scholarly journals Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants (Loxodonta africana)

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3525
Author(s):  
Susan Hambrecht ◽  
Ann-Kathrin Oerke ◽  
Michael Heistermann ◽  
Johannes Hartig ◽  
Paul W. Dierkes

Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.

2021 ◽  
Vol 7 (s2) ◽  
Author(s):  
Irmtraud Kaiser ◽  
Andrea Ender

Abstract This paper explores intra-individual variation as a manifestation of language-internal multilingualism in the Central-Bavarian Austrian context. Based on speech data from children and adults in different contexts, we discuss different methods of measuring and analyzing inter-situational variation along the dialect and standard language spectrum. By contrasting measures of dialectality, on the one hand, and proportions of turns in dialect, standard language or intermediate/mixed forms on the other, we gain complementary insights not only into the individual dialect-standard repertoires but also into the consequences of different methodological choices. The results indicate that intra-individual variation is ubiquitous in adults and children and that individual repertoires need to be taken into account from the beginning of the language acquisition process. We suggest that while intra-individual variation can be attested through the use of various methods, the revealed level of granularity and the conclusions that can be drawn as to the individual repertoires on the dialect-standard spectrum largely depend on the measures used and their inherent assumptions and intrinsically necessary categorizations.


2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.


Behaviour ◽  
2008 ◽  
Vol 145 (3) ◽  
pp. 297-312 ◽  
Author(s):  
Anne Savage ◽  
Joseph Soltis ◽  
Katherine Leighty ◽  
Kirsten Leong

AbstractFemale African elephants are thought to exchange 'rumble' vocalizations, but such temporally associated calls may not constitute communicative events. Affiliated females are more likely to engage in antiphonal calling, but affiliation is defined according to time spent in proximity. Affiliated partners may vocalize in sequence simply because their proximity causes them to collectively respond to shared external stimuli or due to a social facilitation effect. We used bi-variate and partial correlation analyses to test for the independent effects of the strength of the social relationship and distance between vocal partners on the likelihood of a vocal response. Female African elephants at Disney's Animal Kingdom were video-taped and outfitted with audio-recording collars that allowed for the individual identification of low-frequency rumbles. Affiliation had a strong influence on response likelihood, even after controlling for the effects of the distance between vocalizing partners. Further, the distance between vocalizing partners did not correlate with response likelihood, and factoring out the effects of affiliation did not significantly alter this result. These results suggest that rumble exchanges are communicative events that reflect social bonds, not simply artifacts of increased proximity and, therefore, provide support for functional hypotheses concerning rumble exchanges in wild African elephants.


1969 ◽  
Vol 29 (1) ◽  
pp. 57-58 ◽  
Author(s):  
Lowell Cooper ◽  
Joseph Caston

This study measured the effect of a real stress, the announcement of impending heart surgery, on the size of the human figure. The H-T-P was administered before and after the announcement of the operation, with matched controls being told they would not need the operation ( Ns = 10). While the individual variation in coping styles obscured group differences, there was a trend for post-stress drawings by the operated group to be larger than their pre-stress drawings.


2021 ◽  
Author(s):  
Kimberly Doell ◽  
Beatrice Conte ◽  
Tobias Brosch

Emotions are powerful drivers of human behavior that may make people aware of the urgency to act to mitigate climate change and provide a motivational basis to engage in sustainable action. However, attempts to leverage emotions via climate communications have yielded unsatisfactory results, with many interventions failing to produce the desired behaviors. Considering emotions as simple behavioral levers without considering differences in the underlying affective mechanisms may not optimally exploit their potential to promote sustainable action. Across two field experiments, here we show that individual predispositions to experience positive emotions in an environmental context (trait affect) predict pro-environmental actions and corresponding shifts in affective states (towards personal as well as witnessed pro-environmental actions). Moreover, trait affect predicts the individual behavioral impact of emotion-based intervention strategies from positive environmental messages. These findings have important implications for the targeted design of affect-based interventions aiming to promote sustainable behavior.


1948 ◽  
Vol 25 (4) ◽  
pp. 334-343
Author(s):  
MARTIN LÜSCHER

1. Partial regeneration of the legs is possible in Rhodnius prolixus. 2. The regeneration potencies appear at the level of the femur-tibia joint and increase gradually in a distal direction. 3. Regeneration usually ceases after the fourth post-amputation moult. 4. No striking differences in regenerative capacity can be detected either in the different legs on one nymphal instar or in the legs of different nymphal instars. There is, however, considerable individual variation. 5. Regeneration is dependent on the time which elapses between the amputation and the next moult. 6. The regeneration processes have a higher temperature coefficient than the moulting processes. 7. A conception of two limiting factors is briefly discussed.


