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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Otimiza??o no uso de martelos e bigornas para quebrar sementes por macacos prego (Cebus flavius e C. libidinosus) no Bioma Caatinga

Emidio, Ricardo Almeida 28 May 2010 (has links)
Made available in DSpace on 2014-12-17T15:36:59Z (GMT). No. of bitstreams: 1 RicardoAL_DISSERT.pdf: 2035586 bytes, checksum: ca26983e504667d744bf6cb052c449e0 (MD5) Previous issue date: 2010-05-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Recently, capuchin monkeys (Cebus spp.) inhabitants of dry environments and with restriction of fleshy fruits, have been the subject of several studies regarding the use of instruments. During behaviour of using stones to crack open nuts there is evidence of selection of more effective hammers, as well as selection of anvils related to reducing the risk of predation. The aim of this study was to determine whether two groups of capuchin monkeys (C.flavius and and C.libidinosus) inhabitants of the Caatinga of Rio Grande do Norte make choice of hammers and anvils. The record of weight and location of stones indicated active choices of with what (choice of hammers) and where (selection of anvils) to crack open encapsulated seeds. The choice of hammers to break nuts depended on the type and degree of ripeness seed. Thus, smaller seeds were smashed with lighter hammers and larger seeds with heavier hammers. Still, C. flavius was the only species that presented a refinement in the choice of hammers that depended on the ripeness of seeds. For both species of capuchin monkeys studied, the nut-crack sites were not spread in accordance with the spatial distribution of seed-producing species, suggesting that the capuchin monkeys promote active choice of anvils. Thus, in environments with more escape routes through the trees, the nut-crack sites were found further apart than in regions that had less chance of escape through the trees. Also, there was a difference in the spacing of the anvils to depend on the type of seed: sites used to crack larger and more caloric seeds were found farther apart than the sites used to crack smaller and less caloric seeds, suggesting a pattern of avoiding direct competition. We conclude that the capuchin monkeys maximize energy savings and reduced risk of predation and the costs of food competition during the behaviour of using stones to crack open nuts / Recentemente, macacos prego (Cebus spp.) habitantes de ambientes secos e com restri??o de frutos carnosos, v?m sendo alvo de diversos estudos acerca do uso de instrumentos. Em atividades de quebra de sementes, h? ind?cios de escolhas eficientes de martelos, bem como de sele??o de bigornas para redu??o dos riscos de preda??o. O objetivo deste trabalho foi verificar se dois grupos de macacos prego (C. flavius e C. libidinosus) habitantes da caatinga do Rio Grande do Norte realizam escolhas de martelos e bigornas. O registro do peso e da localiza??o das pedras indicou escolhas ativas de com o que (escolha de martelos) e onde (sele??o de bigornas) quebrar sementes encapsuladas. O padr?o de escolha dos martelos para quebrar sementes dependeu da esp?cie e do estado de matura??o. Assim, sementes menores foram quebradas com martelos mais leves e sementes maiores com martelos mais pesados. Ainda, C. flavius foi a ?nica esp?cie que apresentou um refinamento na escolha de martelos que dependia do estado de matura??o de sementes. Para ambas as esp?cies de macacos prego estudadas, os s?tios de quebra n?o estavam dispostos de acordo com a distribui??o espacial das esp?cies produtoras de sementes, sugerindo que os macacos prego promovem escolha ativas de bigornas. Assim, em ambientes que havia maior chance de fuga atrav?s das ?rvores, os s?tios de quebra foram encontrados mais afastados entre si do que em regi?es que havia menor chance de fuga pelas ?rvores. Tamb?m, foi verificada diferen?a no espa?amento das bigornas a depender do tipo de semente: s?tios de quebra de sementes maiores e mais cal?ricas foram encontrados mais distantes entre si do que os s?tios de quebra de sementes menores e menos cal?ricas, sugerindo um padr?o de evitac?o de competi??o direta. Conclu?mos que os macacos prego maximizam os ganhos energ?ticos e reduziram os riscos de preda??o bem como os custos de competi??o por alimento durante o comportamento de uso de pedras para quebra de sementes
242

Secreção epidérmica de Alouatta guariba clamitans (Primates: Atelidae) / Epidermic Secretion of Alouatta guariba clamitans (Primates, Atelidae)

