Coronavírus bovino (BCoV) é o agente causador de doença, tanto entérica como respiratória em bovinos, mas até agora existem controvérsias sobre a relação genealógica entre as amostras de BCoV em diferentes tecidos. Neste estudo, amostras de fezes e secreções nasais de 14 vacas de um mesmo rebanho apresentando simultaneamente disenteria epizoótica e doença respiratória foram estudados quanto a presença de BCoV. As amostras virais detectadas tiveram tanto o gene de espícula (S) como o gene hemaglutinina-esterase (HE) parcialmente sequenciados. Para o gene HE, foram obtidas 12 sequências de secreções nasais e 12 de amostras de fezes e para o gene S, foram obtidas 14 sequências de secreções nasais e 12 de amostras de fezes, com 100% de identidade nucleotídica para cada gene para as amostras deste estudo. Estes resultados apresentam algumas divergências com estudos anteriores os quais relatam que linhagens diferentes de BCoV podem ser esperados em casos de disenteria e doença respiratória em vacas, pois linhagens com sequências idênticas dos genes S e HE podem não mostrar diferenças em relação tropismo pelos diferentes tecidos. Sequências completas de duas amostras brasileiras de BCoV mostram que o já descrito padrão filogeográfico baseado no sequenciamento do gene S parcial foi mantido, foram encontradas substituições de aminoácidos específicos. / Bovine coronavirus (BCoV) is the causative agent of both enteric and respiratory disease in cattle, but hitherto there were some controversy on the genealogic relationship amongst strains from these different tissues. In this study, samples of feces and nasal secretions of 14 cows from a same herd simultaneously presenting epizootic dysentery and respiratory disease were screened for BCoV and the strains detected had both the spike (S) and hemagglutinin-esterase (HE) genes partially sequenced. For HE gene, 12 sequences from nasal secretions and 12 from fecal samples were obtained and for S gene, 14 sequences from nasal secretions and 12 from fecal samples were obtained, with 100% nucleotide identities for each gene for the strains of this study. These results have some disagreements with previous reports which try to put forward that divergent BCoV strain should be expected in cases of dysentery and respiratory disease in cows, showing that strain with identical S and HE sequences might show no differences in tropisms. Complete S gene sequences of two Brazilian BCoV strains show that the already described phylogeographic pattern based on partial S gene is sustained, though specific amino acids subtitutions are found.

Abstract The problem of describing a system of many interacting particles is one of the most fundamental questions in physics. One of the central theories used in condensed matter physics to address the problem is the Fermi liquid theory developed by L. D. Landau in the 1956. The theory describes interacting fermions, and can be used to explain transport phenomena of electrons in metals and dynamics of helium three. Even when the theory is not directly applicable, it forms a basis against which other, more sophisticated theories can be compared. this thesis the Fermi liquid theory is applied to 3He-4He-mixtures at temperatures where the bosonic 4He part is superfluid, and the mechanical properties of the system are largely determined by the 3He component, treated as a degenerate normal Fermi liquid. The dynamics of strongly interacting liquid 3He can be described as a collection of quasiparticles, elementary excitations of the system, which interact only weakly. In 3He-4He mixtures the interactions can be continuously tuned by changing the temperature and the concentration of the mixture. The scattering time of quasiparticles depends on temperature, and thus the transition from the hydrodynamic limit of continuous collisions at higher temperatures to the collisionless ballistic limit at low temperatures can be studied. This gives invaluable information on the role of the interactions in the dynamics of the system. In this work, by using the Fermi liquid theory and Boltzmann transport equation, the dynamics of helium mixture disturbed by a mechanical oscillator is described in the full temperature range. The solution necessarily is numeric, but new analytical results in the low temperature limit are obtained as well. The numerical approach enables one to study various boundary conditions thoroughly, and allows application of the theory to a specic geometry. It is shown that in order to explain the experimental observations, it is necessary to take into account the reflection of quasiparticles from the walls of the container. For suitable choice of oscillator frequency and container size, second sound resonances are observed at higher temperatures, while in the ballistic limit quasiparticle interference can be seen. The numerical results are in quantitative agreement with experiments, thus attesting the accuracy of Fermi liquid theory. In particular, the previously observed decrease of inertia of a mechanical oscillator immersed in helium at low temperatures is reproduced in the calculations, and is explained by elasticity of the fluid due to Fermi liquid interactions.

