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Tarver, William J.

Publications and source records attributed to Tarver, William J..

13 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Re-evaluation of IIH as the Ideal Terrestrial Analog for Sans: Is There a Better Model to Consider?

While astronauts are returning from long duration spaceflight with multiple ocular signs that mimic those seen in terrestrial patients with elevated intracranial pressure (ICP), evidence has yet to prove a clinically significant increase in ICP during space.1 Preliminary research evidence may even suggest that ICP decreases in microgravity. Idiopathic intracranial hypertension (IIH) has long been considered the ideal terrestrial analogue to Spaceflight Associated Neuro-ocular Syndrome (SANS).1 However, there are several critical features of SANS that do not complement any reported case of IIH on Earth. These findings mandate a closer look at the accuracy of IIH as a terrestrial SANS analog.

Batliwala, Shehzad↗
NASA NTRS2013

Clinical Practice Guideline for Vitamin D

Vitamin D and its metabolites have clinical significance because they play a critical function in calcium homeostasis and bone metabolism. Although not all of the pathologic mechanisms have been adequately described, vitamin D insufficiency and deficiency, as measured by low levels of 25-OH vitamin D, are associated with a variety of clinical conditions including osteoporosis, falls and fractures in the elderly, decreased immune function, bone pain, and possibly colon cancer and cardiovascular health.2 Apart from inadequate dietary intake, patients may present with low levels of vitamin D if they receive inadequate sunlight. The astronaut population is potentially vulnerable to low levels of vitamin D for several reasons. Firstly, they may train for long periods in Star City, Russia, which by virtue of its northern latitude receives less sunlight in winter months. Secondly, astronauts are deprived of sunlight while aboard the International Space Station (ISS). In addition, ISS crew members are exposed to microgravity for prolonged durations and are likely to develop low bone mineral density despite the use of countermeasures. Therefore, closely monitoring and maintaining adequate vitamin D levels is important for the astronaut corps.

Tarver, William J.↗
NASA NTRS2012

Occupational Space Medicine

Learning Objectives are: (1) Understand the unique work environment of astronauts. (2) Understand the effect microgravity has on human physiology (3) Understand how NASA Space Medicine Division is mitigating the health risks of space missions.

Tarver, William J.↗
NASA NTRS2010

Occupational Surveillance for Spaceflight Exposures

This slide presentation reviews the importance of longterm occupational health surveillance of astronauts after exposure to the possible hazards of spaceflight. Because there is not much information about long term effects of spaceflight on human health, it is important to identify some of the possible results of exposure to the many possible factors that can influence longterm health impacts. This surveillance also allows for NASA to meet the obligation to care for the astronauts for their lifetime.

Tarver, William J.↗
NASA NTRS2010

NASA's First Atrial Fibrillation Case - Deke Slayton

Concerns about heart dysrhythmia have been present since the earliest days of the US manned space program. While information about an astronaut's health is general kept private, one of the original seven American astronaut's health status was played out in a very public forum. Donald "Deke" Slayton was removed from the second manned space flight when it was discovered he had idiopathic atrial fibrillation. Referencing the original medical documents, details of how this was discovered and managed from the medical perspective will be reviewed. This is NASA's first heart dysrhythmia case in an astronaut and it proves quite interesting when placed in historic perspective.

Tarver, William J.↗
NASA NTRS2010

Impact of CO2 on Intracranial Hypertension in Spaceflight. Visual Impairment and Intracranial Hypertension: An Emerging Spaceflight Risk [Part 1 and 2]

A. CO2 - Acute: Given the history of uneven removal of CO2 from spacecraft areas, there is a history of acute illness that impacts short-term health and performance. 1) Acute CO2 symptoms occur in space flight due to a combination of CO2 scrubbing limitations, microgravity-related lack of convection, and possibly interaction with microgravity-related physiological changes. 2) Reported symptoms mainly include headaches, malaise, and lethargy. Symptoms are treatable with analgesics, rest, temporarily increasing scrubbing capability, and breathing oxygen. This does not treat the underlying pathology. 3)ld prevent occurrence of symptoms. B. CO2 - Chronic: Given prolonged exposure to elevated CO2 levels, there is a history that the long-term health of the crew is impacted. 1) Chronic CO2 exposures occur in space flight due to a combination of CO2 scrubbing limitations and microgravity-related lack of convection, with possible contribution from microgravity-related physiological changes. 2) Since acute symptoms are experienced at levels significantly lower than expected, there are unidentified long-term effects from prolonged exposure to elevated CO2 levels on orbit. There have been long term effects seen terrestrially and research needed to further elucidate long term effects on orbit. 3) Recommended disposition: Research required to further elucidate long term effects. In particular, elucidation of the role of elevated CO2 on various levels of CO2 vasodilatation of intracranial blood vessels and its potential contribution to elevation of intracranial pressure.

Fogarty, Jennifer A.↗
NASA NTRS2007

An Introduction to the History of Aerospace Medicine

This viewgraph presentation reviews the history of aviation and space travel from the precursors of aviation to the lighter than air aviation to the heavier than air to the space travel. The improvement of heavier than air travel, in all dimensions from length of time traveled, to altitude and speed of travel between the first to World War I is reviewed. An understanding of the medical problems associated with air travel was begun. The beginning of the position of flight surgeons is reviewed. The advancement of flight from air to space flight is shown using photos.

Tarver, William J.↗