Zelinda Maria Braga Hirano 30 January 2004 (has links)
Primatas da subespécie A. g. clamitans, popular bugio, possuem um dimorfismo sexual evidenciado na fase adulta com machos de cor ruiva e fêmeas de cor castanho com nuanças avermelhadas. Em estudos de cativeiro com esta subespécie descobriu-se uma secreção epidérmica avermelhada, semelhante à cor da pelagem dos MA. A partir desta constatação diferentes hipóteses têm sido levantadas sobre a função e a origem desta secreção. Assim, o presente estudo objetivou: 1- Analisar se esta secreção é responsável pela coloração do pêlo dos animais e se a água é capaz de descolorir os pêlos 2- Verificar se a liberação de secreção sofre influencia das temperaturas corpórea e ambiente; 3- Identificar através de microscopia óptica e eletrônica as características morfológicas das glândulas produtoras de secreção, 4- Mapear as regiões do corpo dos animais que possuem tal glândula, 5- Definir qual sexo e faixa etária possui a glândula; 6- Determinar se a secreção é capaz de corar o pêlo mesmo após estocada a -4C; 7- Avaliar a cor dos campos cromatogênicos, durante um ano em animais adultos, sub adultos e juvenis; 8- Analisar a composição da secreção; 9- Dosar o hormônio testosterona em animais de diferentes sexo e faixas etárias e 10- Verificar uma possível relação entre comportamento social em bugios silvestres e a cor observada. Constatou-se que MA, MSA, MJ , FA e FSA liberam secreção. A liberação em quase todas as regiões do corpo sofre influência da temperatura corpórea, diferindo apenas na região do hióide em MA e da mandíbula em MSA, regiões que a temperatura corpórea possuem maior influência. Verificou-se que pêlos de MSA quando mantidos em estufa, com a secreção fresca liberada por este animal, muda de cor, de escuro para ruivo, igualando a cor do pêlo de MA; uma vez pigmentado a água não muda a cor do pêlo,. A secreção estocada muda apenas à cor da região central do pêlo. Identificou-se a GPP (glândula produtora de secreção colorida), na região do osso hióide e mandíbula, em MA e MSA. Em FA e FSA identificou-se estrutura glandular menos desenvolvida, denominada de GPPi (glândula produtora de pigmento em fase intermediária) nas regiões do hióide, mandíbula, esterno e região inguinal. As GPPi estão também presentes na região inguinal e nuca de MA e MSA. Os animais juvenis e infantes apresentam somente glândulas sudoríparas normais em todas as regiões do corpo. Na secreção colorida não existem carotenóides. As secreções de MA, FA, MAS e MJ possuem diferentes concentrações de ferro. A secreção de MA apresentou maior concentração de ferro quando comparada às secreções dos animais de outro sexo e/ou idade. A microscopia eletrônica confirmou a característica secretora da GPP e evidenciou estruturas cristalinas dentro das células do ácino semelhantes as inclusões de ferro observadas no citoplasma de células de outros organismos. Os animais que sofreram maior variação de cor nos campos cromatogênicos foram os MSA, e foram os animais que tiveram maiores índices de esfregação, sugerindo um mecanismo de espalhamento da secreção Os níveis de testosterona, foram proporcionais ao sexo e idade dos animais, sendo os maiores valores encontrados em MA. O estudo do comportamento social mostrou que os MA ruivos possuem um elevado status hierárquico e desempenham um papel de guardião do grupo. Os resultados indicam que a secreção colorida, liberada na epiderme de A. g. clamitans, são as responsáveis pela coloração do pêlo de MA devido à concentração de ferro. Um cromóforo que contém ferro seria um dos agentes responsáveis pela coloração. A diferença de cor nesta subespécie é uma característica sexual secundária, e parece ocorrer por um mecanismo ativacional do hormônio testosterona, ativando o desenvolvimento das glândulas GPP. O nível de testosterona, a presença de GPP e a coloração ruiva intensa possuem uma forte correlação com o status hierárquico de MA. / Adult brown howler monkeys, Alouatta guariba clamitans, have a clear sexual dimorphism, with red-haired males and chestnut females with red nuances. Captivity studies with this subspecies revealed an epidermic secretion of red coloration, similar to the coat color of adult males. Different hypotheses have been proposed on the function and origin of this secretion. The present work aimed to: 1 analyze if fresh secretion is responsible for hair coloration in this animals and if water is capable to decolorize hair; 2 verify if secretion release is affected by body and atmospheric temperatures; 3 identify by optic and electronic microscopy the morphologic characteristics of the secretion-producing glands; 4 map the areas of the animal body that have such glands; 5 define which sex-age categories have this gland; 6 determine if secretion is able to color hair after stored at -4º C; 7 evaluate during one year the coloration of cromatogenic fields in adult, subadults and juvenile animals; 8 analyze the secretion composition; 9 measure testosterone levels in animals of different sex-age categories; 10 verify the possible relationship between the social behavior of wild animals and the observed coloration. It was found that adult, subadult and juvenile males and adult and subadult females release secretion. The release in almost all body areas is under influence of the corporal temperature that is greater in adult male hyoid and subadult male jaw areas. The hair of subadult males of A. g. clamitans maintained in a stove treated with fresh secretion changes from dark to reddish color, similar to the adult males hair color. The water does not change the color of the hair, once pigmented. The stored secretion changes only the color of the central area of hair. The gland producing colored secretion (GPP) was identified in the area of the hyoid bone and jaw in adult and subadult males. In adult and subadult females a less developed glandular structure was found, denominated GPPi in the hyoid, jaw, breastbone and inguinal areas. GPPi are also present in the inguinal area and nape of adult and subadult males. The juvenile and infant animals presented only normal sweat glands in all body areas. There are no carotenoids in the colored secretion. The secretions of adult, subadult and juvenile males and adult females have different concentrations of iron and adult males presented larger concentration of iron in their secretions when compared to other sex and age categories. The electronic microscopy confirmed the secretory features of GPP and evidenced crystalline structures inside the acinus cells that resemble iron-containing structures evidenced in other cellular structures. Subadult males suffered the greater degree in color variation in cromatogenic fields, and they were also the animals that presented larger rubbing index, suggesting that this would be the mechanism of secretion dispersal. The testosterone levels were proportional to the sex and age categories of the animals, with the largest values found in adult males. The study of the social behavior showed that the reddish adult males have a superior hierarchic status and play the role of group guardians. Our results indicate that the colored secretions, released in the epidermis of A. g. clamitans, are responsible for the hair coloration in adult males due to iron concentration. An iron-containing chromophore would be one of the agents promoting the coloration. The color difference in this subspecies is a secondary sexual trait that seems to occur through a testosterone-activated mechanism, promoting the development of GPP glands. Testosterone levels, the presences of GPP and the intense red-haired coloration have a strong correlation with the hierarchical status of adult males.
243

