Zur Verbreitung der ABO-Blutgruppen in der Bevölkerung Nordthailands

2048 subjects in North Thailand were examined for AB0 blood groups. A control group representative of the population of the provinces of Chiengmai and Lampun was formed of 382 examinees and 3403 blood donors.The distribution of AB0 groups in this population is similar to that of Central Thailand. Some ethnic groups show significant deviations: The Miao tribe, originating in South China, has a much higher frequency of B. There was a significant reduction in gene A and B in the younger generation of this tribe. The Thai Yong, people who migrated to North Thailand from Yunnan in the 19th century, show an AB0 distribution similar to Chinese in Yunnan. They differ significantly from the Northern Thai. There is also a difference in the distribution of -thalassaemia and hemoglobin E between these two groups.Male leprosy patients showed an excess of group A which was not present in female patients. The percentage of severely ill patients was much higher in the males. Differentiation into lepromatous and tuberculid forms is not available. Among 108 people who had suffered from smallpox approximately 20 years ago there was an excess of groups 0 an B in comparison to the control group.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Burrowing,grooming, and feeding behaviour of Paraceradocus,an antarctic amphipod genus (Crustacea)

Summary Species of the amphipod genus Paraceradocus found near the Antarctic Peninsula were observed in aquaria. The animals live under stones in burrows in sediment which they excavate with their gnathopods. During burrowing the animal regularly turns backwards in a somersault-like movement. Paraceradocus feeds on detritus, which is manipulated by the gnathopods and the antennes. The gnathopods are also used for grooming. A dense brush of setae at the medial surface of the carpi of the gnathopods I is used to clean off fine particles from the antennes. These particles are transferred to the maxillipeds and are ingested. The rear appendages are mainly cleaned by the gnathopods II. Young animals sitting between the gnathopods of the adult participate in feeding.     

Simulated and measured nitrogen conditions in a manured and fertilised soil

The governing factors for soil nitrogen dynamics were identified with a simulation model. In addition, the model was used to interpret measurements from a plot fertilisation experiment in southwest Sweden.Simulated moisture and temperature conditions were the driving variables for the simulation of soil nitrogen dynamics and leaching during a 6-year period. The results of the simulation were compared with monthly observations on two plots with grain crops, one with liquid manure and commercial fertilisers applied and one with commercial fertilisers only.Simulated temporal variations of the nitrate and ammonium storages generally agreed with observations. The dominant role of the crops as a determinant of soil nitrogen conditions was demonstrated. A higher leaching loss from the plot with application of commerical fertilisers only occurred both in simulations and measurements compared to the plot with application of both commercial fertilisers and manure. The main reason was the higher N-application in the former treatment.The effect of water flows in macropores was interpreted as a delay of simulated leaching compared to observed leaching on some occasions in summer and early autumn. No direct effect of the macropores on the yearly rates of leaching could be seen.     

Uptake of phosphate from soils and fertilizers as affected by soil P availability and solubility of phosphorus fertilizers

Fertilizers labelled with ³²P were used to measure amounts of phosphorus, P_s and P_F, taken up by Lolium perenne from available soil P and from P fertilizer respectively, when applied at a rate of 66 mg P·(kg soil^–1) in greenhouse experiments. The quantity P_s of phosphorus taken up from soil in the presence of P fertilizer was compared to the quantity P_o taken up from soil without P fertilizer. The quantity (P_s–P_o) is positive for low P_o values, i.e. in soils poor in available phosphorus, but is negative for high P_o values indicating that an input of P fertilizer can induce a decrease in the utilization of available soil phosphorus. Moreover, for a given soil, the quantity (P_s–P_o) depends on the chemical form of the fertilizer. The standard method of evaluation of P fertilizer efficiency is based on the assumption that P_s=P_o, but P_s can differ from P_o. This result can explain the contradictory data published from field experiments about the efficiency of the various P fertilizers.     

Plasmid-determined resistance to arsenic and antimony inPseudomonas aeruginosa

Resistance to arsenic salts in aPseudomonas aeruginosa clinical isolate was shown to be determined by a 100 kb transferable plasmid. The resistance pattern included arsenate, arsenite, and antimonate ions. Arsenate and arsenite resistances were inducible by previous exposure of cultures to subinhibitory amounts of either of the two ions. Phosphate ions protectedP. aeruginosa cells from the toxic effects of arsenate but did not alter arsenite toxicity.     

Spontaneous hybridization between a male-sterile oilseed rape and two weeds

Spontaneous interspecific hybrids were produced under natural conditions (pollination by wind and bees) between a male-sterile cybrid Brassica napus (AACC, 2n = 38) and two weeds Brassica adpressa (AdAd, 2n = 14) and Raphanus raphanistrum (RrRr, 2n = 18). After characterization by chromosome counts and isozyme analyses, we observed 512 and 3 734 inter-specific seeds per m² for the B. napus-B. adpressa and B. napus-R. raphanistrum trials respectively. Most of the hybrids studied had the expected triploid structure (ACX). In order to quantify the frequency of allosyndesis between the genomes involved in the hybrids, their meiotic behavior was compared to a haploid of B. napus (AC). For the B. napus-B. adpressa hybrids, we concluded that probably no allosyndesis occurred between the two parental genomes, and that genetic factors regulating homoeologous chromosome pairing were carried by the B. adpressa genome. For the B. napus-R. raphanistrum hybrids, high chromosome pairing and the presence of multivalents (in 9.16% of the pollen mother cells) indicate that recombination is possible between chromosomes of different genomes. Pollen fertility of the hybrids ranged from 0 to 30%. Blackleg inoculation tests were performed on the three parental species and on the interspecific hybrids. BC₁ production with the weeds and with rapeseed was attempted. Results are discussed in regard to the risk assessment of transgenic rapeseed cultivation, F₁ hybrid rapeseed variety production, and rapeseed improvement.     

