Jagdgebiet und Ern?hrung der Rohrweihe (Circus aeruginosus) in Schleswig-Holstein

Zusammenfassung Die Ausdehnung des Jagdgebietes der Rohrweihe hängt neben dem Beuteangebot und der Struktur des Gebietes vom Stadium und der Größe der Brut ab. Die Jagdgebietsgröße, ermittelt in einem Mäusejahr an 5 Paaren zur Brutzeit, schwankte zwischen 300–900 ha.1973–1975 wurden an 36 Rohrweihenhorsten 1202 Beutereste gesammelt und ausgewertet. Jagdweise, Beutebehandlung sowie das Auswerten der Beuteaufsammlung werden beschrieben. 58 Wirbeltierarten wurden festgestellt. Der prozentuale Anteil von Säugern und Vögeln an der Beute war in den einzelnen Jahren recht unterschiedlich, während der Anteil der Vögel während zweier Jahre 81 bzw. 75% betrug, sank er in einem Mäusejahr auf ca. 20%. Reptilien, Amphibien und Fische sowie Aas und Vogeleier waren im Untersuchungsgebiet von untergeordneter Bedeutung.Die Frage wird diskutiert, ob Rohrweihen, abgesehen von ihrer angeborenen Vorliebe für Vogeleier, als Nahrungs-Spezialisten zu bezeichnen sind. Ferner werden Hinweise aufgezeigt, die auf große Effizienz beim Nahrungserwerb schließen lassen.

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Hunting-area and food of the marsh-harrier (Cirus aeruginosus) in Schleswig-Holstein

Summary The hunting-area of five pairs of the Marsh-harrier during the breeding season has been investigated in a year with a graduation of field voles (Microtus arvalis). The area varied between 300 and 900 ha per pair. The size of the area was influenced by food availability, the structure of the countryside, clutch size and the growth of the nestlings.From 1973 to 1975, 1202 prey remnants and pellets were collected from 36 nests. The hunting and feeding behaviour of the birds are described. 58 species of vertebrates were identified. The percentage of mammals and birds in the prey was very different in each year. The proportion of birds during two years was 81% and 75% respectively. In a year with a small mammal gradation it decreased to 20%. Other vertebrates (reptiles, amphibians and fishes), carrion, and bird eggs were of minor importance in the study area.The question is discussed whether marsh-harriers tend to a genuine food specialisation, except for their innate preference for bird eggs. Furthermore hints are given concerning the great efficiency of predation.

     

Incidence of aneuploidy in a human population

A population of 40,371 individuals consisting of every baby delivered at two Denver hospitals from 1964 to 1974 has been screened from aneuploidy of the sex chromosomes and chromosome 21. The pattern in time with which aneuploidy occurs suggests an epidemic component of the incidence superimposed on an approximately equal constant frequency. The epidemic incidence is most likely to be high for births from May to October, to persist for several consecutive years, and then to be absent for several consecutive years.     

AvrRps4 effector family processing and recognition in lettuce

During pathogenesis, effector proteins are secreted from the pathogen to the host plant to provide virulence activity for invasion of the host. However, once the host plant recognizes one of the delivered effectors, effector‐triggered immunity activates a robust immune and hypersensitive response (HR). In planta, the effector AvrRps4 is processed into the N‐terminus (AvrRps4^N) and the C‐terminus (AvrRps4^C). AvrRps4^C is sufficient to trigger HR in turnip and activate AtRRS1/AtRPS4‐mediated immunity in Arabidopsis; on the other hand, AvrRps4^N induces HR in lettuce. Furthermore, AvrRps4^N‐mediated HR requires a conserved arginine at position 112 (R112), which is also important for full‐length AvrRps4 (AvrRps4^F) processing. Here, we show that effector processing and effector recognition in lettuce are uncoupled for the AvrRps4 family. In addition, we compared effector recognition by lettuce of AvrRps4 and its homologues, HopK1 and XopO. Interestingly, unlike for AvrRps4 and HopK1, mutation of the conserved R111 in XopO by itself was insufficient to abolish recognition. The combination of amino acid substitutions arginine 111 to leucine with glutamate 114 to lysine abolished the XopO‐mediated HR, suggesting that AvrRps4 family members have distinct structural requirements for perception by lettuce. Together, our results provide an insight into the processing and recognition of AvrRps4 and its homologues.     