Metagenomics in One Health — from standardization to targeted application

Hallmaier-Wacker, Luisa 10 May 2019 (has links)
No description available.
244

Pathologie comparée de la fièvre de Lassa chez le singe cynomolgus : mécanismes pathogéniques précoces, réponses immunitaires et marqueurs d’infection / Comparison of Lassa fever pathology in cynomolgus monkeys : pathogenic mechanisms, immune responses and markers of infection

Baillet, Nicolas 19 December 2018 (has links)
Le virus Lassa entraine une fièvre hémorragique endémique en Afrique de l’Ouest et représente un problème de santé publique. Les connaissances sur la pathogénèse et les réponses immunitaires associées à la maladie sont partielles. Nous avons suivi les paramètres pathologiques, virologiques et immunologiques associés aux infections létales et non létales du LASV chez le singe cynomolgus. Le tableau clinique a été caractérisé par une dépression, une anorexie, une perte de poids et une asthénie chez les animaux survivants, tandis que ces mêmes symptômes ont été accompagnés de fièvre, de difficultés respiratoires et d’épistaxis chez les animaux infectés par une dose létale. Seuls ces derniers ont montré une perturbation des paramètres de coagulation, une rhabdomyolyse et une hausse des marqueurs de lésions rénales. Nous avons observé un tropisme radicalement différent en fonction de la sévérité de la maladie, avec une dissémination virale dans les organes plus importante et plus rapide chez les animaux décédés, la présence de particules infectieuses plus nombreuses et des modifications anatomopathologiques plus sévères. Une réponse immunitaire innée et adaptative précoce et puissante a été associée avec le contrôle de l’infection et la survie tandis que les infections fatales ont été caractérisées par une réponse inflammatoire ressemblant au choc septique, une défaillance de la réponse immunitaire ainsi qu’une réplication virale incontrôlée. Cette étude permet d’améliorer nos connaissances de la pathogénèse de la fièvre de Lassa et d’apporter des marqueurs d’infection prédictifs de la maladie / Lassa virus causes a hemorrhagic fever endemic in West Africa and represents a threat for civilians. The pathogenesis and the immune responses associated with the disease are poorly understood. We followed pathological, virological and immunological parameters associated with fatal and non-fatal Lassa virus infection in the cynomolgus monkey. The clinical picture was characterized by depression, anorexia, weight loss and asthenia in survivors whereas the same symptoms were supported by fever, respiratory difficulties and epistaxis in animals infected with the lethal dose. Only fatalities have shown coagulation parameters dysfunction, rhabdomyolysis and an increase of renal function markers. We observed a different viral tropism in a function of the disease severity, with viral dissemination in organs that was more important and faster in fatalities, the appearance of numerous infectious particles number and more severe pathologic changes. Early and robust innate and adaptive immune response has been associated with the control of infection and recovery whereas fatal infections were characterized by a sepsis like inflammatory response, defective immune response as well as uncontrolled viral replication. This study sheds light on the pathogenesis of Lassa fever and reveals infection markers predictive of the disease outcome
245

Mécanismes psychophysiques et neuronaux de la compensation dynamique de multiples champs de force : facilitation et anticipation liée à des indices de couleur

