Publications by authors named "CA Boyd"

Removal or protection from biostratinomic agents of decomposition, such as predators and scavengers, is widely seen as a requirement for high-quality preservation of soft tissues in the fossil record. In this context, extremely rapid burial is an oft-cited mechanism for shielding remains from degradation, but not all fossils fit nicely into this paradigm. Dinosaurian mummies in particular seemingly require two mutually exclusive taphonomic processes to preserve under that framework: desiccation and rapid burial.

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Ornithischians form a large clade of globally distributed Mesozoic dinosaurs, and represent one of their three major radiations. Throughout their evolutionary history, exceeding 134 million years, ornithischians evolved considerable morphological disparity, expressed especially through the cranial and osteodermal features of their most distinguishable representatives. The nearly two-century-long research history on ornithischians has resulted in the recognition of numerous diverse lineages, many of which have been named.

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Objectives: CT angiography (CTA) is essential in acute stroke to detect emergent large vessel occlusions (ELVO) and must be interpreted by radiologists with and without subspecialized training. Additionally, grayscale inversion has been suggested to improve diagnostic accuracy in other radiology applications. This study examines diagnostic performance in ELVO detection between neuroradiologists, non-neuroradiologists, and radiology residents using standard and grayscale inversion viewing methods.

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Prescription psychostimulants produce rapid changes in mood, energy, and attention. These drugs are widely used and abused. However, their effects in human neocortex on glutamate and glutamine (pooled as Glx), and key neurometabolites such as N-acetylaspartate (tNAA), creatine (tCr), choline (Cho), and myo-inositol (Ins) are poorly understood.

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Exposure to maternal malnutrition impairs postnatal health. Acute nutritional stress is less clearly implicated in intrauterine programming. We studied the effects of stressing pregnant mothers on perinatal growth and adult glucose homeostasis.

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Here we present an examination of type IV pilus genes associated with competence and twitching in the bacterium Acinetobacter baylyi (strain ADP1, BD413). We used bioinformatics to identify potential competence and twitching genes and their operons. We measured the competence and twitching phenotypes of the bioinformatically-identified genes.

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This article describes the development process for creating a digital educational mini game prototype designed to provide practice opportunities for learning fundamental principles of arterial blood gases. Mini games generally take less than an hour to play and focus on specific subject matter. An interdisciplinary team of faculty from two universities mentored student game developers to design a digital educational mini game prototype.

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The systematic relationships of taxa traditionally referred to as 'basal ornithopods' or 'hypsilophodontids' remain poorly resolved since it was discovered that these taxa are not a monophyletic group, but rather a paraphyletic set of neornithischian taxa. Thus, even as the known diversity of these taxa has dramatically increased over the past two decades, our knowledge of their placement relative to each other and the major ornithischian subclades remained incomplete. This study employs the largest phylogenetic dataset yet compiled to assess basal ornithischian relationships (255 characters for 65 species level terminal taxa).

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Knowledge regarding the early evolution within the dinosaurian clade Ankylopollexia drastically increased over the past two decades, in part because of an increase in described taxa from the Early Cretaceous of North America. These advances motivated the recent completion of extensive preparation and conservation work on the holotype and only known specimen of Dakotadon lakotaensis, a basal ankylopollexian from the Lakota Formation of South Dakota. That specimen (SDSM 8656) preserves a partial skull, lower jaws, a single dorsal vertebra, and two caudal vertebrae.

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Though the dinosaur Thescelosaurus neglectus was first described in 1913 and is known from the relatively fossiliferous Lance and Hell Creek formations in the Western Interior Basin of North America, the cranial anatomy of this species remains poorly understood. The only cranial material confidently referred to this species are three fragmentary bones preserved with the paratype, hindering attempts to understand the systematic relationships of this taxon within Neornithischia. Here the cranial anatomy of T.

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Approaches quantifying the relative congruence, or incongruence, of molecular divergence estimates and the fossil record have been limited. Previously proposed methods are largely node specific, assessing incongruence at particular nodes for which both fossil data and molecular divergence estimates are available. These existing metrics, and other methods that quantify incongruence across topologies including entirely extinct clades, have so far not taken into account uncertainty surrounding both the divergence estimates and the ages of fossils.

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This review describes the properties and regulation of the membrane transport proteins which supply the mammary gland with aminonitrogen to support metabolism under different physiological conditions (i.e. pregnancy, lactation and involution).

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Background: Long-term adhesion-related complications and incisional hernias after abdominal surgery are common and costly. There are few data on the risk of these complications after different abdominal operations.

