Pigeons' preference for variable-interval water reinforcement under widely varied water budgets.

Water budget of pigeons was varied to assess the dependence of risk-sensitive preferences upon economic context such as has been reported for energy-budget manipulations with small animals in behavioral ecology research. Fixed- and variable-interval terminal-link water schedules reinforced choice between equal variable-interval initial-link schedules arranged on two pecking keys. While keeping a severely restrictive budget the same across three phases of the experiment, a contrasting distinct ample budget was arranged in each. To mimic typical methods in behavioral ecology studies, in each ample budget a more than three-fold increase in amount of water per reinforcer presentation was instituted simultaneously with significantly increased overall access to water. Total choice response rates plummeted in the ample budgets, and body weights either increased significantly or remained unchanged in different phases as expected by the nature of the different manipulations. Clear preferences for the variable-interval schedule were found throughout the experiment, except for rare instances of key bias. The results agree with similar operant food-reinforcement studies and extend conditions under which risk preference apparently does not depend upon economic context.     

On the low-frequency vibrational spectrum of water

A new assignment is proposed for the low-frequency region of the vibrational spectrum of water, based on a comparison of the times of relevant occurring events. The time-matching is made between the dynamics of the rupture and formation time of the hydrogen bond, and the so-called bending and stretching oscillation periods of the O–H ··· O tetrahedral network. The same assignment also emerges by comparing thermal and solute concentration effects. Furthermore, a critical re-examination of the literature already existing on the subject corroborates the now proposed assignments for the modes at 60 and 170 cm^?1. These are considered to arise first from a transverse acoustic phonon with a low-frequency contribution sensitive to temperature and concentration effects, and second from external motions such as translations or restricted rotations of small water clusters inside a cage, and subjected to its potential field.     

“上善若水”之我见

“上善若水”是道祖老子指导人们修身养性、为人处世、治国平天下的至理名言。何谓“上善”?“上善”是老子理想中最具备完美品德的圣人。道教圣典《道德经》八章中,老子形象地用自然界最不可少的,而最柔弱不争的水之品性来喻圣人之德行,正是因为“水善利万物而不争”,“处众人     

Human responses to various conditions of water temperature

Skin-surface temperatures on thehuman hand were obtained immediately following six exposure times ranging from 5 to 60 sec. for water temperatures varying in 5° increments from 10° to 40°C. The surface of the skin was found to respond rapidly and regularly to both the temperature and time of exposure. In a second study 30 Ss exposed a hand for 5 or 30 sec. to water temperatures ranging from 10° to 45°C. and made ratings on scales of pain and comfort as well as attaching a verbal label (cold, cool, tepid, etc.) to each experience. The experience of cold became more intense over these time intervals while the experience of warmth became less, and with the threshold constant taken into account the sensations of pain and discomfort were found to follow a psychophysical power law. The usefulness of these sorts of data for interpreting the effects of noxious stimuli in basic learning studies is discussed.