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PubMedDate not supplied

Space analogue studies in Antarctica.

Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

Adaptation, Psychological↗

PubMedDate not supplied

Human interactions in space: results from Shuttle/Mir.

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth have suggested that space crewmembers may experience decrements in their interpersonal environment over time and may displace tension and dysphoria to mission control personnel. METHODS: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from subscales of the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis before, during, and after the missions. RESULTS: Among the crewmembers, there was little evidence for significant time effects based on triphasic (U-shaped) or linear models for the 21 subscales tested, although the presence of an initial novelty effect that declined over time was found in three subscales for the astronauts. Compared with work groups on Earth, the crewmembers reported less dysphoria and perceived their crew environment as more constraining, cohesive, and guided by leadership. There was no change in ratings of mood and interpersonal environment before, during, and after the missions. CONCLUSIONS: There was little support for the presence of a moderate to strong time effect that influenced the space crews. Crewmembers perceived their work environment differently from people on Earth, and they demonstrated equanimity in mood and group perceptions, both in space and on the ground. Grant numbers: NAS9-19411.

Adaptation, Psychological↗

PubMed1997

Deviance among expeditioners: defining the off-nominal act through space and polar field analogs.

The space venture resembles other extreme environmental exploration in many respects. Since the beginning of the space program, social and behavioral scientists have predicted that space crews increasingly will begin to experience the kinds of deviant behaviors seen in other extreme environmental duty settings as mission duration, crew size, and heterogeneity increases. However, there has been a long history of neglect by the nation's space agency of those psychosocial human factors which will play such a vital role in future manned spaceflight. The author argues that this is counterproductive, even dangerous, and that social and behavioral studies must be conducted to generate baseline data regarding dysfunctional acts in extreme environments, including the milieu of the space mission. An obstacle to studying occurrences and frequencies of deviant acts is the absence of a standardized definition of such acts in the extreme environment. Borrowing the sanitized NASA term "off-nominal", which generally refers to a maladaptive action, a preliminary reliability test was conducted among five scientists who work with human interaction in extreme environments. They were asked to rate situations from several actual space and polar expeditions for numbers of off-nominal acts. They were told the object of the exercise was to derive a standardized definition and were not provided with any specific definition of off-nominality. Substantial agreement in their ratings provided reliable information to construct a working definition of off-nominality. Various interactions and behaviors which respondents deemed off-nominal could be subsumed under poor expertise, mental disorder, forms of abuse and interpersonal insensitivity, problems of authority and responsibility, task deficits, poor hygiene and fitness, poor field-base communication, and human error with equipment from violating safety procedures and poor judgment as to its usage.

Adaptation, Psychological↗

PubMed1995

Effects of carbon dioxide level and plant density on cowpea canopy productivity for a bioregenerative life support system.

Plant density and atmospheric carbon dioxide level were manipulated to optimize productivity of cowpea [Vigna unguiculata (L.) Walp] for future use in a space-deployed Controlled Ecological Life Support System. Cowpea breeding line IT87D-941-1 was grown at plant densities of 3.6, 7.2, 10.7, or 14.3 plants m-2 in a growth chamber maintained at 400 (control) or 1200 (elevated) micromoles CO2 mol-1. Both green leaves and dried seeds were harvested as edible yield. Crop productivity was measured by edible yield rate (EYR), harvest index (HI), yield efficiency rate (YER), energy efficiency, and net photosynthesis (Pn). Increasing plant density within a canopy tended to increase EYR, but decreased HI and YER. Elevated CO2 also increased EYR, but decreased HI and YER as well. However, when the energy penalty for crop production was taken into consideration, cowpea crops grown under elevated CO2 were more productive than those grown at control CO2. Pn averaged 15 micromoles CO2 m-2 s-1 for cowpeas grown at 400 micromoles CO2 mol-1. Low Pn at the beginning and end of the cropping cycle indicated waste of high irradiance lighting during those times.

Agriculture↗

PubMed2001

Psychosocial issues in long-term space flight: overview.

