Joseph Gale

The Effect of Heat and Salinity Stress on the Carbon Balance of Xanthium strumarium

Photosynthesis and respiration of control and salinised (−0.5 MPa, NaCl) Xanthium strumarium plants were measured throughout the day at different temperatures. Maintenance respiration (Rm) was calculated.

An interactive microcomputer program for calculation of combined parenteral and enteral nutrition for neonates.

A responsive, iterating program is described (available on diskette from first author), which enables the physician to formulate a balanced, total parenteral nutrition (TPN) for low-birth-weight and sick newborns. The program allows for the possibility of TPN or simultaneous intravenous, intraarterial, and oral feeding. It calculates the overall balance of fluids, nutrients, calories, electrolytes, minerals, trace elements, and vitamins. It features the integration of algorithms and limit tests of nutritional balance, to produce a feeding program that can be modified by clinical considerations of the physician, specific for each patient. The entire procedure can be accomplished, and a record of the entries and orders to the pharmacy and to the ward staff printed, within about 4-5 min. The program, which is written in BASIC, can be accommodated within and operated with a 16K byte microcomputer, equipped with a monitor, a printer, and a diskette or other program storage device.

The Potential of Planets Orbiting Red Dwarf Stars to Support Oxygenic Photosynthesis and Complex Life

We review the latest findings on extra-solar planets and their potential to support Earth-like life. Focusing on planets orbiting Red Dwarf (RD) stars, the most abundant stellar type, we show that including RDs as potential host stars could increase the probability of finding biotic planets by a factor of up to a thousand, and reduce the estimate of the distance to our nearest biotic neighbor by up to 10. We argue that binary and multiple star systems need to be taken into account when discussing exoplanet habitability. Early considerations indicated that conditions on RD planets would be inimical to life, as their Habitable Zones (where liquid water could exist) would be so close as to make planets tidally locked to their star. This was thought to cause an erratic climate and expose life forms to flares of ionizing radiation. Recent calculations show that these negative factors are less severe than originally thought. It has been argued that the lesser photon energy of the radiation of the relatively cool RDs would not suffice for Oxygenic Photosynthesis (OP) and other related energy expending reactions. Numerous authors suggest that OP on RD planets may evolve to utilize photons in the infrared. We however argue, by analogy to the evolution of OP and the environmental physiology and distribution of land-based vegetation on Earth, that the evolutionary pressure to utilize infrared radiation would be small. This is because vegetation on RD planets could enjoy continuous illumination of moderate intensity, containing a significant component of photosynthetic 400-700 nm radiation. We conclude that conditions for OP could exist on RD planets and consequently the evolution of complex life might be possible. Furthermore, the huge number and the long lifetime of RDs make it more likely to find planets with photosynthesis and life around RDs than around solar type stars.

Impact of the respiration of ornamental flowers on the composition of the atmosphere in hospital wards

SummaryOrnamental flowers were sampled in hospital wards and their respiration rates measured. We calulated the maximum possible contribution of the flowers to the CO2 and O2 content of the ward air, during an eight hour night. Only 1.6% of the CO2 increment in the ward air during the night (estimated to increase under most unfavourable conditions from 0.03 to 0.37% v.v.) was estimated to result from the presence of the flowers. The depletion of oxygen due to the flowers was calculated to be likewise negligible. Actual measurements of CO2 in the ward air in the early hours of the morning showed CO2 concentrations below 0.1%. It is concluded that nightly removal of ornamental flowers is not justified by their effect on the composition of the ward atmosphere.