369 research outputs found

    Seasonality in gum and honeydew feeding in gray mouse lemurs

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    Touchscreen-based cognitive tasks reveal age-related impairment in a primate aging model, the grey mouse lemur (Microcebus murinus)

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    Mouse lemurs are suggested to represent promising novel non-human primate models for aging research. However, standardized and cross-taxa cognitive testing methods are still lacking. Touchscreen-based testing procedures have proven high stimulus control and reliability in humans and rodents. The aim of this study was to adapt these procedures to mouse lemurs, thereby exploring the effect of age. We measured appetitive learning and cognitive flexibility of two age groups by applying pairwise visual discrimination (PD) and reversal learning (PDR) tasks. On average, mouse lemurs needed 24 days of training before starting with the PD task. Individual performances in PD and PDR tasks correlate significantly, suggesting that individual learning performance is unrelated to the respective task. Compared to the young, aged mouse lemurs showed impairments in both PD and PDR tasks. They needed significantly more trials to reach the task criteria. A much higher inter-individual variation in old than in young adults was revealed. Furthermore, in the PDR task, we found a significantly higher perseverance in aged compared to young adults, indicating an age-related deficit in cognitive flexibility. This study presents the first touchscreen-based data on the cognitive skills and age-related dysfunction in mouse lemurs and provides a unique basis to study mechanisms of inter-individual variation. It furthermore opens exciting perspectives for comparative approaches in aging, personality, and evolutionary research

    Designing a MOOC to foster critical thinking and its application in business education

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    This paper provides a didactical model for Massive Open Online Courses (MOOCs) to support the acquisition of 21st century skills such as critical thinking. For this purpose, the didactic triangle as a model of teaching and learning is extended to allow for the consideration of experts, resources, literacy and an all-encompassing learning space when designing digital learning settings. The “Dr. Internet” MOOC is presented as a case study for the proposed didactic model. Preliminary results from the evaluation of this MOOC indicated that the setting had met with reasonable acceptance from the participants. Based on these findings, we argue for a more extensive introduction of digital learning settings with an output-oriented approach to foster the acquisition of skills rather than simply knowledge

    Volatile Urinary Signals of Two Nocturnal Primates, Microcebus murinus and M. lehilahytsara

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    Mouse lemurs are small, nocturnal, arboreal solitary foragers and are endemic primates of Madagascar. This lifestyle and their high predation risk can explain why mouse lemurs rely heavily on olfaction for intraspecific communication. As they often use urine for this purpose, we investigated dichloromethane extracts of the urine of two mouse lemur species, the gray mouse lemur (Microcebus murinus) and the Godman’s mouse lemur (M. lehilahytsara), using gas-chromatography-mass spectrometry. We detected 977 different volatile compounds of different compound classes in 22 urine extracts obtained from nine M. murinus (four males, five females) and nine M. lehilahytsara (three males, six females) individuals. We compared the volatile profiles of the sexes and species using principal component analyses and discriminant function analyses and detected a significant difference in the urinary profiles of males and females and in the profiles of M. murinus and M. lehilahytsara. These very complex sex- and species-specific signatures could be used for distance communication in the context of species recognition, for mate search and in male-male competition. Our study provides important mechanistic insights into complex chemical signaling pathways in primates that are mirrored, in the case of mouse lemurs, by their extraordinarily rich repertoire of olfactory receptors. The production of highly informative olfactory signals may be complementing the complex acoustic signaling system of these solitary foragers suggesting the existence of a multimodal communication network that should be highly beneficial for any species living in dispersed social networks

    Cross-taxa similarities in affect-induced changes of vocal behavior and voice in arboreal monkeys.

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    International audienceMeasuring the affective state of an individual across species with comparable non-invasive methods is a current challenge in animal communication research. This study aims to explore to which extent affect intensity is conveyed in the vocal behaviours of three nonhuman primate species (Campbell's monkeys, De Brazza's monkeys, red-capped mangabeys), which vary in body size, ecological niche and social system. Similarly in the three species, we experimentally induced a change in captive social groups' affect by locking all group members together in their outside enclosure. The two experimental conditions which varied in affect intensity consisted in imposing a pre-reunion 90 mn-separation by splitting up the respective group into two subgroups (High affect condition) or not (Low affect condition). We measured call rates as well as voice features at the time of reunion in both conditions. The three studied species reacted in a very similar way. Across species, call rates changed significantly between the behaviourally defined states. Furthermore, contact call duration and, to some extent, voice pitch increased. Our results suggest, for the first time in arboreal Old World monkeys, that affect intensity is conveyed reliably in vocal behaviour and specific acoustic characteristics of voice, irrespective of body size and ecological niche differences between species. Cross-taxa similarities in acoustic cues of affect intensity point to phylogenetic constraints and inheritance from a common ancestor, whereas variations in vocal behaviour and affect intensity-related acoustic cues between species may be an adaptation to specific social requirements and depend on social systems. Our findings as well as a comparison with published works on acoustic communication in other vertebrate groups support the hypothesis that affect intensity in human voice originates from precursors already found deep inside the vertebrate phylogeny

    Effectiveness of the clinical decision support tool ESR eGUIDE for teaching medical students the appropriate selection of imaging tests: randomized cross-over evaluation

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    Objectives: To evaluate ESR eGUIDE-the European Society of Radiology (ESR) e-Learning tool for appropriate use of diagnostic imaging modalities-for learning purposes in different clinical scenarios. Methods: This anonymized evaluation was performed after approval of ESR Education on Demand leadership. Forty clinical scenarios were developed in which at least one imaging modality was clinically most appropriate, and the scenarios were divided into sets 1 and 2. These sets were provided to medical students randomly assigned to group A or B to select the most appropriate imaging test for each scenario. Statistical comparisons were made within and across groups. Results: Overall, 40 medical students participated, and 31 medical students (78%) answered both sets. The number of correctly chosen imaging methods per set in these 31 paired samples was significantly higher when answered with versus without use of ESR eGUIDE (13.7 ± 2.6 questions vs. 12.1 ± 3.2, p = 0.012). Among the students in group A, who first answered set 1 without ESR eGUIDE (11.1 ± 3.2), there was significant improvement when set 2 was answered with ESR eGUIDE (14.3 ± 2.5, p = 0.013). The number of correct answers in group B did not drop when set 2 was answered without ESR eGUIDE (12.4 ± 2.6) after having answered set 1 first with ESR eGUIDE (13.0 ± 2.7, p = 0.66). Conclusion: The clinical decision support tool ESR eGUIDE is suitable for training medical students in choosing the best radiological imaging modality in typical scenarios, and its use in teaching radiology can thus be recommended. Key points: ‱ ESR eGUIDE improved the number of appropriately selected imaging modalities among medical students. ‱ This improvement was also seen in the group of students which first selected imaging tests without ESR eGUIDE. ‱ In the student group which used ESR eGUIDE first, appropriate selection remained stable even without the teaching tool
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