Publications by authors named "James P McFadden"

Purpose: Hip fractures in the elderly, especially those discharged to a rehab facility, have historically been associated with poor outcomes. There has yet to be identified which patients have a higher likelihood of a rehab discharge after isolated hip fracture fixation. The purpose of this study was to identify factors that predispose patients to require short or long-term rehab after surgical intervention of traumatic, isolated hip fractures.

View Article and Find Full Text PDF

Venus, lacking an intrinsic global dipole magnetic field, serves as a textbook example of an induced magnetosphere, formed by interplanetary magnetic fields (IMF) enveloping the planet. Yet, various aspects of its magnetospheric dynamics and planetary ion outflows are complex and not well understood. Here we analyze plasma and magnetic field data acquired during the fourth Venus flyby of the Parker Solar Probe (PSP) mission and show evidence for closed topology in the nightside and downstream portion of the Venus magnetosphere (i.

View Article and Find Full Text PDF

The properties of cold, dense, low energy ( 150 eV) ions within Earth's magnetosphere between 6 and 14 distance are examined using data sampled by Time History of Events and Macroscale Interactions during Substorms spacecraft during a new low-energy plasma mode that operated from June 2016 to July 2017. These ions are a persistent feature of the magnetosphere during enhanced solar wind dynamic pressure and/or magnetospheric activity. These ions have densities ranging from 0.

View Article and Find Full Text PDF

The refilling of the lunar wake is relatively well explained by the theory of 1-D plasma expansion into a vacuum; however, the field-aligned wake potential is not a directly measured quantity, and thus, a statistical analysis of wake potentials at high altitudes has not been previously performed. In this study, we obtain the wake potential by comparing the field-aligned electron distributions inside and outside of the lunar wake measured by the two probes of the Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission. The derived potentials from ARTEMIS data vary with solar wind electron temperature and bulk flow velocity as the theory predicts.

View Article and Find Full Text PDF

Purpose: Pediatric motocross injuries occur frequently and with significant associated morbidity; however, data are limited regarding injury occurring during competition. North Central Florida hosts an annual motocross competition with numerous pediatric competitors. We sought to evaluate the rate and severity of injuries sustained at this event over a multiyear period.

View Article and Find Full Text PDF

A common feature of top hat space plasma analyzers are electrostatic "deflector plates" mounted externally to the aperture which steer the incoming particles and permit the sensor to rapidly scan the sky without moving. However, the electric fields generated by these plates can penetrate the mesh or grid on the outside of the sensor, potentially violating spacecraft electromagnetic cleanliness requirements. In this brief report we discuss how this issue was addressed for the Dual Electron Spectrometer for the Magnetospheric Multiscale Mission using a double-grid system and the simple modeling technique employed to assure the safe containment of the stray fields from its deflector plates.

View Article and Find Full Text PDF

Magnetospheric substorms explosively release solar wind energy previously stored in Earth's magnetotail, encompassing the entire magnetosphere and producing spectacular auroral displays. It has been unclear whether a substorm is triggered by a disruption of the electrical current flowing across the near-Earth magnetotail, at approximately 10 R(E) (R(E): Earth radius, or 6374 kilometers), or by the process of magnetic reconnection typically seen farther out in the magnetotail, at approximately 20 to 30 R(E). We report on simultaneous measurements in the magnetotail at multiple distances, at the time of substorm onset.

View Article and Find Full Text PDF