Synthesis of unnatural amino acids for genetic encoding by the pyrrolysyl-tRNA/RNA synthetase system

The complexity of all biomolecules in existence today can be attributed to the variation of the amino acid repertoire. In nature, 20 canonical amino acids are translated to form these biomolecules, however, many of these amino acids have revealed posttranslational modifications (i.e. acetylation, methylation) after incorporation. Amino acids that exhibit PTM are known for their involvement in cellular processes such as DNA repair and DNA replication; these PTMs are commonly found on histones within the chromatin complex. Utilization of in vivo site-specific incorporation has recently reported functionality of post-translationally modified amino acids.1 xii Here we report the synthesis and in vivo site-specific incorporation of the histone PTM, 2-hydroxyisobutyrl lysine (Khib), with the pyrrolysyl tRNA/ RNA synthetase system. This translational machine can better serve to probe Khib for functional benefits. Additionally, this thesis focuses much of its attention on the development of unnatural amino acids (UAA) with optogenetic characteristics. These UAAs, if site-specifically incorporated, can be used to control enzymes and proteins through rapid light perturbation (365nm UV light). Furthermore, discussed is the synthesis of photo-caged threonine and photo-caged serine as potential substrates for the pyrrolysyl translational machinery

Rapid access to new angular phenothiazine and henoxazine dyes

The synthesis of some new thiophenyl-derivatized and furanyl-derivatized phenothiazine and phenoxazine dyestuffs is described. This was achieved by two methods after the synthesis of 6-chloro-5H-benzo[a]phenothiazin-5-one, 6-chloro-5H-benzo[a]phenoxazin-5-one, and 6-chloro-5H-naphtho[2,1-b]pyrido[2,3-e][1,4]oxazin-5-one intermediates via anhydrous base condensation reaction of 2,3-dichloro-1,4-naphthoquinone with 2-aminothiophenol, 2-aminophenol, and 2-aminopyridinol, respectively. The first method involved treatment of tributyl(thien-2-yl) or tributyl(furan-2-yl) stannane with chlorophenothiazine/chlorophenoxazine under mild basic chemical formula (CsF) and 1,4-dioxane or toluene solvent at 80°C to supply dazzling yellow solid in high yields. In the second method, the catalytic system was pre-activated in acetonitrile, followed by addition of coupling partners and K3PO4 to obtain high melting and variety of highly colored products in moderate to high yields. The reaction conditions were compatible with unprotected N–H and carbonyl functional groups. The intense colors of these dyes and their ease of re-oxidation of Na2S2O4-reduced derivatives make them suitable as vat dyes. Also, they were found to be good colorants for textiles, papers, paint, ink, soap, polish, candle, and plastic materials

\u3ci\u3eMyxosoma funduli\u3c/i\u3e Kudo 1918 (Protozoa: Myxosporida) in \u3ci\u3eFundulus kansae\u3c/i\u3e: Summer Epizootiology

The occurrence and distribution of the myxosporidan Myxosoma funduli on the gills of the plains killifish (Fundulus kansae) were investigated; Fundulus kansae is reported as a new host. Host samples from various sites on the South Platte River, Nebraska, were collected during the summer months of 1975 and 1976. The protozoan parasite population was shown to be overdispersed within the host population, and this distribution was similar to that described by the negative binomial equation. Demographic characteristics of the infected fish subpopulation were virtually identical to those of the whole fish population. Infection intensity was independent of gill bar number or side. The frequency of bilateral infections was 0.54, of left only infections was 0.23, and of right only infections was 0.22. Distribution of immature and mature plasmodia indicated that a pre-existing infection did not preclude a new infection, and suggested a prepatent period of less than two months

Loss and assimilation: Lived experiences of Brexit for British citizens living in Luxembourg

Inconsistent political realities are associated with mental health issues such as hopelessness, anxiety, and depression. The psychological impact of Brexit is clearly an important and timely issue, but hitherto has been understudied. This study uses a critical realist approach to qualitatively explore the lived experiences of British citizens living in Luxembourg during the Brexit era. The study reports on semi-structured interviews conducted with 6 British citizens aged 18–65. An experientially focused thematic analysis was conducted, exploring two main themes: Loss (with psychological and broader social implications) and Integration (contrasting the mover’s community with the receiving community). This study demonstrates the psychological impact of Brexit and highlights the urgency for future researchers and mental health practitioners alike — both in the UK and overseas — to consider the human consequences associated with political upheaval. Open access materials for this project can be viewed here: https://osf.io/38rg7/?view_only=b8c04dfc3fe5474f9aff4897e370b3e6