1,720,999 research outputs found
Bonobos, bacteria, and social bonds : investigating the gut bacteriome in humans\u2019 closest living relative
No full textAbstract: The animal gut houses a diverse community of bacteria, called the gut bacteriome, that performs essential functions in physiology, metabolism, and overall health. As such, it allows its host to respond to local environmental conditions, directly influencing host fitness. Despite the well-established role of the gut bacteriome in host biology, the forces shaping its composition within and between individuals of the same species remain poorly understood. In this thesis, I explored the gut bacteriome and its associated exposome and host-intrinsic factors in one of humans\u2019 closest living relatives, the bonobo. In the first section of my thesis, I focus on addressing certain knowledge gaps in potential covariates of the bonobo gut bacteriome. First, I validated a method to assess body condition in bonobos and showed that it is heritable, and independent from dietary patterns. In another study, I examined the predictors of an individual\u2019s position in the grooming network using a decade of data from zoo-housed bonobos. Age and rearing history impacted grooming behaviour, often in sex-specific manners, which fosters a better understanding of the link between grooming and the gut bacteriome. Finally, I showed that respiratory disease spreads following the proximity network in a zoo-housed group of bonobos. The second section focused on mapping the bonobo gut bacteriome and its associated factors. I collected faecal samples with associated data from zoo-housed and wild bonobos and subjected them to 16S rRNA amplicon sequencing to determine gut bacterial profiles. Zoo-housed and wild bonobos differed remarkably in their gut bacteriome diversity and composition. Within zoo-housed individuals, lifestyle factors such as diet, early-life adversity, and medication use influenced bacteriome structure. On a dyadic level, social contact and environmental sharing were strongly correlated with gut bacteriome similarity, overshadowing maternal and genetic effects. Finally, I focused my attention on ageing patterns in the bonobo gut bacteriome, showing that across lifestyles (zoo vs wild) diversity increased with age while the core bacteriome shrank. Interestingly, ageing zoo-housed bonobos became more unique in their gut bacterial composition while this pattern was not observed in the wild, mirroring the human pattern. This points towards conserved aging processes in the hominoid gut bacteriome. In summary, this thesis offers key insights into the mechanisms through which the exposome influences gut bacterial communities in a great ape species of which the gut bacteriome was not yet adequately characterized
Time-lag of urinary and salivary cortisol response after a psychological stressor in bonobos (Pan paniscus)
No full textCortisol is often measured as a marker for stress. Therefore, a profound validation of the time-lag between the stressor and the increase and peak in cortisol levels is needed. No study measured both the urinary and salivary cortisol time-lag after a psychological stressor. In this study, we used a frequent sampling study design to (1) describe the urinary and salivary cortisol pattern during a control day; and (2) characterize the induced excretion pattern of urinary and salivary cortisol after a psychological stressor in six zoo-housed bonobos. Liquid chromatography-tandem mass spectrometry was used to analyze 71 urine and 162 saliva samples collected on a control and a test day. We found that the time-lag between the stressor and the maximal cortisol concentration was similar in urine and saliva (160 min after the stressor). However, salivary cortisol after the stressor did show a faster and steeper increase than urinary cortisol. We also show inter-individual variation in the baseline and stress levels of cortisol, which should be considered in future cortisol studies. Our research highlights the importance of validation studies to confirm relevant sampling windows for cortisol sampling in order to obtain biologically meaningful results.sponsorship: We are grateful to the staff of the Royal Zoological Society of Antwerp (RZSA) for their support in this study. Special thanks go to Marjolein Osieck, Emma Willemen and the bonobo keepers of zoo Planckendael (Mechelen, Belgium) for assisting in the data collection and to Francis Vercammen for his contribution as a psychological stressor. We thank the Flemish government for funding of the Centre for Research and Conservation (CRC). This project was also funded by the Max Planck Society and FWO Flanders. (Flemish government, Max Planck Society, FWO Flanders)status: Published onlin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The role of vasopressin (Avpr1a) and oxytocin (OXTR) receptor gene variation as a proximate base for inter- and intraspecific differences in personality in bonobos (**Pan paniscus**) and chimpanzees (**Pan troglodytes**)
No full textVariations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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