Cette thèse, qui relève de la didactique du français langue étrangère, traite des conventions d’écriture académique en français et en chinois dans une perspective de rhétorique contrastive. Nous étudions deux genres académiques propres à l’enseignement supérieur en France et en Chine : la dissertation et le yilun wen, respectivement. Les deux exercices détiennent un statut comparable ; ils obéissent tous deux à un système de normes relativement stables, à une structure clairement fixée et font figure d’ « exercice-roi » dans chacune des deux cultures éducatives. La comparaison entre ces deux genres scolaires et universitaires nous permet d’analyser les difficultés rencontrées par un groupe d’étudiants chinois en FLE dans la rédaction d’une dissertation et les transferts qu’ils opèrent en français des conventions d’écriture issues du yilun wen. Cette analyse est éclairée par celle des annotations marginales portées sur leurs copies de dissertation par des correcteurs français. A travers les résultats d’une enquête menée par questionnaire auprès de groupes d’étudiants (chinois et français), la thèse s’attache ensuite aux représentations très disparates que les deux ensembles de groupes se font de la signification de ces normes du point culturel et cognitif.La thèse s’attache enfin à décrire la rhétorique traditionnelle chinoise à travers l’analyse du bagu wen et du schéma Qi-Cheng-Zhuan-He, un dispositif traditionnel toujours proposé dans les manuels et pratiqué par les étudiants. / This study compares academic writing conventions in French and Chinese from the point of view of Contrastive Rhetoric in the field of French teaching and learning as a foreign language. We spot respectively in French and Chinese education systems a specific genre: the French dissertation and the Chinese yilun wen. They have a comparable status, a clear structure and strict rules to follow. The comparison between these two genres indicates that the rules are not shared between French and Chinese students and that certain criteria required in the Chinese yilun wen appear far removed from French dissertation. Thus Chinese students encounter intricate difficulties in writing French dissertations and negative transfers under the influence from Chinese writing conventions. This result is also confirmed by the analysis of dissertations written by the Chinese students of our corpus. The surveys conducted among French and Chinese learners show that they are not fully aware of the cultural differences of standards in writing. The analysis of comments by French teachers of dissertation written by Chinese students shows that they are not better armed than their students in face of the differences of textual organization (both the construction and the way of realization) in French and Chinese. We attend to hold endly how the organization of traditional Chinese Rhetoric (the bagu wen and the Qi-Cheng-Zhuan-He schemes), still proposed by textbooks and practiced by learners, exert more or less influence on French writing of the Chinese students.

The popular and scientific literature has been discussing the advent of ‘big data’ with a measure of excitement and apprehension. For the first time in history, it seems, every breath we take, every move we make, someone’s watching us. But beyond their unprecedented volumes and the anxieties they raise, new communication data have a less obvious aspect, in so far as they are (arguably) of a fundamentally different kind, compared to traditional network datasets. Traditionally, social network data describe relationships between individuals; quasistatic social ties such as friendship, trust, kinship and employment relations. But when they are used to model digitally mediated communicative transactions, the connections are of a different nature. Instead of representing stable social ties, transactions (such as emails, text messages and phone calls) constitute sequences of shortlived events, with each transaction being a possible response to a preceding one and a potential stimulus to the next. The point of departure of this dissertation is the distinction between the topology of the tie structure and the temporal structure of sequences of communicative transactions. Theoretically, the dissertation explores mechanisms of co-evolution between these two structures at three levels of aggregation: (i) the macro-level consisting of the network itself or substructures within it, the level of an organization or a community as a whole; (ii) the meso-level consisting of nodes and social ties; and (iii) the micro-level consisting of sequences of interrelated communicative transactions. On the one hand, networks, individuals and ties are seen as the backdrop against which sequences of transactions unfold. On the other hand, transactions are considered to have (cumulative) consequences on the evolving structure of social ties and the network at large. Methodologically, the thesis uses a publicly available dataset consisting of email transactions within Enron, an American energy and services company, during the few months of its bankruptcy. Two methods are applied to identify and explore the mechanisms. First, the dataset is disaggregated into various types of email transactions, revealing how different transactions contribute to various structural properties of the network. Second, a multilevel analysis approach is used to reveal how structural and transactional mechanisms combine to elicit new communicative transactions on the part of email recipients. The mechanisms identified in the empirical chapters challenge received wisdom about the nature of social networks and their link to the notion of social (trans)action while at the same time addressing practical problems faced by network modellers who need to construct networks out of digitally mediated transaction datasets. In addition, the findings raise general questions about new types of data and the consequences they may have, not only for the field of social networks, but also for popular ways of thinking about ‘the social’ and ways of intervening in its course.