Anecdotal evidence of the individual and interpersonal problems that occurred during the Shuttle-Mir Space Program (SMSP) and other long-duration Russian/Soviet missions, and studies of personnel in other isolated and confined extreme (ICE) environments suggest that psychosocial elements of behavior and performance are likely to have a significant impact on the outcome of long-duration missions in space. This impact may range from individual decrements in performance, health and well being, to catastrophic mission failure. This paper reviews our current understanding of the psychosocial issues related to long duration space missions according to three different domains of behavior: the individual domain, the interpersonal domain and the organizational domain. Individual issues include: personality characteristics that predict successful performance, stress due to isolation and confinement and its effect on emotions and cognitive performance, adaptive and maladaptive coping styles and strategies, and requirements for the psychological support of astronauts and their families during the mission. Interpersonal issues include: impact of crew diversity and leadership styles on small group dynamics, adaptive and maladaptive features of ground-crew interactions, and processes of crew cohesion, tension and conflict. Organizational issues include: the influence of organizational culture and mission duration on individual and group performance, and managerial requirements for long duration missions. Improved screening and selection of astronaut candidates, leadership, coping and interpersonal skills training of personnel, and organizational change are key elements in the prevention of performance decrements on long-duration missions.

Adaptation, Psychological↗

PubMed2002

Nutrition and renal stone disease in space.

There is a growing body of evidence from the National Aeronautics and Space Administration and the Russian space program showing that humans exposed to the microgravity environment of space have a greater risk for developing renal stones. Increased bone resorption and the attendant hypercalciuria and hyperphosphaturia contribute significantly to raising the urinary state of saturation with respect to the calcium salts, namely calcium oxalate and calcium phosphate. In addition, other environmental and dietary factors may adversely affect urine composition and increase stone formation risk during space flight. For example, reductions in urinary volume, pH, and citrate contribute to raising stone formation risk. In addition to raising the risk for calcium stone formation, this metabolic profile is conducive to the formation of uric acid stones. Although observations to date have suggested that there may actually be a reduced food intake during the early phase of flight, crew members on longer-duration flights may increase food intake and be at increased risk for stone formation. Taken together, these findings support the use of nutritional recommendations for crew members that would serve to reduce the stone-forming propensity of the urinary environment. Pharmacologic intervention should be directed at raising urinary volumes, diminishing bone losses, and preventing reductions in urinary pH and citrate. Success in reducing the risk for stone formation in astronauts would also be of potential major benefit to the estimated 20 million Americans with nephrolithiasis.

Aerospace Medicine↗

PubMed2005

Exercise and pharmacological countermeasures for bone loss during long-duration space flight.

Bone loss in the lower extremities and lumbar spine is an established consequence of long-duration human space flight. Astronauts typically lose as much bone mass in the proximal femur in 1 month as postmenopausal women on Earth lose in 1 year. Pharmacological interventions have not been routinely used in space, and countermeasure programs have depended solely upon exercise. However, it is clear that the osteogenic stimulus from exercise has been inadequate to maintain bone mass, due to insufficient load or duration. Attention has therefore been focused on several pharmacological interventions that have been successful in preventing or attenuating osteoporosis on Earth. Anti-resorptives are the class of drugs most commonly used to treat osteoporosis in postmenopausal women, notably alendronate sodium, risedronate sodium, zoledronic acid, and selective estrogen receptor modulators, such as raloxifene. There has also been considerable recent interest in anabolic agents such as parathyroid hormone (PTH) and teriparatide (rhPTH [1-34]). Vitamin D and calcium supplementation have also been used. Recent studies of kindreds with abnormally high bone mineral density have provided insight into the genetic regulation of bone mass. This has led to potential therapeutic interventions based on the LRP5, Wnt and BMP2 pathways. Another target is the RANK-L/osteoprotegerin signaling pathway, which influences bone turnover by regulating osteoclast formation and maturation. Trials using such therapies in space are being planned. Among the factors to be considered are dose-response relationships, bone quality, post-use recovery, and combination therapies--all of which may have unique characteristics when the drugs are used in space.

Aerospace Medicine↗

PubMed1996

The nutritional adequacy of a limited vegan diet for a Controlled Ecological Life-Support System.

