Behavior and adrenal physiology of Magellanic penguins (Spheniscus magellanicus) serving as ambassador animals

Ambassador animals are part of many zoo programs, but studies assessing their impact on these animals are relatively rare. This study validated an excrement glucocorticoid metabolite (GCM) assay for Magellanic penguins and used GCM measures in conjunction with behavioral observations to evaluate individual responses to participation in an ambassador animal program. Excrement samples and behavioral observations were collected daily from each bird during two phases, 1 week during which it participated in a twice-daily ambassador program and 1 week in which it did not. We found no differences in GCMs between phases or in comparisons between penguins with 5 or 10 years of program experience. GCM also did not show significant individual variation and did not increase over time during the program phase. There were no significant correlations between bird experience and behavior frequencies, nor GCM concentrations and behavior, across birds. We observed significant positive correlations between the penguins' engagement with novel objects during programs and their unguided approach to guests. Our results suggest that there is no adverse physiological effect of program participation on these penguins, that behavioral and physiological responses may be decoupled, and that choice and control can increase desired behaviors behavior during ambassador programs.     

Thermal behavior of HeLa and KB cells in suspension and attached to glass

HeLa S-3 and KB cells were grown in a LKB Batch Microcalorimeter under a variety of nutrient medium conditions and mixing intervals. These conditions produced rather large apparent endothermic and exothermic responses on mixing that could be correlated with the presence of suspended cells (unattached) as well as cells attached to the glass calorimeter vessel. Cells capable of being resuspended upon mixing of the calorimeter vessel produces first an endothermic followed by an exothermic signal while attached cells produced only an apparent endothermic response. The exothermic response is believed to be associated with increased metabolic heat on suspending the cells followed by partial suppression of the steady state metabolic heat on cell settling. Rates of cell settling correlated well with the rate of decay of the exothermic signal. The rapid appearance of endothermicity on mixing suggests it is associated with rapid events such as binding of nutrients to cell surfaces. The response in the endothermic direction on mixing is discussed in terms of the disruption of mechanisms which tend to exclude nutrients from the surface of the cell.     

Egg albumin embedding: A procedure compatible with neurological staining techniques

A water-soluble embedding medium for frozen sections of central nervous system and peripheral nerves which will tolerate on-the-slide alcohol dehydration, xylene clearing and synthetic resin mounting can be prepared by dissolving 20 gm of powdered egg albumin in 30 ml of distilled water. Formalin-fixed, thoroughly washed tissue is immersed in the albumin solution for several hours and then embedded in it. For embedding, a two-layered box is constructed with an inner layer of vegetable parchment paper. This is supported by an outer layer of aluminum foil with 6-8 perforations about 0.5 nun in diameter in its bottom. Hardening of the tissue-albumin block is achieved by formalin dialysis through the parchment paper when the box is stood for 24-48 hr in a layer of 25% formalin that wets only the bottom of the box. Frozen sections from such blocks are compatible with Nauta silver impregnations for degenerating axons, Cajal's gold chloride-sublimate for astrocytes and Pen-field's modified silver carbonate for oligodendroglia and microglia. These, as well as Nissl and myelin sheath preparations show minimal shrinkage and distortion.