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Apex Mills Corporation's superinsulators are used by makers of cold weather apparel, parkas, jackets, boots and outdoor gear such as sleeping bags. Their attraction in such applications is that radiant barrier insulation offers excellent warmth retention at minimal weight and bulk.
MPI Outdoor Safety Products developed aluminized mylar to make Echo Satellites more reflective, to insulate cryogenic fluids, and for space suit insulation. This technology has spun off to a variety of consumer products. Sportsman's blankets and jackets, ski parkas, sleeping bags, and even life-raft canopies are among them. Sportsman's blanket weighing 12 ounces can be used equally well to keep heat away or keep available heat in. Emergency rescue blanket has heat retention qualities similar to those of Sportsman's blanket. Strong enough to be used as a litter, yet folds up so small you can carry it in your shirt pocket. 10 ounce reversible jacket absorbs warmth from sun. A silver colored side next to your body retains a large portion of body heat. In warm weather you wear silver side out to reflect sun's rays.
Your body protects you from illness with its own security system - the immune system. This system keeps illness at bay not only by mounting a defense against foreign organisms, but also by controlling the population of bacteria and viruses that normally live in your body. But there's no need to panic: certain microbes can actually exist in your body without causing illness. Some bacteria are even beneficial - like the E. coli in the large intestine that are an important source of vitamin K. While viruses are not exactly considered beneficial, they can also inhabit the human body without causing immediate harm or infection. A good example is the herpes simplex virus type 1 (HSV1), more commonly known as cold sores or fever blisters. This virus infects 70 to 80 percent of all adults but remains latent much of the time. While latent, the virus within cells remains dormant. Activation of the dormant virus causes it to make copies of itself (known as replication) constantly detectable in body fluids such as urine or saliva in a process called shedding. When a person becomes sick or stressed, however, this weakened condition allows the virus to reactivate and multiply. These elevated levels may be enough to produce symptoms, but shedding can also occur without symptoms. This ability to shed without showing signs of infection, or asymptomatic shedding, is of great interest, as it increases the chances of infecting others. The stresses associated with space flight - adapting to microgravity, isolation from family and friends, living and working in a confined space, sleep deprivation, and busy schedules, to name but a few - may weaken astronauts' immune systems, leaving them at greater risk of viral reactivation. Members of the STS-107 crew will participate in this experiment, Incidence of Latent Viral Shedding in Space Flight, to help scientists understand how reactivation works in space, and at what level replication reaches before symptoms begin to show. This study also promises more insight into the behavior of the larger virus family, herpesvirus, which will help us understand how to prevent infection in populations on Earth and reactivation in those already infected.
This video shows the activities of the STS-107 crew (Rick Husband, Commander; William McCool, Pilot; Kalpana Chawla, David Brown, Michael Anderson, Laurel Clark, Mission Specialists; Ilan Ramon, Payload Specialist) during flight day 10 of the Columbia orbiter's final mission. Flight day 10 includes an interview by Mission Control of astronauts Brown, McCool, and Anderson, who answer questions on the mission's spaceborne experiments, as well as biographical and other questions. Much of the video is shot and narrated by Payload Specialist Ramon, who shows the crew members at work on experiments in the SpaceHab RDM (Research Double Module), and performing other tasks. Experiments featured in the video include SOFBALL (Structure of Flame Balls at Low Lewis-Number), the STARS (Space Technology and Research Students) experiments, and experiments on cancer and osteoporosis. Crew activities shown include making a video of Earth, and preparing for sleep. Earth views shown in the video include the Gulf of Aden, Ghana, Lake Chad, and the coast of North Carolina.
This video shows the activities of the STS-107 crew (Rick Husband, Commander; William McCool, Pilot; Kalpana Chawla, David Brown, Michael Anderson, Laurel Clark, Mission Specialists; Ilan Ramon, Payload Specialist) during flight day 11 of the Columbia orbiter's final mission. In the video, crew members from the Blue Team (McCool, Brown, Anderson) and the Red Team (Husband, Chawla, Clark, Ramon) are shown at work on experiments in the SpaceHab RDM (Research Double Module), and performing other tasks. Much of the video is shot and narrated by Commander Husband. Mission Specialist Brown is shown operating the MEIDEX (Mediterranean Israeli Dust Experiment). Crew activities shown include making breakfast, entering sleep stations, and programming shuttle maneuvers necessary for the spaceborne experiments onboard. Earth views shown in the video include one of Egypt, Israel and Jerusalem.
