Electron microscopic observations of synaptic endings in cultures of mammalian central nervous tissue

Summary Synapses were found in rat cerebellar and brainstem cultures with the electron microscope. Three distinct types of synaptic terminals were described. The similarity between synapses found in vitro and in vivo was emphasized.Supported by USPHS Grants 5 Tl 459-04 and NB 03114-03S1 from the National Institutes of Health, Bethesda, Maryland.The authors wish to express their sincere appreciation to Mrs. Eleanor Morris for her assistance in preparing the cultures and Mr. Earl Pitsinger for his photographic assistance.     

Bestandsschwankungen und heutige Verbreitung des Wei?en Storches in Schleswig-Holstein

Ohne Zusammenfassung     

Studium der Vererbung des Geschlechts und des Wuchstyps beim Hanf

Zusammenfassung Beim diözischen Hanf (Sorte Schurig-Markee) wurde ein vom 1:1-Verhältnis abweichendes Geschlechtsverhältnis von 42 Männchen : 58 Weibchen gefunden. Danach war eine Subletalität der Männchen anzunehmen.Es wurden Nachkommenschaftsprüfungen der Kreuzungen einerseits von Monözisten mit weiblichem Habitus und andererseits solchen mit männlichem Habitus mit Weibchen mit weiblichem Habitus durchgeführt. Sie ergaben die Zugehörigkeit der Monözisten mit weiblichem Habitus zum XX-Typ und der Monözisten mit männlichem Habitus zum XY-Typ.Bei den Nachkommenschaften von Monözisten mit männlichem Habitus war ein Spaltungsverhältnis von 3:1 oder 2:1 zu erwarten. Gefunden wurde ein Verhältnis, das der diözischen Spaltung entspricht.Für das andersartige Verhalten der Nachkommenschaften eines Monözisten mit männlichem Habitus mußte die Letalität der Y-Eizellen angenommen werden. Kreuzungen von Monözisten mit männlichem Habitus mit solchen mit weiblichem Habitus ergaben Nachkommenschaften mit rein weiblichem Habitus.Die reziproke Kreuzung dagegen spaltete nach dem diözischen Verhältnis. Damit wurde die Letalität der Y-Eizelle bestätigt.Dieses Ergebnis zeigt, weshalb ein monözischer Hanf mit männlichem Habitus nicht gezüchtet werden konnte.

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Studies on the inheritance of sex and growth type in hemp

Summary In dioecious hemp (variety Schurig-Markee) a sex ratio of 42 males:58 females rather than the expected 1:1 ratio was found. From this we assumed sublethality of the males.Progeny tests on the offspring from monoecious plants of female growth type and from those of male growth type with female plants of female growth type were carried out. They showed that monoecious plants of female growth type are of the XX genotype, those of male growth type XY.Among the offspring of monoecious plants with male growth type the expected sex ratio was 3:1 or 2:1. The actual ratio found corresponded to dioecious segregation. We assumed lethality of Y eggcells to be responsible for the abnormal ratios in the offspring of monoecious plants with male growth type. When the latter were crossed with plants of female growth type only offspring with female growth type resulted. Reciprocal crosses, however, showed only the dioecious segregation ratios. Thus lethality of Y eggcells has been confirmed.These results show why the breeding of monoecious hemp with male growth type has been an impossibility.

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Herrn Prof. Dr.Hans Stubbe zum 65. Geburtstag gewidmet.     

Untersuchungen zum cytochemischen Glykogennachweis

Ohne ZusammenfassungMit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Evaluation of lead concentrations in 18th-century Omaha Indian skeletons using ICP-MS.

The analysis of skeletal remains of Omaha Indians buried between AD 1780 and 1820 indicated that lead was incorporated in cortical bone. The diagenetic or biogenetic origin of the lead was evaluated by examination of lead isotope ratios of the bones and artifacts, and comparison of lead concentrations in burial soils with those of the bones. The isotopic values of the lead artifacts demonstrate that the lead was mined in the Missouri region. Although the isotope ratios in the bones are not identical with that from the lead artifacts, there is a strong relationship between them. This finding indicates that the lead in the bone was at least partly derived from the artifacts. Because lead artifacts rarely accompanied the burials but lead was ubiquitous in the bones, we suggest a biogenetic origin for the lead. There is also the possibility that some of the lead may have been derived from pigments applied to the corpse during mortuary ritual.     

Metabolic by-products of anaerobic toluene degradation by sulfate-reducing enrichment cultures.

Two dead-end metabolites of anaerobic toluene transformation, benzylsuccinic acid and benzylfumaric acid, accumulated in sulfate-reducing enrichment cultures that were fed toluene as the sole carbon source. Stable isotope-labeled toluene and gas chromatography-mass spectrometry were used to confirm that the compounds resulted from toluene metabolism. The two metabolites constituted less than 10% of the toluene carbon (over 80% was mineralized to carbon dioxide, according to a previous study). This study demonstrates that the novel nonproductive pathway proposed by Evans and coworkers (P. J. Evans, W. Ling, B. Goldschmidt, E. R. Ritter, and L. Y. Young, Appl. Environ. Microbiol. 58:496-501, 1992) for a denitrifying pure culture applies to disparate anaerobic bacteria.     

Microbial degradation of toluene under sulfate-reducing conditions and the influence of iron on the process.

Toluene degradation occurred concomitantly with sulfate reduction in anaerobic microcosms inoculated with contaminated subsurface soil from an aviation fuel storage facility near the Patuxent River (Md.). Similar results were obtained for enrichment cultures in which toluene was the sole carbon source. Several lines of evidence suggest that toluene degradation was directly coupled to sulfate reduction in Patuxent River microcosms and enrichment cultures: (i) the two processes were synchronous and highly correlated, (ii) the observed stoichiometric ratios of moles of sulfate consumed per mole of toluene consumed were consistent with the theoretical ratio for the oxidation of toluene to CO2 coupled with the reduction of sulfate to hydrogen sulfide, and (iii) toluene degradation ceased when sulfate was depleted, and conversely, sulfate reduction ceased when toluene was depleted. Mineralization of toluene was confirmed in experiments with [ring-U-14C]toluene. The addition of millimolar concentrations of amorphous Fe(OH)3 to Patuxent River microcosms and enrichment cultures either greatly facilitated the onset of toluene degradation or accelerated the rate once degradation had begun. In iron-amended microcosms and enrichment cultures, ferric iron reduction proceeded concurrently with toluene degradation and sulfate reduction. Stoichiometric data and other observations indicate that ferric iron reduction was not directly coupled to toluene oxidation but was a secondary, presumably abiotic, reaction between ferric iron and biogenic hydrogen sulfide.