Blutregen und Blutschnee: Stickstoffmangel-Zellen von Haematococcus pluvialis und Chlamydomonas nivalis

Zusammenfassung Blutregen und Blutschnee sind zwei auffallende Naturerscheinungen, die in der Hauptsache durch Massenvorkommen von Aplanosporen der volvocalen Grünalgen Haematococcus pluvialis und Chlamydomonas nivalis verursacht werden. Die für die rote Farbe verantwortlichen Pigmente sind Keto-Carotinoide. Die Versuche zeigen, daß auch unter natürlichen Bedingungen für die Biosynthese dieser Polyene und für den gleichzeitig ablaufenden Abbau der Chlorophylle Stickstoffmangel der entscheidende Faktor ist.

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Blood-rain and blood-snow: Nitrogen-deficient cells of Haematococcus pluvialis and Chlamydomonas nivalis

Summary The blood-rain and the blood-snow, two phenomena caused mainly by mass occurrence of aplanospores of the volvocalean green algae Haematococcus pluvialis and Chlamydomonas nivalis, have been studied under natural conditions. The red pigments belong to the keto-carotenoids. The experiments show that also in nature the biosynthesis of these polyenes and the parallel decomposition of the chlorophylls are caused by nitrogen deficiency.

     

DON- und ZEA-Gehalte in Weizen, Roggen und Gerste: Besondere Ernteermittlung

In the annual national survey (‘Besondere Ernteermittlung’) the quality of German cereals was analysed. The samples for this approach were collected from statistically selected fields. One of the analysed parameters was the content of mycotoxins. Thus, it was possible to get an area-wide survey of the content of mycotoxins under natural growing conditions. In 2003 a total number of 974 samples were analysed consisting of wheat, rye and barley samples. A special mode of choosing the wheat samples ensured also a statistically validated result for the federal states of Germany. In the year 2003 the content of the mycotoxins DON and ZEA in wheat and rye samples was lower than in 2002 referred to the median. On the other hand the frequency of detection of DON was not reduced. In barley, which was analysed for the first time in this kind of study, the level of DON was in between the levels of wheat and rye.     

Vogel und Mensch: Die freundlichen und feindlichen Beziehungen zwischen beiden und daraus sich ergebende Besonderheiten in der Entwickelung und Verbreitung der Arten

Ohne Zusammenfassung     

Pseudo-ADP: Darstellung und Biomimetische Eigenschaften

Abstract

By the preparation of (3) via an amide bond like linkage of the diarylmonoazo dye (la) with adenosine-5′-uronic acid (2) we succeeded, for the first time, in the substitution of the pyrophosphate chain of adenosine-5′-diphosphate with a bioanalogeus, synthetic structural element. The biomimetic properties of (3) are demonstrated by its binding and transport properties with respect to the highly ADP-specific mitochondrial adenine-nucleotide carrier using the phenol-[u- ¹⁴ C] labeled compound of (3), which was prepared additionally in a microsynthesis     

Erbliche Zystennierenerkrankungen: Autosomal-dominante und autosomal-rezessive polyzystische Nierenerkrankung (ADPKD und ARPKD)

medizinische genetik - Zystische Nierenerkrankungen gehören zu den wichtigsten Ursachen eines terminalen Nierenversagens bei Kindern und Erwachsenen. Während die häufigere...     

Geographic covariation of hosts und parasites: Evidence from Populus und Pemphigus1

The geographic covariation of the eastern cottonwood Populus deltoides with three different gallforming aphids in the genus Pemphigus is studied over eastern North America. Ten vegetative Populus characters were analyzed together with 32 stem mother, slate und gall dimension characters in Pemphigus populicaulis und in two morphs of P. populitransversus. The number of locality samples studied ranges from 56 to 157. The covariation between host und parasite characters was examined by correlation analysis und canonical correlations und shown to be slight. Multiple regressions of factor scores of Pemphigus variables on Populus characters show relatively low percentages of explained variance und few significant partial regression coefficients. Spatial autocorrelation analyses of Pemphigus factor scores und of their residuals on Populus variables demonstrated largely independent spatial structure of the two sets of variables. These findings were confirmed by multiple Mantel tests of distance matrices based on cottonwood und aphid phenetics und on geography. The undoubtedly close Pemphigus-Populus coevolution over geological time is not reflected in the microevolutionary variation over geographic space. Possible esplanations for these surprising findings are discussed.     

Zur Anatomie und Ökologie von Ammoniten: Funde von Kropf und Kiemen

Soft parts within the living chambers of specimens of the generaArnioceras, Hildoceras, «Oppelia», andPhysodoceras are described. Special attention is given to the contents of the crops and, in consequence, to the feeding habits of ammonites. Our analysis shows that foraminifera, ostracods, small ammonites, and crinoids have been eaten by ammonites. A find of ammonite gills is demonstrated.