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See detailParents d'un enfant en rémission de cancer: Prédicteurs psychologiques et cognitifs de l'intolérance à l'incertitude dans le maintien des inquiétudes et dans l'orientation de l'attention sélective
Vander Haegen, Marie ULiege

Doctoral thesis (2017)

In spite of core medical advances realized these last years, the childhood cancer remains a distressing experience for the child and their parents. The cancer history is rarely linear and takes place into ... [more ▼]

In spite of core medical advances realized these last years, the childhood cancer remains a distressing experience for the child and their parents. The cancer history is rarely linear and takes place into a space and a particular time when marks are shaken. The stake in paediatric oncology is double: that the child is cured without side effects and that the child and parents cross this experience without psychological destabilization. When the cancer survivorship is diagnosed, new challenges are expecting for the child and parents. Indeed, the childhood cancer survivorship is considered as integrated into the field of chronic diseases where the factor of uncertainty coexists and requires continuous adjustments of the child and parents. Therefore, it is a period of progressive rehabilitation where the stake is double: control the relapse and treatments’ late effects (or aftereffects) of the child and allow the child and parents, “to pursue their life the most normally possible”. The survivorship experience is thus intense transforming deeply “the psyche” of the child and parents. Since a few years, empirical studies examine the child adjustment and parents in the course of treatments. These reveal namely some adaptation difficulties, anxious and depressive symptoms. However, the social/family support and the problem-focused coping seem positively moderate the distress intensity. Studies investigated the cancer survivorship were mainly centred on the child and showed its effects on the child’s psychological adjustment (e.g. anxiety, depression). Nevertheless, the distress intensity could be positively influenced in particular by social and family support factors. The thorough examination of the literature observes that studies rarely include the parent and that no study has associated the factor of uncertainty with the vulnerability factor of intolerance of uncertainty. The originality of this research lives in the interest centred on the concept of intolerance of uncertainty [IU] and its effects on the psychological and cognitive adjustment among parents of a child cancer survivor. This quasi-experimental, quantitative, longitudinal research combines standardized questionnaires (IUS, NPOQ, CAQ, Mini-CERTS, HADS, and WW-II), questionnaires created for the needs of the study (sociodemographic, QIPS-R15, OncoMed and SomaOnco) and two neuropsychological tasks (classic Stroop and emotional Stroop). The sample consists of 61 parents (45 mothers and 16 fathers) of a child cancer survivor (from 4 to 6 years of survivorship without relapse and with mainly a neoadjuvant chemotherapy during treatments). Three months later, parents returned to the laboratory and completed the same questionnaires and performed Stroop tasks (with the exception of words which are modified). The time was decided with medical teams. It seemed relevant to retest parents when the medical assessment of the child was completed in order to observe if the distress decreased. Besides, this time was sufficient to avoid memory biases. The first aim of this research is the study of parental distress. The proposed hypothesis is the existence of anxious, depressive, somatic symptoms and worries. Results showed that 70 % of parents had anxious symptoms (HADS), 39 % presented depressive symptoms (HADS), 14 % suffered from somatic symptoms (SomaOnco) and 70 % had worries (QIPS-R15). Results from moderation analyses indicated no main effect of gender, remission time, and couple on distress criteria (except the interaction of these three factors for