Since their appearance in the fossil record 34 million years ago, modern cetaceans (dolphins, whales, and porpoises) have radiated into diverse habitats circumglobally, developing vast phenotypic variations among species. Traits such as skeletal morphology and ecologically linked behaviors denote swimming activity; trade-offs in flexibility and rigidity along the vertebral column determine patterns of caudal oscillation. Here, we categorized 10 species of cetaceans (families Delphinidae and Kogiidae; N = 21 animals) into functional groups based on vertebral centra morphology, swimming speeds, diving behavior, and inferred swimming patterns. We quantified trabecular bone mechanical properties (yield strength, apparent stiffness, and resilience) among functional groups and regions of the vertebral column (thoracic, lumbar, and caudal). We extracted 6 mm3 samples from vertebral bodies and tested them in compression in 3 orientations (rostrocaudal, dorsoventral, and mediolateral) at 2 mm min−1. Overall, bone from the pre-fluke/fluke boundary had the greatest yield strength and resilience, indicating that the greatest forces are translated to the tail during caudal oscillatory swimming. Group 1, composed of 5 shallow-diving delphinid species, had the greatest vertebral trabecular bone yield strength, apparent stiffness, and resilience of all functional groups. Conversely, Group 3, composed of 2 deep-diving kogiid species, had the least strong, stiff, and resilient bone, while Group 2 (3 deep-diving delphinid species) exhibited intermediate values. These data suggest that species that incorporate prolonged glides during deep descents in the water column actively swim less, and place relatively smaller loads on their vertebral columns, compared with species that execute shallower dives. We found that cetacean vertebral trabecular bone properties differed from the properties of terrestrial mammals; for every given bone strength, cetacean bone was less stiff by comparison. This relative lack of material rigidity within vertebral bone may be attributed to the non-weight-bearing locomotor modes of fully aquatic mammals.
Little quantitative information on the behavior, health, and activity level of managed marine mammals is currently collected, though it has the potential to significantly contribute to management and welfare of these animals. To address this, high‐resolution motion‐sensing digital acoustic recording tags (
- NSF-PAR ID:
- 10028921
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Marine Mammal Science
- Volume:
- 33
- Issue:
- 3
- ISSN:
- 0824-0469
- Format(s):
- Medium: X Size: p. 785-802
- Size(s):
- ["p. 785-802"]
- Sponsoring Org:
- National Science Foundation
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Abstract Objectives The impact of anthropogenic environmental changes may impose strong pressures on the behavioral flexibility of free‐ranging animals. Here, we examine whether rates of interactions with humans had both a
direct andindirect influence on the duration and distribution of social grooming in commensal rhesus macaques (Macaca mulatta Materials and Methods Data were collected in two locations in the city of Shimla in northern India: an urban setting and a temple area. We divided these two locations in a series of similar‐sized physical blocks (
N = 48) with varying rates of human–macaque interactions. We conducted focal observations on three free‐ranging rhesus macaque groups, one in the urban area and two in the temple area.Results Our analysis shows that macaques engaged in shorter grooming bouts and were more vigilant while grooming in focal sessions during which they interacted with people more frequently, suggesting that humans directly affected grooming effort and vigilance behavior. Furthermore, we found that in blocks characterized by higher rates of human–macaque interactions grooming bouts were shorter, more frequently interrupted by vigilance behavior, and were less frequently reciprocated.
Discussion Our work shows that the rates of human–macaque interaction had both a direct and indirect impact on grooming behavior and that macaques flexibly modified their grooming interactions in relation to the rates of human–macaque interaction to which they were exposed. Because grooming has important social and hygienic functions in nonhuman primates, our work suggests that human presence can have important implications for animal health, social relationships and, ultimately, fitness. Our results point to the need of areas away from people even for highly adaptable species where they can engage in social interactions without human disruption.
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Background Cognitive training may partially reverse cognitive deficits in people with HIV (PWH). Previous functional MRI (fMRI) studies demonstrate that working memory training (WMT) alters brain activity during working memory tasks, but its effects on resting brain network organization remain unknown.
Purpose To test whether WMT affects PWH brain functional connectivity in resting‐state fMRI (rsfMRI).
Study Type Prospective.
Population A total of 53 PWH (ages 50.7 ± 1.5 years, two women) and 53
HIV ‐seronegative controls (SN , ages 49.5 ± 1.6 years, six women).Field Strength/Sequence Axial single‐shot gradient‐echo echo‐planar imaging at 3.0 T was performed at baseline (TL1), at 1‐month (TL2), and at 6‐months (TL3), after WMT.
