The effect of lake restoration measures on the physical,chemical and phytoplankton variables of Lake Bled

Monthly changes of physical, chemical and biological variables due a combination of artificial inflow of clean water, removal of hypolimnetic water, and diversion of sewage were studied in Lake Bled from December 1980 to December 1982.During the winter period 1981/82 the species composition of the phytoplankton changed. New species replaced those observed in previous years. We conclude that the combined effect of these three lake restoration measures was responsible for the sudden disappearance ofOscillatoria rubescens D.C. A marked decrease in some nutrients and an increase in temperature and oxygen concentration also occurred.     

Bioconversion of steroid glycosides by Nocardia restricta

The bioconversion of steroid alkaloid tomatine by Nocardia restricta yields the conjugate with lactic acid. We studied the bioconversion of some steroid glycosides without a nitrogen atom in the molecule to determine the effect of the nitrogen atom. The glycosides were of three different types: sterol glycosides, bufadienolide rhamnoside and steroid saponine. The results of bioconversions showed that Nocardia restricta converts steroid glycosides differently according to the sugar bound to the steroid aglycone. It can be concluded that in the absence of a nitrogen atom in the steroid molecule no conjugation with lactic acid by Nocardia restricta occurs.     

Analysis of standing up and sitting down in humans: definitions and normative data presentation

A formal definition of human standing up and sitting down movements based on sagittal plane goniometric and force plate data from 20 normal subjects is presented. This definition is comparable to the established gait cycle diagram, and consists of defined characteristic events and relative time intervals between them. The characteristic events are selected primarily on changes in ground reaction forces. The terminology proposed may be valuable for introducing more formalized and standardized reporting of both qualitative and quantitative studies in both normals and in patients. This presentation is directed toward the process of defining generally acceptable standards for human standing up and sitting down movements.     

Phylogeny of Greya (Lepidoptera: Prodoxidae), based on nucleotide sequence variation in mitochondrial cytochrome oxidase I and II: congruence with morphological data

The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from nucleotide sequence variation across a 765-bp region in the cytochrome oxidase I and II genes of the mitochondrial genome. Most parsimonious relationships of 25 haplotypes from 16 Greya species and two outgroup genera (Tetragma and Prodoxus) showed substantial congruence with the species relationships indicated by morphological variation. Differences between mitochondrial and morphological trees were found primarily in the positions of two species, G. variabilis and G. pectinifera, and in the branching order of the three major species groups in the genus. Conflicts between the data sets were examined by comparing levels of homoplasy in characters supporting alternative hypotheses. The phylogeny of Greya species suggests that host-plant association at the family level and larval feeding mode are conservative characters. Transition/transversion ratios estimated by reconstruction of nucleotide substitutions on the phylogeny had a range of 2.0-9.3, when different subsets of the phylogeny were used. The decline of this ratio with the increase in maximum sequence divergence among taxa indicates that transitions are masked by transversions along deeper internodes or long branches of the phylogeny. Among transitions, substitutions of A-->G and T-->C outnumbered their reciprocal substitutions by 2-6 times, presumably because of the approximately 4:1 (77%) A+T-bias in nucleotide base composition. Of all transversions, 73%-80% were A<-->T substitutions, 85% of which occurred at third positions of codons; these estimates did not decrease with an increase in maximum sequence divergence of taxa included in the analysis. The high frequency of A<-->T substitutions is either a reflection or an explanation of the 92% A+T bias at third codon positions.