Добірка наукової літератури з теми "Marmosets Anatomy"

Die vorsätzliche Freisetzung von Variola Virus (VARV) und schwere Erkrankungen des Menschen durch zoonotische Affen- (MPXV) und Kuh- (CPXV) pocken Viren stellen nach wie vor eine Bedrohung für die Bevölkerung dar. Klassische Pockenimpfstoffe bergen die Gefahr einer schweren Erkrankung. Deshalb ist die Entwicklung neuer Impfstoffe und Therapeutika von entscheidender Bedeutung. Deren Wirksamkeit und Sicherheit muss zunächst in verschiedenen Tiermodellen bewiesen werden. Existierende Makakken-Primatenmodelle leiden unter sehr artifiziellen Bedingungen der letalen Krankheitsinduktion durch VARV oder MPXV. Aus diesem Grund wurde das Calpox Virus/Krallenaffen-modell etabliert, welches auf einem CPXV aus natürlich infizierten Neuweltaffen (Marmosets) basiert. Das neue Modell hat drei wesentliche Vorteile: Die Arbeit mit Calpox Virus kann unter Sicherheitsstufe 2 durchgeführt werden und ist folglich einfacher in der Handhabung. 2. Die intranasale (i.n.) Infektion von Marmosets (Krallenaffen; Callithrix jacchus) spiegelt den natürlichen Infektionsweg von VARV wieder. Infizierte Affen entwickelten Pocken ähnliche Symptome und verstarben innerhalb von 2-3 Tagen nach Auftreten erster Symptome. Hohe Viruslasten wurden im Blut, Speichel und allen untersuchten Organen nachgewiesen. 3. Die i.n. Titration des Calpox Virus ergab eine 50 % Affen-Infektions-Dosis (MID50) von 8.3x102 pfu. Diese ist um den Faktor 10000 niedriger als in anderen Pocken-Primatenmodellen. Neun bis zehn Wochen nach einer Immunisierung mit dem Lister-Elstree Impfstoff waren alle Krallenaffen gegen eine letale Dosis des Calpox Virus (10 MID50) geschützt. Damit konnte der Nutzen des Calpox Virus/Krallenaffen-modells für die Erforschung neuer Impfstoffe gezeigt werden. Das Calpox Virus/Krallenaffen-modell überwindet wesentliche Nachteile bestehender Primatenmodelle und ist somit ein geeignetes Model für die Evaluierung von neuen Impfstoffen, Impfstrategien und antiviralen Therapien.
The intentional re-introduction of Variola virus (VARV), the agents of smallpox, into the human population remains of concern today. Moreover, zoonotic infections with Cowpox (CPXV) and Monkeypox virus (MPXV) cause severe diseases in humans. Smallpox vaccines presently available can have severe adverse effects that are no longer acceptable. The efficacy and safety of new vaccines and antivirals have to be demonstrated by different animal models. The existing primate models, using VARV and MPXV, need very high viral doses that have to be applied intravenously to induce a lethal infection in macaque monkeys. To overcome these drawbacks, the main objective of this study was to develop a primate model in which a smallpox-like disease could be induced by a CPXV virus designated calpox virus which was isolated from a lethal orthopox virus (OPV) outbreak in New World monkeys (marmosets). The new non-human primate model has three major advantages: 1. Working with calpox virus is less challenging and can be done under bio-safety-level two. 2. Mimicking the natural route of VARV infection, intranasally infected marmosets (Callithrix jacchus) reproducibly developed clinical symptoms of an OPV infection and died within two to three days after onset of the first symptoms. High viral loads of calpox virus were detected in blood, saliva and all analyzed organs. 3. Intranasal titration of the virus resulted in a 50 % monkey infectious dose (MID50) of 8.3x102 pfu, a lethal infectious dose 10,000 lower than those used in any other primate model. Moreover, we showed the aptitude of the primate model for the testing of new vaccines since nine to ten weeks after immunization with Vaccinia virus Lister-Elstree marmosets were completely protected against intranasal challenge with 10 MID50 of calpox virus. As the calpox virus/marmoset model overcomes major limitations of current primate models it is suitable to evaluate new vaccines, new vaccination strategies and antiviral therapies.

