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Optimisation des techniques de codage pour les transmissions radio avec voie de retourEL AOUN, Moustapha 12 July 2012 (has links) (PDF)
Dans la plupart des systèmes radio, la correction des erreurs de transmission se base sur un protocole ARQ hybride (HARQ), qui combine un code correcteur d'erreurs (FEC) avec un protocole de retransmission (ARQ). La grande majorité des études portant sur l'HARQ se focalise essentiellement sur l'analyse et l'optimisation du code correcteur d'erreurs. Dans cette thèse, nous proposons une optimisation conjointe inter-couches du protocole ARQ hybride, en considérant à la fois des aspects de communications numériques et des aspects protocolaires. Dans les schémas HARQ classiques, dits simple paquet (SP), les paquets de redondance transmis sont tous relatifs au même paquet de données. Chaque retransmission réduit alors significativement le débit utile lorsque la taille des paquets est fixe. D'autre part, le débit est également très sensible à la présence d¿erreurs sur la voie retour. Nous proposons donc une nouvelle approche dite multi-paquets (MP), qui vise à réduire le nombre moyen de retransmissions par paquet grâce à la construction de paquets de redondance pouvant aider au décodage simultané de plusieurs paquets de données. Cette approche offre un gain significatif en débit par rapport aux schémas HARQ-SP lorsque le rapport signal à bruit (RSB) est suffisamment élevé. Les schémas HARQ classiques demeurent toutefois plus performants à faible RSB. Nous montrons par ailleurs que l'approche MP est plus robuste aux erreurs sur la voie de retour que l'approche SP. Ces résultats nous ont conduits à proposer un protocole hybride SP/MP qui bénéficie des avantages propres à chaque stratégie. Nous montrons par une analyse théorique ainsi que par simulation, que ce schéma hybride réalise un très bon compromis entre SP et MP sur toute la plage de RSB.
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Evolution des compétences de la région en matière de formation professionnelle / Evolution of the skills of the region in vocational trainingAidara, Mouhamadou Moustapha 09 July 2010 (has links)
La formation professionnelle constitue un des grands domaines d’intervention de la région.Formellement, le transfert de compétences de formation professionnelle à la région débuta en 1983 par la reconnaissance à la région d’une compétence de droit commun en matière de formation professionnelle et d’apprentissage. Mais cette première phase de décentralisation de la formation professionnelle apparaîtparadoxale pour ne pas dire contradictoire. En effet, autant la volonté affichée de transférer à la région laformation professionnelle est réelle autant aussi semble évident le maintien des prérogatives de l’Etat dans lesecteur de la formation.Une décennie plus tard, interviendra l’importante réforme quinquennale de 1993 qui envisage de renforcer lespouvoirs d’intervention et les responsabilités des conseils régionaux dans la construction des politiques régionales de formation professionnelle.Mais en même temps qu’elle consolide le pouvoir régional, la réforme remet en question les anciennes régulations de la formation professionnelle et appelle le développement d’une coopération au niveau régional dont les modalités et le contenu restent très indécis.Une décennie plus tard, les réformes de 2002 et de 2004 consacrent l’entière responsabilité de la région pour la définition et la mise en oeuvre de la politique régionale d’apprentissage et de formation professionnelle des jeunes et des adultes.Cependant, et aussi paradoxal que cela puisse paraître, l’affirmation de principe de la compétence générale de la région ne garantit pas une effectivité de son autonomie en matière de formation professionnelle. En effet, la réforme laisse en suspens de nombreuses questions. Pour les régions, les nouvelles compétences s’apparentent à une lutte, souvent épuisante, contre les rigidités du système. / The vocational training constitutes one of the big fields of intervention of the region in France. Formally, the know-how transmission of vocational training in the region began in 1983 with the recognition inthe region of a competence of common law in vocational training and in learning (apprenticeship). But this firstphase of decentralization of the vocational training seems paradoxical not to say contradictory. Indeed, so muchthe will shown to transfer to the region the vocational training is real so also seems evident the preservation of theprivileges of the State in the sector of the training(formation).A decade later, will intervene the important quinquennial reform of 1993 which intends to strengthen the powersof intervention and the responsibilities of regional councils in the construction of the regional policies ofvocational training.But at the same time as it strengthens the regional power, the reform questions the ancient regulations of thevocational training and calls the development of a cooperation to the regional level among which the modalitiesand the contents remain veryindecisive.A decade later, the reforms of 2002 and 2004 dedicate the whole responsibility of the region for the definition andthe implementation of the regional policy of learning (apprenticeship) and vocational training of the young peopleand the adults.However, and however paradoxical it can appear, the principal assertion of the general competence of the regiondoes not guarantee an effectiveness of its autonomy in vocational training. Indeed, the reform leaves unresolvedof numerous questions. For regions, the new skills are similar to a fight often exhausting, against the rigidity ofthe system.