Purdue University, as well as the Johnson and Kennedy Space Centers and NASA Ames Research Center, are investigating approximately 5-10 plants that will be grown hydroponically to provide not only the energy and nutrients, but also the oxygen for humans habitating in Mars and lunar bases. The growth and nutritional status of rats fed either a control diet (adequate in all macro- and micronutrients) or a strict vegetarian diet consisting of 5 (vegan-5) or 10 (vegan-10) candidate crop species were investigated. In addition, vegan-10 diets were supplemented with mineral and/or vitamin mix at a level similar to the control diets to assess the effect of supplementation on nutrient status. The assessment of inedible plant material as an alternative food source was also investigated. Results of this study demonstrated that consumption of the vegan-10 diet significantly improved weight gain of rats compared to that for rats fed the vegan-5 diet. Mineral supplementation, at a level present in the control diet, to the vegan-10 diet improved growth and nutrient status, but growth was significantly lower compared to the control-fed rats. Inclusion of inedible plant material, high in ash content, improved some indices of nutrient status, without improving growth.

Animals↗

PubMed1996

Musculoskeletal adaptations to weightlessness and development of effective countermeasures.

A Research Roundtable, organized by the American College of Sports Medicine with sponsorship from the National Aeronautics and Space Administration, met in November 1995 to define research strategies for effective exercise countermeasures to weightlessness. Exercise was considered both independently of, and in conjunction with, other therapeutic modalities (e.g., pharmacological nutritional, hormonal, and growth-related factors) that could prevent or minimize the structural and functional deficits involving skeletal muscle and bone in response to chronic exposure to weightlessness, as well as return to Earth baseline function if a degree of loss is inevitable. Musculoskeletal deficits and countermeasures are described with respect to: 1) muscle and connective tissue atrophy and localized bone loss, 2) reductions in motor performance, 3) potential proneness to injury of hard and soft tissues, and 4) probable interaction between muscle atrophy and cardiovascular alterations that contribute to the postural hypotension observed immediately upon return from space flight. In spite of a variety of countermeasure protocols utilized previously involving largely endurance types of exercise, there is presently no activity-specific countermeasure(s) that adequately prevent or reduce musculoskeletal deficiencies. It seems apparent that countermeasure exercises that have a greater resistance element, as compared to endurance activities, may prove beneficial to the musculoskeletal system. Many questions remain for scientific investigation to identify efficacious countermeasure protocols, which will be imperative with the emerging era of long-term space flight.

Adaptation, Physiological↗

PubMed2000

Error, stress, and teamwork in medicine and aviation: cross sectional surveys.

OBJECTIVES: To survey operating theatre and intensive care unit staff about attitudes concerning error, stress, and teamwork and to compare these attitudes with those of airline cockpit crew. DESIGN: : Cross sectional surveys. SETTING: : Urban teaching and non-teaching hospitals in the United States, Israel, Germany, Switzerland, and Italy. Major airlines around the world. PARTICIPANTS: : 1033 doctors, nurses, fellows, and residents working in operating theatres and intensive care units and over 30 000 cockpit crew members (captains, first officers, and second officers). MAIN OUTCOME MEASURES: : Perceptions of error, stress, and teamwork. RESULTS: : Pilots were least likely to deny the effects of fatigue on performance (26% v 70% of consultant surgeons and 47% of consultant anaesthetists). Most pilots (97%) and intensive care staff (94%) rejected steep hierarchies (in which senior team members are not open to input from junior members), but only 55% of consultant surgeons rejected such hierarchies. High levels of teamwork with consultant surgeons were reported by 73% of surgical residents, 64% of consultant surgeons, 39% of anaesthesia consultants, 28% of surgical nurses, 25% of anaesthetic nurses, and 10% of anaesthetic residents. Only a third of staff reported that errors are handled appropriately at their hospital. A third of intensive care staff did not acknowledge that they make errors. Over half of intensive care staff reported that they find it difficult to discuss mistakes. CONCLUSIONS: Medical staff reported that error is important but difficult to discuss and not handled well in their hospital. Barriers to discussing error are more important since medical staff seem to deny the effect of stress and fatigue on performance. Further problems include differing perceptions of teamwork among team members and reluctance of senior theatre staff to accept input from junior members.

Attitude↗