This dissertation investigates the role of grammatical versus methodological influences in the production and perception of final devoicing in experimentally-elicited speech from Russian. It addresses the question of how the partial preservation of the phonological voicing contrast in word-final obstruents is affected by (i) task-independent factors that reflect phonological and lexical properties of stimuli words (underlying voicing, word length, lexical competition) and (ii) task-dependent biases that arise due to the nature of the experimental task performed by the speaker (availability of orthographic inputs, presence of minimal pairs among the stimuli). Results of a series of acoustic production and perceptual identification tasks reveal that task-dependent factors account for the presence of robust and perceptually salient differences in the parameter of phonetic voicing. Several types of stimuli items also show limited but statistically significant differences in closure/frication duration and release duration that are independent of the presence of orthography or inclusion of full minimal pairs among test items. Taken together, these findings indicate that non-grammatical factors can play a prominent biasing role in both production and perception of the voicing contrast in experimentally-elicited speech, such that certain voicing-dependent cues are maintained only in the presence of task-dependent pressures. However, not all incompletely neutralized differences between phonologically voiced versus voiceless final obstruents can be attributed to the effects of orthography or inclusion of minimal pairs among the stimuli. In the theoretical domain, these results are argued to favour a less restrictive definition of neutralization and a model of phonology that views devoicing as a loss of the primary acoustic cue to the underlying voicing contrast rather than complete identity of the [voiced] feature.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Thesis (Ph.D.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)

The As- and Mo- bearing secondary mineral phases formed during the neutralization of uranium mill wastes were studied for a variety of ore blends including current and future ore sources at the Key Lake milling operation, northern Saskatchewan, Canada. A lab-scale plant model was employed to characterize secondary precipitates obtained during the mill waste neutralization process. Three scenarios of ore blends were processed through the lab-scale plant to produce mill waste solutions for neutralization before combination into final tailings. Slurry samples (n = 12) were collected from the secondary precipitates formed during the neutralization of mill wastes (raffinate) by precipitation with Ca(OH)2 (slaked lime) from pH 1.5 to 10.5. Synchrotron based X-ray absorption spectroscopy of mill and lab-scale plant precipitates showed arsenate adsorbed to ferrihydrite was the dominant As mineral phase regardless of pH or sample blend (53-77%), with fractional contributions from ferric arsenates, and adsorption to aluminum phases (AlOHSO4, As(OH)3 and hydrotalcite). Molybdate adsorbed to ferrihydrite was the dominant Mo mineral phase, regardless of pH or sample blend, with fractional contribution decreasing with increasing pH, and minor contributions from calcium molybdate, ferric molybdate and nickel molybdate. These results were used in geochemical modelling to predict the source terms for these mineral phases in tailings facilities. Sequestration of As and Mo in the model showed solubility was controlled by adsorption to both Fe and Al oxide surfaces as well as by direct precipitation with other dissolved constituents (Ni, Ca and SO4).The models developed pH profiles of mineral phase precipitation to explain the solubility of As, Mo, Fe, Al, Mg and Ni during sequestration from pH 1.5 to 10.5 that were consistent regardless of ore blend used in simulations. Since adsorption of anions to the surface of ferrihydrite has been shown to slow conversion to crystalline forms of Fe oxides (goethite and hematite) and sequestration of arsenate effectively controls As solubility at high pH (pH >10), As-bearing mineral phases are expected to be stable for thousands of years. With adsorption as well as direct precipitation considered, Mo phases though effectively sequestering below pH 8, became unstable and released Mo back into the tailings porewater (pH >10), as predicted by the thermodynamic model. Historical data obtained from as-discharged tailings as well as previously published U mill tailings studies agree with these findings.