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The accessory glycoprotein gp3 of canine Coronavirus type 1 : investigations of sequence variability in feline host and of the basic features of the different variants / Etude de la glycoprotéine accessoire gp3 du Coronavirus canine de type I : études de la variabilité de séquences chez l'hôte félin et des caractéristiques biochimiques de ses différentes formesPham-Hung d'Alexandry d'Orengiani, Anne-Laure 24 October 2014 (has links)
Les différents génotypes de Coronavirus canins (CCoV-I/II) et félins (FCoV-I/II) sont phylogénétiquement proches, suggérant des transmissions inter-espèces entre chiens et chats. Lors d’analyses de séquences menées sur des chats infectés, des souches félines atypiques ont pu être mises en évidence, contenant un gène S de type FCoV-I, un gène N de type CCoV-I, ainsi que la présence du gène ORF3, spécifique à CCoV-I. Dans ces souches, le gène ORF3 est présent avec une ou deux délétions toujours identiques, conduisant à la synthèse de protéines tronquées gp3-Δ1 et gp3-Δ2. Les délétions de protéines accessoires étant déjà impliquées dans les transmissions inter-espèces, une étude de caractérisation de la protéine gp3 et de ses différentes formes a été menée. Les trois protéines s’oligomérisent de manière covalente et sont retenues dans le réticulum endoplasmique, en absence de signal spécifique de rétention. Les délétions influencent le niveau d’expression des protéines en cellules félines, où seule l’expression de gp3-Δ1 est visible, alors qu’elles conservent toutes une expression optimale en cellules canines. En l’absence de souches de Coronavirus cultivables en laboratoire contenant le gène ORF3, des cellules canines exprimant l’une des protéines gp3 ont été infectées par une souche CCoV-II. Dans ce modèle, les protéines gp3 ne modifient pas le cycle viral. Dans un contexte d’émergence de nouveaux Coronavirus, la compréhension des mécanismes moléculaires de changement d’hôte est cruciale et les Coronavirus félins et canins peuvent représenter un modèle d’étude utile. / The different genotypes of canine (CCoV-I/II) and feline (FCoV-I/II) Coronaviruses share a close phylogenetic relationship, suggesting inter-species transmissions between cats and dogs. Through sequence analyses of cat samples, atypical FCoV strains, harbouring an S gene related to FCoV-I, an N gene close to the CCoV-I cluster and the ORF3 gene, peculiar to CCoV-I, were discovered. This ORF3 gene was systematically truncated in feline samples, displaying either one or two identical deletions, leading to the translation of gp3-Δ1 and gp3-Δ2. As deletions in accessory proteins have already been involved in host-switch, studies of the different variants of gp3 were conducted. Results demonstrate that all proteins oligomerize through covalent bonds and are retained in the ER, without any specific retention signal. Deletions influence the expression level with a proper expression of the three proteins in canine cells, whereas only gp3-Δ1 expression is sustained in feline cells. As no isolates of Coronavirus harbouring the ORF3 gene exists, cells expressing the different gp3 proteins have been infected with a CCoV-II strain. In this model, the gp3 proteins do not influence the viral life cycle. In the light of emergence of new Coronaviruses, investigations on their molecular mechanisms during the host-switch are crucial and canine and feline Coronaviruses could represent a useful model.
