine d’un ensemble de N-[âge] dont le fonctionnement est resté méconnu jusqu’à présent. En démontrant leur caractère hybride – les N-[âge] dénotent à la fois des propriétés référentiellement essentielles et intrinsèquement transitoires – nous mettons en évidence des paramètres inédits pour la description des NH en général. Enfin, notre thèse explore la possibilité d’un élargissement notionnel du domaine aspectuel vers la sémantique nominale en interrogeant la notion de phase et en démontrant que l’ensemble des N-[âge] bénéficie d’une structure phasale. / This thesis research lies in the field of nominal semantics and focuses on a sample of nouns denoting humans (HN) during different stages of life: infant, child, teenager, adult, elderly (N-[age]). It is three fold. First, this works aims at offering a linguistic description of a set of N-[age] whose operation has remained unknown until now. Demonstrating their hybrid nature - N-[age] denote both referentially essential and intrinsically transient properties - we provide novel parameters for the description of HN in general. Finally, this thesis explores the possibility of notional extension of the aspectual domain to nominal semantics by questioning the concept of phase and by demonstrating that all N-[age] have a phasal structure.

The present study addresses the question of how taxpayers' perceptions of government and tax authorities are influenced by media coverage. The effect that national political topics, such as tax legislation and the expenditure of tax revenues, have on the tax payer is examined. Tax compliance depends on trust in authorities, i.e., a commonly shared belief that politicians and tax authorities act in order to promote social welfare, and the perceived power of authorities, i.e., taxpayers' perceptions of tax authorities' ability to detect and pursue tax crime. We investigate the influence of specific tax related information in the news on intended tax compliance. Results from a questionnaire-based experiment with 487 employees indicate that media coverage influences the indicated trust in tax authorities, as well as the perceived power of governmental institutions, and consequently, has an impact on participants' intended tax compliance. The findings suggest that governments should actively engage in the provision of relevant information on tax matters. This would increase both trust in the state and the authorities as well as awareness of their power regarding the enforcement of tax laws, effectively acting as a means to regulate taxpayers' behavior. (authors' abstract) / Series: WU International Taxation Research Paper Series

Trotz weit entwickelter Technologien und dem weltweiten Zugang zu Informationen müssen diese immer noch von jedem einzelnen in Wissen umgewandelt werden, um sinnvoll und nützlich zu sein (Rüschoff, 1999). Um die immer wachsenden Sprachausbildung in der Lingua Franca Englisch zu unterstützen, wurde die Chemnitz InternetGrammar (CING) entwickelt. Sie vereint authentische Sprachmaterialien mit Grammatikübungen und Feedback sowie eine Auswahl von deduktivem und/oder induktivem Grammatikmaterial (Dual Approach) in einem einzigen web-basierten Selbstlernmmittel für fortgeschrittene Lerner. Um den Erfolg des besonderen CING Grammatikmaterials (Hypertext, DualApproach, Feedback) CING als Lehrmittel nachhaltig zu sichern, wurde das Programm einer empirischen Usability-Evaluation (im Sinne von Jakobs & Lehnen, 2005) unterzogen. Durch die Untersuchung wurde der Inhaltsrahmen der CING für die Grammatikstrukturen definiert, die in der empirischen Untersuchung verwendet wurden (Simple Past und Present Perfect). Ausserdem wurden die Lernfortschritte von Lernern mit der CING und deren Verhalten in der InternetGrammar beobachtet sowie ihre Erfahrungen mit dem Programm in Kommentaren zu lernrelevanten Aspekten (z.B. Autonomes Lernen, Verständlichkeit des Materials) ermittelt. Dabei werden zentral vor allem die Fragestellung der CING-eigenen Struktur der Grammatikthemen, des Hypertextverhaltens fortgeschrittener deutscher Englischlerner und die des autonomen Lernens mit Hilfe von quantitativen und qualitativen Forschungsmethoden untersucht. Die Ergebnisse der Studie zeigen, dass die InternetGrammar schon ein nützliches Grammatiklerntool ist, doch dass sein Einfluss durch Nutzerunterstützung in den verschiedenen Bereichen weiter verbessert werden kann. Ein Ansatz den die Autorin vorschlägt für einen neuen, verbesserten Einsatz der CING ist ein Lehrerunterstütztes Lernszenario wie Blended Learning (Kapitel 6), wo Lerner nur in Phasen mit Instruktoren zusammen arbeiten und sonst autonom lernen. Damit wird nicht nur fachliche (z.B. in der Fremdsprache) sondern auch die Ausbildung des Lerners zu einem autonomen, fähigen Nutzer moderner Lernmethoden ermöglicht. Nur unter diesen Voraussetzungen werden wir aktive Mitglieder einer modernen Wissensgesellschaft werden und uns ihre Vorzüge erfolgreich zu Nutzen machen können.

