“Xeno-pumice” describes a pumice-like material, high in silica content and vesiculation, found as a xenolith in a more mafic rock. A xeno-pumice is an indicator of magma-crust interaction; however, the origin, nature, and processes behind this xenolith are still debated. Xeno-pumice has been described in a few places worldwide, including the Canary Islands in Spain, Indonesia, Iceland, the USA, Chile and Mexico. This thesis, for the first time, presents and analyzes the mineralogy, textural features, whole-rock geochemistry (major and trace element), and oxygen isotopes of xeno-pumice samples found in Harrat Rahat, Saudi Arabia. Harrat Rahat is a volcanic field whose last eruption was in 1256A.D. and reached the outskirts of Madinah, one of the main cities in Saudi Arabia. Harrat Rahat is characterized by a wide range of volcanic products: from basalts to trachyte. Previous studies suggested that this chemical variation has its source in the mantle and minor crustal contamination; however, the xeno-pumice samples found indicate magma-crust interaction. Thus, in this thesis, the crust-melt interaction hypothesis is addressed as a process that could modify the composition of the melt and thus the resulting volcanic products and eruptive style of the volcanic field. Indeed, the chemistry and oxygen isotope values of the studied volcanic rocks show a variation in composition, which is suggested to be the consequence of crust-melt interaction. The petrology, chemistry and oxygen isotope values suggest that the melt interacted with either the metamorphosed plutonic portion of the upper Arabian crust or with (meta-) sediments below Harrat Rahat. Finally, this thesis proved that magma-crust interaction occurred at Harrat Rahat, which has important implications for interpreting eruption mechanisms and mantle sources.

L’objectif de ce travail de thèse est d’évaluer le potentiel de nouveaux bio-essais in vitro et in vivo basés sur le poisson zèbre pour la biosurveillance de la contamination chimique de l’eau par les xeno-estrogènes. Pour cela, les bio-essais ont été appliqués pour évaluer les effets de polluants aquatiques environnementaux seuls, mais aussi en mélanges simples (reconstitués) et complexes (échantillons environnementaux). L’évaluation d’échantillons d’eau à travers les bioessais in vitro humain (MELN) et poisson zèbre (ZELH-zfERβ2) a montré des différences qualitatives et quantitatives de réponse, non expliquées par les molécules estrogéniques détectées. Afin de mieux comprendre ces différences, l’activité de polluants aquatiques a été caractérisée sur les différents modèles, individuellement et au sein de mélanges de 2 à 12 polluants, combinant molécules estrogéniques et non estrogéniques pour simuler des situations environnementales.Les résultats obtenus montrent que les bio-essais basés sur le poisson zèbre répondent différemment, et parfois de manière opposée, au modèle humain MELN aux mélanges reconstitués. Ces différences s’expliquent par des sensibilités différentes à certaines molécules entrainant des interactions avec la réponse aux xeno-oestrogènes spécifiques à chaque modèle biologique. Dans son ensemble, ce travail montre que les particularités biologiques de chaque bioessai peuvent influencer la réponse des xeno-estrogènes quand présents au sein de mélange avec d’autres polluants. Ces résultats sont discutés au regard de l’utilisation de bio-essais dans l’évaluation de la contamination chimique des masses d’eau. / This PhD thesis aims at assessing the potential of innovative in vitro and in vivo zebrafish based bioassays for biomonitoring of surface water contamination by xeno-estrogens. For this purpose, the bioassays were applied to assess the effect of environmentally relevant surface water pollutants, alone and in simple (artificial) and complex (environmental samples) mixtures. The screening of surface water samples in zebrafish- (ZELH-zfERβ2 cells) and human-based (MELNcells) bioassays revealed qualitative and quantitative differences which could not be entirely explained by the xeno-estrogens identified. To better understand the response of bioassays to complex environmental mixtures, the activity of environmentally relevant surface waterpollutants was characterized across the bioassays, alone and in 2 to 12-component mixtures combining estrogenic and non-estrogenic chemicals to simulate an environmental contamination.The results indicate that zebrafish-based bioassays have a different and even in some cases an opposite response to the simple mixtures compared with the human-based bioassay MELN. These differences are explained by different sensitivity to some pollutants leading to bioassay-specific interactions with estrogen receptor activation. Al together, this work shows that the biological particularities of each bioassay can influence the response to estrogenic chemicals when mixed with other environmental pollutants, opening the discussion regarding their implementation in chemical water biomonitoring.