Assessment All participants had rsfMRI and clinical assessments (including neuropsychological tests) at TL1 before randomization to Cogmed WMT (adaptive training,
n = 58: 28 PWH, 30 SN; nonadaptive training,n = 48: 25 PWH, 23 SN), 25 sessions over 5–8 weeks. All assessments were repeated at TL2 and at TL3. The functional connectivity estimated by independent component analysis (ICA) or graph theory (GT) metrics (eigenvector centrality, etc.) for different link densities (LDs) were compared between PWH and SN groups at TL1 and TL2.Statistical Tests Two‐way analyses of variance (ANOVA) on GT metrics and two‐sample
t ‐tests on FC or GT metrics were performed. Cognitive (eg memory) measures were correlated with eigenvector centrality (eCent) using Pearson's correlations. The significance level was set atP < 0.05 after false discovery rate correction.Results The ventral default mode network (vDMN) eCent differed between PWH and SN groups at TL1 but not at TL2 (
P = 0.28). In PWH, vDMN eCent changes significantly correlated with changes in the memory ability in PWH (r = −0.62 at LD = 50%) and vDMN eCent before training significantly correlated with memory performance changes (r = 0.53 at LD = 50%).Data Conclusion ICA and GT analyses showed that adaptive WMT normalized graph properties of the vDMN in PWH.
Evidence Level 1
Technical Efficacy 1
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Diel vertical migration (DVM) is a vital behavior for many pelagic marine fauna. Locomotory tactics that animals use during DVM define the metabolic costs of migrations and influence the risk of detection and capture by predators, yet, for squids, there is little understanding of the fine-scale movements and potential variability during these migrations. Vertical migratory behaviors of 5 veined squid Loligo forbesii were investigated with biologging tags (ITags) off the Azores Islands (central North Atlantic). Diel movements ranged from 400 to 5 m and were aligned with sunset and sunrise. During ascent periods, 2 squid exhibited cyclic climb-and-glide movements using primarily jet propulsion, while 3 squid ascended more continuously and at a lower vertical speed using mostly a finning gait. Descents for all 5 squid were consistently more rapid and direct. While all squid swam in both arms-first and mantle-first directions during DVM, mantle-first swimming was more common during upward movements, particularly at vertical speeds greater than 25 cm s -1 . The in situ variability of animal posture, swim direction, and gait use revealed behavioral flexibility interpreted as energy conservation, prey capture, and predator avoidance.more » « less
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Background Dysregulation of the corticotropin‐releasing factor (
CRF ) system has been observed in rodent models of binge drinking, with a large focus onCRF receptor 1 (CRF ‐R1). The role ofCRF ‐binding protein (CRF ‐BP ), a key regulator ofCRF activity, in binge drinking is less well understood. In humans, single‐nucleotide polymorphisms inCRHBP CRF ‐BP in vulnerability to alcohol addiction.Methods The role and regulation of
CRF ‐BP in binge drinking were examined in mice exposed to the drinking in the dark (DID ) paradigm. Using in situ hybridization, the regulation ofCRF ‐BP ,CRF ‐R1, andCRF mRNA expression was determined in the stress and reward systems of C57BL /6J mice after repeated cycles ofDID . To determine the functional role ofCRF ‐BP in binge drinking,CRF ‐BP knockout (CRF ‐BP KO ) mice were exposed to 6 cycles ofDID , during which alcohol consumption was measured and compared to wild‐type mice.Results CRF ‐BP mRNA expression was significantly decreased in the prelimbic (PL ) and infralimbic medial prefrontal cortex (mPFC ) of C57BL /6J mice after 3 cycles and in thePL mPFC after 6 cycles ofDID . No significant changes inCRF orCRF ‐R1 mRNA levels were observed in mPFC , ventral tegmental area, bed nucleus of the stria terminalis, or amygdala after 3 cycles ofDID .CRF ‐BP KO mice do not show significant alterations in drinking compared to wild‐type mice across 6 cycles of DID.Conclusions These results reveal that repeated cycles of binge drinking alter
CRF ‐BP mRNA expression in the mPFC , a region responsible for executive function and regulation of emotion and behavior, including responses to stress. We observed a persistent decrease inCRF ‐BP mRNA expression in the mPFC after 3 and 6DID cycles, which may allow for increasedCRF signaling atCRF ‐R1 and contribute to excessive binge‐like ethanol consumption.
