While the terrestrial fossil record of the mid-Cretaceous interval (Aptian to Cenomanian) in North America has been poorly studied, the recent focus on fossil localities from the western United States has offered a more detailed picture of vertebrate diversity, ecosystem dynamics and faunal turnover that took place on the western landmass of Laramidia. This is in stark contrast to the terrestrial record from the eastern landmass of Appalachia, where vertebrate fossils are rare and consist mostly of isolated and fragmentary remains. However, a detailed understanding of these fossil communities during this interval is necessary for comparison of the faunal patterns that developed during the opening of the Western Interior Seaway (WIS).
View Article and Find Full Text PDFFour turtle taxa are previously documented from the Cenomanian Arlington Archosaur Site (AAS) of the Lewisville Formation (Woodbine Group) in Texas. Herein, we describe a new side-necked turtle (Pleurodira), Pleurochayah appalachius gen. et sp.
View Article and Find Full Text PDFTerrestrial tetrapods use their claws to interact with their environments in a plethora of ways. Birds in particular have developed a diversity of claw shapes since they are often not bound to terrestrial locomotion and have heterogeneous body masses ranging several orders of magnitude. Numerous previous studies have hypothesized a connection between pedal claw shape and ecological mode in birds, yet have generated conflicting results, spanning from clear ecological groupings based on claw shape to a complete overlap of ecological modes.
View Article and Find Full Text PDFNew discoveries at the Arlington Archosaur Site (AAS), a Cenomanian (Late Cretaceous) locality in north-central Texas, are filling gaps in our knowledge of mid-Cretaceous Appalachian ecosystems, which remain poorly characterized. The AAS is notable because it preserves a diverse crocodyliform record. As seen in other sites that preserve four or more crocodyliform taxa, the species present at the AAS exhibit different snout shapes and body sizes, indicating that this high diversity of sympatric species was likely sustainable due to niche partitioning.
View Article and Find Full Text PDFWe report details of a unique association of hadrosaur and therizinosaur tracks found in the Late Cretaceous lower Cantwell Formation, Denali National Park, central Alaska Range, Alaska. This rock unit is now well-documented as a source of thousands of fossil footprints of vertebrates such as fishes, pterosaurs, and avialan and non-avialan dinosaurs. The lower Cantwell Formation in this area consists of numerous fining-upward successions of conglomerates and pebbly sandstones, cross-stratified and massive sandstones, interbedded sandstones and siltstones, organic-rich siltstones and shales, and rare, thin, bentonites, typically bounded by thin coal seams, and it contains a diverse fossil flora.
View Article and Find Full Text PDFThe Cleveland-Lloyd Dinosaur Quarry (CLDQ) is the densest deposit of Jurassic theropod dinosaurs discovered to date. Unlike typical Jurassic bone deposits, it is dominated by the presence of . Since excavation began in the 1920s, numerous hypotheses have been put forward to explain the taphonomy of CLDQ, including a predator trap, a drought assemblage, and a poison spring.
View Article and Find Full Text PDFAs a result of the aging US population and the subsequent increase in the prevalence of coronary disease and atrial fibrillation, therapeutic use of anticoagulants has increased. Perioperative and periprocedural management of anticoagulated patients has become routine for anesthesiologists, who frequently mediate communication between the prescribing physician and the surgeon and assess the risks of both thromboembolic complications and hemorrhage. Data from randomized clinical trials on perioperative management of antithrombotic therapy are lacking.
View Article and Find Full Text PDFBrain circuits controlling eye movements are widely distributed and complex. The etiology of irrepressible square wave saccades is not fully understood and is likely different for different neuropathologies. In a previous study, spontaneously occurring irrepressible saccades were noted after a cerebrovascular accident that damaged the rostral superior colliculus (SC) and its commissure in a Rhesus monkey.
View Article and Find Full Text PDFIntravenous (i.v.) bisphosphonates relieve pain in conditions such as Paget's disease of bone, metastatic bone disease, and multiple myeloma.