In this dissertation, the denaturalization of migrants in the US and Italy as represented in newspaper crime reports was identified and compared to the opposing naturalization of Italian crime organizations in Italy and Wall Street/ corporate criminals in the US. This was accomplished through careful, multidisciplinary, scientific analysis of over 100 articles taken from Italian and US newspapers of assorted political tendencies from the years 2004-2010. Quantitative and qualitative methods were combined beginning with a corpus analysis of texts from each group studied followed by a topic analysis designed to identify topics discussed in the media for each group analyzed. In addition, lexical choices were categorized as denaturalization, naturalization or derogation, and examples from texts were examined in depth to reveal linguistic (such as metaphor) strategies involved in negative or positive representation of these groups. A Critical Discourse Analysis Approach combined with Social Semiotics and grounded in Social Identity and Nationalism theories was employed to reveal an underlying racist and xenophobic ideology in both Italian and US media. Results show that in both the United States and Italy, the highlighting of migrants' lack of proficiency in the host country language as well as cultural practices functions as evidence of how migrants are different thus justifying discriminatory practices against them. The resulting categorization of migrants as "Them" serves the dominant group's purpose of staying in power. In conclusion, the author points to a need for teacher educators in the field of second language education and literacy to make it a top priority to educate teachers and students as to how discourse contains underlying ideologies and how to think critically to de-construct and de-mystify them.

Thesis advisor: Jia Niu / Nucleic acid aptamers are promising alternatives to antibodies for a wide array of diagnostic and therapeutic applications. However, state-of-the-art aptamers suffer from poor pharmacokinetics and diversity, limiting their affinity and specificity for many therapeutically relevant targets. The emerging field of glycoscience provides opportunities to improve the utility of aptamers over antibodies. Combining synthetic chemistry with modern molecular biology and polymer science, the synthesis of Xeno Nucleic Acid monomers and chemoenzymatic polymerization via engineered polymerase enzymes allows the production of nucleic acid drugs with superior resistance to endogenous nucleases. The modular structure of nucleic acids provides for the design of sequence defined polymers capable of post-synthetically appending complex synthetic glycans, extending the catalytic geometry of aptamers. Our SELEX inspired FACS based particle display approach allows for high-throughput screening. Additionally, we expect this method has the capability of screening aptamers in human serum. Our synthetic approach utilizes a Sonogashira cross-coupling reaction to install a flexible alkyne to the major groove of 2′-deoxy-2′-fluoro-arabinose uracil base. By incorporated recent advances in nucleic acid synthesis, one-pot nucleobase activation and sugar glycosylation is achieved and bis-oxybenzyl phosphoamidite synthesis can afford gram scale HPLC-free purification of the triphosphates. The FANA C8-alkyl-uridine triphosphate will be incorporated by an engineered Tgo DNA polymerase to allow systematic introduction of alkynyl conjugation handles into a DNA-templated FANA polymer. Subsequent conjugation with azido-modified glycans via the Huisgen coppercatalyzed alkyne-azide cycloaddition (CuAAC) click reaction will generate sequence controlled nucleic acid-carbohydrate hybrid molecules amendable for directed evolution. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Knowledge of the provenance of crustal volatiles and the processes by which they are released is extremely important for the dynamics of magmatic systems. Presented here are the results of multiple investigations, which aim to understand magmatic volatile contamination from contrasting but complementary perspectives. The main methodologies used include He and C isotope values and CO2/3He ratios of volcanic gases and fluids; simulation of magma-carbonate interaction using high-pressure high-temperature experimental petrology; X-ray microtomography of vesiculated xenoliths and computer modeling. Findings show that the contribution from upper crustal volatiles can be substantial, and is dependant on the upper crustal lithology on which a volcano lies, as well as the composition of the magma supplied. Carbonate dissolution in particular is strongly controlled by the viscosity of the host magma. The details of the breakdown of vesiculated xenoliths is complex but has wide reaching implications, ranging from the dissemination of crustally derived materials through a magma body to highlighting that crustal volatiles are largely unaccounted for in both individual volcano and global volatile budgets. In synthesizing the conclusions from each of the individual perspectives presented, I propose the contribution of volatiles from crustal sources to play a significant role in many geological systems. This volatile component should be taken into consideration in future research efforts.

