The minimal cost of life in space.

The cost of keeping people alive in space is assessed from a theoretical viewpoint and using two actual designs for plant growth systems. While life support is theoretically not very demanding, our ability to implement life support is well below theoretical limits. A theoretical limit has been calculated from requirements and the state of the art for plant growth has been calculated using data from the BIO-Plex PDR and from the Cornell CEA prototype system. The very low efficiency of our current approaches results in a high mission impact, though we can still see how to get a significant reduction in cost of food when compared to supplying it from Earth. Seeing the distribution of costs should allow us to improve our current designs.

Waste system implications for Mars missions.

Waste technologies for Mars missions have been analyzed, considering equivalent system mass and interface loads. Storage or dumping seems most appropriate for early missions with low food closure. Composting or other treatment of inedible biomass in a bioreactor seems most attractive for moderate food closure (50-75%). Some form of physicochemical oxidation of the composted residue might be needed for increased food closure, but oxidation of all waste does not seem appropriate due to excess of production of carbon dioxide over demand. More comprehensive analysis considering interfaces with other mission systems is needed. In particular, in-situ resource utilization is not considered, and might provide resources more cheaply than waste processing.

Life support approaches for Mars missions.

Life support approaches for Mars missions are evaluated using an equivalent system mass (ESM) approach, in which all significant costs are converted into mass units. The best approach, as defined by the lowest mission ESM, depends on several mission parameters, notably duration, environment and consequent infrastructure costs, and crew size, as well as the characteristics of the technologies which are available. Generally, for the missions under consideration, physicochemical regeneration is most cost effective. However, bioregeneration is likely to be of use for producing salad crops for any mission, for producing staple crops for medium duration missions, and for most food, air and water regeneration for long missions (durations of a decade). Potential applications of in situ resource utilization need to be considered further.

Families need help too: group treatment for families of nursing home residents.

Despite long-standing interest in the family as the focal point of nursing care, there are few published reports of clinical interventions with families after they institutionalize an elderly relative. Family members experience loss, guilt, and grief, and report that these emotions continue throughout the time that their older member is in the nursing home. This paper presents the rationale for using a supportive, educational group approach with families of nursing home residents and describes a family group intervention, detailing the role of the geriatric mental health nurse specialist, group goals, and the focus of each session. Evaluations by families and staff are presented, and recommendations for practice are made.

Speech recognition with dynamic range reduction: (1) deaf and normal subjects in laboratory conditions.

Processing to reduce the dynamic range of speech should increase intelligibility and protect the impaired ear from overloading. There are theoretical and practical objections to using AGC devices to reduce dynamic range. These are overcome by using recently available signal processing employing high frequency carrier clipping. An increase in intelligibility of speech with this HFCC has been demonstrated, for normal subjects with simulated deafness, and for most partially hearing patients. Intelligibility is not improved for some patients; possibly due to their having learned to extract features which are lost. These patients may also benefit after training.