Les étapes précoces de l’infection virale sont des évènements critiques dans le déroulement du cycle viral. Notamment, l’entrée virale est la première étape d’interaction entre un virus et une cellule permettant d’initier, de maintenir et de propager l’infection. De ce fait, cette étape constitue une cible majeure de la réponse immunitaire adaptative de l’hôte. C’est ainsi que cette étude bipartite s’est intéressée aux étapes précoces de l’infection du virus de l’hépatite C (HCV). Dans un premier temps, l’obtention de clones de cellules Huh-7.5 n’exprimant plus le récepteur néonatal des immunoglobulines, le FcRn, a permis d’analyser l’implication de ce récepteur dans la neutralisation du HCV par des anticorps neutralisants. Les résultats obtenus nous informent que le récepteur FcRn n’intervient vraisemblablement pas dans la modulation de la neutralisation du HCV. Dans un second temps, nous avons réalisé une étude préliminaire afin d’approfondir les mécanismes régissant l’endocytose du HCV : à savoir, quelles sont les protéines adaptatrices responsables du déclenchement de l’endocytose dépendante de la clathrine et s’il existe une potentielle voie d’entrée alternative pour ce virus. A ces fins, nous avons opté pour une stratégie basée sur la transfection de siRNA, couplée à l’utilisation des pseudoparticules HCVpp qui constituent une approche encore pertinente appliquée à l’étude de l’entrée du HCV. / The early steps during a viral infection are critical events in the course of the viral cycle. Particularly, the viral entry is the first step allowing the interaction between a virus and a cell to initiate, maintain and propagate an infection. Therefore, this very step is a major target for the host adaptive immunity. This bipartite study is focused on the early steps of the infection by the hepatitis C virus (HCV). First of all, generation of Huh-7.5 clones whose expression of the neonatal Fc receptor, FcRn, has been deleted gave us the opportunity to analyze the involvement of this receptor during the neutralization of HCV by neutralizing antibodies. Regarding the results, it appears unlikely that the FcRn modulates the neutralization of HCV. Then we conducted a preliminary study to further explore the mechanisms underlying the endocytosis of HCV: that is, which are the adaptor proteins that trigger the clathrine-mediated endocytosis and if there is another putative entry pathway for the virus. To these ends we opted for a RNAi based strategy coupled to the use of HCV-derived pseudo-particles (HCVpp) that are still useful and relevant tools dedicated to HCV-entry studies.

Notre laboratoire a développé une stratégie d'isolement de fragments d'anticorps recombinants à partir de primates non humains (Macaca fascicularis) immunisés, en utilisant la technologie des phages. Dans le cadre de cette thèse, une comparaison des séquences d'anticorps de macaques (Macaca Mulatta) et d'anticorps humains a toutefois montré que les anticorps des deux espèces présentent des différences qui rendent souhaitable une étape d'humanisation des anticorps de macaques. Cette stratégie a été utilisée dans le cadre du projet Européen AntiBotABE (www.antibotabe.com) et l'étape de criblage a été adaptée pour isoler des scFv neutralisant de façon croisée les toxines botuliques BoNT/B des sous-types B1 et B2, en utilisant séquentiellement l'holotoxine BoNT/B1 et un fragment recombinant représentant la région C-terminale de la chaîne lourde de BoNT/B2. Le meilleur scFv ciblant les régions C-terminales des chaînes lourdes de BoNT/B1 et BoNT/B2, B2-7, a montré une bonne capacité de neutralisation de BoNT/B1 et BoNT/B2 dans le test ex vivo de paralysie hémidiaphragmatique. Les régions charpentes du scFv B2-7 ont un pourcentage d'identité élevé (80 %) avec leurs homologues humains. Des scFv neutralisant BoNT/A1 en ciblant sa chaîne légère ont aussi été isolés, dont le scFv le plus efficace, 2H8, induit une diminution de 50% de l'activité endopeptidasique à une concentration correspondant à un rapport molaire 2H8/BoNT/A1 de 64000. Les régions charpentes de 2H8 ont également un pourcentage d'identité élevée (88%) avec leurs homologues humains. La versatilité de cette stratégie en fait un outil permettant l'isolement de nombreux autres fragments d'anticorps à visée thérapeutique. / Our laboratory has developed a strategy to isolate recombinant antibody fragments technology from immunized non human primates (Macaca fascicularis) by phage display. In the course of the present thesis, a comparison between macaque (Macaca mulatta) and human antibody sequences has demonstrated that antibodies of the two species are different. This difference makes the humanization of macaque antibodies desirable. The strategy was used in the framework of the European AntiBotABE project, and the screening was adapted to isolate antibody fragments cross neutralizing the B1 and B2 subtypes of botulinum B neurotoxin, by using sequentially the holotoxin BoNT/B1 and a recombinant fragment representing the C-terminal region of the heavy chain of BoNTB2. The best scFv targeting the C-terminal region of BoNT/B1 and BoNTB2 heavy chains, B2-7, demonstrated a high capacity to neutralize BoNT/B1 and BoNT/B2 in the ex vivo hemidiaphragmatic assay. A high identity (80%) between the framework regions of B2-7 and their human homologs was observed. ScFvs neutralizing BoNT/A1 by targeting its light chain were also isolated and among them, the scFv 2H8 induced a decrease of 50% in the endopeptidase activity at a concentration corresponding to a molar ratio of 2H8/BoNT/A1 of 64000. A high identity (88%) between the framework regions of 2H8 and their human homologs was also observed. Our strategy can be used to isolate other therapeutic antibody fragments.