Thema der Dissertation sind Nominalphrasen im Deutschen und Spanischen. Die Dissertation ist in 5 Abschnitte unterteilt. Das erste Kapitel gibt die Motivation der Arbeit, und im letzten Kapitel werden die Ergebnisse zusammengefasst und mögliche Erweiterungen diskutiert. Im zweiten Kapitel wird eine Einführung in den theoretischen Rahmen, die Head-Driven Phrase Structure Grammar (HPSG), gegeben und mit generativen Ansätzen verglichen. Dabei werden die Grundlagen und die Beschreibungsmechanismen der Theorie erklärt. HPSG ist ein oberflächenorientiertes, deklaratives, beschränkungsbasiertes Framework. Im dritten Kapitel werden vier zentrale syntaktische Begriffe besprochen und diskutiert: Kopf, Argument, Adjunkt und Spezifikator. Trotz ihrer Relevanz in der linguistischen Literatur werden diese vier Relationen verschieden interpretiert. Bei der Diskussion dieser syntaktischen Hauptrelationen werden die entsprechenden HPSG Mechanismen erklärt, mit denen sie beschrieben werden, u.a. das Semantik-Prinzip und das Kopfmerkmalsprinzip. Das vierte Kapitel der Dissertation beinhaltet Analysen für drei verschiedene Phänomene der NPs im Deutschen und Spanischen: Kasusmarkierung, optionale Argumente und pränominale Argumente. Deutsch und Spanisch unterscheiden sich in der Art und Weise, wie sie Kasus an ihren NPs markieren. Deutsch markiert sie morphologisch und Spanisch syntaktisch. Beide Arten der Markierung werden modelliert und verglichen. In Bezug auf die Optionalität von Argumenten wird zunächst die verbale Domäne betrachtet. Anhand dieser Analyse wird dann die nominale Domäne modelliert. Im letzten Teil wird eine Analyse für die pränominalen Argumente gegeben. Dabei werden folgende Aspekte betrachtet: Kombinatorik verschiedener Argumente, Theta-Rollenvergabe für die Argumente, Fakultativität der Argumente und Behandlung der (In-)Definitheit bei pränominalen Genitiven. / The topic of this dissertation are noun phrases in German and Spanish. This thesis is divided into five chapters. The first chapter presents the motivation of the work, and in the last chapter a summary is presented and discussed. In the second chapter, I give an introduction into the theoretical framework, Head-Driven Phase Structure Grammar (HPSG) by explaining its fundamental mechanisms, and compare it to generative approaches. HPSG is a surface oriented, declarative, constraint-based framework. In the third chapter, four central syntactic concepts are critically discussed: head, argument, adjunct, and specifier. Although these four concepts are highly relevant in the linguistic literature, they are often interpreted differently. While discussing these fours syntactic relations, I explain the main mechanisms of HPSG to describe them, e.g. the Semantic Principle and the Head Feature Principle. The fourth chapter contains analyses for three different NP phenomena in German and Spanish: case marking, optionality of arguments, and prenominal arguments. German and Spanish differ in the way they mark case on their NPs. German case-marks NPs morphologically, while case marking in Spanish is syntactic. Both types of marking are modelled and compared. Regarding argument optionality, I first look at the verbal domain and use this analysis to model optionality in the nominal domain. The last part of this chapter gives an analysis of prenominal arguments. The following aspects are considered: combinatory of a head noun with different arguments, theta role assignment for the arguments of a nominal head, optionality of arguments and treatment of (in-)definiteness in prenominal genitives.