View Article and Find Full Text PDFA major problem facing behavioral neuroscientists is a lack of unified, vendor-distributed data acquisition systems that allow stimulus presentation and behavioral monitoring while recording neural activity. Numerous systems perform one of these tasks well independently, but to our knowledge, a useful package with a straightforward user interface does not exist. Here we describe the development of a flexible, script-based user interface that enables customization for real-time stimulus presentation, behavioral monitoring and data acquisition.
View Article and Find Full Text PDFThis article provides a concise overview of post-thoracotomy pain syndrome, describes anesthetic and surgical factors that have been investigated to reduce the incidence of the syndrome, and explores the effectiveness of various treatments for this condition. Although some interventions (both procedural and pharmacologic) have been investigated in both preventing and treating post-thoracotomy pain syndrome, definitive studies are lacking and firm conclusions regarding the benefit of any intervention cannot be drawn. The problem is compounded further by our lack of understanding of the pathophysiologic mechanisms underlying the development of chronic pain after surgery.
View Article and Find Full Text PDFBackground: There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs.
View Article and Find Full Text PDFThis chapter seeks to provide a concise overview of the pharmacologic armamentarium available to treat pain. Drugs will be discussed in terms of their indications, mechanisms of action, and major side effects. For the purposes of this chapter, analgesics will be divided into two groups: current and emerging; current analgesics will be further subdivided into older analgesics and newer analgesics.
View Article and Find Full Text PDFUsing microstimulation we employed an explicit experimental control of activity in the superior colliculus at two sites within the motor map. We compared saccade metrics and dynamics evoked at each site independently with those caused by sequential presentation and collisions of the two stimulation trains. Essentially, we forced controlled spatio-temporal patterns of activity into the saccade control circuit with various timing relationships from known sites within the collicular motor map, thus revealing the spatio-temporal transformation from superior colliculus to eye movement dynamics under experimentally controlled conditions.
View Article and Find Full Text PDFNeurogesX Inc is developing NGX-4010, a rapid-delivery dermal patch application system that contains high-concentration trans-capsaicin, for the treatment of peripheral neuropathic pain. Capsaicin evokes a lasting and reversible refractory state in primary sensory neurons involved in the generation and maintenance of neuropathic pain. NGX-4010 can be applied to the painful skin area up to a total surface area of 1120 cm2.
View Article and Find Full Text PDFCerebellar output changes during motor learning. How these changes cause alterations of motoneuron activity and movement remains an unresolved question for voluntary movements. To answer this question, we examined premotor neurons for saccadic eye movement.
View Article and Find Full Text PDFDiabetic neuropathy (DN) is a common severe complication of type 2 diabetes. The symptoms of chronic pain, tingling, and numbness are generally attributed to small fiber dysfunction. However, little is known about the pathology among innervation to distal extremities, where symptoms start earliest and are most severe, and where the innervation density is the highest and includes a wide variety of large fiber sensory endings.
View Article and Find Full Text PDFIn monkeys, saccades that repeatedly overshoot their targets adapt to become smaller by the time the monkey has made 1,000-2,000 saccades. In life, adaptation must keep movements accurate for long periods of time. Previous work describes only saccade adaptation that occurs within a few hours.
View Article and Find Full Text PDFSaccades that consistently over- or undershoot their targets gradually become smaller or larger, respectively. The signal that elicits adaptation of saccade size is a difference between eye and target positions appearing repeatedly at the ends of saccades. Here we describe how visual error size affects the size of saccade adaptation.
View Article and Find Full Text PDFRecent experiments have characterized the dependence of saccade gain adaptation on the characteristics of the visual error following inaccurate saccades. We currently know little about the potential role of non-visual information in driving saccade adaptation. The brain could use non-visual signals from the saccade burst generator or extraocular muscle (EOM) proprioceptors to determine if the eye had rotated the appropriate distance to aim at a target.
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