Addou, Touria 01 1900 (has links)
Dans cette thèse, nous abordons le contrôle moteur du mouvement du coude à travers deux approches expérimentales : une première étude psychophysique a été effectuée chez les sujets humains, et une seconde implique des enregistrements neurophysiologiques chez le singe. Nous avons recensé plusieurs aspects non résolus jusqu’à présent dans l’apprentissage moteur, particulièrement concernant l’interférence survenant lors de l’adaptation à deux ou plusieurs champs de force anti-corrélés. Nous avons conçu un paradigme où des stimuli de couleur aident les sujets à prédire la nature du champ de force externe actuel avant qu’ils ne l’expérimentent physiquement durant des mouvements d’atteinte. Ces connaissances contextuelles faciliteraient l’adaptation à des champs de forces en diminuant l’interférence. Selon le modèle computationnel de l’apprentissage moteur MOSAIC (MOdular Selection And Identification model for Control), les stimuli de couleur aident les sujets à former « un modèle interne » de chaque champ de forces, à s’en rappeler et à faire la transition entre deux champs de force différents, sans interférence. Dans l’expérience psychophysique, quatre groupes de sujets humains ont exécuté des mouvements de flexion/extension du coude contre deux champs de forces. Chaque force visqueuse était associée à une couleur de l’écran de l’ordinateur et les deux forces étaient anti-corrélées : une force résistante (Vr) a été associée à la couleur rouge de l’écran et l’autre, assistante (Va), à la couleur verte de l’écran. Les deux premiers groupes de sujets étaient des groupes témoins : la couleur de l’écran changeait à chaque bloc de 4 essais, tandis que le champ de force ne changeait pas. Les sujets du groupe témoin Va ne rencontraient que la force assistante Va et les sujets du groupe témoin Vr performaient leurs mouvements uniquement contre une force résistante Vr. Ainsi, dans ces deux groupes témoins, les stimuli de couleur n’étaient pas pertinents pour adapter le mouvement et les sujets ne s’adaptaient qu’à une seule force (Va ou Vr). Dans les deux groupes expérimentaux, cependant, les sujets expérimentaient deux champs de forces différents dans les différents blocs d’essais (4 par bloc), associés à ces couleurs. Dans le premier groupe expérimental (groupe « indice certain », IC), la relation entre le champ de force et le stimulus (couleur de l’écran) était constante. La couleur rouge signalait toujours la force Vr tandis que la force Va était signalée par la couleur verte. L’adaptation aux deux forces anti-corrélées pour le groupe IC s’est avérée significative au cours des 10 jours d’entraînement et leurs mouvements étaient presque aussi bien ajustés que ceux des deux groupes témoins qui n’avaient expérimenté qu’une seule des deux forces. De plus, les sujets du groupe IC ont rapidement démontré des changements adaptatifs prédictifs dans leurs sorties motrices à chaque changement de couleur de l’écran, et ceci même durant leur première journée d’entraînement. Ceci démontre qu’ils pouvaient utiliser les stimuli de couleur afin de se rappeler de la commande motrice adéquate. Dans le deuxième groupe expérimental, la couleur de l’écran changeait régulièrement de vert à rouge à chaque transition de blocs d’essais, mais le changement des champs de forces était randomisé par rapport aux changements de couleur (groupe « indice-incertain », II). Ces sujets ont pris plus de temps à s’adapter aux champs de forces que les 3 autres groupes et ne pouvaient pas utiliser les stimuli de couleurs, qui n’étaient pas fiables puisque non systématiquement reliés aux champs de forces, pour faire des changements prédictifs dans leurs sorties motrices. Toutefois, tous les sujets de ce groupe ont développé une stratégie ingénieuse leur permettant d’émettre une réponse motrice « par défaut » afin de palper ou de sentir le type de la force qu’ils allaient rencontrer dans le premier essai de chaque bloc, à chaque changement de couleur. En effet, ils utilisaient la rétroaction proprioceptive liée à la nature du champ de force afin de prédire la sortie motrice appropriée pour les essais qui suivent, jusqu’au prochain changement de couleur d’écran qui signifiait la possibilité de changement de force. Cette stratégie était efficace puisque la force demeurait la même dans chaque bloc, pendant lequel la couleur de l’écran restait inchangée. Cette étude a démontré que les sujets du groupe II étaient capables d’utiliser les stimuli de couleur pour extraire des informations implicites et explicites nécessaires à la réalisation des mouvements, et qu’ils pouvaient utiliser ces informations pour diminuer l’interférence lors de l’adaptation aux forces anti-corrélées. Les