worries). These results demonstrated the existence of a significant distress within the sample but also the presence of additional factors which may influence the parental adjustment. The second aim is the examination of IU and its maintaining factors (i.e. positive beliefs about worry, cognitive avoidance, negative attitude towards problems and repetitive thinking (ruminations)). The advanced hypothesis is the causal track between IU and its maintaining factors. Results of IUS questionnaire demonstrated on average that parents had a low tolerance of uncertainty (64 % of the sample) and that 60 % of the sample were located in a moderated to severe profile of generalized anxiety disorder (GAD). Concerning IU’s maintaining factors, results of NPOQ, CAQ, WW-II and Mini-CERTS questionnaires highlighted the existence of positive beliefs towards worry (WW-II: problem solving and positive trait of personality) and cognitive avoidance (CAQ: distraction and thought suppression). Results of regressions bear out the predictor status of IU for the development of its maintaining factors. Nevertheless, protective factors arose from analyses, particularly an effective problem orientation and the use of concrete experiential thinking mode (CET; Mini-CERTS), which could protect them from a deterioration of the mood (e.g. depression). These results indicated the negative influence of IU on the psychological adjustment, the protective effect of a positive attitude orientation and the use of CET among parents. The third aim concerns the study of cognitive processes in terms of orientation of selective attention and cognitive inhibition. The proposed hypothesis is the orientation of selective attention towards threat into the IU context. Results seem to indicate a longer latency for negative and coloured words during Stroop tasks. The within-group regression and mediation results reveal the mediating effect of IU between the orientation of selective attention towards threat and distress components (i.e. anxious, depressive, somatic symptoms and worries). Moreover, depressive symptoms contribute to predicting the coloured word latency (cognitive inhibition process). These results seem to demonstrate the negative influence of the IU on the orientation of selective attention and depressive symptoms for cognitive inhibition. Lastly, the fourth aim is the analysis of IU stability and its maintaining factors over time. The proposed hypothesis is the stability of IU and its maintaining factors because IU is considered as a feature of the personality. At the second assessment (n=51/N=61), three significant differences were observed. The first difference concerns a decrease for anxiety symptoms with nevertheless a score being located in the pathological border. The second difference relates to a decrease for the cognitive avoidance with a score situated in the superior border of the standards. Lastly, an increase for somatic symptoms level was observed at the second assessment. Concerning IU, results indicate no significant change. Parents who presented a high level of IU at the first assessment kept it at the second assessment. This observation is also true for parents who had a low level of IU. These results supported the hypothesis of IU stability and its maintaining factors over time. Overall, results emphasize the implication of IU in the psychological distress among parents and its effect on cognitive processes of the orientation of selective attention towards threatening words (negative words). This research brings out the necessity to identify parents who are at risk for IU (and its maintaining factors) at an early stage of the cancer management in order to avoid excessive worries and the use of dysfunctional strategies over time. Furthermore, this research allows future clinical avenues for the development of follow-up tools in paediatric oncology, and recommends the parents’ psychological adjustment follow-up in close collaboration with medical teams. Implications of this research are discussed into the "general discussion" part of the thesis. [less ▲]

