Filter Results
212 results
The large, triangular or cylindrical second brachial plate of the Petalocrinidae was formed through fusion of brachial plates along the distal margin of the growing arms. Based on the number of ambulacral bifurcations, brachials from the primibrachitaxis through at least the quintibrachitaxis may have been fused to form this large plate. In Petalocrinus, all calcite of fused second brachials assume the same crystallographic orientation, but in Spirocrinus more than one crystal comprises the second brachial plate.
Data Types:
  • Image
  • Video
  • Dataset
Large mammalian herbivores regularly encounter noxious insects on their food plants. Recent evidence revealed that goats efficiently avoid insect ingestion while feeding, yet it is unknown whether this ability is innate. We experimentally examined the behavioural responses of naïve goat kids to a common insect, the spring-webworm (Ocnogyna loewii). We filmed and analysed the kids’ behaviour while feeding and compared it to the behaviour described in adults. Naïve kids sorted the webworms apart from the food without ingesting them (all webworms survived). They exhibited behaviours similar to those displayed by adults, demonstrating an innate ability to avoid insect ingestion. The kids detected webworms using tactile stimulation, obtained by repeatedly touching the leaves with their muzzles. This enabled them to pick webworm-free leaves (leaving 93% of webworms behind). While adults frequently shook or discarded leaves with webworms or spat out webworms, these behaviours were rare in kids. The kids’ mean feeding rates doubled over the trials, indicating that their feeding efficiency on plants with and without insects improved with experience. Since ingesting noxious insects could be fatal, innate avoidance is critical. These findings highlight the importance of direct interactions between mammalian and insect herbivores.
Data Types:
  • Other
  • Video
  • Dataset
Large mammalian herbivores regularly encounter noxious insects on their food plants. Recent evidence revealed that goats efficiently avoid insect ingestion while feeding, yet it is unknown whether this ability is innate. We experimentally examined the behavioural responses of naïve goat kids to a common insect, the spring-webworm (Ocnogyna loewii). We filmed and analysed the kids’ behaviour while feeding and compared it to the behaviour described in adults. Naïve kids sorted the webworms apart from the food without ingesting them (all webworms survived). They exhibited behaviours similar to those displayed by adults, demonstrating an innate ability to avoid insect ingestion. The kids detected webworms using tactile stimulation, obtained by repeatedly touching the leaves with their muzzles. This enabled them to pick webworm-free leaves (leaving 93% of webworms behind). While adults frequently shook or discarded leaves with webworms or spat out webworms, these behaviours were rare in kids. The kids’ mean feeding rates doubled over the trials, indicating that their feeding efficiency on plants with and without insects improved with experience. Since ingesting noxious insects could be fatal, innate avoidance is critical. These findings highlight the importance of direct interactions between mammalian and insect herbivores.
Data Types:
  • Other
  • Video
  • Dataset
Large mammalian herbivores regularly encounter noxious insects on their food plants. Recent evidence revealed that goats efficiently avoid insect ingestion while feeding, yet it is unknown whether this ability is innate. We experimentally examined the behavioural responses of naïve goat kids to a common insect, the spring-webworm (Ocnogyna loewii). We filmed and analysed the kids’ behaviour while feeding and compared it to the behaviour described in adults. Naïve kids sorted the webworms apart from the food without ingesting them (all webworms survived). They exhibited behaviours similar to those displayed by adults, demonstrating an innate ability to avoid insect ingestion. The kids detected webworms using tactile stimulation, obtained by repeatedly touching the leaves with their muzzles. This enabled them to pick webworm-free leaves (leaving 93% of webworms behind). While adults frequently shook or discarded leaves with webworms or spat out webworms, these behaviours were rare in kids. The kids’ mean feeding rates doubled over the trials, indicating that their feeding efficiency on plants with and without insects improved with experience. Since ingesting noxious insects could be fatal, innate avoidance is critical. These findings highlight the importance of direct interactions between mammalian and insect herbivores.