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Avaliação da dinâmica da infecção por Rickettsia parkeri cepa Mata Atlântica, agente etiológico de uma nova riquetsiose brasileira, em carrapatos Amblyomma ovale Koch, 1844 naturalmente infectados / Dynamics of the infection by Rickettsia parkeri strain Atlantic rainforest, the etiologic agent of a novel rickettsiosis in Brazil, in naturally infected Amblyomma ovale Koch, 1844 ticksKrawczak, Felipe da Silva 29 January 2013 (has links)
No início de 2010, uma nova riquetsiose foi descrita em um paciente humano, que foi infestado por carrapato em Barra do Una, no litoral sul do Estado de São Paulo. Técnicas moleculares indicaram que esta nova doença foi causada por uma nova cepa de riquétsia, que foi denominada de Rickettsia parkeri cepa Mata Atlântica. Estudos mais recentes demonstraram que 10 a 15% dos carrapatos Amblyomma ovale, coletados em áreas de Mata Atlântica nos estados de São Paulo (incluindo a área do caso índice da infecção humana em Barra do Una) e Santa Catarina estavam infectados com R. parkeri cepa Mata Atlântica. Desta forma, o presente estudo iniciou-se a partir de fêmeas ingurgitadas de A. ovale, coletadas de cães naturalmente infestados em Barra do Una. No laboratório, foi constatado por PCR que parte dessas fêmeas (6,25%) estavam naturalmente infectadas por R. parkeri cepa Mata Atlântica; os ovos dessas fêmeas foram utilizados para formar uma colônia de A. ovale naturalmente infectada por R. parkeri. Ovos de fêmeas não infectadas, foram utilizados para formar uma colônia não infectada. As duas colônias foram estudadas de forma paralela no laboratório, visando analisar e quantificar a transmissão transestadial e transovariana de R. parkeri cepa Mata Atlântica e a competência vetorial do A. ovale. As infestações por larvas foram realizadas em roedores (Calomys callosus), enquanto ninfas e adultos foram alimentados em Oryctolagus cunicullus (coelho doméstico). Amostras de 10 indivíduos de cada uma das fases (larvas, ninfas e adultos F1, ovos, larvas e ninfas F2) foram testadas individualmente por um sistema de taqman real-time PCR, para presença de Rickettsia spp. Os soros sanguíneos de todos animais infestados foram testados por imunofluorescência indireta com antígeno de R. parkeri, no dia zero e 21 dias após a infestação por carrapatos, a fim de verificar soroconversão para antígenos de Rickettsia. Os resultados obtidos demonstraram 100% de transmissões transestadial (larva para ninfas e ninfas para adultos) e transovariana de R. parkeri em A. ovale, uma vez que todas as amostras de ovos, larvas, ninfas e adultos do grupo infectado foram positivas na PCR. Larvas e ninfas de A. ovale demonstraram alta competência vetorial, pois todos animais infestados por esses estágios infectados soroconverteram para R. parkeri. Por outro lado, adultos foram parcialmente competentes, pois apenas metade dos coelhos soroconverteu após ser infestada com carrapatos adultos infectados. Nenhum carrapato do grupo controle foi positivo na PCR, assim como nenhum animal deste grupo soroconverteu para R. parkeri. Fêmeas infectadas por R. parkeri cepa Mata Atlântica tiveram parâmetros reprodutivos inferiores aos das fêmeas não infectadas, indicando algum efeito deletério da infecção por este agente sobre os carrapatos. Os resultados sugerem a importância do carrapato A. ovale na epidemiologia desta nova riquetsiose brasileira, assim como sugerem uma capacidade vetorial de A. ovale para R. parkeri cepa Mata Atlântica, uma vez que este carrapato é frequentemente encontrado infestando humanos no bioma de Mata Atlântica. / In early 2010, a novel rickettsiosis was described in a human patient that had been infested by a tick in Barra do Una, southern coast of the state of São Paulo, Brazil. Molecular tests indicated that the disease was caused by a new rickettsial strain, named Rickettsia parkeri strain Atlantic rainforest. More recent studies demonstrated that 10 to 15% of Amblyomma ovale ticks, collected in Atlantic rainforest areas in the states of São Paulo (including the human index case area in Barra do Una) and Santa Catarina were infected with R. parkeri strain Atlantic rainforest. Within this context, the present study started with A. ovale engorged females collected from naturally infested dogs in Barra do Una. In the laboratory, it was shown by PCR that part of these females (6.25%) were naturally infected with R. parkeri strain Atlantic rainforest; the eggs of these females were used to form a lab colony of A. ovale, naturally infected by R. parkeri. Eggs laid by uninfected females were used to form an uninfected tick colony. Both colonies were evaluated in parallel in the lab, aiming to verify and quantify the transstadial and transovarian transmissions of R. parkeri strain Atlantic rainforest in A. ovale ticks, and the vector competence of the different parasitic stages of this tick. Larval infestations were done on rodents (Calomys callosus), while nymphal and adult infestations were done on rabbits (Oryctolagus cunicullus). Samples of 10 individuals of each tick stage (F1 larvae, nymphs and adults; F2, eggs, larvae, and nymphs) were tested individually by a taqman real-time PCR targeting the genus Rickettsia. Blood serum samples from all infested animals were tested through immunofluorescence assay employing R. parkeri antigens, on zero and 21 days post tick infestation, in order to verify seroconversion to rickettsial antigens. The results demonstrated 100% of transstadial (larvae to nynphs; nymphs to adults) and transovarian transmissions of R. parkeri in A. ovale ticks, since all egg, larval, nymphal, and adult samples from the infected colony were PCR-positive. A. ovale larvae and nymphs demonstrated high vector competence because all animals infested by these tick infected stages seroconverted to R. parkeri. On the other hand, adult ticks were partially competent since only half of the animals seroconverted after being infested by infected adult ticks. None tick of the uninfected control colony was PCR positive, as well as no animal from this group seroconverted to R. parkeri. Tick females infected by R. parkeri strain Atlantic rainforest had lower reproductive parameters than uninfected females, indicating some deleterious effect of the infection on these ticks. The results suggest an important role of A. ovale ticks in the epidemiology of this novel Brazilian rickettsiosis, and also suggest that A. ovale are capable to transmit R. parkeri strain Atlantic rainforest under natural conditions, since this tick is frequently found infesting humans on the Atlantic rainforest biome.