Mammalian estrogens and estrogen-like compounds known as xeno-estrogens are being found in and excreted into the environment in ever increasing amounts. The xeno-estrogen DDE has been found at high concentrations of 1-5 mg/kg of soil (Aislabie et. al, 1997). These estrogens and xeno-estrogens are having a devastating effect on animal-life, yet little is known or understood on the effects of estrogens on plant-life. Thus it is important to determine what effects (if any) estrogens may have on plants. Other research has shown that estrogen has an effect on plants grown in vitro (Janeczko and Skoczowski, 2005). This research aims to help increase the amount of information on what effects estrogens may have on plants. In this study, the effects of mammalian estrogens (17-β-estradiol, estrone and estriol) on the growth and tuberization of potato plants (Solanum tuberosum L. cv 'Iwa') grown in liquid tissue culture medium are presented. It was found that at even 0.1 mg/L of estrogen, root growth of the plants was diminished and at 10 mg/L of estrogen, plant deformity was apparent and callus growth induced. Acid phosphatase activity of the plants was increased with the addition of 0.1 mg/L and 1 mg/L of estrogen but then decreased with the addition of 10 mg/L of estrogen. Tuber production was slightly reduced in plants treated with estrogen compared to the control.

<p>A number of environmental pollutants have been shown to mimick the action of the female sex hormone estrogen and are, therefore, suspected to be responsible for reproductive abnormalities seen in wildlife. Test systems which can be used in hazard and risk assessment of chemicals with estrogenic effects are consequently needed. In this thesis, I propose the avian egg as an <i>in vivo</i> test system for estrogenic compounds. I conclude that malformation of the left testis and the Müllerian ducts (MDs: embryonic oviducts) in avian embryos can be used as endpoints to examine estrogenic activity of chemicals. MD malformation is more easily determined and thereby faster to use as an endpoint than histologically observed feminization of the testis. The usefulness of MD/oviduct malformations as biomarkers for estrogenic effects in wild birds should be considered. </p><p>The environmental pollutants bisphenol A (BPA) and <i>o,p´</i>-DDT induced similar effects as the synthetic estrogens, ethynylestradiol and diethylstilbestrol. BPA caused MD malformations in quail embryos and ovotestis formation in chicken embryos. <i>o,p´</i>-DDT induced MD malformations in both quail and chicken embryos and ovotestis in chicken embryos. The flame retardant, tetrabromobisphenol A did not induce estrogen-like effects in quail or chicken embryos, but showed a relatively high embryolethality. </p><p>Embryonic exposure to estrogen caused persisting malformations of the oviduct, as well as a changed distribution pattern of the enzyme carbonic anhydrase in the shell gland of adult females. Considering the crucial role of carbonic anhydrase in shell formation, such changes could result in decreased shell quality. I propose that eggshell thinning in avian wildlife could reflect a functional malformation in the shell gland that is induced by xeno-estrogens during embryonic development, rather than being caused by exposure of the adult bird to environmental pollutants. This hypothesis opens new possibilities for studying the mechanisms behind contaminant-induced eggshell thinning in birds.</p>

A number of environmental pollutants have been shown to mimick the action of the female sex hormone estrogen and are, therefore, suspected to be responsible for reproductive abnormalities seen in wildlife. Test systems which can be used in hazard and risk assessment of chemicals with estrogenic effects are consequently needed. In this thesis, I propose the avian egg as an in vivo test system for estrogenic compounds. I conclude that malformation of the left testis and the Müllerian ducts (MDs: embryonic oviducts) in avian embryos can be used as endpoints to examine estrogenic activity of chemicals. MD malformation is more easily determined and thereby faster to use as an endpoint than histologically observed feminization of the testis. The usefulness of MD/oviduct malformations as biomarkers for estrogenic effects in wild birds should be considered. The environmental pollutants bisphenol A (BPA) and o,p´-DDT induced similar effects as the synthetic estrogens, ethynylestradiol and diethylstilbestrol. BPA caused MD malformations in quail embryos and ovotestis formation in chicken embryos. o,p´-DDT induced MD malformations in both quail and chicken embryos and ovotestis in chicken embryos. The flame retardant, tetrabromobisphenol A did not induce estrogen-like effects in quail or chicken embryos, but showed a relatively high embryolethality. Embryonic exposure to estrogen caused persisting malformations of the oviduct, as well as a changed distribution pattern of the enzyme carbonic anhydrase in the shell gland of adult females. Considering the crucial role of carbonic anhydrase in shell formation, such changes could result in decreased shell quality. I propose that eggshell thinning in avian wildlife could reflect a functional malformation in the shell gland that is induced by xeno-estrogens during embryonic development, rather than being caused by exposure of the adult bird to environmental pollutants. This hypothesis opens new possibilities for studying the mechanisms behind contaminant-induced eggshell thinning in birds.