Individual variation can be seen in many aspects of an organism, from its physical structure to its behaviour. Contributing factors to variation in behaviour may includes, age, genetic differences and even size. The response to new objects and environments is a varying behavioural trait found in a wide range of species. The aim of this thesis was to investigate the causes of variation in response to novel stimuli in the common marmoset, Callithrix jacchus. The investigation focused on the effects of sex, age, genetic differences and size. Variation in response was tested by a simple novel stimulus presentation test paradigm. Sixty eight animals were each individually presented with nine novel stimuli in home cage tests. Five measures of response were recorded: latency to approach and contact, duration of proximity and contact, and visual attendance. Responses were analysed and stimuli were categorised as: mirror, food related stimuli, unattractive stimuli and novel stimuli. Response across the nine stimuli was investigated for variation due to sex, age or weight of the subjects. Across the analysis, limited significant sex differences were seen in response to food related stimuli, with males being more responsive. To investigate whether general measures of response could be derived from the individual behaviours recorded, principal component analysis was carried out on the response data, which was split into the four stimulus groups. Simple response continua were successfully derived from components from analysis of mean stimulus group scores. The mirror and food stimulus groups each had two continua, one reflecting latency to response, and one reflecting the duration of time spent near the stimulus. The responses to the unattractive stimulus group and novel stimulus group could each be described by one response continuum. In order to assess whether genetic variation contributed to response, heritability analyses were carried out on both the derived continua and the five response measures, separated by stimulus group. No significant heritabilities were found after correction for multiple comparisons. This study thus demonstrates that sex is a more important determinant of response that individual genetic differences, age or weight in the common marmoset.

The common marmoset is the most frequently used New World primate in laboratory research and testing. In the UK, their use is strictly controlled by the Animals (Scientific Procedures) Act, which is underpinned by the principles of humane science: Replacement, Reduction and Refinement. Despite their use, there are a number of problems associated with the breeding of marmosets, including low dam longevity and increasing litter sizes. Large litters have led to high infant mortality and the need for human intervention to improve infant survival, which involves removal from the family for substantial periods of time. Previous research in a range of primate species shows that early life family separation is associated with numerous adverse behavioural and physiological effects. This project therefore sought to systematically investigate the effects of breeding and infant rearing practices, integrating a number of measures to assess the welfare of laboratory- housed marmosets. Potential predictors of dam longevity and litter size were first identified in three captive UK colonies, over four decades. Dam longevity was found to be approximately 6 years, with heavier dams living longer, but overall there was no consistent improvement in longevity over the decades. As longevity varied widely between colonies and over time, environment may be one of the most important factors. Approximately half of all births at each colony were litters larger than two, and these larger litters had greater infant mortality. Only dam weight at conception was useful in predicting litter size, with heavier dams producing larger litters. The consequences of large litters and early separation from the family for supplementary feeding were then investigated. Although twins had lower body weight than 2stays (two infants remaining with the family after death of the other littermate/s) and supplementary fed triplets, they also had the fewest health problems. There was also some evidence that animals from larger litters were more at risk of suffering from extreme low weight. Some minor differences were found in behavioural development between litter sizes. Singleton infants received more rejective rearing, while 2stays received more protective rearing, perhaps following the loss of an infant. While twin infants gained independence earlier than singletons or 2stays, they did not appear to cope better with stress in adulthood, displaying more significant increases in stress-related behaviour following the routine stressor of capture and weighing, compared to 2stays and supplementary fed triplets. While overall cortisol unexpectedly decreased from baseline to post capture, there were only significant fluctuations in 2stay marmosets. Instead, there were some increases in positive behaviour in supplementary fed triplets following the stressor, suggesting enhanced coping ability. However, in another group of supplementary fed triplets, there were subtle increases in depressive-like symptoms, measured using cognitive bias and preference tests, suggesting a reduced expectation of and interest in rewards. There were however no differences between family-reared and supplementary fed marmosets in time to learn a visual discrimination task, or in responses to temperament tests. Therefore, while it was hypothesised that early family separation would have adverse developmental consequences, there were actually very little differences between marmosets of different litter sizes and rearing backgrounds, across the range of measures. Results suggest that the current supplementary feeding programme, along with a regular human socialisation programme, minimises any potential negative effects. However, we should always be finding ways to improve the lives of animals in our care. Possible Refinements include reducing dam weight to increase twin births and improve infant survival, and training to allow supplementary feeding on the carrier’s back, to prevent infant separation and reduce disruption to the family. These Refinements could reduce fear and allow monkeys to become more resilient to the laboratory environment.