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Etude d'une méthodologie de modélisation et de commande d'un robot multiaxe pour une application en radiologie médicaleAl Assad, Omar 16 June 2009 (has links) (PDF)
Cette thèse s'inscrit dans le cadre de la modélisation et la commande des robots poly-articulés utilisés dans les applications d'imagerie médicale. Ces travaux ont porté sur deux aspects complémentaires, d'une part, la méthodologie de modélisation des robots positionneurs dans les applications d'imagerie médicale. D'autre part, les méthodologies de contrôle de mouvements et de réduction des vibrations. Les concepts développés dans ce travail sont présentés selon une approche « Bottom-up » visant à étudier le cas mono-axe afin de mieux définir la problématique identifiée et de comprendre l'impact des solutions. Ensuite, l'étude portera sur l'extension des concepts retenus dans le cadre de la commande multiaxe du robot. Dans la phase de modélisation, une démarche formalisée en vue d'obtenir les modèles des robots (de connaissances, d'analyse et de commande) est exposée. Aussi, ce travail vise à démontrer, via une étude comparative, le potentiel d'application de plusieurs approches de modélisation et de commande dans ce cadre précis. En complément au travail de modélisation, un outil d'aide à la modélisation a été mise en place. Les modèles établis ont permis d'étudier différentes stratégies de commande, l'étude a porté sur l'élaboration de trois actions de commande, à savoir, la génération de trajectoire du système, le calcul du couple d'anticipation, et le calcul du correcteur qui permet de garantir la poursuite de la trajectoire. Enfin, une part importante de ce travail a été consacrée à la validation expérimentale des modèles établis et aux essais des lois de commandes retenues sur les robots d'imagerie médicale.
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Διερεύνηση και εφαρμογή της τεχνικής “Μεταβλητός αστερισμός συμβόλων” (Constellation Remapping) σε επικοινωνίες πολλαπλών κεραιών (ΜΙΜΟ)Μπλάτσας, Μιλτιάδης 31 August 2012 (has links)
Οι επικοινωνίες με χρήση πολλαπλών κεραιών αποτελούν μια πολλά υποσχόμενη τεχνολογία προκειμένου να αντιμετωπιστεί αποδοτικά το φαινόμενο της τυχαίας εξασθένησης που παρουσιάζει ο ασύρματος τηλεπικοινωνιακός δίαυλος (κανάλι). Τα συστήματα επικοινωνίας στα οποία τόσο ο δέκτης όσο και ο πομπός είναι εξοπλισμένοι με περισσότερες της μιας κεραίας ορίζουν ένα σύστημα πολλαπλών εισόδων πολλαπλών εξόδων (Multiple Input Multiple Output, MIMO) στο οποίο η πιθανότητα όλα τα κανάλια που ορίζονται να βρίσκονται σε εξασθένηση είναι σαφώς μικρότερη σε σχέση με τα συστήματα που χρησιμοποιούν μόνο μια κεραία (χωρική διαφορετικότητα, spatial diversity). Συνήθως, σε ένα σύστημα MIMO, ο πομπός εκτελεί μια επεξεργασία γνωστή με το όνομα “χώρο-χρονική κωδικοποίηση” (space-time coding) προκειμένου να βελτιώσει την απόδοση του συστήματος σε σχέση με την πιθανότητα λανθασμένης μετάδοσης. Πρόσφατα, (1) προτάθηκε μια νέα τεχνική βελτίωσης της πιθανότητας εσφαλμένης μετάδοσης σε ένα σύστημα το οποίο χρησιμοποιεί την τεχνική της επαναμετάδοσης (retransmission). Η τεχνική αυτή έγκειται στην τροποποίηση του κανόνα με βάση τον οποίο τα δυαδικά προς μετάδοση δεδομένα απεικονίζονται σε σύμβολα, σε κάθε επαναμετάδοση. Αντικείμενο της εργασίας αποτελεί η εφαρμογή της προαναφερθείσας τεχνικής σε ένα σύστημα MIMO όπου ο πομπός του συστήματος θα χρησιμοποιεί έναν διαφορετικό κανόνα απεικόνισης των δυαδικών δεδομένων σε σύμβολα σε κάθε έναν από τους κλάδους των κεραιών εκπομπής. Επιμέρους στόχοι της εργασίας είναι:
1. Η σύγκριση της τεχνικής με διάφορες γνωστές τεχνικές χωρο-χρονικής κωδικοποίησης.