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See detailDetermining astrophysical parameters of quasars within the Gaia mission
Delchambre, Ludovic ULiege

Doctoral thesis (2017)

Quasars are one of the most peculiar types of objects in astronomy. The supermassive black hole these harbour effectively makes the surrounding matter radiates an enormous amount of energy before getting ... [more ▼]

Quasars are one of the most peculiar types of objects in astronomy. The supermassive black hole these harbour effectively makes the surrounding matter radiates an enormous amount of energy before getting in the vicinity of the black hole horizon out of which it will never escape. This ironically leads to the most luminous phenomenon in the Universe while being non-transient. It is hence quite natural to rely on these cosmic headlights, visible up to ages when the Universe was still very young, so as to achieve some of the currently most important cosmological applications, notably regarding the determination of the cosmological parameters $H_0$, $\Omega_\Lambda$ and $\Omega_m$. The Gaia mission, on its side, is one of a kind given the one billion of celestial objects it is intended to observe, among which more than half a million quasars are expected. Furthermore, owing to its exceptional astrometric precision, Gaia stands out to be extremely well suited for the detection of gravitational lens (GL) systems. In the latter, light rays coming from a distant background quasar are deflected by the presence of a massive galaxy being in the line-of-sight that leads to the production of multiple images of this background quasar upon a favourable alignment between the quasar, the galaxy and the observer. Supplemental constraints on the aforementioned cosmological parameters being then gained based on these GLs. Gaia hence provides an unprecedented opportunity to detect and characterize quasars as well as to identify GLs which ultimately bring a better understanding of the Universe we live in. This thesis is accordingly concerned with the development of software solutions dedicated to the determination of the astrophysical parameters (APs) of the quasars that Gaia will observe, on one hand, and to the recognition of the GLs among the billion of sources it will uncover, on the other hand. Although Gaia provides state-of-the-art astrometric and photometric observations, its capability in characterizing these celestial objects remains however restricted by the relatively low spectral resolution of the blue and red spectrophotometers upon which it is based as well as by the limited signal-to-noise ratio that is associated with faint objects, including quasars. In addition, the overwhelming amount of data that Gaia has to process translates into a stringent need for algorithms having both low numerical complexities as well as low memory usages. These restrictions and shortcomings along with the requirement for reliable APs were at the heart of this research that led to the development of two specifically designed methods that are the weighted principal components analysis and the weighted phase correlation method. The former of these methods allowed us to extract the most significant patterns out of quasars with a view of using these in the production of a spectral library of quasars as observed by Gaia. These were subsequently used in a fast and automated procedure designed to guess the redshift of the quasars within the Gaia mission through the latter mentioned method. Other APs that are the slope of the quasar continua, the total equivalent width of their emission lines and whether these encompass broad absorption lines or not, being then concurrently derived based on the results of these methods. Finally, the identification of GL candidates relies on the recognition of the structures and symmetries that are observed within lensed images through supervised learning methods. The specific method we choose to use, based on extremely randomized trees, was shown to yield a low contamination rate on simulated configurations composed of three images as well as a very high probability of detection in cases of four image configurations. Real observations out of the first Gaia data release were processed and resulted in the identification of candidates having three potentially lensed images which are currently waiting for confirmation using ground-based facilities. [less ▲]

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See detailInfluence d'une prise en charge posturale sur la position assise, les capacités cognitives, le comportement et le bien-être de l'enfant en classe
Fettweis, Tatiana ULiege

Doctoral thesis (2017)

Cette thèse analyse l’impact d’une prise en charge posturale associée à l’utilisation d’un coussin triangulaire dynamique sur la position assise, les capacités cognitives, la concentration et le bien-être ... [more ▼]

Cette thèse analyse l’impact d’une prise en charge posturale associée à l’utilisation d’un coussin triangulaire dynamique sur la position assise, les capacités cognitives, la concentration et le bien-être de l’enfant en début d'école primaire. Elle comporte 4 sections principales. La revue de la littérature présentée dans la première section souligne le rôle de l’école et plus spécifiquement l’impact du mobilier scolaire sur la santé et les apprentissages des élèves. La deuxième section consiste à mettre en place et à étudier les qualités métrologiques d’une batterie de tests permettant d’évaluer la qualité de la position assise, les capacités posturales, le comportement en classe et les capacités cognitives d’enfants du premier cycle du primaire. La troisième section comprend trois études de terrain évaluant l’influence de la prise en charge en milieu scolaire. La partie principale consiste en un suivi longitudinal réalisé au cours des deux premières années primaires. Dans ce cadre, le cousin dynamique a amélioré la qualité de la position assise, les plaintes musculo-squelettiques, les capacités cognitives et le comportement des enfants en classe. Une première étude complémentaire a mis en évidence le caractère instantané de l’effet de la prise en charge et une seconde a confirmé l’impact positif du coussin dans une population présentant des troubles de l’attention. Enfin, la quatrième section comporte deux études réalisées au sein du Laboratoire d’Analyse du Mouvement Humain : une analyse biomécanique de la position assise a précisé l’effet positif et immédiat du coussin dynamique et une évaluation du contrôle moteur lombaire a démontré une meilleure proprioception lombaire chez les enfants habitués à utiliser le coussin. En conclusion, bien que cette recherche ne porte que sur une partie des facteurs entrant en ligne de compte pour le bien-être des élèves en classe ainsi que pour leur réussite scolaire, les différentes analyses et perspectives développées tout au long de cette thèse suggèrent la pertinence d’un coussin dynamique dans la mise en place de campagnes posturales préventives. [less ▲]