The STS-113 post-flight presentation begins with a view of Mission Specialists Michael E. Lopez-Alegria and John B. Herrington getting suited for the space mission. The STS-113 crew consists of: Commander James D. Wetherbee, Pilot Paul Lockhart, Mission Specialists Michael Lopez-Alegria and John Herrington. Cosmonauts Valery Korzun, and Sergei Treschev, and astronaut Peggy Whitson who are all members of the expedition five crew, and Commander Kenneth Bowersox, Flight Engineers Nikolai Budarin and Donald Pettit, members of Expedition Six. The main goal of this mission is to take Expedition Six up to the International Space Station and Return Expedition Five to the Earth. The second objective is to install the P(1) Truss segment. Three hours prior to launch, the crew of Expedition Six along with James Wetherbee, Paul Lockhart, Michael Lopez-Alegria and John Herrington are shown walking to an astrovan, which takes them to the launch pad. The actual liftoff is presented. Three Extravehicular Activities (EVA)'s are performed on this mission. Michael Lopez-Alegria and John Herrington are shown performing EVA 1 and EVA 2 which include making connections between the P1 and S(0) Truss segments, and installing fluid jumpers. A panoramic view of the ISS with the Earth in the background is shown. The grand ceremony of the crew exchange is presented. The astronauts performing everyday duties such as brushing teeth, washing hair, sleeping, and eating pistachio nuts are shown. The actual landing of the Space Shuttle is presented.
This video, part 3 of 4, shows the activities of the crew of Space Shuttle Envdeavour and the Expedition 5 and 6 crews of the International Space Station (ISS) during flight days 7 through 11 of STS-113. Endeavour's crew consists of Commander Jim Wetherbee, Pilot Paul Lockhart, and Mission Specialists Michael Lopez-Alegria and John Herrington. Footage of flight day 7 includes a change of command ceremony on board the ISS, and Endeavour dumping supply water through a nozzle. On flight day 8 the Space Station Mobile Transporter jams while traveling on the P1 truss of the ISS, and Herrington attempts to free it as part of a lengthy extravehicular activity (EVA) with Lopez-Alegria. Flight day 9 is the last full day the three crews spend together. Expedition 5 NASA ISS Science Officer Peggy Whitsun troubleshoots the Microgravity Glovebox on board the ISS with her successor Don Pettit. The undocking of Endeavour and the ISS is the main activity of flight day 10. Endeavour also deploys a pair of experimental tethered microsatellites for the Department of Defense. The footage from flight day 11 shows the Expedition 5 crew exercising, laying in recumbant seats to help them adjust to the gravity on Earth, and sleeping. The video includes numerous views of the earth, some with the ISS and Endeavour in the foreground. There are close-ups of Italy, Spain and Portugal, Tierra del Fuego, and Baja California, and a night view of Chicago and the Great Lakes.
Space flight conditions have a dramatic effect on a variety of physiologic functions of mammals, including muscle, bone, and neurovestibular function. Among the physiological functions that are affected when humans or animals are exposed to space flight conditions is the immune response. The focus of this review is on the function of the immune system in space flight conditions during actual space flights, as well as in models of space flight conditions on the earth. The experiments were carried out in tissue culture systems, in animal models, and in human subjects. The results indicate that space flight conditions alter cell-mediated immune responses, including lymphocyte proliferation and subset distribution, and cytokine production. The mechanism(s) of space flight-induced alterations in immune system function remain(s) to be established. It is likely, however, that multiple factors, including microgravity, stress, neuroendocrine factors, sleep disruption, and nutritional factors, are involved in altering certain functions of the immune system. Such alterations could lead to compromised defenses against infections and tumors.
The separate contribution of circadian rhythmicity and elapsed time awake on electroencephalographic (EEG) activity during wakefulness was assessed. Seven men lived in an environmental scheduling facility for 4 weeks and completed fourteen 42.85-h 'days', each consisting of an extended (28.57-h) wake episode and a 14.28-h sleep opportunity. The circadian rhythm of plasma melatonin desynchronized from the 42.85-h day. This allowed quantification of the separate contribution of circadian phase and elapsed time awake to variation in EEG power spectra (1-32 Hz). EEG activity during standardized behavioral conditions was markedly affected by both circadian phase and elapsed time awake in an EEG frequency- and derivation-specific manner. The nadir of the circadian rhythm in alpha (8-12 Hz) activity in both fronto-central and occipito-parietal derivations occurred during the biological night, close to the crest of the melatonin rhythm. The nadir of the circadian rhythm of theta (4.5-8 Hz) and beta (20-32 Hz) activity in the fronto-central derivation was located close to the onset of melatonin secretion, i.e. during the wake maintenance zone. As time awake progressed, delta frequency (1-4.5 Hz) and beta (20-32 Hz) activity rose monotonically in frontal derivations. The interaction between the circadian and wake-dependent increase in frontal delta was such that the intrusion of delta was minimal when sustained wakefulness coincided with the biological day, but pronounced during the biological night. Our data imply that the circadian pacemaker facilitates frontal EEG activation during the wake maintenance zone, by generating an arousal signal that prevents the intrusion of low-frequency EEG components, the propensity for which increases progressively during wakefulness.
