Synthesis and acid-catalyzed polymerization of 1,6-anhydro-beta-D-glucopyranose derivatives.

The protic acid-catalyzed polymerization of 1,6-anhydro-6-D-glucopyranose (I) was first reported one-half century ago; however, the mechanism of this reaction has not been resolved and is the topic under investigation in this thesis. In an attempt to resolve this mechanism, a number of 1,6-anhydrides structurally related to 1,6-anhydro-B-D-glucopyranose (I) were prepared and polymerized. The C-2, C-3, or C-4 hydroxyl group was either specifically blocked, replaced by a hydrogen atom or positioned different sterically. The relative rates of disappearance of monomer in the polymerization reaction were measured and this information used to propose a reaction mechanism.Ph.D

The flocculation of papermaking fibers.

see pdfPh.D

Cultural effects on musical preferences: An fmri study

Bu tez çalısmasında kisinin bir müzik parçasını "begenip-begenmedigini" ifade etmesindeki etkenler incelendi ve katılımcıların tepkilerinin beyinde izlenebilirligi arastırıldı. Dört farklı türde müzik örnegi 22–37 yas aralıgında, saglıklı, sag el baskın on bir kadın, on üç erkek toplam yirmi dört katılımcıya fMRI (fonksiyonel manyetik rezonans görüntüleme) çekilirken dinletildi ve aktif olan beyin bölgeleri belirlendi. Daha sonra katılımcılarla görüsmeler yapılarak kisilerin kültürel geçmisleri, müzik begenileri ve dinletilen müzikleri begenip-begenmedigi belirlendi. En sonra da katılımcıların ifade ettigi müziksel tercihler ve dinletilen müzik örnegini begenme durumu ile fMRI taramasından çıkan beyin görüntülerinin sonuçları karsılastırıldı. "Müzik begenisi" ile "beyin" arasındaki iliskiyi arastıran bir çalısmanın olmaması ve insanın "müzigi begenme / begenmeme" islemiyle ilgili beyin bölgelerinin henüz belirlenememis olması bu tezin kısıtlılıklarındandır. Bu konuya da odaklanmaya çalısılan bu tezde, fMRI çekiminde belirlenen bazı beyin bölgelerinin literatürle karsılastırıldıgında bu islemle ilgili oldugu tahmin edilse bile bu kanıtlanamadı. Kültürel etkenlerin müzik begenisine olan katkısının ve insan beyninde "müzigi begenme" bölgesinin belirlenmeye çalısıldıgı bu tezde; istatistiksel olarak anlamlı bir sonuca ulasılamasa da, "kültürel olarak etkilenmenin kisinin söylemlerini degistirdigi" varsayımı dogrulandı. Katılımcıların müzik begenileri gözetilmeden seçilen bu örneklerde yanıtları aranılan ilk sey, katılımcıların türler hakkında düsündükleri, müzik begenileri içinde yer alıp almadıgı ve bu begeniyi olusturan kültürel etkenlerin varlıgının arastırılmasıydı. Alınan yanıtlarla fMRI çekimlerinin karsılastırılması ve sonuca gidilmesi ise ikinci asamayı olusturdu. Müzik begenisinde kültürel etkenlerin saptanmasının o denli kolay olmadıgı bilinmekteydi kaldı ki elde edilen sonuçlar katılımcıların dinletilen müziklere verdikleri tepkilerin ne denli degisken ve ilginç oldugunu ortaya koydu. Müzik begenisini tanımlama yolunda verilen ugrasların aslında net seyler ortaya koyamayacagı saptandı. In this thesis research the reasons behind the participants' declarations as "pleasant - unpleasant" about a musical piece and the traceability of their responses in the brain are searched. Musical pieces from four different genres are listened by eleven women and thirteen men ( age between 22-37) in an fMRI setting and their brain activations are observed. After the fMRI experiment interviews are made with the participants in order to determine their cultural background, musical tastes and their responses to those musical pieces used in the experiment. Finally participants' declarations about their musical preferences and responses to musical pieces are compared with their fMRI scans. Two points can be mentioned about the limitations of this study: first, there are not any study on the relation of "musical taste" and "brain", second still there's no brain region determined in relation with musical tastes. Although this relation is tried to be concentrated on, when brain regions determined from fMRI scans are compared with the ones found on the literature, only some suggestions about this relation could be expressed without any robust proof. However even there could not be found any meaningful statistical results, the hypotheses, "cultural effects could change one' discourses" is confirmed. Firstly participants' thoughts on musical genres, their genre tastes and cultural backgrounds that constitute these tastes are searched in this study where musical pieces are determined without considiring participants' tastes. Secondly these interview results are compared with fMRI scans. It was clear that determination of cultural effects on musical tastes were not easy. Nevertheless the results showed that participants' responses to musical pieces are highly variable and interesting. As a result it can be said that studies on the determination of musical tastes would never give explicit conclusions

Expansion of the APC superfamily of secondary carriers.

The amino acid-polyamine-organoCation (APC) superfamily is the second largest superfamily of secondary carriers currently known. In this study, we establish homology between previously recognized APC superfamily members and proteins of seven new families. These families include the PAAP (Putative Amino Acid Permease), LIVCS (Branched Chain Amino Acid:Cation Symporter), NRAMP (Natural Resistance-Associated Macrophage Protein), CstA (Carbon starvation A protein), KUP (K⁺ Uptake Permease), BenE (Benzoate:H⁺ Virginia Symporter), and AE (Anion Exchanger). The topology of the well-characterized human Anion Exchanger 1 (AE1) conforms to a UraA-like topology of 14 TMSs (12 α-helical TMSs and 2 mixed coil/helical TMSs). All functionally characterized members of the APC superfamily use cation symport for substrate accumulation except for some members of the AE family which frequently use anion:anion exchange. We show how the different topologies fit into the framework of the common LeuT-like fold, defined earlier (Proteins. 2014 Feb;82(2):336-46), and determine that some of the new members contain previously undocumented topological variations. All new entries contain the two 5 or 7 TMS APC superfamily repeat units, sometimes with extra TMSs at the ends, the variations being greatest within the CstA family. New, functionally characterized members transport amino acids, peptides, and inorganic anions or cations. Except for anions, these are typical substrates of established APC superfamily members. Active site TMSs are rich in glycyl residues in variable but conserved constellations. This work expands the APC superfamily and our understanding of its topological variations