This thesis investigates seafarers’ experiences of ill-treatment onboard ships. A sociological approach to ill-treatment is adopted, with a focus on characteristics of the work environment onboard which affect seafarers’ experiences of and responses to ill-treatment. A qualitative approach was employed to understand seafarers’ perceptions of ill-treatment. Semi-structured interviews based on the Negative Acts Questionnaire were conducted with seafarers and managerial personnel from one multinational and one Indian company. The seafarers were drawn from all ranks. Thematic analysis of the data revealed that seafarers’ perceptions, experiences and responses to ill-treatment were heavily influenced by characteristics of the work environment, including industry and company norms such as short-term contracts, the hierarchy, onboard, distance management and HR policies and training. Seafarers encountering ill-treatment can choose to exit their situation, raise their voice or remain silent. The findings showed that while support structures such as grievance procedures and union membership existed for seafarers experiencing ill-treatment, the majority of seafarers chose to remain silent because of complex interactions between a variety of workplace features. Fears included job insecurity, concern for career advancement, fear of blacklisting and personal financial concerns. Those seafarers that did choose to escape their situations found that there could be repercussions on their finances and their career ambitions, or that exercising their voice resulted in a reshuffle of seafarers but nothing of import changed. The professional socialisation process and culture onboard the ship are very important in influencing seafarers’ perceptions of ill-treatment, and play a role in the occurrence of preventative behaviour and use of coping mechanisms. In addition, the industry norms of short-term contracts, the purported manning crisis and a race to the bottom mentality force seafarers to be highly insecure in their jobs and encourage them to accept their situation until they can escape it.

This thesis studies processes of cultural mediation and the role of digital media within them. It is based on the experiences of a group of cultural mediators within a particular music scene in contemporary Chile, and focuses on actors’ meaningful repertoires of action, their material arrangements and their relation with information and communication technologies (ICTs). ‘Mediation’ in a broader sense means processes through which human and non-human agencies produce and shape meanings, attaching them to various cultural flows such as information, images, and identities. As cultural mediators, actors define the music scene, curating and circulating through digital media various flows which they deem worthy of being considered by audiences, and distinguishing themselves across different fields. The thesis is based on nine months of fieldwork (2011) in Santiago, following the everyday practices of the creators of eight music websites through which global and local cultural flows are mediated, organised, and circulated. It analyses how various technological devices facilitate individuals’ construction of networks where cultural flows circulate, and through which their uses of taste are displayed and objectified. It proposes the concept of ‘digital capital’ as an assemblage of actors, practices, objects, and meanings, which is convertible into other types of capital (e.g. economic) and exchangeable in various fields. It is a mode of practice and expertise through which, using digital technologies, individuals create networks where cultural flows circulate. Through the making of websites, music fans become cultural mediators, developing their digital capital as cultural and technical expertise. This expertise is convertible into economic capital and positionality across different fields, especially the field of advertising. Digital capital can be summarised in the question: ‘what are the connections and associations between technical knowledge, cultural flows, and social position, as well as conversions of capital, behind someone who is using Twitter or Facebook, or making a website about a music scene?’ Against this backdrop, it is explored how actors produce and perform ‘cultures of mediation’, commoditising culture as consumption goods.

This thesis addresses the challenges of producing digitally mediated healthcare information, a high-stakes arena which is conceptualised as a complex discourse and its diverse producers as interlocutors within this discourse. The study is located theoretically in the tradition of universal or formal pragmatics, the foundation of Habermas’s theory of communicative action. Building on this theoretical core a conceptual framework is developed that integrates insight from several other traditions, including communication studies. The notion of communicative transparency is aligned with the idealised goal of a rich informational context supporting a range of perspectives in movement towards a balanced and consensual understanding by lay and expert actors of healthcare in our world. The central research question is: Can digital mediation increase the transparency of healthcare communication? The empirical focus rests on two organisations involved in the creation of digital information products. Key mediators of meaning in digital healthcare information are identified as the diverse types of expertise of its producers, the materiality of digital artefacts, and the communicative mechanisms, processes and practices that often lead to departures from the normative idealised standard of transparency. The methodology is a comparative case analysis based on field research employing principally interviews to build a rich corpus, analysed using a recursive in-depth thematic coding procedure to reveal the ways in which digitally mediated healthcare meanings are shaped and shared. The study demonstrates how communicative transparency emerges from shared frames of reference and common models of communication. It is concluded that digital mediation can indeed increase the transparency of healthcare information by supporting the deepening of Habermasian rational discourse, providing that validity claims to truth, truthfulness, and rightness can be raised and resolved at all stages in the discourse among all interlocutors, whatever their role and status.

