Swallow and breathing coordination following suprahyoid muscle injury.

Swallowing motility disorders (dysphagia) are a major complication following radiation treatment for head and neck cancer, affecting ~50% of those treated. One reason for this is that radiation causes muscle damage, provoking sensorimotor pathologies. Previous work has suggested that injury may cause discoordination between breathing and swallowing behaviors. We sought to determine if muscle injury provokes changes in this behavior. We hypothesized that acute suprahyoid muscle damage would alter cross-behavior excitability, causing destabilization of the respiratory-swallow pattern. Swallowing was evoked in anesthetized spontaneously breathing cats via injection of a 3cc bolus of water into the oropharyngeal cavity. A suprahyoid injury was induced unilaterally by applying a ~2mm cryoprobe to the belly of the mylohyoid muscle. Electromyography (EMG) activity (duration, amplitude) was measured concurrently in thyrohyoid, mylohyoid, thyropharyngeal, and diaphragm muscles. Swallow-breathing coordination (SBC) was measured by determining inspiration/expiration phase during the onset and offset of a swallowing event, based off the mylohyoid initiation and thyropharyngeal termination bursts, respectively. Results showed an injury-related effect in the mylohyoid muscle, as indicated by a significant decrease in the mean amplitude post-injury compared to pre-injury. During swallowing, the expiratory phase was found to predominate the respiratory cycle in both pre- and post-injury. No significant changes to the swallow-breathing coordination were found following injury. Results demonstrate that mylohyoid muscle injury does not appear to interfere with short-term changes in the respiratory-swallow pattern. Although deficits in muscle function were found immediately following injury, an extended time or more severe injury may be needed to adversely inhibit these behaviors. Thus, disrupting the stable coupling between respirations and swallowing, which has been found clinically, may not be apparent immediately after injury and require long-term changes in function

The Ecological And Economic Failures Of Florida\u27s Mangrove Regulatory Scheme

The mangrove ecosystem is one of the most productive and biologically diverse wetlands on Earth, providing habitats worldwide for thousands of species, including both threatened and endangered species. Although the mangroves of Florida are concurrently governed by federal, state and, often, local regulations, they are still subject to depletion through dredging and filling, and are sacrificed for private riparian rights of view. At the foundation6 of mangrove depletion is the failure of the Florida Legislature and the Florida Department of Environmental Protection (DEP) to fully account for the values served by the mangrove ecosystem in dredge and fill permitting and under the Mangrove Trimming and Preservation Act ( Mangrove Act ). This article will briefly identify the use and nonuse values served by the mangrove ecosystem, examine the real societal cost of dredging or trimming a mangrove under the current legal structure in Florida, and propose adjustments to account for the loss incurred by society when a mangrove is dredged or trimmed

The Ecological And Economic Failures Of Florida\u27s Mangrove Regulatory Scheme

The mangrove ecosystem is one of the most productive and biologically diverse wetlands on Earth, providing habitats worldwide for thousands of species, including both threatened and endangered species. Although the mangroves of Florida are concurrently governed by federal, state and, often, local regulations, they are still subject to depletion through dredging and filling, and are sacrificed for private riparian rights of view. At the foundation6 of mangrove depletion is the failure of the Florida Legislature and the Florida Department of Environmental Protection (DEP) to fully account for the values served by the mangrove ecosystem in dredge and fill permitting and under the Mangrove Trimming and Preservation Act ( Mangrove Act ). This article will briefly identify the use and nonuse values served by the mangrove ecosystem, examine the real societal cost of dredging or trimming a mangrove under the current legal structure in Florida, and propose adjustments to account for the loss incurred by society when a mangrove is dredged or trimmed

Linking through LibGuides: Collaborating with Faculty through an Adaptable Teaching and Marketing Tool

This presentation will demonstrate how LibGuides can be used as a winning teaching and marketing tool to promote collaboration between the library and academic departments that benefit from information literacy instruction. Two librarians with a diverse range of subject liaison responsibilities will illustrate how you can successfully market LibGuides across any and all disciplines and will present examples of LibGuides created as successful research guides and instruction tools

Australopithecus afarensis endocasts suggest ape-like brain organization and prolonged brain growth

Human brains are three times larger, are organized differently, and mature for a longer period of time than those of our closest living relatives, the chimpanzees. Together, these characteristics are important for human cognition and social behavior, but their evolutionary origins remain unclear. To study brain growth and organization in the hominin species Australopithecus afarensis more than 3 million years ago, we scanned eight fossil crania using conventional and synchrotron computed tomography. We inferred key features of brain organization from endocranial imprints and explored the pattern of brain growth by combining new endocranial volume estimates with narrow age at death estimates for two infants. Contrary to previous claims, sulcal imprints reveal an ape-like brain organization and no features derived toward humans. A comparison of infant to adult endocranial volumes indicates protracted brain growth in A. afarensis, likely critical for the evolution of a long period of childhood learning in hominins

Experimental Perspective on Fallback Foods and Dietary Adaptations in Early Hominins

The robust jaws and large, thick-enameled molars of the Plio–Pleistocene hominins Australopithecus and Paranthropus have long been interpreted as adaptations for hard-object feeding. Recent studies of dental microwear indicate that only Paranthropus robustus regularly ate hard items, suggesting that the dentognathic anatomy of other australopiths reflects rare, seasonal exploitation of hard fallback foods. Here, we show that hard-object feeding cannot explain the extreme morphology of Paranthropus boisei. Rather, analysis of long-term dietary plasticity in an animal model suggests year-round reliance on tough foods requiring prolonged postcanine processing in P. boisei. Increased consumption of such items may have marked the earlier transition from Ardipithecus to Australopithecus, with routine hard-object feeding in P. robustus representing a novel behaviour

Relationship between foramen magnum position and locomotion in extant and extinct hominoids

International audienceFrom the Miocene Sahelanthropus tchadensis to Pleistocene Homo sapiens, hominins are characterized by a derived anterior position of the foramen magnum relative to basicranial structures. It has been previously suggested that the anterior position of the foramen magnum in hominins is related to bipedal locomotor behavior. Yet, the functional relationship between foramen magnum position and bipedal locomotion remains unclear. Recent studies, using ratios based on cranial linear measurements, have found a link between the anterior position of the foramen magnum and bipedalism in several mammalian clades: marsupials, rodents, and primates. In the present study, we compute these ratios in a sample including a more comprehensive dataset of extant hominoids and fossil hominins. First, we verify if the values of ratios can distinguish extant humans from apes. Then, we test whether extinct hominins can be distinguished from non-bipedal extant hominoids. Finally, we assess if the studied ratios are effective predictors of bipedal behavior by testing if they mainly relate to variation in foramen magnum position rather than changes in other cranial structures. Our results confirm that the ratios discriminate between extant bipeds and non-bipeds. However, the only ratio clearly discriminating between fossil hominins and other extant apes is that which only includes basicranial structures. We show that a large proportion of the interspecific variation in the other ratios relates to changes in facial, rather than basicranial, structures. In this context, we advocate the use of measurements based only on basicranial structures when assessing the relationship between foramen magnum position and bipedalism in future studies