Phosphorus saturation and pH differentially regulate the efficiency of organic acid anion-mediated P solubilization mechanisms in soil

Exudation of organic acid anions by plants as well as root-induced changes in rhizosphere pH can potentially improve phosphate (P_i) availability in the rhizosphere and are frequently found to occur simultaneously. In non-calcareous soils, a major proportion of P_i is strongly sorbed to metal oxi(hydr)oxides of mainly iron (Fe) and aluminium (Al) and organic anions are known to compete with P_i for the same sorption sites (ligand exchange) or solubilize P_i via ligand-promoted mineral dissolution. Root-induced co-acidification may also further promote P_i release from soil. The relative efficiency of these different solubilization mechanisms, however, is poorly understood. The aims of this study were to gain a better mechanistic understanding of the solubilizing mechanisms of four carboxylates (citrate, malate, oxalate, malonate) in five soils with high and low P surface site saturation. Results indicate that at a lower P saturation of solid phase sorption sites, ligand-promoted mineral dissolution was the main P_i solubilization mechanism, while ligand exchange became more important at higher soil P concentrations. Co-acidification generally increased P_i solubility in the presence of carboxylates; however the relative solubilizing effect of carboxylates compared to the background electrolyte (KCl) control decreased by 20–50%. In soils with high amounts of exchangeable calcium (Ca), the proton-induced Ca solubilization reduced soluble P_i, presumably due to ionic-strength-driven changes in the electric surface potential favoring a higher P_i retention. Across a wider soil pH range (pH 3–8), P_i solubility increased with increasing alkalinity, as a result of both, more negatively charged sorption sites, as well as DOC-driven changes in Fe and Al solubility, which were further enhanced by the presence of citrate. Overall, the relative efficiency of carboxylates in solubilizing P_i was greatest in soils with medium to high amounts of anionic binding sites (mainly Fe- and Al-oxy(hydr)oxides) and a medium P sorption site coverage, with citrate being most effective in solubilizing P_i.     

A weighing method to identify the microbial growth phases in solid-state fermentation tests

A general equation correlating the variation rate of the fermenting medium weight (dry matter) and the cell biomass growth rate in solid-state fermentation tests is proposed with the main purpose of identifying the microbial growth phases. This revised version was published online in July 2006 with corrections to the Cover Date.     

Quantitative Metaproteomics and Activity-based Protein Profiling of Patient Fecal Microbiome Identifies Host and Microbial Serine-type Endopeptidase Activity Associated With Ulcerative Colitis

The gut microbiota plays an important yet incompletely understood role in the induction and propagation of ulcerative colitis (UC). Organism-level efforts to identify UC-associated microbes have revealed the importance of community structure, but less is known about the molecular effectors of disease. We performed 16S rRNA gene sequencing in parallel with label-free data-dependent LC-MS/MS proteomics to characterize the stool microbiomes of healthy (n = 8) and UC (n = 10) patients. Comparisons of taxonomic composition between techniques revealed major differences in community structure partially attributable to the additional detection of host, fungal, viral, and food peptides by metaproteomics. Differential expression analysis of metaproteomic data identified 176 significantly enriched protein groups between healthy and UC patients. Gene ontology analysis revealed several enriched functions with serine-type endopeptidase activity overrepresented in UC patients. Using a biotinylated fluorophosphonate probe and streptavidin-based enrichment, we show that serine endopeptidases are active in patient fecal samples and that additional putative serine hydrolases are detectable by this approach compared with unenriched profiling. Finally, as metaproteomic databases expand, they are expected to asymptotically approach completeness. Using ComPIL and de novo peptide sequencing, we estimate the size of the probable peptide space unidentified (“dark peptidome”) by our large database approach to establish a rough benchmark for database sufficiency. Despite high variability inherent in patient samples, our analysis yielded a catalog of differentially enriched proteins between healthy and UC fecal proteomes. This catalog provides a clinically relevant jumping-off point for further molecular-level studies aimed at identifying the microbial underpinnings of UC.