Data Types:
  • Other
  • Video
  • Dataset
Objective: To characterize peri-ictal apnea and post-ictal asystole in generalized convulsive seizures (GCS) of intractable epilepsy. Methods: Prospective, multi-center epilepsy monitoring study of autonomic and breathing biomarkers of SUDEP in patient’s ≥18 years old with intractable epilepsy and monitored GCS. Video EEG, thoraco-abdominal excursions, nasal airflow, capillary oxygen saturation and electrocardiography were analyzed. Results: We studied 148 GCS in 87 patients. Nineteen patients had generalized epilepsy, 65 had focal, one had both and in two, the epileptogenic zone was unknown. Ictal central apnea (ICA) preceded GCS in 49/121 (40.4%) seizures in 23 patients, all with focal epilepsy. Post-convulsive central apnea (PCCA) occurred in 31/140 (22.1%) seizures in 22 patients, with generalized, focal or unknown epileptogenic zones. In two patients, PCCA occurred concurrently with asystole (near-SUDEP), with an incidence rate of 10.2/1000 patient-years. One PCCA patient died of probable SUDEP during follow up, suggesting a SUDEP incidence rate 5.1 per 1000 patient-years. No cases of laryngospasm were detected. Rhythmical muscle artifact synchronous with breathing was present in 75/147 seizures, and related to stertorous breathing (OR 3.856, 95%CI 1.395-10.663, p=0.009). Conclusions: PCCA occurred in both focal and generalized epilepsies, suggesting a different pathophysiology from ICA, which only occurred in focal epilepsy. PCCA was seen in two near-SUDEP and one probable SUDEP case, suggesting that this phenomenon may serve as a clinical biomarker of SUDEP. Larger studies are needed to validate this observation. Rhythmical post-ictal muscle artifact is suggestive of post-GCS breathing effort, rather than a specific biomarker of laryngospasm.
Data Types:
  • Video
  • Dataset
  • Document
Convoluted nasal passages are an enigmatic hallmark of Ankylosauria. Previous research suggested that these convoluted nasal passages functioned as heat exchangers analogous to the respiratory turbinates of mammals and birds. We tested this hypothesis by performing a computational fluid dynamic analysis on the nasal passages of two ankylosaurs: Panoplosaurus mirus and Euoplocephalus tutus. Our models predicted that Panoplosaurus and Euoplocephalus would have required 833 and 1568 thermal calories, respectively, to warm a single breath of air by 20°C. Heat recovery during exhalation resulted in energy savings of 65% for Panoplosaurus and 84% for Euoplocephalus. Our results fell well within the range of values for heat and water savings observed in extant terrestrial amniotes. We further tested alternate airway reconstructions that removed nasal passage convolutions or reduced nasal vestibule length. Our results revealed that the extensive elaboration observed in the nasal vestibules of ankylosaurs was a viable alternative to respiratory turbinates with regards to air conditioning. Of the two dinosaurs tested, Euoplocephalus repeatedly exhibited a more efficient nasal passage than Panoplosaurus. We suggest that the higher heat loads associated with the larger body mass of Euoplocephalus necessitated these more efficient nasal passages. Our findings further indicate that the evolution of complicated airways in dinosaurs may have been driven by the thermal requirements of maintaining cerebral thermal homeostasis.
Data Types:
  • Video
  • Dataset
  • Document
  • File Set
Flying organisms frequently confront the challenge of maintaining stability when moving within highly dynamic airflows near the Earth's surface. Either aerodynamic or inertial forces generated by appendages and other structures, such as the tail, may be used to offset aerial perturbations, but these responses have not been well characterized. To better understand how hummingbirds modify wing and tail motions in response to individual gusts, we filmed Anna's Hummingbirds as they negotiated an upward jet of fast moving air. Birds exhibited large variation in wing elevation, tail pitch, and tail fan angles among transits as they repeatedly negotiated the same gust, and often exhibited a dramatic decrease in body angle (28 ± 6 degrees) post-transit. After extracting three-dimensional kinematic features, we identified a spectrum of control strategies for gust transit, with one extreme involving continuous flapping, no tail fanning, and little disruption to body posture (23 ± 3 degrees downward pitch), and the other extreme characterized by dorsal wing pausing, tail fanning, and greater downward body pitch (38 ± 4 degrees). The use of a deflectable tail on a glider model transiting the same gust resulted in enhanced stability and can easily be implemented in design of aerial robots.