résultats de cette première étude nous ont encouragés à étudier les mécanismes permettant aux sujets de se rappeler d’habiletés motrices multiples jumelées à des stimuli contextuels de couleur. Dans le cadre de notre deuxième étude, nos expériences ont été effectuées au niveau neuronal chez le singe. Notre but était alors d’élucider à quel point les neurones du cortex moteur primaire (M1) peuvent contribuer à la compensation d’un large éventail de différentes forces externes durant un mouvement de flexion/extension du coude. Par cette étude, nous avons testé l’hypothèse liée au modèle MOSAIC, selon laquelle il existe plusieurs modules contrôleurs dans le cervelet qui peuvent prédire chaque contexte et produire un signal de sortie motrice approprié pour un nombre restreint de conditions. Selon ce modèle, les neurones de M1 recevraient des entrées de la part de plusieurs contrôleurs cérébelleux spécialisés et montreraient ensuite une modulation appropriée de la réponse pour une large variété de conditions. Nous avons entraîné deux singes à adapter leurs mouvements de flexion/extension du coude dans le cadre de 5 champs de force différents : un champ nul ne présentant aucune perturbation, deux forces visqueuses anti-corrélées (assistante et résistante) qui dépendaient de la vitesse du mouvement et qui ressemblaient à celles utilisées dans notre étude psychophysique chez l’homme, une force élastique résistante qui dépendait de la position de l’articulation du coude et, finalement, un champ viscoélastique comportant une sommation linéaire de la force élastique et de la force visqueuse. Chaque champ de force était couplé à une couleur d’écran de l’ordinateur, donc nous avions un total de 5 couleurs différentes associées chacune à un champ de force (relation fixe). Les singes étaient bien adaptés aux 5 conditions de champs de forces et utilisaient les stimuli contextuels de couleur pour se rappeler de la sortie motrice appropriée au contexte de forces associé à chaque couleur, prédisant ainsi leur sortie motrice avant de sentir les effets du champ de force. Les enregistrements d’EMG ont permis d’éliminer la possibilité de co-contractions sous-tendant ces adaptations, étant donné que le patron des EMG était approprié pour compenser chaque condition de champ de force. En parallèle, les neurones de M1 ont montré des changements systématiques dans leurs activités, sur le plan unitaire et populationnel, dans chaque condition de champ de force, signalant les changements requis dans la direction, l’amplitude et le décours temporel de la sortie de force musculaire nécessaire pour compenser les 5 conditions de champs de force. Les changements dans le patron de réponse pour chaque champ de force étaient assez cohérents entre les divers neurones de M1, ce qui suggère que la plupart des neurones de M1 contribuent à la compensation de toutes les conditions de champs de force, conformément aux prédictions du modèle MOSAIC. Aussi, cette modulation de l’activité neuronale ne supporte pas l’hypothèse d’une organisation fortement modulaire de M1. / In this thesis, we addressed motor control by two experimental approaches: psychophysical studies in human subjects and neurophysiological recordings in non-human primates. We identified unresolved issues concerning interference in motor learning during adaptation of subjects to two or more anti-correlated force fields. We designed paradigms in which arbitrary color stimuli provided contextual cues that allowed subjects to predict the nature of impending external force fields before encountering them physically during arm movements. This contextual knowledge helped to facilitate adaptation to the force fields by reducing this interference. According to one computational model of motor learning (MOdular Selection And Identification model for Control; MOSAIC), the color context cues made it easier for subjects to build “internal models” of each force field, to recall them and to switch between them with minimal interference. In our first experiment, four groups of human subjects performed elbow flexion/extension movements against two anti-correlated viscous force fields. We combined two different colors for the computer monitor background with two forces: resistive (Vr) and assistive (Va). The first two groups were control subjects. In those subjects, the color of the computer monitor changed at regular intervals but the force field remained constant; Vr was presented to the first group while the second group only experienced Va. As a result, the color cues were irrelevant in the two control groups. All control subjects adapted well to the single experienced force field (Vr or Va). In the two experimental groups, in contrast, the