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See detailConclusions
Cormann, Grégory ULiege

Conference (2017, December 20)

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See detailLa spatialité de la gouvernance des régions urbaines intermédiaires en Europe
Breuer, Christophe ULiege

Doctoral thesis (2017)

The governance of urban regions is a central research topic of urban sciences, and a major challenge for urban actors. In this research, we contribute to the analysis of governance processes by studying ... [more ▼]

The governance of urban regions is a central research topic of urban sciences, and a major challenge for urban actors. In this research, we contribute to the analysis of governance processes by studying the transformation of its spatiality in intermediate European urban regions. Our research postulates the intrinsically spatial nature of urban governance, and is based on three hypotheses: (1) the territorial characteristics of urban regions relate to local politico-administrative fragmentation, (2) the characteristics of politico-administrative fragmentation relate to the construction of a governance scale for urban regions, and (3) governance structures at the level of urban regions relate to territorial characteristics. In order to test these hypotheses, we conducted a research in three complementary parts. The first part is devolted to the state of the art on governance, territorial rescaling and institutional change. The second part analyses quantitatively the politico-administrative fragmentation of 123 intermediate European urban regions, and its links with territorial indicators. The third part analyses qualitatively the processes of transformation of spatial governance in the urban regions of Saint-Étienne (France), Metz (France), Sheffield (United Kingdom) and Liège (Belgium). This complementary research confirms the existence of links between the different aspects of spatiality in the governance of intermediate urban regions in Europe, and concludes that the recomposition processes are intrinsically spatial, territorial and multiscalar. [less ▲]

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See detailContribution à l'enseignement de la traduction au Niger : le renforcement du français langue cible dans la formation des futurs traducteurs.
Amadou Gazali, Alkassoum ULiege

Doctoral thesis (2017)

Teaching translation is a very old activity. While it often used to be performed in the context of language learning, it has changed fundamentally over the past few decades, i.e. since the ... [more ▼]

Teaching translation is a very old activity. While it often used to be performed in the context of language learning, it has changed fundamentally over the past few decades, i.e. since the institutionalization of translation as an autonomous scientific discipline with specific objects and methods. Now, it covers not only linguistics but also other fields including the operating aspect of knowledge and has undergone more methodological transformations over half a century than it did since the Middle-Age, or even since Cicero. In Niger, however, the situation has not yet changed. Teaching translation has remained part of language learning. In this context, the learners’ translation competence is directly associated to linguistic competence. But the latter is far from satisfactory for quite a lot of Niger students, whatever their field of study. In fact, several studies confirmed the poor performance of Niger students in relation to mastery of their working language, French. Indeed, despite its exclusive status as the language of administration and education, French is not mastered enough to be used as a basis for the learning of another language and even less for translation purposes. This is why this study is based on the hypothesis according to which improving the target language in translator training would largely contribute to upgrade their translation competence. It therefore aims to enhance Niger prospective translators’ translation competence by improving their knowledge of the working language. To this end, an experimental research method is used that relies on a classical type scheme involving pre- and post-experimentation observations. An experimental treatment is applied between the two observation stages, which consists of language remedial courses. The verification of the hypothesis depends on operational aspects of the study as well as on the results yielded by the interpreting of collected data. [less ▲]

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See detailFive years of harvest with the vortex coronagraph
Absil, Olivier ULiege

Scientific conference (2017, December 15)

While the concept of vortex coronagraphy dates back to 2005, the first science-grade Annular Groove Phase Masks (AGPM), working in the thermal infrared regime, have been installed at the VLT only in 2012 ... [more ▼]