HIV est principalement transmis par voie sexuelle. Bien que les stratégies de prévention basées sur les antirétroviraux (TasP et PrEP) soient efficaces, d'autres approches (en particulier vaccinales) restent d' actualité.Dans la première partie de ce travail, nous avons caractérisé le réservoir séminal de HIV chez des patients chroniquement infectés et sous trithérapie antirétrovirale (TARV). Dans le sperme, HIV est présent sous forme libre et/ou associée aux NSMC. Ces deux formes peuvent être transmises. Le TARV réduit la quantité de virus libre dans le sperme, sans éliminer le virus associé aux NSMC. A heure du TasP, comme meilleur outil de prévention de la transmission sexuelle, mieux caractériser l'état de ce virus résiduel (latent, réplicatif, défectif ?) est nécessaire. Dans notre travail, le virus associé aux NSMC n'a pas été réactivé, laissant supposer que le virus résiduel dans les NSMC de patients sous TARV au long cours, peut être défectif. Ces données restent à confirmer dans de plus grandes cohortes.Dans la deuxième partie du travail, nous avons caractérisé sur le plan isotypique et fonctionnel, les anticorps dirigés contre HIV du sperme. L'objectif est de mettre en évidence des anticorps « large spectre » neutralisant HIV, et/ou inhibant la transcytose, et/ou capables d'ADCC et ciblant les souches virales potentiellement transmissibles par voie sexuelle. Nous avons identifié dans le plasma séminal de certains patients des anticorps neutralisant des souches X4 tropiques, alors que les souches majoritairement transmises par voie sexuelle sont R5 tropiques. Nous avons observé la capacité d' anticorps dirigés contre HIV du plasma séminal à traverser un épithélium monocouche. Le rôle protecteur ou facilitateur est à préciser. Des anticorps protecteurs pourraient être utilisés dans des formulations de type microbicides ou en immunothérapie et contribuer également à un développement de vaccin après identification des épitopes cibles. / HIV new infections are mostly related to sexual transmission. Semen contains HIV free particles and cell-associated HIV. Both forms are sexually transmitted. Although PrEP and TasP are efficient to prevent HIV sexual transmission, other strategies like a Vaccine remain needed.In a first part, we studies HIV reservoir in HIV-infected patients receiving combined antiretroviral treatment (cART) in semen. cART reduced HIV viral load in semen, but had a no activity against cell-associated HIV. We tried to reactivate HIV cell reservoir in semen to better characterize its role. We did not observe any reactivation; HIV reservoir in semen might be mostly latent, or defective. This observation should be confirmed in larger cohort of patients.In a second part, we aimed to study the prevalence of anti-HIV antibodies in semen and their role in sexual transmission. Semen of HIV-infected men contains anti-HIV immunoglobulins (Igs), mostly IgG. We observed that unspecific Igs (IgG, IgAl, IgA2) and anti-HIV IgG and IgA were able to transmigrate across an epithelium monolayer mimicking endocervix. This transmigration property may facilitate HIV transcytosis. We also observed a neutralizing activity by Igs purified from semen of 2 chronically infected patients against a X4-tropic viral strain. Seminal anti-HIV may exhibit a dual role (facilitating or limiting) HIV sexual transmission. Protective antibodies purified from semen might be used in preventive strategies like microbicides or serotherapy, and may help to develop vaccine after identification of their epitopes.