Mammalian estrogens and estrogen-like compounds known as xeno-estrogens are being found in and excreted into the environment in ever increasing amounts. The xeno-estrogen DDE has been found at high concentrations of 1-5 mg/kg of soil (Aislabie et. al, 1997). These estrogens and xeno-estrogens are having a devastating effect on animal-life, yet little is known or understood on the effects of estrogens on plant-life. Thus it is important to determine what effects (if any) estrogens may have on plants. Other research has shown that estrogen has an effect on plants grown in vitro (Janeczko and Skoczowski, 2005). This research aims to help increase the amount of information on what effects estrogens may have on plants. In this study, the effects of mammalian estrogens (17-β-estradiol, estrone and estriol) on the growth and tuberization of potato plants (Solanum tuberosum L. cv 'Iwa') grown in liquid tissue culture medium are presented. It was found that at even 0.1 mg/L of estrogen, root growth of the plants was diminished and at 10 mg/L of estrogen, plant deformity was apparent and callus growth induced. Acid phosphatase activity of the plants was increased with the addition of 0.1 mg/L and 1 mg/L of estrogen but then decreased with the addition of 10 mg/L of estrogen. Tuber production was slightly reduced in plants treated with estrogen compared to the control.

Les poly(triazole amide)s sont une classe de polymères à séquences définies synthétisés par une approche « AB+CD » itérative, chimiosélective et supportée. Cette stratégie permet de contrôler parfaitement la séquence des monomères, puisque les unités constitutives sont ajoutées une à une. De plus, la chimiosélectivité des réactions de couplage permet de s’affranchir d’étapes de déprotection. En outre, l’utilisation d’un support solide minimise également le temps d’expérimentation et facilite les étapes de lavage, réduisant donc le temps total de synthèse. Cette voie de synthèse a été utilisée pour la préparation de différents types de polymères fonctionnels. Premièrement, plusieurs oligomères comme des structures composées de chaînes alkyles ou PEG ont été préparées, contenant des séquences de monomères non naturels qui forment un code binaire. Ces produits ont été analysés grâce à deux techniques de séquençage : la spectrométrie de masse en tandem et l’analyse de chaînes uniques par les nanopores. Une synthèse sans cuivre de ce type d’oligomères a également été considérée. Enfin, une nouvelle classe d’acides xénonucléiques (XNAs), les peptide triazole nucleic acids (PTzNAs), a été synthétisée et étudiée. En particulier, les propriétés d’hybridation de ces polymères contenant des séquences génétiques ont été examinées. / Poly(triazole amide)s are a class of sequence-defined polymers synthesized via a chemoselective iterative “AB+CD” approach on a solid support. This strategy allows to perfectly control the sequence of monomers, since the building blocks are added one by one. Moreover, the chemoselectivity of the coupling reactions enables to avoid the use of deprotection steps and to save time. In addition, the use of a solid support also minimizes the experiment time and facilitates the cleaning steps, thus reducing the total synthesis time. This synthesis pathway was used for the synthesis of different types of functional polymers. First of all, several oligomers such as structures based on alkyl or PEG chains were prepared, containing sequences of non-natural monomers that form a binary code. Those products were analyzed with two sequencing techniques: tandem mass spectrometry and nanopore single-chain analysis. A copper-free synthesis of this type of oligomers was also considered. Then, a new class of xeno nucleic acids (XNAs), peptide triazole nucleic acids (PTzNAs) was synthesized and studied. In particular, the hybridization properties of those natural sequence-containing polymers were investigated.