2. Ο συνδυασμός της τεχνικής με τεχνικές χωρο-χρονικής κωδικοποίησης.
3. Η διερεύνηση της επιπλέον πολυπλοκότητας που απαιτείται στο δέκτη λόγω της χρήσης της τεχνικής αυτής, ειδικά στην περίπτωση όπου το εμπλεκόμενο MIMO κανάλι είναι συχνοτικά επιλεκτικό και απαιτείται η χρήση κάποιου ισοσταθμιστή. / In this project, we present a simple, but effective method of enhancing and exploiting diversity from multiple packet transmissions in systems that employ nonbinary linear modulations such as phase-shift keying (PSK) and quadrature amplitude modulation (QAM). This diversity improvement results from redesigning the symbol mapping for each packet transmission. By developing a general framework for evaluating the upper bound of the bit error rate (BER) with multiple transmissions, a criterion to obtain optimal symbol mappings is attained. The optimal adaptation scheme reduces to solutions of the well known quadratic assignment problem (QAP). Symbol mapping adaptation only requires a small increase in receiver complexity but provides very substantial BER gains when applied to additive white Gaussian noise (AWGN) and flat-fading channels.
My own idea in this research was the combination of this Constellation Remapping technique with the Alamouti code. The results that extracted from this combination shows that this method leads to lower BER compared with the corresponding BER of the Alamouti code (only) and the corresponding BER of the conventional Constellation Remapping technique.
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Avaliação da dinâmica da infecção por Rickettsia parkeri cepa Mata Atlântica, agente etiológico de uma nova riquetsiose brasileira, em carrapatos Amblyomma ovale Koch, 1844 naturalmente infectados / Dynamics of the infection by Rickettsia parkeri strain Atlantic rainforest, the etiologic agent of a novel rickettsiosis in Brazil, in naturally infected Amblyomma ovale Koch, 1844 ticksFelipe da Silva Krawczak 29 January 2013 (has links)
No início de 2010, uma nova riquetsiose foi descrita em um paciente humano, que foi infestado por carrapato em Barra do Una, no litoral sul do Estado de São Paulo. Técnicas moleculares indicaram que esta nova doença foi causada por uma nova cepa de riquétsia, que foi denominada de Rickettsia parkeri cepa Mata Atlântica. Estudos mais recentes demonstraram que 10 a 15% dos carrapatos Amblyomma ovale, coletados em áreas de Mata Atlântica nos estados de São Paulo (incluindo a área do caso índice da infecção humana em Barra do Una) e Santa Catarina estavam infectados com R. parkeri cepa Mata Atlântica. Desta forma, o presente estudo iniciou-se a partir de fêmeas ingurgitadas de A. ovale, coletadas de cães naturalmente infestados em Barra do Una. No laboratório, foi constatado por PCR que parte dessas fêmeas (6,25%) estavam naturalmente infectadas por R. parkeri cepa Mata Atlântica; os ovos dessas fêmeas foram utilizados para formar uma colônia de A. ovale naturalmente infectada por R. parkeri. Ovos de fêmeas não infectadas, foram utilizados para formar uma colônia não infectada. As duas colônias foram estudadas de forma paralela no laboratório, visando analisar e quantificar a transmissão transestadial e transovariana de R. parkeri cepa Mata Atlântica e a competência vetorial do A. ovale. As infestações por larvas foram realizadas em roedores (Calomys callosus), enquanto ninfas e adultos foram alimentados em Oryctolagus cunicullus (coelho doméstico). Amostras de 10 indivíduos de cada uma das fases (larvas, ninfas e adultos F1, ovos, larvas e ninfas F2) foram testadas individualmente por um sistema de taqman real-time PCR, para presença de Rickettsia spp. Os soros sanguíneos de todos animais infestados foram testados por imunofluorescência indireta com antígeno de R. parkeri, no dia zero e 21 dias após a infestação por carrapatos, a fim de verificar soroconversão para antígenos de Rickettsia. Os resultados obtidos demonstraram 100% de transmissões transestadial (larva para ninfas e ninfas para adultos) e transovariana de R. parkeri em A. ovale, uma vez que