Made available in DSpace on 2016-03-04T13:55:10Z (GMT). No. of bitstreams: 2 9.pdf: 3952596 bytes, checksum: cfcd87da861ff1eb06b00de845149fc4 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos/Farmanguinhos. Rio de Janeiro, RJ, Brasil. / A caxumba é uma doença infecto-contagiosa imunoprevinível por vacinação. A imunogenicidade vacinal é avaliada através de testes sorológicos que detectam anticorpos neutralizantes, que são considerados correlatos de proteção. O Teste de Neutralização (PRNT) apresenta vantagens frente a outros testes por ser mais específico na detecção desses anticorpos neutralizantes. O presente estudo visou padronizar e validar a técnica. Durante a padronização foram definidos o M.O.I de 0,001 e o melhor dia de pico de vírus infeciosos (3 dias), para definir um protocolo de produção viral. A partir do vírus produzido foram avaliados qualitativamente o fenótipo da placa de lise e a diluição viral em diferentes condições analíticas. Os seguintes parâmetros foram definidos: diluição viral de 1:1600 para obter 30 placas de lise/poço, bicarbonato de sódio como tampão no meio de cultura, meio semi-sólido com carboximetilcelulose (CMC) 1,5%, tempo de adsorção de 3 horas e tempo de incubação final de 4 dias. Para avaliar o impacto do tempo de neutralização na potência viral e no de título de anticorpos neutralizantes, dois intervalos de tempo (1 e 2 horas) foram testados e a neutralização por 2 horas se demonstrou mais adequada ao ensaio. Posteriormente, foi definido um ponto de corte de 23, utilizando um painel sorológico contendo 126 soros pré e pós-vacinais de crianças imunizadas com a vacina tríplice viral. O ponto de corte foi determinado como a área sob a curva ROC usando os resultados de ELISA previamente avaliados em comparados com os resultados de PRNT. Dentre os resultados analisados, 35% foram concordantes na positividade dos resultados em ambos os testes. Valores preditivos positivos de 95,373 e valores negativos 97,680 determinam a real presença ou não da doença. Critérios de aceitação para o teste foram estabelecidos como: faixas de variação do end point do vírus (13 a 22) e faixas de variação dos controles (baixo, médio e alto). Também foi estabelecido como as amostras indeterminadas devem ser tratadas. Posteriormente, o PRNT foi submetido ao processo de validação, avaliando os parâmetros de linearidade, especificidade, exatidão e precisão, conforme preconizado pela RDC 27 da ANVISA. Nas análises de precisão foram obtidos coeficientes de variação a 15% para o limite inferior de quantificação do método (LIQ) e 20% para as demais concentrações. O mesmo ocorreu nas análises de exatidão. Quanto a seletividade, não foi detectada reação cruzada nas amostras quando desafiadas com o vírus de sarampo. / Mumps is an infectious disease preventable by an available vaccine. Vaccine immunogenicity is evaluated by serological tests for detection of neutralizing antibodies, which are considered the correlate of protection. Plaque Reduction Neutralization Test (PRNT) shows advantages for neutralizing antibodies’ dosage because of its better specificity when compared to other tests. The present study aims to standardize and validate this technique. During the standardization process, it was defined the multiplicity of infection of 0,001 and the viral peak production on the third day, for defining a viral production protocol. From the virus lot produced, it were qualitatively evaluated the plaque phenotypes and viral dilutions under different analytical conditions. The following parameters were defined: viral dilution of 1:1600 to achieve 30 plaques per well; sodium bicarbonate as buffer of the culture media, semisolid overlay media content of 1,5% of carboxymethylcellulose (CMC); adsorption time of 3 hours and final incubation of 4 days. In order to evaluate the impact of incubation time for neutralization step on viral potency and neutralizing antibodies’ titers, two intervals (1 and 2 hours) were evaluated and the 2-hour neutralization time was considered more appropriate. After that, a cutoff value of 23 was defined using a serological panel containing 126 pre and post- vaccination sera of children immunized with MMR vaccine. The cutoff value was defined from the area under the ROC curve using ELISA data previously analyzed in comparison with PRNT results. Among the results, there were 35% of positive results in agreement in both tests. Positive predictive value of 95.373 and negative predictive value of 97.680 determine the actual presence or absence of disease. Acceptance criteria for the test were established such as: viral endpoint range (13 to 22) and titer variation ranges for control samples (low, medium and high titer). It was also determined how indeterminate samples should be treated. Finally, PRNT were submitted to validation regarding linearity, specificity, accuracy and precision as recommended by RDC 27 of ANVISA. Regarding the precision analyses, coefficient of variations lower than 15% were achieved for the sample with the lower limit of quantification, and lower than 20% for the other sample concentrations tested. The same occurred in the accuracy analyses. Regarding specificity, no cross reaction was detected in the samples when challenged with measles virus.