Habilitationsschrift--Hamburg. / Includes bibliographical references (p. [111]-116).

Thesis (M.S.) -- Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.

Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2008. / Committee Chair: Wine, Paul; Committee Member: Huey, Greg; Committee Member: Nenes, Athanasios; Committee Member: Weber, Rodney; Committee Member: Whetten, Robert.

Thesis--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.71-72).

Thesis (M.S.)--Institute of Paper Chemistry, Lawrence College, 1939. / Includes bibliographical references (p. 75-77).

Thesis (Ph. D.)--University of Florida, 2003. / Title from title page of source document. Includes vita. Includes bibliographical references.

Thesis (Habilitationsschrift)--Friedrich-Alexander-Universität Erlangen-Nürnberg. / Includes bibliographical references (p. 225-232).

Universiẗat, Diss., 2004--Köln.

The misfolding and aggregation of the beta cell hormone islet amyloid polypeptide (IAPP) into amyloid fibrils is the main pathological finding in islets of Langerhans in type 2 diabetes. Pathological assemblies of IAPP are cytotoxic and believed to contribute to the loss of insulin-producing beta cells. Changes in the microenvironment that could trigger the aggregation of IAPP are largely unknown. So is the possibility that islet amyloid can spread within or between tissues. The present thesis have explored the roles of glycosaminoglycan heparan sulfate (HS) and the novel anti-amyloid chaperone Bri2 BRICHOS domain in the assembly of IAPP amyloid and cytotoxic IAPP aggregates. Furthermore, cross-seeding as a molecular interaction between the observed connection of type 2 diabetes and Alzheimer disease has been examined. The N-terminal region of IAPP was required for binding to HS structures and induction of binding promoted amyloid formation. Interference in the HS-IAPP interaction by heparanase degradation of HS or by introducing short, soluble HS-structure fragments reduced amyloid deposition in cultured islets. Cytotoxicity induced by extracellular, aggregating IAPP was mediated via interactions with cell-surface HS. This suggests that HS plays an important role in islet amyloid deposition and associated toxicity. BRICHOS domain containing protein Bri2 was highly expressed in human beta cells and colocalized with IAPP intracellularly and in islet amyloid deposits. The BRICHOS domain effectively attenuated both IAPP amyloid formation and IAPP-induced cytotoxicity. These results propose Bri2 BRICHOS as a novel chaperone preventing IAPP aggregation in beta cells. The intravenous injection of IAPP, proIAPP or amyloid-β (Aβ) fibrils enhanced islet amyloidosis in transgenic human IAPP mice, demonstrating that both homologous- and heterologous seeding of islet amyloid can occur in vivo. IAPP colocalized with Aβ in brain amyloid from AD patients, and AD patients diagnosed with T2D displayed increased proportions of neuritic plaques, the more pathogenic plaque subtype. In conclusion, both IAPP amyloid formation and the cytotoxic effects of IAPP is dependent on interactions with HS whereas interactions with Bri2 BRICHOS is protective. Cross-seeding between Aβ and IAPP can occur in vivo and the two peptides colocalize in brain amyloid in AD patients.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The extractive materials in wood often cause pitch problems in pulp mills. During pulping and bleaching extractives are released from the wood and pulp and later stick to ceramic and metal parts, forming pitch deposits. Pitch deposits impair both product quality and production rates. It decreases the efficiency of pulp washing, screening, centrifugal cleaning, and refining, and can disrupt many paper machine operations. The deposits also break loose from equipment and cause spots in the final product. There are a few triggering mechanisms that induce pitch deposition. Hydrodynamic or mechanical shear can destabilise the colloidal pitch emulsion, causing pitch to agglomerate and deposits to form. Similarly, sudden temperature drops and/or pH shocks and/or the introduction of water hardness ions from fresh water inlets or showers can also cause pitch deposits by destabilising the colloidal pitch emulsion. Inorganic salts, such as calcium carbonate, can catalyse pitch deposition by acting as the building blocks for the sticky pitch. Calcium ions in the white water can react with fatty acids, forming insoluble, sticky calcium soaps. Triglycerides have also been shown to be a major contributor to pitch deposition in kraft pulping and bleaching mills. It forms a sticky deposit to which less sticky particles attach. To attain an improved understanding of pitch problems associated with the kraft pulping and bleaching of Eucalyptus spp., various analyses were done on wood- and pulp extractives and pitch from a South African kraft pulp mill. High molecular weight compounds (involatile) constituted a large portion of the extracts and pitch. Approximately 40% of volatile Eucalyptus grandis extract was f3-sitosterol, with fatty acids (22.8%) and triglycerides (15.5%) also making a substantial contribution. Fatty acid amides were a prominent fraction of pulp extracts from the latter stages of bleaching. The amides constituted 38.3% and triglycerides 10.1% to total volatile pitch deposits. Lipases hydrolyse triglycerides and could therefore help to reduce pitch problems. Consequently 381 filamentous fungi isolated from indigenous and commercial forests in South Africa were screened