todas as amostras de ovos, larvas, ninfas e adultos do grupo infectado foram positivas na PCR. Larvas e ninfas de A. ovale demonstraram alta competência vetorial, pois todos animais infestados por esses estágios infectados soroconverteram para R. parkeri. Por outro lado, adultos foram parcialmente competentes, pois apenas metade dos coelhos soroconverteu após ser infestada com carrapatos adultos infectados. Nenhum carrapato do grupo controle foi positivo na PCR, assim como nenhum animal deste grupo soroconverteu para R. parkeri. Fêmeas infectadas por R. parkeri cepa Mata Atlântica tiveram parâmetros reprodutivos inferiores aos das fêmeas não infectadas, indicando algum efeito deletério da infecção por este agente sobre os carrapatos. Os resultados sugerem a importância do carrapato A. ovale na epidemiologia desta nova riquetsiose brasileira, assim como sugerem uma capacidade vetorial de A. ovale para R. parkeri cepa Mata Atlântica, uma vez que este carrapato é frequentemente encontrado infestando humanos no bioma de Mata Atlântica. / In early 2010, a novel rickettsiosis was described in a human patient that had been infested by a tick in Barra do Una, southern coast of the state of São Paulo, Brazil. Molecular tests indicated that the disease was caused by a new rickettsial strain, named Rickettsia parkeri strain Atlantic rainforest. More recent studies demonstrated that 10 to 15% of Amblyomma ovale ticks, collected in Atlantic rainforest areas in the states of São Paulo (including the human index case area in Barra do Una) and Santa Catarina were infected with R. parkeri strain Atlantic rainforest. Within this context, the present study started with A. ovale engorged females collected from naturally infested dogs in Barra do Una. In the laboratory, it was shown by PCR that part of these females (6.25%) were naturally infected with R. parkeri strain Atlantic rainforest; the eggs of these females were used to form a lab colony of A. ovale, naturally infected by R. parkeri. Eggs laid by uninfected females were used to form an uninfected tick colony. Both colonies were evaluated in parallel in the lab, aiming to verify and quantify the transstadial and transovarian transmissions of R. parkeri strain Atlantic rainforest in A. ovale ticks, and the vector competence of the different parasitic stages of this tick. Larval infestations were done on rodents (Calomys callosus), while nymphal and adult infestations were done on rabbits (Oryctolagus cunicullus). Samples of 10 individuals of each tick stage (F1 larvae, nymphs and adults; F2, eggs, larvae, and nymphs) were tested individually by a taqman real-time PCR targeting the genus Rickettsia. Blood serum samples from all infested animals were tested through immunofluorescence assay employing R. parkeri antigens, on zero and 21 days post tick infestation, in order to verify seroconversion to rickettsial antigens. The results demonstrated 100% of transstadial (larvae to nynphs; nymphs to adults) and transovarian transmissions of R. parkeri in A. ovale ticks, since all egg, larval, nymphal, and adult samples from the infected colony were PCR-positive. A. ovale larvae and nymphs demonstrated high vector competence because all animals infested by these tick infected stages seroconverted to R. parkeri. On the other hand, adult ticks were partially competent since only half of the animals seroconverted after being infested by infected adult ticks. None tick of the uninfected control colony was PCR positive, as well as no animal from this group seroconverted to R. parkeri. Tick females infected by R. parkeri strain Atlantic rainforest had lower reproductive parameters than uninfected females, indicating some deleterious effect of the infection on these ticks. The results suggest an important role of A. ovale ticks in the epidemiology of this novel Brazilian rickettsiosis, and also suggest that A. ovale are capable to transmit R. parkeri strain Atlantic rainforest under natural conditions, since this tick is frequently found infesting humans on the Atlantic rainforest biome.
