Regulation of the Oxidative Processes in the Organs of Mice under the Effects of Chemical and Physical Factors at Low Doses

Biophysics - The effects of the separate and combined action of lead nitrate in a wide range of doses, uranyl nitrate, and chronic low-dose gamma irradiation on the formation of oxidative stress in...     

Effect of TNF-α, IL-2, IL-5 and IL-6 on Rat Tracheal and Bronchial Smooth Muscle Contractions

Journal of Evolutionary Biochemistry and Physiology - The article addresses the role of TNF-α, IL-2, IL-5 and IL-6 in the contractile activity of rat tracheal and bronchial smooth muscle...     

Restoring avian wing digits

The precise identification of the digits of the avian wing is of importance in evolutionary studies. If the digits are numbered two, three and four, this has been taken to suggest that birds are not descended directly from dinosaurs. If the digits are numbered one, two and three, dinosaur origins become more plausible. Studies of the development of the avian wing have failed to resolve this dilemma. However, in some instances, it is possible to deduce information about evolutionary morphologies by manipulating development experimentally. We grafted beads loaded with fibroblast growth factor 4 into the distal tip of chick wing buds at times when the apical ectodermal ridge is regressing. The consequence was that the cartilage structure conventionally labelled ''element 5'' increased dramatically in size and acquired a digit-like morphology in some instances. Corresponding changes in soft tissue morphology were also observed. We conclude that it may be possible to resolve the issue of avian digit homology by the induction of experimental atavisms of this kind.     

Cruoriella rhodoliths from shallow-water back reef environments in La Parguera, Puerto Rico (Caribbean Sea)

The occurrence of shallow-water (0.9 to 1.3 m) rhodoliths in back reef environments in southwest Puerto Rico is reported. The rhodoliths were generally cylindrical, discoidal or irregular in shape with an average longest dimension of 7.2 cm. They occurred at a maximum density of 524 m⁻². The rhodoliths were composed of mostly coral nuclei with concentric laminations of aragonite-producing Cruoriella armorica (Peyssonneliaceae, Rhodophyta). Maximum Cruoriella accretion around coral nuclei was 30 mm although accretions of 1 to 20 mm were more common. Based on measurements of Cruoriella accretion, these shallow water rhodoliths are estimated to have minimum ages of 12 to 24 years. It is further estimated that approximately 2% of the rhodoliths are turned over daily. Accepted: 1 October 1999     

Human Discrimination of the Angular Velocity of the Vertical Movement of an Acoustic Image in Opposite Directions

The discrimination of the angular velocity of ventrodorsal and dorsoventral movement of an acoustic image was studied in nine test subjects. The experiments were performed using an apparent movement produced by consecutive activation of loudspeakers located along an arc in the vertical plane. The differential thresholds were measured by the minimum increment method. As the velocity of an acoustic image movement in opposite directions increased, the values of its mean absolute differential thresholds increased monotonically. Regression lines plotted by linear approximation of these values did not differ significantly.     

Isolation and characterization of polymorphic microsatellite markers in the blowflies Lucilia illustris and Lucilia sericata

Thirteen polymorphic microsatellite loci were developed for blowflies for use in studies of genetic differentiation in wild populations of Lucilia illustris, to detect the possible occurrence of bottlenecks and to study changes in genetic variation in laboratory populations of Lucilia sericata following artificial bottlenecks. In this preliminary study it was revealed that heterozygosity was lower than expected in wild populations and genetic variation had been lost in the laboratory population despite being kept at a large size.