It is very likely that the human immune system will be altered in astronauts exposed to the conditions of long-term space flight: isolation, containment, microgravity, radiation, microbial contamination, sleep disruption, and insufficient nutrition. In human and animal subjects flown in space, there is evidence of immune compromise, reactivation of latent virus infection, and possible development of a premalignant or malignant condition. Moreover, in ground-based space flight model investigations, there is evidence of immune compromise and reactivation of latent virus infection. All of these observations in space flight itself or in ground-based models of space flight have a strong resonance in a wealth of human pathologic conditions involving the immune system where reactivated virus infections and cancer appear as natural consequences. The clinical conditions of Epstein-Barr-driven lymphomas in transplant patients and Kaposi's sarcoma in patients with autoimmune deficiency virus come easily to mind in trying to identify these conditions. With these thoughts in mind, it is highly appropriate, indeed imperative, that careful investigations of human immunity, infection, and cancer be made by space flight researchers.
Fluid and energy metabolism and related endocrine changes have been studied nearly from the beginning of human space flight in association with short- and long-duration flights. Fluid and electrolyte nutrition status is affected by many factors including the microgravity environment, stress, changes in body composition, diet, exercise habits, sleep cycles, and ambient temperature and humidity conditions. Space flight exposes astronauts to all these factors and consequently poses significant challenges to establishing dietary water, sodium, potassium, and energy recommendations. The purpose of this article is to review the results of ground-based and space flight research studies that have led to current water, electrolyte, and energy dietary requirements for humans during space flight and to give an overview of related endocrinologic changes that have been observed in humans during short- and long-duration space flight.
On June 25, 1997, the Russian supply spacecraft Progress 234 collided with the Mir space station, rupturing Mir's pressure hull, throwing it into an uncontrolled attitude drift, and nearly forcing evacuation of the station. Like many high-profile accidents, this collision was the consequence of a chain of events leading to the final piloting errors that were its immediate cause. The discussion in this article does not resolve the relative contributions of the actions and decisions in this chain. Neither does it suggest corrective measures, many of which are straightforward and have already been implemented by the National Aeronautics and Space Administration (NASA) and the Russian Space Agency. Rather, its purpose is to identify the human factors that played a pervasive role in the incident. Workplace stress, fatigue, and sleep deprivation were identified by NASA as contributory factors in the Mir-Progress collision (Culbertson, 1997; NASA, forthcoming), but other contributing factors, such as requiring crew to perform difficult tasks for which their training is not current, could potentially become important factors in future situations.
The possibility that drugs administered to Skylab 3 (SL-3) and 4 (SL-4) crewmen for space motion sickness may have interfered with their biomedical evaluation in space was investigated. Healthy volunteers received combinations of Scopolamine/Dexedrine for four days in regimens similar to those used in these missions. Urine samples, heart rate, body temperature, mood and performance were analyzed for drug-related changes. Twenty-four hour urine samples were analyzed by the same procedures as those used to analyze the flight samples. Hormone concentrations determined included cortisol, epinephrine, norepinephrine, aldosterone and antidiuretic hormone (ADH). In addition, volume, specific gravity, osmolarity, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), inorganic phosphate, uric acid and creatinine were measured. Performance was not affected by the Scopolamine/Dexedrine. The drug combination increased daily mean heart rate (HR) significantly in all the subjects and daily mean rectal temperature (RT) in some of the subjects. A 2-4 hr phase shift in the HR circadian rhythm was also observed which indicates that internal circadian synchrony was disturbed by the drugs. Psychological and subjective evaluation indicated that the subjects could usually identify which days they were given the drugs by an increase in tension and anxiety, decreased patience, restlessness, decreased appetite, difficulty in sleeping and feelings of increased heart rate and body temperature. Urinary electrolytes were not changed significantly by the drug, but marked and significant changes occurred in urine volume and hormone excretion patterns. Scopolamine/Dexedrine caused consistent elevations in urinary cortisol and epinephrine and a transient elevation in ADH. Norepinephrine excretion was decreased, but there was no significant change in aldosterone excretion or in 24 hr urine volume. A comparison of these findings with the first four days of inflight data from the SL-3 and SL-4 missions leads to the conclusion that the dramatic increases in aldosterone excretion during the first three days of spaceflight probably can be directly attributed to weightlessness, whereas the antimotion sickness medication could have substantially contributed to the early increased excretion of epinephrine and cortisol during these missions.