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[pt] DE PAI PARA FILHO: O APRENDIZADO DAS PRÁTICAS EDUCATIVAS PARENTAIS ENTRE GERAÇÕES DE HOMENS / [en] FROM FATHER TO SON: LEARNING PARENTING PRACTICES BETWEEN GENERATIONS OF MENJESSICA MORAES ROSA 17 June 2021 (has links)
[pt] A família permanece como a principal responsável pela transmissão das regras sociais e, portanto, pela inserção dos seus membros na sociedade. As relações estabelecidas entre pais e filhos são representadas pelas práticas educativas parentais, que consistem no conjunto de estratégias utilizadas por estes, objetivando orientar os comportamentos socialmente adequados dos filhos, e são divididas em práticas positivas e negativas. As práticas mais utilizadas pelos pais influenciam no desenvolvimento socioemocional dos filhos. Além disso, parte dos comportamentos dos filhos são aprendidos com seus pais, seja através da modelagem, da modelação ou do uso de regras. O que implica dizer que os filhos podem utilizar as mesmas práticas educativas que seus pais no exercício de sua parentalidade. Dessa forma, o presente estudo objetivou investigar se as práticas educativas parentais são transmitidas entre gerações e quais dessas práticas aprendidas os filhos utilizam no exercício de sua parentalidade. Foram realizadas entrevistas semiestruturadas e aplicou-se o RE-HSE-P com 10 pares de homens (pais e filhos) que exercem a parentalidade e residem no estado do Ceará. Os resultados obtidos foram analisados estatisticamente através do software SPSS versão 20.0 e lexicograficamente pelo software IRaMuTeQ. Constatou-se que as práticas positivas foram as mais transmitidas entre as gerações participantes, ressaltando a monitoria positiva e o comportamento moral. Os pais da Geração 1 demonstraram fazer mais uso das práticas negativas do que os pais da Geração 2. Assim, este estudo contribui para o surgimento de novas perspectivas quanto à transmissão das práticas educativas parentais. / [en] The family remains the main responsible for the transmission of social rules and, therefore, for the insertion of its members in society. The relationships established between parents and children are represented by parenting educational practices, which consist of the set of strategies used by them, aiming to guide the socially appropriate behaviors of the children, and are divided into positive and negative practices. The practices most used by parents influence the socio-emotional development of their children. In addition, part of the children s behaviors is learned from their parents, either through modeling, modeling or using rules. The implies that children can use the same parenting practices as their parents in the exercise of their parenting. Thus, the present study aimed to investigate whether parenting educational practices are transmitted between generations and which of these learned practices children use in the exercise of parenting. Through semi-structured interviews and the application of the RE-HSE-P with 10 pairs of men (parents and children) who exercise parenting and live in the state of Ceará. The results obtained were analyzed statistically using the SPSS software version 20.0 and lexicographically by the IRaMuTeQ software. It was found that positive practices are the most transmitted among the participating generations, emphasizing positive monitoring and moral behavior. Generation 1 parents demonstrated to make more use of negative practices than generation 2 parents. Thus, this study contributes to the emergence of new perspectives regarding the transmission of parental educational practices.
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Ultra-wideband Concurrent Transmissions for Ranging and LocalizationCorbalan Pelegrin, Pablo 14 May 2020 (has links)
Global navigation satellite systems (GNSS) have radically changed business, industry, and society, shaping the way we transport, navigate, and generally live every day. After all these years, however, GNSS location information remains only valuable outdoors, leaving indoor environments where people dwell most of the time without proper localization support. Many technologies and systems have approached this problem including optical, inertial, ultrasonic, and radio-frequency (RF), to name a few; yet the problem remains.
In this thesis, inspired by the indisputable success of GNSS and the re-emergence of ultra-wideband (UWB) radios to the forefront of technology, we aim to change the state of affairs in RF localization by proposing novel clean-slate UWB ranging and localization schemes based on concurrent transmissions. These are generally considered harmful for communication but become a rich source of localization information when combined with knowledge of the channel impulse response (CIR).
Our first novel contribution lies in the concept of concurrent ranging, which allows mobile nodes to simultaneously measure the distance to multiple devices—hereafter, called responders—removing the need for the wasteful long packet exchanges traditionally used for ranging and localization. Different from conventional schemes, which spread responder transmissions over time, we force responders to transmit concurrently and let their signals “fuse” in the wireless channel; the resulting impulse response, as measured by commercial UWB radios, contains all the necessary timing information to extract the desired distance to all responders. This first contribution, however, also serves us to realize the many challenges ahead to unlock the real power of concurrent transmissions for localization.
We address these challenges along the way, starting with Chorus, our second contribution. Chorus exploits an anchor infrastructure that transmits packets concurrently. Mobile nodes listen for these transmissions and measure from the CIR the time difference of arrival (TDoA) of the concurrent signals, privately computing their own position at a high rate using hyperbolic localization. This reverse TDoA scheme, although simple in concept, is extremely powerful in that it enables passive self-localization of infinitely many targets at once, a feature largely missing in the RF literature. In Chorus, we address the difficult challenges to reliably detect and identify the signal from the different responders. Yet, the limited transmission precision of commercial UWB transceivers constrains the many benefits of Chorus.
