57 research outputs found
Individual variation in the antisnake behavior of California ground squirrels (Spermophilus beecheyi)
California ground squirrels (Spermophilus beecheyi) have evolved behavioral defenses against their two predators, the northern Pacific rattlesnake (Crotalus viridis oreganus) and Pacific gopher snake (Pituophis melanoleucus catenifer). Two studies were used to examine individual variation in antisnake behavior as it might be affected by selection operating on arousability, fearfulness, and aggressiveness. In Study 1 the behavioral consistency of two litters of lab-reared juveniles was examined at two age periods during encounters with a caged gopher snake and domestic cat. Close-range investigation and tail flagging appeared to be governed by short-term motivational states that were not strongly correlated across age. Age correlations revealed that individual tendencies to throw substrate were relatively consistent for the snake and even more so for the cat. In Study 2, wild-caught adults were obtained from five sites where rattlesnakes and gopher snakes were abundant and from five sites where these snakes were rare or absent. Squirrels in a seminatural laboratory setting were given balanced presentations of a caged rattlesnake and gopher snake separated by 5 days. Snakes were recognized by all squirrels as potentially dangerous, irrespective of experience, age, and selective regime. Substrate throwing also was positively correlated for the two snakes in both groups of adults, indicating that level of aggressiveness is a consistent component of temperament not specific to species of snakes. Physiological arousal was not correlated strongly for the two snakes, but it was significantly lower in squirrels from sites where snakes were abundant. This suggests some specialization to reduce anxiety that possibly enhances tactical decision making
Threat-Related Acoustical Differences in Alarm Calls by Wild Bonnet Macaques (Macaca radiata) Elicited by Python and Leopard Models
NALP3 inflammasome upregulation and CASP1 cleavage of the glucocorticoid receptor cause glucocorticoid resistance in leukemia cells
Glucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and resistance to glucocorticoids in leukemia cells confers poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the prednisolone sensitivity of primary leukemia cells from 444 patients newly diagnosed with ALL and found significantly higher expression of CASP1 (encoding caspase 1) and its activator NLRP3 in glucocorticoid-resistant leukemia cells, resulting from significantly lower somatic methylation of the CASP1 and NLRP3 promoters. Overexpression of CASP1 resulted in cleavage of the glucocorticoid receptor, diminished the glucocorticoid-induced transcriptional response and increased glucocorticoid resistance. Knockdown or inhibition of CASP1 significantly increased glucocorticoid receptor levels and mitigated glucocorticoid resistance in CASP1-overexpressing ALL. Our findings establish a new mechanism by which the NLRP3-CASP1 inflammasome modulates cellular levels of the glucocorticoid receptor and diminishes cell sensitivity to glucocorticoids. The broad impact on the glucocorticoid transcriptional response suggests that this mechanism could also modify glucocorticoid effects in other diseases
The ontogeny of antipredator behavior: age differences in California ground squirrels (Otospermophilus beecheyi) at multiple stages of rattlesnake encounters
Newborn offspring of animals often exhibit fully functional innate antipredator behaviors, but they may also require learning or further development to acquire appropriate responses. Experience allows offspring to modify responses to specific threats and also leaves them vulnerable during the learning period. However, antipredator behaviors used at one stage of a predator encounter may compensate for deficiencies at another stage, a phenomenon that may reduce the overall risk of young that are vulnerable at one or more stages. Few studies have examined age differences in the effectiveness of antipredator behaviors across multiple stages of a predator encounter. In this study, we examined age differences in the antipredator behaviors of California ground squirrels (Otospermophilus beecheyi) during the detection, interaction, and attack stages of Pacific rattlesnake (Crotalus oreganus) encounters. Using free-ranging squirrels, we examined the ability to detect free-ranging rattlesnakes, snake-directed behaviors after discovery of a snake, and responses to simulated rattlesnake strikes. We found that age was the most important factor in snake detection, with adults being more likely to detect snakes than pups. We also found that adults performed more tail flagging (a predator-deterrent signal) toward snakes and were more likely to investigate a snake’s refuge when interacting with a hidden snake. In field experiments simulating snake strikes, adults exhibited faster reaction times than pups. Our results show that snake detection improves with age and that pups probably avoid rattlesnakes and minimize time spent in close proximity to them to compensate for their reduced reaction times to strikes
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
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Something scary is out there II: the interplay of childhood experiences, relict sexual dinichism, and cross‑cultural differences in spatial fears