While the concept of vortex coronagraphy dates back to 2005, the first science-grade Annular Groove Phase Masks (AGPM), working in the thermal infrared regime, have been installed at the VLT only in 2012. They are now also equipping the Keck telescope and the Large Binocular Telescope, and will soon be at the core of more ground-based high-contrast imaging instruments. In this seminar, I will shortly review the technology development undertaken over the last 10 years, and describe the on-sky operations and performance of the vortex coronagraph. I will then present the main scientific results obtained since 2012, and explain how we have recently adapted deep learning techniques to the problem of post-processing in high-contrast imaging. I will finally discuss the perspectives with new instruments, including the Breakthrough Watch project. [less ▲]

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Peer Reviewed
See detailLe tout (n’)égale (pas) la somme des parties : Lecture phénoménologique d’une hypothèse systémique
Englebert, Jérôme ULiege; Follet, Valérie

Conference (2017, December 15)

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Peer Reviewed
See detailÉvaluation des anomalies de l’expérience du monde : apports de l’échelle EAWE à l’étude de l’intersubjectivité schizophrénique
Mossay, Françoise; Valentiny, Caroline; Englebert, Jérôme ULiege

Conference (2017, December 15)

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See detailSensitivity of the Antarctic surface mass balance to oceanic perturbations
Kittel, Christoph ULiege; Amory, Charles ULiege; Agosta, Cécile ULiege et al

Poster (2017, December 15)

Regional climate models (RCMs) are suitable numerical tools to study the surface mass balance (SMB) of the wide polar ice sheets due to their high spatial resolution and polar-adapted physics. Nonetheless ... [more ▼]

Regional climate models (RCMs) are suitable numerical tools to study the surface mass balance (SMB) of the wide polar ice sheets due to their high spatial resolution and polar-adapted physics. Nonetheless, RCMs are driven at their boundaries and over the ocean by reanalysis or global climate model (GCM) products and are thus influenced by potential biases in these large-scale fields. These biases can be significant for both the atmosphere and the sea surface conditions (i.e. sea ice concentration and sea surface temperature). With the RCM MAR, a set of sensitivity experiments has been realized to assess the direct response of the SMB of the Antarctic ice sheet to oceanic perturbations. MAR is forced by ERA-Interim and anomalies based on mean GCM biases are introduced in sea surface conditions. Results show significant increases (decreases) of liquid and solid precipitation due to biases related to warm (cold) oceans. As precipitation is mainly caused by low-pressure systems that intrude into the continent and do not penetrate far inland, coastal areas are more sensitive than inland regions. Furthermore, warm ocean representative biases lead to anomalies as large as anomalies simulated by other RCMs or GCMs for the end of the 21st century. [less ▲]

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See detailLe mode de gestion du service de l’eau d’irrigation : Un déterminant de l’efficacité technique des exploitations agrumicoles du périmètre de Souss-Massa au Maroc
Maatala, Nassreddine ULiege; Lebailly, Philippe ULiege

Conference (2017, December 14)

La région du Souss-Massa, connue par la culture agrumicole à haute valeur ajoutée, est confrontée au problème de mobilisation des ressources en eau. Depuis le début de l’année 2000, la nappe du ... [more ▼]

La région du Souss-Massa, connue par la culture agrumicole à haute valeur ajoutée, est confrontée au problème de mobilisation des ressources en eau. Depuis le début de l’année 2000, la nappe du périmètre de la région a atteint la limite de son potentiel renouvelable Cette situation a incité le gouvernement marocain à réaliser un projet de sauvegarde du périmètre El Guerdane situé dans cette région. Ce projet, lancé en 2005, a été réalisé dans le cadre du Partenariat Public-Privé avec un partenaire en charge de la conception et la construction et qui veille à l’exploitation et à la maintenance depuis la mise en eau en 2009. Pour le périmètre d’Issen, situé dans la même région, les agriculteurs souffrent du même problème de mobilisation des ressources en eau et il est toujours géré par l’Office Régional de Mise en Valeur Agricole du Souss-Massa (ORMVASM). L’objectif de cet article est d’étudier l’effet du mode de gestion du service de l’eau d’irrigation (Partenariat public-privé et gestion publique) sur l’efficacité technique des exploitations agrumicoles dans les deux périmètres. L’estimation de la frontière de production et les scores de l’efficacité technique a été réalisée à partir des données collectées sur le terrain d’un échantillon de 121 exploitations agrumicoles situées dans les deux périmètres. La variabilité de ces scores d’efficacité technique est déterminée par plusieurs facteurs notamment la participation au Programme de Partenariat Public-Privé (PPP) et l’adhésion à des coopératives agricoles. L’estimation de la frontière de production et les scores de l’efficacité technique ont été effectués par le logiciel FRONTIER 4.1, l’analyse de l’efficacité a été réalisée à l’aide du logiciel GRETL en utilisant un modèle Tobit. [less ▲]