The social transmission of social behaviours in nonhuman primates has been understudied, experimentally, relative to instrumental, food-related behaviours. This is disproportional in relation to the comparatively high percentage of potential social traditions reported in wild primates. I report a systematic survey of the social learning literature and provide quantitative evidence of the discrepancy (Watson and Caldwell, 2009). Addressing the identified deficit in experimental work on social behaviours, I also report three empirical studies investigating the contagious nature of affective states in captive, socially housed marmosets. I carried out an observational study, to determine whether marmosets are influenced by spontaneously produced neighbour calls to perform a range of behaviours associated with similar affect. My results supported a neighbour effect for anxiety in marmosets. Consistent with previous findings for chimpanzees (Baker and Aureli, 1996; Videan et al., 2005), I also found evidence for neighbour effects for aggression and affiliation (Watson and Caldwell, 2010). Through experimental playback, I investigated contingent social contagion in the auditory and visual modalities. The playback of pre-recorded affiliative (chirp) calls was found to be associated with marmosets spending increased time in a range of affiliative behaviours. Playback of video showing conspecifics engaged in a positive affiliative behaviour (allogrooming) also appeared to cause marmosets to spend longer performing various affiliative behaviours. My results indicate that social contagion of affiliation is a multi-modal phenomenon in marmosets and also represent the first evidence that allogrooming is visually contagious in primates. Sapolsky (2006) conceptualised culture as the performance of species-typical behaviours to an unusual extent, termed ‘social culture’. Researchers have yet to directly investigate a transmission mechanism. I investigated whether a social culture of increased affiliation could be initiated in marmosets through the long-term playback, of positive calls, or of video of positive behaviour. The results were consistent with a relatively long-lasting influence of the playback of affiliative calls across several affiliative behaviours. The effect appeared to last substantially beyond the specific hours of playback, between playbacks, and after playback had ceased, potentially indicating a temporary shift in social culture. These results are preliminary but provide some support for the proposal that auditory social contagion may be a transmission mechanism for social culture. The long-term video playback of allogrooming appeared to result in a transitory shift in performance of the identical behaviour (increased allogrooming) after playbacks had ceased. In addition to theoretical implications for social cognition and social culture, my findings have potential practical application for the enhancement of welfare in captive marmosets through sensory, and non-contact social, enrichment.

Mandible form in cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus) provides insight into effects of dietary differences. Mandible shape is due to both genetic factors as well as environmental, with functional differences included in the environmental (Klingenberg and Leamy, 2001). Forces associated with differences in food acquisition can be expected to lead to morphological changes. Common marmosets (Callithrix jacchus ) and cotton-top tamarins (Saguinus oedipus) have different feeding styles, and therefore, have different mandible and other craniofacial adaptations. Whether these taxa are wild-born or lab-born could also affect their mandible form. There is a lack of agreement whether there is sexual dimorphism between these two species, but this study indicates there is sexual dimorphism even after adjusting for size. Standardized lateral and superior views of mandible photographs of both species were analyzed at different mandibular regions and individual dimensions. Not only did it reveal intraspecific and interspecific sexual dimorphism, there is also a difference in mandible form whether a species is wild-born or lab-born. S. oedipus males and females are larger if born in the wild and C. jacchus are larger if born in the lab. This could have implications in the future on how lab-born monkeys are being cared for and fed to better mimic their natural habitat.

Examining the perception of literary decline in Greek, Latin, Arabic, and Persian, this study unearths an enduring taboo, one little changed by place and time, against verbal creation too readily sacrificing “nature” and “truth” to artifice and phantasy. The fading of the taboo after the nineteenth century, when “Decadent” yields to a non-normative name for the present (“Modern”), is without precedent. Demonstrating the opprobrium’s enduring nature, this study compares for the first time four literary traditions’ confrontations with a “Decadence” whose similarities have been conjectured since philology’s “golden age.” Chapter I examines two ancient polemics against decline, the tableaux of decay painted by the Avestan liturgical texts and the Attic Greek thinkers before new attitudes towards verbal creation. A similar tableau emerges in Roman reactions to post-Augustan eloquentia’s “decline,” as the analysis of Tacitus in chapter II demonstrates. Chapter III gives voice to non-specialist Imperial reactions to the “decline” heralded by the Second Sophistic, analyzing Plutarch’s and Marcus Aurelius’s rejections of verbal art. Chapter IV considers the effort to regulate artifice within the rhetorical tradition, examining the two great Hellenistic and Imperial authorities (Demetrius and Quintilian). Chapter V finds the prohibition unbroken in the earliest Arabic debate over suqāṭ (“Decadence”). Al-Āmidī’s Muwāzana is a summary statement of the rejection of verbal creation too enamored of facticity. Conversely, chapter VI looks to post-Classical Persian voices enshrining this very conception of verbal creation. Suhrawardī, Mullā Ṣadrā, and Ṣāʾib call for a language reflective of little other than wahm (“imagination”) and himma (“desire”). Chapter VII examines “Decadence” in Greek and Arabic post-Classical fiction. The erosion of μῦθος by ψυχή as the banal desire of non-heroic protagonists eclipses action, as phantasy, shown through the pathetic fallacy, irradiates out into the world, supports critics’ contention: Imperiousness of imagination goes with the genera dicendi’s loosening and the pull of language from the inhuman towards personal fancy. “Decadence” in fiction reflects a literature democratized, one mirroring (petty-) bourgeois interests. This is, argues chapter VIII, a premonition of Modernity: With Gutenberg and Calvin, with an unprecedented accessibility and banality of letters, the taboo against subjectivism and facticity recedes.
Comparative Literature