Children’s nighttime fear is hypothesized as a cognitive relict reflecting a long history of natural selection for anticipating thedirection of nighttime predatory attacks on the presumed human ancestor, Australopithecus afarensis, whose small-bodied females nesting in trees would have anticipated predatory attacks from below. Heavier males nesting on the ground wouldhave anticipated nighttime predatory attacks from their sides. Previous research on preschool children and adults supportsthis cognitive-relict hypothesis by showing developmental consistencies in their remembrances of the location of a “scarything” relative to their beds. The current study expands this research by investigating whether nighttime fear in childhood,including the effect of parental threats to behave, influenced adult spatial fears in different biotic and abiotic situations. A25-item questionnaire employing ordinal scales was given to 474 foreign-born Vietnamese and ethnic Chinese adults livingin the USA. Univariate analyses of adult remembrances of childhood indicated that females were more fearful of somethingscary below their beds than males. To examine the influence of childhood nighttime fear on adult fears, exploratory factor analyses supported three factors: (1) indeterminate agents, indicated something scary under the bed, the difficulty locatingunspecific threats, and the brief appearances of large apparitions; (2) environmental uncertainty, indicated by potential encounters with unseen animate threats; (3) predictable animals, as the relative comfort of viewing animals in zoo exhibits. Using structural equation modeling, the results suggest that childhood nighttime fear influenced only the latent variable,indeterminate agents, in both groups via the mediating variable, parental threats
The influence of image salience on the artistic renditions of cave lions in the early Upper Paleolithic
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Transient decreases in blood pressure and heart rate with increased subjective level of relaxation while viewing water compared with adjacent ground
Over the course of human evolution, the successful detection of drinking water in arid environments mitigated the physiological stress of dehydration and acted as a strong source of natural selection for recognizing the optical cues for water and perhaps physiological indices of relief. The current research consisted of two studiesinvestigating whether viewing water in outdoor settings affected autonomic tone and subjective ratings of relaxation. The first study examined blood pressure and heart rate of 32 participants who focused their attention on water in a swimming pool, a tree in a parking lot, and a small sign over a busy street. The results of this studyshowed that viewing water for 1 min 40 s reduced blood pressure reliably compared with viewing the tree and sign. Heart rate was also lower reliably while viewing water than the sign. The second study extended this research to a university arboretum, recording blood pressure, heart rate, and subjective ratings of relaxation of 73 participants successively at six sites along a 1.62 km path next to a creek, two small lakes, and the adjacent ground with open grassy areas and trees. At each site, participants alternated randomly in viewing the water or the ground first. Averaged for the six sites, analyses showed that the systolic/diastolic ratio for blood pressureand heart rate were reliably lower when viewing the water compared with the adjacent ground, an effect associated with the subjective rating of relaxation. Together, these findings indicate that viewing water can affect autonomic tone in a way that might account for the subjective rating of relaxation
Development of snake‐directed antipredator behavior by wild white‐faced capuchin monkeys: III. the signaling properties of alarm‐call tonality
Sex difference in choice of concealed or exposed refuge sites by preschool children viewing a model leopard in a playground simulation of antipredator behavior
The current study of preschool children characterizes a semi-natural extension of experimental questions on how human ancestors evaded predation when encountering dangerous felids. In a pretend game on a playground, we presented full-size leopard and deer models to children (N = 39) in a repeated-measures experimental design. Prior to viewing the model presented 15-m away, each child was instructed by the experimenter to go where she or he would feel safe. The rationale for this study was based on the anthropological construct of “sexual dinichism,” positing that, during the Pliocene, smaller-bodied hominin females engaged in more arboreal behavior than larger-bodied males. Consistent with this construct, our previous simulation research using images of an African rock outcrop showed that, after viewing a lion, girls preferred a tree as refuge rather than a crevice or large boulder whereas boys did not differentiate these refuge sites. In this follow-up study, we predicted that, after viewing the model leopard, the preschool girls would differ from the boys by not choosing enclosed refuge sites analogous to the crevice. Analyses of a contingency table for the leopard model supported this hypothesis by yielding a significant interaction of sex and refuge location (p = .031, d = .76), the source of which was a reliably larger percentage of girls not choosing concealed refuge (p = .005, d = 2.3). The interaction of sex and refuge location for the model deer was not significant (p > .5). Our findings suggest that, in contrast to the deer, the girls selected exposed playground refuge sites rather than concealing ones to maintain visual contact with the leopard as a contingency for future action
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