2013 ◽  
Vol 02 (03) ◽  
pp. 122-127
Author(s):  
Bishwajeet Saikia ◽  
Kunjalal Talukdar ◽  
Joydev Sarma ◽  
Amitav Sarma ◽  
Sandeep Madaan

Abstract Background and aims: Stroke, the most frequent expression of cerebrovascular disease is one of the leading causes of death and disability throughout the world. The manifestations are largely accounted by the anatomical distribution of the stems and branches of the circle of Willis supplying the brain. Considerable individual variation exists in the pattern and caliber of the individual vessels forming the circle of Willis, which may possibly impair the collateral blood flow. The knowledge of these variations thus, becomes essential for medical as well as surgical interventions. There may possibly be some regional variations in the cerebral arteries not mentioned in standard available texts. Thus, the regional based study of variations present becomes essential. The present study aims to focus on the variation of one of such branches, the anterior cerebral artery (ACA) in the population of Assam, India. Material and Methods: The ACAs of 70 human cadaveric brains were examined by gross dissection in the department of Anatomy and Forensic medicine in Gauhati Medical College. Results: Hypoplastic A-1 segment were found in 7% cases, Hypoplastic A-2 segment in 2.85% cases, Buttonhole formation in 8.57% cases and aneurysmal dilatation in 1.42% cases. The results were compared with that of other authors and variations noted. Conclusion: The present study of ACA using gross dissection is an initial step in providing a reference to the healthcare professionals in the region of Assam. Based on this further studies using newer imaging methods should be carried out to correlate the manifestations clinically.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hanna Lantto

AbstractThis article examines individual variation of contact features in the speech patterns of four L2 Basque speakers. The individual styles are examined through the concepts of individual entrenchment and community-wide conventionalization to bridge the gap between linguistic variation and change at the individual and social levels. All the informants speak Spanish as their L1. They have acquired Basque in classroom contexts, and they belong to the same macrosociolinguistic categories. Yet their patterns of using the language contact between standard Basque, vernacular Basque dialects and Spanish as a resource in creating individual speech styles differ considerably, reflecting their language attitudes and their personal experience. Nevertheless, there are conventionalized patterns that emerge out of this diversity: All speakers use the standard Basque as the base language, and none of them adopts of vernacular variety as a whole. The Spanish resources seem to be used mainly for pragmatic and stylistic functions, whereas the features of vernacular Basque that the speakers have adopted as part of their individual styles are high frequency elements of core grammar.


1992 ◽  
Vol 6 ◽  
pp. 321-321 ◽  
Author(s):  
E.L. Yochelson ◽  
M. Parrish

Climactichnites Logan, 1860, is known only from its large trail up to 20 cm in width, a trace superficially resembling a rope ladder. Prominent lateral ridges are parallel throughout the length of the trail; they may be smooth and hemispherical in cross-section or crenulated, much like a pie crust. Between these ridges is a series of raised dune-like bars and furrows dug into the substrate. The bars and furrows show considerable individual variation between trails and also variation along a trail. Ovoid impressions are known which occur at the start of trails. The posterior of these impressions is well rounded; the anterior is triangular, and for a short distance from the impression, the trail is developed on only one side. One exceptionally preserved impression shows curved, closely spaced, fine lines parallel to the posterior.The trails are found only in sandstone, and where they are present, they are abundant. Slightly equivocable evidence indicates a Dresbachian (early Late Cambrian) age for the occurrences in New York, Missouri, and Wisconsin; trails in Ontario and Quebec are less certainly dated. Desiccation cracks and air escape hole suggest that the trail was fully exposed to the atmosphere.From this data, a large number of sketches were made to reconstruct an animal able to make such a trail. Each attempt produced new speculation on the morphology. In the final rendition, the animal is bilaterally symmetrical, broad and low. The integument is tough, and the sole bears a subcentral mouth anteriorward. Lateral flaps scraped and compressed damp sand to make the parallel ridges. The anterior was strongly musculated and thin. This anterior flap grasped the sediment, alternating on either side of the animal to pull the form forward when the lateral flaps were relaxed. Curved rows of cilia on the posterior moved loose sand into dunes between the furrows formed by the anterior flaps.This reconstruction is like that of no other animal known in the Vendian or the Phanerozoic.


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