Kraus, Cornelia

[["dc.bibliographiccitation.artnumber","25"],["dc.bibliographiccitation.journal","Frontiers in Zoology"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Haemaelaeinen, Anni"],["dc.contributor.author","Raharivololona, Brigitte"],["dc.contributor.author","Ravoniarimbinina, Pascaline"],["dc.contributor.author","Kraus, Cornelia"],["dc.date.accessioned","2018-11-07T09:51:02Z"],["dc.date.available","2018-11-07T09:51:02Z"],["dc.date.issued","2015"],["dc.description.abstract","Introduction: Immunosenescence (deteriorating immune function at old age) affects humans and laboratory animals, but little is known about immunosenescence in natural populations despite its potential importance for population and disease dynamics and individual fitness. Although life histories and immune system profiles often differ between the sexes, sex-specific effects of aging on health are rarely studied in the wild. Life history theory predicts that due to their shorter lifespan and higher investment into reproduction at the expense of immune defences, males might experience accelerated immunosenescence. We tested this hypothesis by examining sex-specific age trajectories of endoparasite burden (helminth prevalence and morphotype richness measured via fecal egg counts), an indicator of overall health, in wild gray mouse lemurs (Microcebus murinus). To account for potential interactions between seasonality and host sex or age we examined the predictors of parasite burdens separately for the dry and rainy season. Results: Contrary to the prediction of immunosenescence, parasite prevalence and morphotype richness decreased at old age in the dry season, indicating acquired immunity by older animals. This pattern was primarily caused by within-individual decline in parasite loads rather than the earlier mortality of highly parasitized individuals. With the exception of an increasing cestode prevalence in males from yearlings to prime age in the rainy season, no evidence was found of male-biased ageing in parasite resistance. Besides this sex age interaction, host age was uncorrelated with rainy season parasite loads. Seasonality did not affect the overall parasite loads but seasonal patterns were found in the predictors of parasite prevalence and morphotype richness. Conclusions: These results provide rare information about the age-related patterns of health in a wild vertebrate population and suggest improvement rather than senescence in the ability to resist helminth infections at old age. Overall, males appear not to suffer from earlier immunosenescence relative to females. This may partially reflect the earlier mortality of males, which can render senescence difficult to detect. While helminth infections are not strongly associated with survival in wild gray mouse lemurs, parasite load may, however, reflect overall good phenotypic quality of long-lived individuals, and is a potential correlate of fitness."],["dc.description.sponsorship","DFG [KR3834/1-1]"],["dc.identifier.doi","10.1186/s12983-015-0118-9"],["dc.identifier.isi","000362068700002"],["dc.identifier.pmid","26435728"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/12724"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35831"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1742-9994"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Host sex and age influence endoparasite burdens in the gray mouse lemur"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","68"],["dc.bibliographiccitation.journal","General and Comparative Endocrinology"],["dc.bibliographiccitation.lastpage","79"],["dc.bibliographiccitation.volume","195"],["dc.contributor.author","Haemaelaeinen, Anni"],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Fenosoa, Zo Samuel Ella"],["dc.contributor.author","Kraus, Cornelia"],["dc.date.accessioned","2018-11-07T09:46:48Z"],["dc.date.available","2018-11-07T09:46:48Z"],["dc.date.issued","2014"],["dc.description.abstract","Reliable measurements of physiological stress are increasingly needed for eco-physiological research and for species conservation or management. Stress can be estimated by quantifying plasma glucocorticoid levels, but when this is not feasible, glucocorticoid metabolites are often measured from feces (FGCM). However, evidence is accumulating on the sensitivity of FGCM measurements to various nuisance factors. Careful species- and context-specific validations are therefore necessary to confirm the biological relevance and specificity of the method. The goals of this study were to: (1) establish and validate sampling methods and an enzymeimmunoassay to measure FGCM in the gray mouse lemur (Microcebus murinus); (2) explore causes of variability in the FGCM measurements, and; (3) assess the consequences of capturing and handling for free-living individuals by quantifying their stress responses via repeated fecal sampling within capture sessions. We further assessed the influence of different handling protocols and the animals' previous capture experience on the magnitude of the physiological response. Our validations identified the group-specific measurement of 11 beta-hydroxyetiocholanolone as the most suitable assay for monitoring adrenocortical activity. The sample water content and the animal's age were found to significantly influence baseline FGCM-levels. Most captured animals exhibited a post-capture FGCMelevation but its magnitude was not related to the handling protocol or capture experience. We found no evidence for long-term consequences of routine capturing on the animals' stress physiology. Hence the described methods can be employed to measure physiological stress in mouse lemurs in an effective and relatively non-invasive way. (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved."],["dc.description.sponsorship","DFG [KR3834/1-1]"],["dc.identifier.doi","10.1016/j.ygcen.2013.10.017"],["dc.identifier.isi","000330257100008"],["dc.identifier.pmid","24212051"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11364"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34965"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1095-6840"],["dc.relation.issn","0016-6480"],["dc.rights","CC BY-NC-SA 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-sa/3.0"],["dc.title","Evaluating capture stress in wild gray mouse lemurs via repeated fecal sampling: Method validation and the influence of prior experience and handling protocols on stress responses"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]