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See detailMatériaux, métiers et techniques. Vers une histoire matérielle du chantier de restauration (1830-1914): Introduction au colloque
Houbart, Claudine ULiege; Piavaux, Mathieu; Timbert, Arnaud

Conference (2017, December 14)

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See detailDiagnostic de la maladie de Lyme.
Pitel, Pierre Hugues; Hary, Claudine; Amory, Hélène ULiege et al

Conference (2017, December 14)

Le diagnostic de certitude de la maladie Borreliose de Lyme est éminemment complexe. La seule efficacité thérapeutique n’étant pas une preuve absolue, seule un faisceau de concordance et la réalisation ... [more ▼]

Le diagnostic de certitude de la maladie Borreliose de Lyme est éminemment complexe. La seule efficacité thérapeutique n’étant pas une preuve absolue, seule un faisceau de concordance et la réalisation d’études terrain pourront nous aider à essayer de débroussailler ce qui est encore chez le cheval une nébuleuse sujette à de nombreuses croyances et controverses. Certaines de ces études françaises et belges seront exposées lors de la présentation orale. [less ▲]

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See detailThe concept of frailty in patients on dialysis
DELANAYE, Pierre ULiege

Scientific conference (2017, December 14)

See detailIntroduction du colloque international « Psychopathologie phénoménologique : Dépassement et ouverture »
Englebert, Jérôme ULiege; Adam, Christophe

Conference (2017, December 13)

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See detailObservation and simulation of ethane (C2H6) at 23 FTIR sites
Mahieu, Emmanuel ULiege; Franco, B; Pozzer, A et al

Poster (2017, December 13)

Ethane is the most abundant non-methane hydrocarbon (NMHC) in the Earth atmosphere. Its main sources are of anthropogenic origin, with globally 62% from leakage during production and transport of natural ... [more ▼]

Ethane is the most abundant non-methane hydrocarbon (NMHC) in the Earth atmosphere. Its main sources are of anthropogenic origin, with globally 62% from leakage during production and transport of natural gas, 20% from biofuel combustion and 18% from biomass burning. In the Southern hemisphere, anthropogenic emissions are lower which makes biomass burning emissions a more significant source. The main removal process is oxidation by the hydroxyl radical (OH), leading to a mean atmospheric lifetime of 2 months. Until recently, a prolonged decrease of its abundance has been documented, at rates of -1 to -2.7%/yr, with global emissions dropping from 14 to 11 Tg/yr over 1984-2010 owing to successful measures reducing fugitive emissions from its fossil fuel sources. However, subsequent investigations have reported on an upturn in the ethane trend, characterized by a sharp rise from about 2009 onwards. The ethane increase is attributed to the oil and natural gas production boom in North America, although significant changes in OH could also be at play.In the present contribution, we report the trend of ethane at 23 ground-based Fourier Transform Infrared (FTIR) sites spanning the 80ºN to 79ºS latitude range. Over 2010-2015, a significant ethane rise of 3-5%/yr is determined for most sites in the Northern Hemisphere, while for the Southern hemisphere the rates of changes are not significant at the 2-sigma uncertainty level. Dedicated model simulations by EMAC (ECHAM5/MESSy Atmospheric Chemistry; ~1.8×1.8 degrees) implementing various emission scenarios are included in order to support data interpretation. The usual underestimation of the NMHCs emissions in the main inventories is confirmed here for RCP85 (Representative Concentration Pathway Database v8.5). Scaling them by 1.5 is needed to capture the background levels of atmospheric ethane. Moreover, additional and significant emissions (~7 Tg over 2009-2015) are needed to capture the ethane rise in the Northern hemisphere. Attributing them to the oil and gas sector and locating them in North America allows EMAC to produce adequate trends in the Northern hemisphere, but not in the Southern hemisphere, where they are overestimated. Possible causes for this difference are discussed. [less ▲]