for lipase activity on tributyrin and Tween 80. Eight strains were selected and the tributyrin and Tween 80 assays were repeated by monitoring lipase activity over a seven-day period. The selected strains were also assayed for their activity toward p-nitrophenyl palmitate. Ophiostoma piliferum Cartapip 58™ and Phanerochaete chrysosporium BKM-F-1767, two strains known for respectively their biodepitching and biopulping ability, were' used as controls. A few of the strains compared well and even outperformed the control strains, indicating their potential for use in pitch control. The effect of pretreatment with the eight selected fungal strains on E. grandis wood- and pulp extractives was determined. Cartapip 58™ and P. chrysosporium BKM-F-1767 were used as control strains. Several of the strains compared well to the control strains in their ability to reduce the triglyceride content of wood extract. The South African isolate, white-rot fungus Phanerochaete psuedomagnoliae nom. prov., reduced triglyceride content significantly. Consequently it can act as an agent for both biopulping and biodepitching. The treated wood samples had a lower triglyceride content than the sterile controls. Consequently more triglycerides would be released into process waters by the sterile controls than the treated samples. The effect of commerciallipases on deposited brown stock pulp extract was also evaluated. The lipases did not reduce the triglyceride content of the deposited extract. The addition of lipases in pulping and bleaching processes would therefore not affect already deposited pitch. / AFRIKAANSE OPSOMMING: Die ekstrakstowwe van hout veroorsaak dikwels 'n neerslag tydens verpulping. Gedurende verpulping en bleiking kom ekstrakstowwe van die hout enpulp vry en kleef aan keramiek- en metaalonderdele. Gevolglik benadeel dié neerslag produkkwaliteit en produksietempo. Dit verlaag die effektiwiteit van pulpwas, sifting, sentrifugale skoonmaakprosesse en suiwering, en kan die werkverrigting van papiermasjiene ontwrig. Die neerslag kan ook later los breek en kolletjies op die finale produk veroorsaak. Verskeie meganismes kan die neerslag veroorsaak. Hidrodinamiese of meganiese wrywing kan die kolloïdale ekstrakstofemulsie destabiliseer en sodoende die ekstrakstof laat konglomereer en neerslaan. Op soortgelyke wyse veroorsaak skielike temperatuurverlaging en/of pH-skokke en/of die toevoeging van ione in varswater om waterhardheid te beheer ook die neerslag deur die kolloïdale ekstrakstofemulsie te destabiliseer. Anorganiese sout soos kalsiumkarbonaat kan neerslagvorming kataliseer omdat dit optree as bousteen vir die klewerige, sementagtige ekstrakstowwe. Kalsiumione in die proseswater kan ook reageer met vetsure om onoplosbare, klewerige kalsiumsepe te vorm. Dit is bewys dat trigliseriede een van die hoofoorsake is in die vorming van die neerslag tydens kraft verpulpingen bleikingprosesse. Om die neerslagreaksie wat met die kraft verpulping en bleiking van Eucalyptus spp. geassosieer word, beter te verstaan, is verskeie analises op hout- en pulpekstrakte asook die neerslag van 'n Suid-Afrikaanse kraft verpulpingsaanleg uitgevoer. Hoë molekulêre massa (nie-vlugtige) stowwe het 'n groot gedeelte van die ekstrakte en neerslag uitgemaak. Ongeveer 40% van die vlugtige Eucalyptus grand is ekstrak bestaan uit ~-sitosterol met vet sure (22.8%) en trigliseriede (15.5%) wat ook aansienlike bydraes lewer. Vetsuuramiede verteenwoordig 'n beduidende komponent van pulpekstrak by die laaste stadiums van bleiking. Die amiede het 38.3% en trigliseriede 10.1%tot die vlugtige fraksie van die neerslag bygedra. Lipases hidroliseer trigliseriede en kan dus help om neerslagprobleme te voorkom. Gevolglik is 381 filamentagtige fungi geïsoleer uit inheemse en kommersiële woude van Suid-Afrika en hul lipase-aktiwiteit op tributyrin en Tween 80 geëvalueer. Agt rasse is geselekteer en die tributyrin en Tween 80 toetse is herhaal deur lipase-aktiwiteit oor 'n sewe-dag periode te monitor. Die geselekteerde rasse is ook getoets vir lipase-aktiwiteit met p-nitrofenielpalmitaat. Ophiostoma piliferum Cartapip 58™ en Phanerochaete chrysosporium BKM-F-1767, twee rasse wat daarvoor bekend staan vir onderskeidelik hul vermoë om houtekstrakstowwe te verminder en te bioverpulp, is as kontroles gebruik. 'n Paar van die geselekteerde rasse het goed vergelyk en selfs beter presteer as die kontrolerasse; 'n aanduiding van hul potensiaal om neerslagreaksies te beheer. Die effek van voorafbehandeling met die agt geselekteerde fungi rasse op E. grandis hout- en pulpekstrak is vasgestel. Cartapip 58™ en P. chrysosporium BKM-F-1767 is gebruik as kontrolerasse. Verskeie rasse het goed vergelyk met die kontrolerasse in hul vermoë om die trigliseriedinhoud van die houtekstrak te verlaag. Die Suid-Afrikaanse isolaat, witverrottingswam Phanerochaete pseudomagnoliae nom. prov., het ook die trigliseried inhoud beduidend verminder. Gevolglik sou dit as 'n middel kon dien vir beide neerslagvoorkoming en bioverpulping. Die trigliseriedinhoud van die behandelde monsters was laer as dié van steriele kontroles. Gevolglik sal meer trigliseriede in proseswater vrygestel word deur die steriele kontroles as die behandelde monsters. Die effek van kommersiële lipases op ongebleikte kraft pulpekstrakneerslag is ook geëvalueer. Omdat lipases nie die trigliseriedinhoud van die neerslag kon verlaag nie sal die gebruik van lipases dus nie die ekstrakstofneerslag in verpulpings- en bleikingsprosesse beïnvloed nie.