Data Types:
  • Other
  • Video
  • Dataset
  • File Set
The shell of the oldest true turtle (Testudinata) branch (Proterochersidae) from the Late Triassic (Norian) of Poland and Germany was built in its anterior and posterior part from an osteodermal mosaic which developed several million years after the plastron, neurals, and costal bones. The most detailed description of the shell composition in proterochersids thus far is provided together with a review of the shell composition in other Triassic pantestudinates, the scenario of early evolution of the turtle shell is proposed based on new data, and the possible adaptive meaning of the observed evolutionary changes is discussed. These observations are consistent with the trend of shell simplification previously reported in turtles. Several aspects of proterochersid shell anatomy are intermediate between O. semitestacea and more derived turtles, supporting their stem phylogenetic position. Three additional ossifications were sutured to xiphiplastra and pelvis in Proterochersis spp. and at least in some individuals the nuchal bone was paired. The peripherals, suprapygals, and pygal bone are most likely of osteodermal origin and homologous to the proterochersid shell mosaic.
Data Types:
  • Other
  • Software/Code
  • Video
  • Dataset
  • Document
Lack of sleep incurs physiological costs that include increased inflammation and alterations in the hypothalamic-pituitary-adrenal (HPA) axis. Specifically, sleep restriction or deprivation leads to increased pro-inflammatory cytokine expression and elevated glucocorticoids in rodent models, but whether birds exact similar costs is unknown. In this study, we examined whether zebra finch (Taeniopygia guttata), an avian model species, exhibits physiological costs of sleep loss using a novel automated sleep fragmentation/deprivation method; a horizontal wire sweeps across a test cage to disrupt sleep every 120 s. We measured pro-inflammatory (IL-1β and IL-6) and anti-inflammatory (IL-10) cytokine gene expression in the periphery (fat, liver, spleen, and heart) and brain (hypothalamus, hippocampus, and apical hyperpallium) of captive finches after 12 h of exposure to a moving or stationary (control) bar during the night or the day. Plasma corticosterone, body mass, and behavioral profiles were also assessed. We predicted that birds undergoing sleep loss would exhibit elevated pro-inflammatory and reduced anti-inflammatory gene expression in brain and peripheral tissues compared with control birds. In addition, we predicted an increase in plasma corticosterone levels after sleep loss. As predicted, sleep loss increased pro-inflammatory gene expression, specifically in adipose tissue (IL-6), spleen (IL-1), and hippocampus (IL-6), but a decrease in anti-inflammatory expression (IL-10) was not detected. However, sleep loss elevated baseline concentrations of plasma corticosterone. Taken together, these results suggest that a diurnal, non-migratory songbird is sensitive to the costs of sleep loss.
Data Types:
  • Video
  • Tabular Data
  • Dataset
Large-scale cooperation is a hallmark of our species and appears to be unique among primates. Yet the evolutionary mechanisms that drove the emergence of humanlike patterns of cooperation remain unclear. Studying the cognitive processes underlying cooperative behavior in apes, our closest living relatives, can help identify these mechanisms. Accordingly, we employed a novel test battery to assess the willingness of 40 chimpanzees to donate resources, instrumentally help others, and punish a culpable thief. We found that chimpanzees were faster to make prosocial than selfish choices and that more prosocial individuals made the fastest responses. Further, two measures of self-control did not predict variation in prosocial responding, and individual performance across cooperative tasks did not covary. These results show that chimpanzees and humans share key cognitive processes for cooperation, despite differences in the scope of their cooperative behaviors.
Data Types:
  • Other
  • Video
  • Tabular Data
  • Dataset
4