Early and late damages induced by heavy charged particle irradiation in embryonic tissue of Arabidopsis seeds.

Early and late effects of accelerated heavy ions (HZE) on the embryonic tissue of Arabidopsis thaliana seeds were investigated seeing that initial cells of the plant eumeristems resemble the original cells of animal and human tissues with continuous cell proliferation. The endpoints measured were lethality and tumorization in the M1-generation for early effects and embryonic lethality in the M2-generation for late effects. The biological endpoints are plotted as functions of the physical parameters of the irradiation i.

Ureteral stone extraction with the Steffens lasso loop. A neglected procedure.

The main advantages of the Steffens lasso loop are its olive-tipped, 45 degrees-angled Tiemann guide, which allows easier and less traumatic passage above the ureteral stone, the tri-part lasso, which affords a better grasp of the stone, and the outlet for urine drainage. Between 1976 and 1986 we used this loop in 560 of 919 patients with distal ureteral stones. Immediate stone extraction was possible in 85.

[Treatment of female urinary stress incontinence with a Zoedler suspension-plasty and a new, stable, radiopaque polyester sling].

We report on 183 patients with urinary stress incontinence treated with bladder-neck suspension plasty according to Zoedler from 1972-1982 using the conventional nylon sling. 86.1% of the patients were continent postoperatively.

Genetic and physiological damage induced by cosmic radiation on dry plant seeds during space flight.

Total evaluation of cosmic radiation effect with or without discrimination of individualized HZE-ion effects in dry Arabidopsis seeds flown for 10 days on STS-9, yielded significant evidence for radiation damage in space. They depend on the biological criteria tested (seed germination, morphogenesis, embryo lethality, mutation rate) which stand for early, physiological and late genetic effects. They are also related to the radiation shielding environment in the space shuttle.

Biological effects of heavy ions in Arabidopsis seeds.

Irradiation of dry seeds of Arabidopsis with heavy ions (HZE-particles) produced by UNILAC-accelerator (GSI, Darmstadt) yielded aberrations in varied developmental endpoints such as survival rate and embryo vitality. The damage increased with particle density and charge. Cross sections in the range of 0.

Life sciences: radiobiological advanced biostack experiment.

The radiobiological properties of the heavy ions of cosmic radiation were investigated on Spacelab 1 by use of biostacks, monolayers of biological test organisms sandwiched between thin foils of different types of nuclear track detectors. Biostacks were exposed to cosmic radiation at several locations with different shielding environments in the module and on the pallet. Evaluations of the physical and biological components of the experiment to date indicate that in general they survived the spaceflight in good condition.

Advanced biostack: experiment 1 ES 027 on Spacelab-1.

The radiobiological properties of the heavy ions of cosmic radiation were investigated on Spacelab 1 by use of biostacks, monolayers of biological test organisms sandwiched between thin foils of different types of nuclear track detectors. Biostacks were exposed to cosmic radiation at several locations with different shielding environments in the module and on the pallet. Evaluations of the physical and biological components of the experiment to date indicate that in general they survived the spaceflight in good condition.

Karyotype analysis in meiosis: Giemsa banding in the genus Secale L.

Terminal bands of meiotic chromosomes stained by the Giemsa technique are permanent genetic structures of the nucleus during PMC differentiation in 8 samples of wild, primitive, and cultivated species of rye. The characteristic meiotic banding pattern is probably identical with the heterochromatic regions of mitotic chromosomes of root meristem cells (RMC) which have so far been studied. Karyotype analysis can be significantly improved by quantitative studies of the number and size of the bands combined with certain well-known chromosome characters in diplotene and diakinesis.

[Physiological genetics of quantitative characters in Arabidopsis thaliana (L.) Heynh. : Part 3. Dauermodifications of pleiotropic effects of homoallelic genes].

The genephysiological and developmental basis of "Dauermodifications" (DM) have still not been explained. In particular definite evidence for DM in plastids is lacking up to now. Moreover no attention has been paid to the connections with the problem of quantitative gene effects.

[Physiological genetics of quantitative characters in Arabidopsis thaliana (L.) Heynh. : Part 2: Modification of primary and secondary genetic effects of single-gene chlorophyll-b mutants by long-wave irradiation].

An analysis of the quantitative molecular effects of genes requires information on the norm of reaction ("Reaktionsnorm") and on its variability in the genotype tested. 1) Experiments were carried out in an automatically controlled growth chamber to determine the optimal conditions for the norm of reaction of the plants to be tested. Genotypically determined variances between the characters studied and differences of means between test samples were most frequently significant when the growth conditions were those of an intermittent 16 hour day.

[Physiological genetics of quantitative characters in Arabidopsis thaliana (L.) Heynh. : Part 1: segregation and biosynthesis of pigments in chlorophyll-b defect mutants].

In biometric studies on the genetics of quantitative characters the problem of regulation of the activity of genes is rarely considered. Mutants of Arabidopsis thaliana (L.) Heynh.