Study Design: We identified Medicare beneficiaries who underwent endovascular repair of an abdominal aortic aneurysm from 2001-2008 who presumably are not at risk for laparotomy-related complications.

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Crocodyliforms serve as important taphonomic agents, accumulating and modifying vertebrate remains. Previous discussions of Mesozoic crocodyliform feeding in terrestrial and riverine ecosystems have often focused on larger taxa and their interactions with equally large dinosaurian prey. However, recent evidence suggests that the impact of smaller crocodyliforms on their environments should not be discounted.

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The placenta must act as a surrogate lung, gastrointestinal tract and kidney for the fetus as well as acting as an endocrine gland necessary for the maintenance of a successful pregnancy: to achieve this, to what extent does the trophoblast necessarily share a similar epithelial phenotype? Here I review from a historical and a contemporary perspective some relevant studies with an emphasis on the similarities and differences between small intestinal and trophoblast biology. Certain physiological, structural and cell biological similarities are striking.

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Background: Venous thromboembolic events after saphenous vein ablation procedures for varicose veins have been reported. Current knowledge of these events is based on single-institution studies or studies with small numbers of patients.

Methods: The National Surgical Quality Improvement Program (NSQIP) database (2005-2009) was used to identify 3874 patients who underwent radiofrequency ablation (RFA) or endovenous laser ablation (EVLA) of the saphenous veins with or without stab phlebectomy.

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Objective: To determine the frequency and predictors of cardiac stress testing before elective noncardiac surgery in Medicare patients with no indications for cardiovascular evaluation.

Background: The American College of Cardiology/American Heart Association guidelines indicate that patients without class I (American Heart Association high risk) or class II cardiac conditions (clinical risk factors) should not undergo cardiac stress testing before elective noncardiac, nonvascular surgery.

Methods: We used 5% Medicare inpatient claims data (1996-2008) to identify patients aged ≥ 66 years who underwent elective general surgical, urological, or orthopedic procedures (N = 211,202).

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Background: Depression has been associated with delayed presentation, inadequate treatment, and poor survival in patients with cancer.

Methods: Using Surveillance, Epidemiology and End Results and Medicare linked data (1992-2005), we identified patients with pancreatic adenocarcinoma (N = 23,745). International classification of diseases, 9th edition, clinical modification codes were used to evaluate depression during the 3 to 27 months before the diagnosis of cancer.

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Background: Controversy exists regarding the use of concurrent cholecystectomy during Roux-en-Y gastric bypass performed for morbid obesity.

Methods: A decision model was developed to evaluate the cost-effectiveness of current strategies: routine concurrent cholecystectomy, Roux-en-Y gastric bypass alone with or without postoperative ursodiol therapy, and selective cholecystectomy based on preoperative findings on ultrasonography. Probabilities were obtained from a comprehensive literature review.

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The primary purpose of this qualitative study was to explore the knowledge, attitudes, and behaviors of low-income women considered high priority for receiving the novel influenza A (H1N1) vaccine to improve communication in emergency preparedness and response. Researchers sought to identify the factors that affect this high priority population's ability to successfully comply with vaccination recommendations. By utilizing an existing communication framework through the special supplemental nutrition program for women, infants, and children (WIC) they were able to document the systems and infrastructure needed to foster constructive responses in a sustainable manner in the future.

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Background: Little is known about resource utilization (number of days in the hospital or medical care) between diagnosis and death in patients with pancreatic cancer.

Methods: Using Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data, we identified 25,476 patients with pancreatic cancer (1992-2005). Hospital and medical care days per person-month from the time of diagnosis were described, stratified by stage, treatment, and survival duration.

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This study aimed to test an interactive model of perceived parental expectations and the meaning of those expectations in relation to bulimic symptoms in Black (n=97) and White (n=179) college women. Black young women reported higher parental expectations and attached more positive meanings to high parental expectations, in comparison to their White peers. There was an interactive effect for Black young women such that, in the context of perceived high parental expectations, interpreting high parental expectations as negative was associated with higher levels of bulimic symptoms whereas interpreting high expectations as positive was associated with lower levels of bulimic symptoms.

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Background: Neoplasms of the pancreas during pregnancy are rare, with less than 25 cases of benign and malignant tumors reported in the literature.

Methods: We present three unique cases of pancreatic tumors occurring during pregnancy--one mucinous cystic neoplasm and two adenocarcinomas. We review the literature regarding pancreatic neoplasms during pregnancy and discuss the diagnosis, complications, and management of these tumors.

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