Publications by authors named "Joseph Ayers"

Objective: This study aims to assess the safety and viability of popliteal endarterectomy for isolated popliteal disease.

Method: The study is a retrospective review, single-institution review (2010-2020) which assessed all popliteal endarterectomies performed at a rural 180-bed teaching hospital. Cases were identified based on the CPT code.

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Background: Duplex ultrasound vein mapping (DUVM) may increase autogenous dialysis access procedures but has not been universally adopted by surgeons.

Methods: We determined reliability and accuracy of arm vein measurements on physical examination (PE) and DUVM, compared to direct measurements in the operating room (OR, gold standard). Operative plans were developed from each set of measurements and we evaluated which approach identified more options for autogenous procedures.

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Background: Endovascular simulation employing computer, animal, and static models are common and useful adjuncts for teaching endovascular procedures and developing novel, complex endovascular techniques. Unfortunately, these models lack realistic haptic feedback and thus do not faithfully replicate many of the technical challenges associated with clinical endovascular procedures (e.g.

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Blunt thoracic aortic injury (BTAI) in a patient with an aberrant right subclavian artery (ARSA) presents unique challenges for patient management and aortic repair. Specific considerations include the need to treat coincidental ARSA, subclavian revascularization, and ARSA exclusion. Despite the rise of endovascular repair as the primary modality for aortic repair for BTAI, reports of this technique in the setting of ARSA are limited.

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The crustacean stomatogastric nervous system is a classic model for understanding the effects of modulating ionic currents and synapses at both the cell and network levels. The stomatogastric ganglion in this system contains two distinct central pattern generators: a slow gastric mill network that generates flexible rhythmic outputs (8-20 s) and is often silent, and a fast pyloric network that generates more consistent rhythmic outputs (0.5-2 s) and is always active in vitro.

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Background: Pelvic vascular injuries (PVIs) rarely occur in isolation and are often associated with significant morbidity. The purpose of this study was to examine the incidence, trends, and early outcomes of PVIs sustained in combat.

Methods: The Department of Defense Trauma Registry was queried to identify all patients treated with PVIs during the first 10 years of Operation Enduring Freedom.

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The hyperpolarization-activated inward cationic current (Ih) is known to regulate the rhythmicity, excitability, and synaptic transmission in heart cells and many types of neurons across a variety of species, including some pyloric and gastric mill neurons in the stomatogastric ganglion (STG) in Cancer borealis and Panulirus interruptus However, little is known about the role of Ih in regulating the gastric mill dynamics and its contribution to the dynamical bifurcation of the gastric mill and pyloric networks. We investigated the role of Ih in the rhythmic activity and cellular excitability of both the gastric mill neurons (medial gastric, gastric mill) and pyloric neurons (pyloric dilator, lateral pyloric) in Homarus americanus Through testing the burst period between 5 and 50 mM CsCl, and elimination of postinhibitory rebound and voltage sag, we found that 30 mM CsCl can sufficiently block Ih in both the pyloric and gastric mill neurons. Our results show that Ih maintains the excitability of both the pyloric and gastric mill neurons.

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Background: The American lobster, Homarus americanus, is an important species as an economically valuable fishery, a key member in marine ecosystems, and a well-studied model for central pattern generation, the neural networks that control rhythmic motor patterns. Despite multi-faceted scientific interest in this species, currently our genetic resources for the lobster are limited. In this study, we de novo assemble a transcriptome for Homarus americanus using central nervous system (CNS), muscle, and hybrid neurosecretory tissues and compare gene expression across these tissue types.

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We present a method to use the commercially available LEGO Mindstorms NXT robotics platform to test systems level neuroscience hypotheses. The first step of the method is to develop a nervous system simulation of specific reflexive behaviors of an appropriate model organism; here we use the American Lobster. Exteroceptive reflexes mediated by decussating (crossing) neural connections can explain an animal's taxis towards or away from a stimulus as described by Braitenberg and are particularly well suited for investigation using the NXT platform.

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Background: Salmonella enterica serovar Typhi (Salmonella Typhi) causes an estimated 22 million typhoid fever cases and 216 000 deaths annually worldwide. In Africa, the lack of laboratory diagnostic capacity limits the ability to recognize endemic typhoid fever and to detect outbreaks. We report a large laboratory-confirmed outbreak of typhoid fever in Uganda with a high proportion of intestinal perforations (IPs).

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Despite several reports of proximal arm ischemia due to radiation therapy, there are no reports of hand ischemia, presumably due to the rarity of radiation treatment of the distal upper extremity. We present a case of a 42-year-old male presenting with acute hand ischemia 36 years after being treated with forearm radiation for Ewing's sarcoma. Angiography demonstrated a patent brachial artery, occluded radial and ulnar arteries in the forearm, and a normal-caliber reconstituted radial artery at the anatomical snuffbox feeding a patent palmar arch.

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Underwater walking.

Arthropod Struct Dev

July 2004

Lobsters are generalist decapods that evolved in a broad variety of niches in the Northwestern Atlantic. Due to their inherent buoyancy they have acquired adaptations to reduced traction and surge. We have developed a biomimetic robot based on the lobster that features artificial muscle actuators and sensors employing labeled-line codes.

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In order to determine the dynamical properties of central pattern generators (CPGs), we have examined the lobster stomatogastric ganglion using the tools of nonlinear dynamics. The lobster pyloric and gastric mill central pattern generators can be analyzed at both the cellular and network levels because they are small, i.e.

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We have developed a biomimetic robot based on the American lobster. The robot is designed to achieve the performance advantages of the animal model by adopting biomechanical features and neurobiological control principles. Three types of controllers are described.

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