The purpose of this report is to describe some recent progress in applying scaling concepts to various systems in nature. We review several systems characterized by scaling laws such as DNA sequences, heartbeat rates and weather variations. We discuss the finding that the exponent alpha quantifying the scaling in DNA in smaller for coding than for noncoding sequences. We also discuss the application of fractal scaling analysis to the dynamics of heartbeat regulation, and report the recent finding that the scaling exponent alpha is smaller during sleep periods compared to wake periods. We also discuss the recent findings that suggest a universal scaling exponent characterizing the weather fluctuations.
The physiological system responsible for the temporal coordination of an organism is the circadian timing system (CTS). This system provides two forms of temporal coordination. First, the CTS provides for synchronization of the organism with the 24 hour period of the external environment. This synchronization of the organism with the environment is termed entrainment. Second, this system also provides for internal coordination of the various physiological, behavioral, and biochemical events within the organism. When either of these two temporal relationships are disturbed, various dysfunctions can be manifest within the organism. Homeostatic capacity of other physiological systems may be reduced. Performance is decreased and sleep disorders, mental health impairment (e.g., depression), jet lag syndrome, and shift work maladaptation frequently occur. Over the last several years, several studies have evaluated the potential influence of gravity on this physiological control system by examining changes in rhythmic characteristics of organisms exposed to altered gravitational environments. The altered gravitational environments have included the microgravity of spaceflight as well as hyperdynamic fields produced via centrifugation.
The daily rhythm of melatonin influences multiple physiological measures, including sleep tendency, circadian rhythms, and reproductive function in seasonally breeding mammals. The biological signal for photoperiodic changes in seasonally breeding mammals is a change in the duration of melatonin secretion, which in a natural environment reflects the different durations of daylight across the year, with longer nights leading to a longer duration of melatonin secretion. These seasonal changes in the duration of melatonin secretion do not simply reflect the known acute suppression of melatonin secretion by ocular light exposure, but also represent long-term changes in the endogenous nocturnal melatonin episode that persist in constant conditions. As the eyes of totally blind individuals do not transmit ocular light information, we hypothesized that the duration of the melatonin secretory episode in blind subjects would be longer than those in sighted individuals, who are exposed to light for all their waking hours in an urban environment. We assessed the melatonin secretory profile during constant posture, dim light conditions in 17 blind and 157 sighted adults, all of whom were healthy and using no prescription or nonprescription medications. The duration of melatonin secretion was not significantly different between blind and sighted individuals. Healthy blind individuals after years without ocular light exposure do not have a longer duration of melatonin secretion than healthy sighted individuals.
BACKGROUND: The concentration of C-reactive protein (CRP) in otherwise healthy subjects has been shown to predict future risk of myocardial infarction and stroke. CRP is synthesized by the liver in response to interleukin-6, the serum concentration of which is subject to diurnal variation. METHODS: To examine the existence of a time-of-day effect for baseline CRP values, we determined CRP concentrations in hourly blood samples drawn from healthy subjects (10 males, 3 females; age range, 21-35 years) during a baseline day in a controlled environment (8 h of nighttime sleep). RESULTS: Overall CRP concentrations were low, with only three subjects having CRP concentrations >2 mg/L. Comparison of raw data showed stability of CRP concentrations throughout the 24 h studied. When compared with cutoff values of CRP quintile derived from population-based studies, misclassification of greater than one quintile did not occur as a result of diurnal variation in any of the subjects studied. Nonparametric ANOVA comparing different time points showed no significant differences for both raw and z-transformed data. Analysis for rhythmic diurnal variation using a method fitting a cosine curve to the group data was negative. CONCLUSIONS: Our data show that baseline CRP concentrations are not subject to time-of-day variation and thus help to explain why CRP concentrations are a better predictor of vascular risk than interleukin-6. Determination of CRP for cardiovascular risk prediction may be performed without concern for diurnal variation.
Gravity appears to alter thermoregulation through changes in both the regulated level of body temperature and the rhythmic organization of temperature regulation. Gravity has been hypothesized to have an associated metabolic cost. Increased resting energy expenditure and dietary intake have been observed in animals during centrifuge experiments at hypergravity. Thus far, only animals have shown a corresponding reduction in metabolism in microgravity. Altered heat loss has been proposed as a response to altered gravitational environments, but remains documented only as changes in skin temperature. Changes in circadian timing, including the body temperature rhythm, have been shown in both hypergravity and microgravity, and probably contribute to alterations in sleep and performance. Changes in body temperature regulation may result from circadian disturbance, from the direct or indirect actions of gravity on the regulated temperature, or from changes in thermoregulatory effectors (heat production and heat loss) due to altered gravitational load and convective changes. To date, however, we have little data on the underlying thermoregulatory changes in altered gravity, and thus the precise mechanisms by which gravity alters temperature regulation remain largely unknown.