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Peer Reviewed
See detailVersatile Catalyst Materials Fabrication by Low-Pressure Plasma Treatments
Busby, Yan; da Silva Pires, Mathieu; Haye., Emile et al

Conference (2017, December 12)

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See detailDiscussant The institutional functioning of the European Central Bank
Van Cleynenbreugel, Pieter ULiege

Scientific conference (2017, December 12)

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See detailBovine brucellosis in Argentina: current situation and intraherd simulation model
Aznar, Maria Natalia ULiege

Doctoral thesis (2017)

Bovine brucellosis is an infectious disease, which can negatively affect cattle productivity and human health. It is endemic in Argentina, where 0.8% of cattle and 12% of farms are infected, having this ... [more ▼]

Bovine brucellosis is an infectious disease, which can negatively affect cattle productivity and human health. It is endemic in Argentina, where 0.8% of cattle and 12% of farms are infected, having this percentages remained stable throughout the years. This thesis studies the disease in the country. At first a review on the Argentine situation is presented, which leads to two remarkable aspects: brucellosis remains endemic and it is not possible to reach its eradication. In order to to clarify those points, four main studies were performed. The study 1 is an analysis of cattle movement that showed that there are some districts potential spreaders of the disease while others have more at risk of introduction. The study 2 constitutes an estimation of the brucellosis prevalence and identification of the risk factors associated with an increased occurrence, which helps to improve the knowledge of the epidemiology of the disease in the country. When assessing the situation at the provinces under study, a spatial cluster of infected farms was detected. In that region, farms are considerably large, having lowanimal densities and few movements. Those factors probably correlate with infrequent veterinary control and poor sanitary conditions of the herds. Special attention should be paid to those zones sharing these characteristics since there is high chance of finding clusters of the disease. In the study 3 a method for evaluating some farmers' and veterinarians' management practices in relation to brucellosis and for assessing the vaccination campaign and coverage is developed. It shows that the vaccination campaign is globally well implemented, but the immunization coverage and some management practices should be improved. Finally, the study 4 develops an intra herd simulation model. Its aim is to predict the effects of the disease and to test different control and eradication strategies in different situations. As brucellosis is a contagious disease, when introducing one infected animal in a free herd, it might become endemic. In the case of endemic farms that do not eliminate the reactors, all the tested vaccination strategies produce a reduction in the disease outputs (abortions, infectious deliveries, new infected and born infected) whereas when no vaccination is applied, the outputs remain stable. The isolation of heifers from the general herd reduces the disease outputs by a half. Despite it, if the reactors are not eliminated the sources of infection are kept in the herd. Therefore, a strategy of elimination of infected animals has to be applied. Independently from the chosen vaccination strategy, applying serological tests of high sensitivity and specificity with immediate elimination of reactors produces a dramatic reduction in the disease prevalence. These results might explain the fact that the disease keeps on being endemic in Argentina. Since for achieving eradication at country level, other measures additional to vaccination have to be applied, the mandatory elimination of infected cattle could be taken into account. Summarizing all these issues, it can be concluded that, although there are good regulations to control and eradicate bovine brucellosis in Argentina. The prevalence is not so high and stable throughout the years and, some improvements have to be made in order to achieve eradication. This thesis attempted to assess the Argentine current situation and to provide tools for policy makers and farmers to obtain that goal.   [less ▲]

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