Evidence for a humoral factor mediating the effect of a pressure load on lysine incorporation in rabbit heart

The M1 and M2 isozymes of pyruvate kinase from several mammalian species were compared in their reactivity toward monoclonal anti-pyruvate kinase antibodies and by one and two-dimensional peptide mapping. Inter-species differences between the M2 isozymes were always accompanied by similar interspecies differences in the M1 isozymes, supporting the conclusion that these two isozymes are the products of the same gene.     

Differentiated ratings of perceived exertion at ventilatory threshold in children and adults

The purpose of this study was to examine overall, leg and chest ratings of perceived exertion (RPE) at ventilatory threshold (Th_vent) in 16 children (mean age 10.9 years) and 17 adults (mean age 24.3 years). Th_vent and maximum oxygen consumption (V˙O_{2 max} ) were measured during a graded exercise test on a cycle ergometer. Overall, leg and chest RPE were obtained at the end of each exercise stage. V˙O_{2 max} was 49.9 (8.5) and 47.1 (6.1) ml · kg⁻¹· min⁻¹ [mean (SD)] in the adults and children, respectively (P > 0.05). Relative to V˙O_{2 max} , Th_vent was 61.7 (5.3)% in the adults and 64.7 (5.2)% in the children (P > 0.05). Overall, leg, and chest RPE values at Th_vent for the adults were 11.5 (2.6), 11.9 (2.5), and 10.5 (2.5), while for the children these values were 13.6 (2.2), 14.1 (2.2), and 12.6 (2.3), respectively. All RPE values were higher for the children (P < 0.05). These results suggest that children are able to discriminate levels of exertion in different parts of their body during graded exercise. Furthermore, children rate an intensity corresponding to Th_vent to require a greater overall, leg and chest effort than adults exercising at a similar intensity. This indicates that children experience more pronounced cardiorespiratory and muscular sensations during this type of exercise. Accepted: 19 February 1998     

Preferences for paper bedding material of the laboratory mice.

In order to identify indicators of the preferences for bedding materials, the paper bedding material preferences of laboratory mice were investigated in the present study. Four cages, each containing a different structure of paper bedding material were connected to allow free access to each cage. The preferences for paper bedding materials of laboratory mice were judged by the differences in the length of stay and sleep in each cage. The mice preferred the bedding material that allowed them to easily hide and build nests and was soft. We conclude that the comfort and well-being of laboratory mice can be increased through the appropriate selection of bedding material.     

Study of kinetics of thermal aggregation of mitochondrial aspartate aminotransferase by dynamic light scattering: protective effect of α-crystallin

Thermal aggregation of aspartate aminotransferase from pig heart mitochondria (mAAT) has been studied at various temperatures and various protein concentrations by dynamic light scattering. The character of the dependence of protein aggregate size on time indicates that aggregation of mAAT proceeds in the regime of diffusion-limited cluster–cluster aggregation. Suppression of mAAT aggregation by α-crystallin is due to transition of the aggregation process into the regime of reaction-limited cluster–cluster aggregation. Realization of this regime of aggregation means that the sticking probability for the colliding particles is less than unity.     

Forest ecosystems of east and southeast Asia in a global perspective

Owing to the influence of the Tibeto-Himalayan Highland, the east-and southeastcoastal zone of the Asian continent lacks the subtropical dry belt, which elsewhere in the world separates temperate forest areas from the humid tropics. Thus forest climates with sufficient rainfall cover coastal areas of the Western Pacific from subarctic eastern Siberia to equatorial SE Asia, giving rise to a sequence of five forest formations. The warmtemperate evergreen (lucidophyll) forest formation is peculiar to this region and represents the east-coast counterpart of Mediterranean sclerophyll forest, which develops under the west-coast climate with a different pattern of seasonal rainfall distribution. The characteristics of the five formations and their latitudinal distribution were briefly described as being related to climatic environments. Certain ecosystem properties such as floristic diversity and the rate of organic matter decomposition were found to be very sensitive to thermal gradients, whereas the responses of plant biomass, primary productivity, etc. to changes in thermal climate were less apparent.