In this context, we i) contribute a model to ascertain the impact of the transmission uncertainty on concurrent transmissions, and ii) address the issue with a compensation mechanism that fine-tunes the local oscillator frequency of responders while they prepare to transmit, allowing us to simultaneously tackle the impact of clock drift on distance estimation. We demonstrate in our evaluation that with this compensation mechanism we can schedule transmissions with < 1 ns error, removing the need to share timestamps to precisely measure distance. We rebuild concurrent ranging around this mechanism, obtaining decimeter-level ranging and localization at a fraction of the cost of conventional schemes. These results turn concurrent ranging into an immediately applicable technique that new systems can now exploit, benefiting from a different set of trade-offs hitherto unavailable. Further, the TX compensation mechanism can be directly applied to Chorus, similarly making fast and accurate passive self-localization a tangible reality.
We continue our endeavor with a systematic characterization of the conditions under which UWB concurrent transmissions succeed to provide reliable ranging and communication across different complex channels. The results we put forth empower developers to fully exploit concurrent transmissions in their designs, potentially inspiring a new wave of ranging, and also communication, primitives that can bring to UWB the same striking benefits found in low-power narrowband radios.
The thesis is completed by looking at other challenges preventing the wide adoption of UWB localization systems, namely, large-scale operation, energy efficiency, and the complexity to install anchor deployments. We tackle these aspects in the last part of the thesis with three additional contributions. First, we propose Talla, a TDoA system that provides seamless large-scale localization for many tags across cells of time-synchronized anchors. Secondly, we fuse UWB ranging with odometry information and build an uncertainty model that only triggers new UWB estimates if and when needed, reducing consumption and channel utilization while satisfying the application-specific demands in terms of accuracy. And thirdly, we build state-of-the-art mechanisms to automatically compute the positions of all anchors deployed across large areas based on ranging information, facilitating anchor network deployment for the many UWB-based real-time location systems (RTLS) to come.
Overall, this thesis changes the landscape of UWB localization with a new set of potentially disruptive schemes and systems that exploit the peculiar benefits of concurrent transmissions and that consequently redefine the trade-offs of the technology.
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Les écoutes radioélectriques et les services techniques des Transmissions dans la Résistance française, 1940-1945 : le Groupement des contrôles radioélectriques (GCR), le Service des transmissions nationales (STN) et le « Groupe Romon » du Service de renseignements (SR) Alliance / The radio listening and the technical services of Transmissions in the French Résistance, 1940-1945Romon, François 15 April 2015 (has links)
Une forme de résistance spécifique et méconnue : la continuation du combat contre l’envahisseur allemand menée au sein des services techniques des Transmissions de l’armée française, notamment du Groupement des contrôles radioélectriques (GCR), dès le lendemain de l’armistice de juin 1940, et poursuivie jusqu’à la victoire finale. Une résistance initiée par des officiers des Transmissions au coeur même des institutions de l’Etat français, consistant à communiquer secrètement du renseignement militaire aux Forces alliées. Cette résistance latente débouche, après novembre 1942, sur une résistance active par la formation d’un réseau clandestin, le Service des transmissions nationales (STN), sous l’égide de NAP-PTT, puis sur son intégration, en octobre 1943, sous le nom de « Groupe Romon », au réseau Alliance, ainsi que sur l’entrée de nombreux opérateurs radio du GCR dans divers autres réseaux de résistance.Le cas d’une résistance intérieure, qui a contribué efficacement à la victoire finale des Forces alliées, malgré une répression systématique et féroce de l’occupant. / A specific and hardly known way of resistance: the continuation of the fight against the german invader led within the technical services of Transmissions of French army, especially the Groupement des contrôles radioélectriques (GCR), the Radio control Group, immediatly after the armistice of June 1940 and carried on until the final victory. A resistance at the initiative of Transmission officers, which, at the heart of the institutions of the Etat français, French State, have secretly communicated military intelligence to the allied Forces. This latent resistance leads, after november 1942, up to an active resistance by the implementation of a clandestine network, the Service des transmissions nationales (STN), the National Transmissions Service, under the aegis of NAP-PTT, then to its integration, in october 1943, under the name « Groupe Romon », to the resistance network Alliance, as well as the commitment of numerous GCR transmitters in various other resistance networks.The case of a resistance from the inside which has effectively contributed to the final victory of the Allied, despite a systematic and ferocious repression from the occupant.
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