Biomarker: indications for microbial contributions to Recent and Late Jurassic carbonate deposits

Biomarker investigations were applied to the hydrocarbon fractions of three Recent (cyanobacterial mat, Lake Van microbialite and Lake Satonda microbialite) and two Late Jurassic carbonate samples obtained from sponge bioherms. The relative concentrations of n-alkanes, monomethyl alkanes, acyclic isoprenoids, steroids and hopanoids in these samples are studied and their probable biological precursors are discussed. Normal alkanes with carbon chain lenghts ranging from C15 to C34 and monomethyl alkanes ranging from C17 to C21 with a varying methyl branching pattern are found. The major hydrocarbons are low molecular (LMW) n-alkanes (C15 - C21) with a slight to strong predominance of n-heptadecane (C17). High molecular weight (HMW) n-alkanes occur in low to moderate relative concentrations showing a preference of odd-numbered compounds with a maximum at C29. Within the acyclic isoprenoids, pristane, phytane/phytene, pentamethyleicosane, squalane and lycopane could be identified. Polycyclic terpenoids of the sterane and/or hopane type are present in all carbonate samples. The carbon atom numbers of these compounds range from 27 to 29 and 27 to 32, respectively. These organic compounds identified can be attributed to various source organisms such as cyanobacteria, archaebacteria, algae and vascular plants. All hydrocarbon fractions of the samples are characterized by moderate to high relative concentrations of cmpounds derived from caynobacteria, signifying the role of these organisms as contributors to the Recent as well as to the Late Jurassic carbonate deposits

Coastal and sea space development

The group proceeded in selecting a range of existing, planned or proposed projects relevant to its goal and representative for the state-of-the-art. So far 4 projects related to the coastline and 1 project in the coastal shelf have been selected. Furthermore the field of offshore renewable energy has been outlined; in addition a possible supporting project on earth observation, one which could provide important feedback of data on the quality of the environment and the morphology o f the coastline, is included. These projects are considered to be representative for the variety of challenges, techniques and theoretical insights necessary : they should form a valid basis for defining innovation needs and development trends

Fine mapping of the psoriasis susceptibility gene PSORS1: A reassessment of risk associated with a putative risk haplotype lacking HLA-Cw6

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldHuman leukocyte antigen (HLA)-Cw6 has long been associated with psoriasis, and PSORS1 (psoriasis susceptibility 1), a major gene for psoriasis susceptibility, has been mapped to its vicinity. A previous analysis identified multiple risk haplotypes carrying HLA-Cw6 and one haplotype (cluster 17, HLA-Cw8-B65) that appeared to carry risk for psoriasis but did not carry HLA-Cw6. This haplotype was very similar to other risk haplotypes for at least 60 kb telomeric to HLA-C, suggesting identity by descent with the remaining risk chromosomes. The association, however, between psoriasis and this haplotype as assessed by the transmission/disequilibrium test (TDT) was of borderline significance (p-value 0.048). In order to better assess the risk associated with cluster 17, a multicenter collaboration typed additional subjects for a single marker (M6S161) for which one allele (249 bp) was found only on cluster 17. The new sample included 1275 pedigrees as well as 300 cases and 913 controls. Transmission of this allele to affected individuals was examined using the TDT and the pedigree disequilibrium test (PDT), and case-control samples were analyzed by a trend test across genotype categories. By all methods, the newly acquired genotypes failed to confirm the association originally reported, despite adequate power. In contrast, the 248 bp allele, which is found on all HLA-Cw6-positive risk haplotypes as well as several non-risk haplotypes, shows significant excess transmission for all cohorts. Taken together, these results indicate that cluster 17 does not carry a psoriasis-susceptibility allele, and expand the PSORS1 risk interval to approximately 300 kb