Single-cell cloning of a crown gall from protoplasts regenerated in hormone-free medium. Establishment of pure transformed cell-lines of Catharanthus roseus

Protoplasts enzymatically isolated from cell line of Catharanthus roseus G. Don crown gall, were cultured at high density (10⁵ P ml^-1) in modified B5 liquid medium (Gamborg et al. 1976). In the absence of growth regulators C. roseus protoplasts were able to regenerate a cell-wall, divide and, subsequently, yield very numerous clones in the absence of growth regulators. After two weeks, the cultures were greatly diluted in order to obtain clones of single-cell origin. Most of the clones individually transferred onto solid medium can proliferate indefinitely, without growth regulators. Among analyzed clones, 90% were nopaline positive. Their ajmalicine and serpentine content was compared with that of the parental crown gall line, and was found to be low. The CR10 protoplasts were very easy to grow, they were an interesting model for the development of pure tumorous lines. Moreover, we found that the tumorous protoplasts were useful for cell fusion experiments or for the delicate culture of tree protoplasts.Abbreviations B5 Gamborg et al. (1976) medium - 2,4-d 2,4-dichlorophenoxyacetic acid - Kin Kinetin - NAA naphthalene acetic acid - BA N⁶ (benzyl) adenine     

H2 production by mixed cultures

Production of H₂ from glucose by an anoxygenic phototrophic bacterium (Rhodobacter sphaeroides), a cyanobacterium (Synechococcus cedrorum) and a heterotrophic bacterium (Pseudomonas fluorescens) was tested individually and in mixed cultures of various combinations in light. H₂ production was maximal with a mixed culture of R. sphaeroides and P. fluorescens, which could be further enhanced by immobilization of the bacteria in alginate gel. Inhibition of H₂ photoproduction was observed in a mixture of S. cedrorum and P. fluorescens and a co-culture of all the three organisms.Ch. Sasikala and Ch. V. Ramana are and G. S. Prasad was with the Microbial Biotechnology Laboratory, Department of Botany, Osmania University, Hyderabad-500 007, India. G. S. Prasad is now with the Microbial Type Culture Collection Centre (MTCC), IMTECH, Chandigar, India.     

Uptake and metabolism of glutamate and aspartate by astroglial and neuronal preparations of rat cerebellum

Astrocytes, neuronal perikarya and synaptosomes were prepared from rat cerebellum. Kinetics of high and low affinity uptake systems of glutamate and aspartate, nominal rates of¹⁴CO₂ production from [U–¹⁴C]glutamate, [U–¹⁴C]aspartate and [1–¹⁴C]glutamate and activities of enzymes of glutamate metabolism were studied in these preparations. The rate of uptake and the nomial rate of production of¹⁴CO₂ from these amino acids was higher in the astroglia than neuronal perikarya and synaptosomes. Activities of glutamine synthetase and glutamate dehydrogenase were higher in astrocytes than in neuronal perikarya and synaptosomes. Activities of glutaminase and glutamic acid decarboxylase were observed to be highest in neuronal perikarya and synaptosomes respectively. These results are in agreement with the postulates of theory of metabolic compartmentation of glutamate while others (presence of glutaminase in astrocytes and glutamine synthetase in synaptosomes) are not. Results of this study also indicated that (i) at high extracellular concentrations, glutamate/aspartate uptake may be predominantly into astrocytes while at low extracellular concentrations, it would be into neurons (ii) production of -ketoglutarate from glutamate is chiefly by way of transamination but not by oxidative deamination in these three preparations and (iii) there are topographical differences glutamate metabolism within the neurons.     

Resource availability at three presumed stages of a heathland succession on the Lüneburger Heide,Germany

Abstract. The availability of maj or plant resources was investigated in three vegetation types that were assumed to represent different stages of a secondary succession on heathland on the Lüneburger Heide, northwestern Germany. Canopy transmission and absorption of photosynthetically active radiation (PAR), soil-water availability, and nutrient (Ca, K, Mg, N, P) availability were monitored with high spatial and temporal resolution in (1) a Calluna vulgaris heathland, (2) a pioneer birch-pine forest and (3) a late-successional oak-beech forest, situated close to each other on comparable geological substrate (diluvial). Mean fractional transmission of PAR during summer decreased from 0.48 in the heathland to 0.04 in the oak-beech forest while the fractional canopy absorption increased from 0.49 to 0.92. Soil-water availability as indicated by the soil-water potential, was significantly influenced by differential canopy interception loss and characteristic rooting patterns in the three vegetation types. Annual mean nutrient concentrations in the equilibrium soil solution were similar or, for some elements, increased from the heathland to the birch-pine and the oak-beech forest despite a growing demand. A marked increase was found for the total nutrient pools in the soil-organic layer between early and late successional vegetation types. On the poor glacial parent material, nutrient pools seem to be strongly dependent on stand productivity and litter production which increased with succession. Thus, for nutrients, facilitation seems to be important in this type of succession.