anti-correlated force fields and the monitor colors changed repeatedly between short blocks of trials. In the first experimental group (Reliable-cue subjects), there was a consistent relationship between the force and the stimulus (color of the monitor) - the red colour always signalled the resistive force while the green colour always signalled the assistive force. Adaptation to the two anti-correlated forces for the Reliable-cue group was significant during 10 days of training and almost as good as in the Irrelevant-cue groups who only experienced one of the two force fields. Furthermore, the Reliable-cue subjects quickly demonstrated predictive adaptive changes in their motor output whenever the monitor color changed, even during their first day of training, showing that they could use the reliable color context cues to recall the appropriate motor skills. In contrast, the monitor color also changed regularly between red and green in the second experimental group, but the force fields were not consistently associated with the color cue (Unreliable-cue group). These subjects took longer to adapt to the two force fields than the other three groups, and could not use the unreliable color cue change to make predictive changes to their motor output. Nevertheless, all Unreliable-cue subjects developed an ingenious strategy of making a specific “default” arm movement to probe the type of force field they would encounter in the first trial after the monitor color changed and used the proprioceptive feedback about the nature of the field to make appropriate predictive changes to their motor output for the next few trials, until the monitor color changed again, signifying the possibility of a change in force fields. This strategy was effective since the force remained constant in each short block of trials while the monitor color remained unchanged. This showed that the Unreliable-cue subjects were able to extract implicit and explicit information about the structure of the task from the color stimuli and use that knowledge to reduce interference when adapting to anti-correlated forces. The results of this first study encouraged us to advance our understanding of how subjects can recall multiple motor skills coupled to color context stimuli can be recalled, and how this phenomenon can be reflected by the neuronal activity in monkeys. Our aim was to elucidate how neurons of primary motor cortex (M1) can contribute to adaptive compensation for a wide range of different external forces during single-joint elbow flexion/extension movements. At the same time, we aimed to test the hypothesis evoked in the MOSAIC model, whereby multiple controller modules located in the cerebellum may predict each context and produce appropriate adaptive output signals for a small range of task conditions. Also, according to this hypothesis, M1 neurons may receive inputs from many specialized cerebellar controllers and show appropriate response modulations for a wide range of task conditions. We trained two monkeys to adapt their flexion/extension elbow movements against 5 different force-field conditions: null field without any external force disturbance, two anti-correlated viscous forces (assistive and resistive), which depended on movement speed and resembled that used in the human psychophysical study, a resistive elastic force which depended on elbow-joint position and finally, a visco-elastic field that was the linear sum of the elastic and viscous forces field. Each force field was reliably coupled to 5 different computer monitor background colors. The monkeys properly adapted to the 5 different force-field conditions and used the color context cues to recall the corresponding motor skill for the force field associated with each color, so that they could make predictive changes to their motor output before they physically encountered the force fields. EMG recordings eliminated the possibility that a co-contraction strategy was used by the monkeys to adapt to the force fields, since the EMG patterns were appropriate to compensate for each force-field condition. In parallel, M1 neurons showed systematic changes in their activity at the single-neuron and population level in each force-field condition that could signal the required changes in the direction, magnitude and time course of muscle force output required to compensate for the 5 force-field conditions. The patterns of response changes in each force field were consistent enough across M1 neurons to suggest that most M1 neurons contributed to the compensation for all force field conditions, in line with the predictions of the MOSAIC model. Also, these response changes do not support a strongly modular organization for M1.
246