The Fish Creek-Vallecito Basin exposes an archive of sediment related to early rifting of the Gulf of California beginning at 8.0 Ma followed by Colorado River delta progradation from 5.3-3.0 Ma. Mio-Pliocene deposits from the Fish Creek-Vallecito Basin of southern California and a sample from the modern Colorado River delta were analyzed through detrital zircon U-Pb (n=1996) and (U-Th)/He (n=280) double-dating in order to better constrain sediment provenance, hinterland exhumation, and Colorado River evolution. Coupling this dataset with outcrop study of the first Colorado River-sourced turbidites into the basin at 5.3 Ma, allows for evolution of the Colorado River system to be viewed from a source-to-sink perspective. Detrital zircon U-Pb and (U-Th)/He (ZHe) ages obtained in this study suggest earliest derivation of sediment was from the Peninsular Ranges followed by more distant sediment sourcing from the Colorado River. Initial Colorado River-sourced deposits show Yavapai-Mazatzal U-Pb ages with Laramide ZHe ages suggesting that the river was sourcing from Laramide basement cored uplifts at the onset of deposition into the Gulf of California, supporting a top-down model of river evolution. An increased percentage of Grenville U-Pb age grains as well as a wider range of ZHe ages associated with western US basement-derived zircon from a modern Colorado River delta sample indicate erosion into older stratigraphic units through time which is consistent with deep erosion on the Colorado Plateau since ~6 Ma. Vertically measured sedimentology logs through the Wind Caves Member, the first Colorado River-sourced unit deposited, were used to determine slope and basin floor architecture as the Colorado River and delta dispersed subaqueous sediment gravity flows into the marine Gulf. Measured sections arrayed along depositional strike show a 4.5 km wide pod of sand-rich turbidites that were delivered through a broad Fish Creek exit point from the paleo-Colorado shelf. The vertical sedimentation trend is one showing thick bedded, amalgamated channelized and sheet-like sandstones initially, shifting to thinnerbedded sheets and more isolated channels higher in the increasingly muddy section. The facies variability up section is interpreted as a change from a submarine basin floor fan to a lower slope environment as the Colorado River prograded its delta into the Gulf. / text

Close coupling scattering calculations have been conducted for the para spin modification of H₂-{He, Ne and Ar}. The XC(fit) potential energy surfaces for H₂-Ne and H₂-Ar have been used for calculations for these two systems, while a newly fitted version of the Schaefer and Kohler potential energy surface was used for the H₂-He system. The fitting procedure employs nine modified Lennard-Jones oscillator functions to describe accurately 90% of the original tabulated potential energy surface to better than 12% error. The scattering calculations for H₂-Arfailed at higher energies due to the presence of a previously undocumented potential energy surface turn-over at R less than 1. 0 Angstroms. Manifold-to-manifold v=1 vibrational relaxation calculations for each of these systems are compared with other experimental and theoretical calculations. These comparisons demonstrate a common discrepancy between previous calculations and the current calculations for each system. The current vibrational relaxation rate constants are generally too small when compared to low temperature values of Audibert et al. and Orlikowski, and the high temperature values obtained by Flower et al. and Dove andTeitelbaum. The current calculations indicate the presence of a dramatic up-turn in the low temperature H₂-He rate constants. Other experimental and theoretical treatments do not exhibit this same up-turn, which is puzzling. A set of follow-up calculations featuring a larger basis set (such as the {16,12,10,8} Flower et al. basis set) and a larger manifold of included relaxation pathways are needed to improve these calculations.

This thesis examines media representations and audience reception processes through a detailed study of media reporting and public understandings of asylum and refugee issues. It is based on sixty interviews in which refugees seeking asylum, professionals working with them and members of the general public were invited to comment on their own memories and beliefs using pictures from the TV coverage. The pictures used are included in a detailed thematic content analysis of national and regional broadcast news. Public understandings are systematically compared to the content of media reporting. In particular it explore people’s memories and beliefs of national and regional broadcast news. The content analysis revealed that the national news represents asylum in unsubstantiated and problematic ways whilst the regional news has a more balanced approach to representation of the issue. The thesis explores the diversity of audience reactions and the different ways in which people may accept or reject the media representations. However it also draws attention to the themes which recurred in all of the interviews and argues that there is strong evidence of media effects. The thesis highlights factors in media coverage which are particularly influential. It demonstrates how language, structures, and images may influence audience responses and examines how media representations may structure patterns of misinformation. The audience were poorly informed on asylum and refugee issues. In addition attention is drawn to viewers’ everyday relations and experiences. Some interviewees use specific knowledge to reject news reports. The research provides comprehensive and fruitful insights of cultural differentiation linked to ‘race’/ethnicity, gender, class and geographical location. The thesis concludes by arguing for a media studies schema which connects questions about audience reception with questions about media production and content as well as the construction of broader relations within society enabling researchers to contribute to current debates about power, control and social conditions.