Charakterisierung der angeborenen Immunantwort in SIV-infizierten Rhesusaffen / Characterization of the innate immune response in SIV-infected rhesus monkeys

Mußil, Bianka 30 June 2009 (has links)
No description available.
247

Social and Physical Cognition in Old World Monkeys - A Comparative Perspective / Soziale und Physikalische Kognition bei Altweltaffen - eine vergleichende Perspektive

Schmitt, Vanessa 13 April 2012 (has links)
No description available.
248

What's in a tooth? : signals of ecogeography and phylogeny in the dentition of macaques (Cercopithecidae: Macaca)

Grunstra, Nicole Dieneke Sybille January 2018 (has links)
The aim of the present work was to investigate the impact of the varying environmental conditions on the taxonomic and phenotypic diversification of a geographically widespread and ecologically successful Old World primate genus, the macaques (Cercopithecidae: Macaca). To this end, the relationship between geography, ecology, phylogeny, and phenotypic variation among macaques was investigated. Constraints to phenotypic variation – and thus evolution – were also analysed in the form of observed amounts of phenotypic variation and patterns of phenotypic integration. A total of 72 standard linear measurements of teeth and associated cranial and mandibular structures were taken for a total sample of 744 specimens from 13 species of macaques. Climate and ecological data were collated from the literature. Univariate and multivariate statistics were employed for the analysis. Patterns of variation, covariation, and allometry were analysed in the dentition, both within and between species. The ecogeographical analysis was carried out by means of two-block partial least squares and a type of multivariate regression, both in a phylogenetic framework. Phylogenetic signal was tested for by means of Blomberg’s K. Macaque teeth differ in their variability. All teeth covary with each other, although correlations are strongest within tooth classes. Size was a strong contributing factor to dental integration, as evinced by lower correlations between teeth once allometric effects were removed. Integration patterns also showed modularity between the anterior and the posterior dentition. Between-species variation in overall craniodental size was associated with temperature, latitude, and body size. Species also varied, albeit to a lesser degree, along an antero-posterior contrast in relative tooth size. Larger anterior were found to be associated with frugivory and tropical ecology, whereas a larger posterior dentition was linked to a more folivorous diet and temperate environments. The latter pattern was largely a function of phylogenetic relatedness. Phylogenetic signal was generally strong in the dentition, although it was substantially greater in the anterior teeth (incisors and canines) than in the posterior teeth (premolars and molars). Macaques show adaptive differentiation in body size in response to temperature along a latitudinal cline, corroborating the presence of the Bergmann effect in macaques. There was no conclusive support for further adaptive differentiation, despite an association between relative tooth size and diet. Allometry appears to channel evolutionary divergence of macaques along a line of least evolutionary resistance, and developmental modularity allows for partly uncoupled evolution of the anterior and posterior dentition. Future research should be aimed at broadening the taxonomic scope to include craniodental variation of the African papionins and cercopithecins in order to put the observed macaque patterns in a broader evolutionary context.

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