High Fidelity Digital Terrain Modelling for the Reconstruction of the Antarctic Sea Floor

Shape-based modelling is a general approach to surface representation, which has a great importance in the specific context of the Antarctic sea floor reconstruction, where measurements can involve critical operations. Here, a method is proposed where shape-based surface reconstruction is achieved performing a geometric reasoning on the raw data to delineate a shape structure on which the final surface model can be built. Data of the Antarctic sea floor are collected by surveys carried out along parallel courses during which the depth of the sea is measured at almost regular intervals. The seabed is then represented by a set of profiles, corresponding to almost vertical cross sections. The surface reconstruction is performed in three steps. First, a shape-based simplification is carried out on the profiles, using a combination of the wavelet theory and the classical Douglas and Peucker algorithm. The second step consists of finding similarities in the morphology of adjacent profiles, which may suggest the presence of surface features, such as ridges and ravines. Finally, the deduced surface features are used to build a kind of skeleton on which the most appropriate triangulation can be constructed.     

Occurrence and characterization of Staphylococcus aureus isolated from raw milk for cheesemaking

Fifty-four samples of raw milk for cheesemaking were tested for the presence of Staphylococcus aureus . Multiplex polymerase chain reactions were performed to identify presumptive isolates and the presence of enterotoxin-coding genes sea-see . The strains were tested for antibiotic resistance. Eighty strains were identified as S. aureus and 31 of these carried one or more enterotoxin genes ( sea-see ). Resistance to eritromycin, penicillin and ampicillin was widespread among isolates . Staphylococcus aureus in raw milk for cheesemaking may constitute a risk with respect to staphylococcal food poisoning from raw milk products.     

The DNA Sequence of Cosmid 14–13b from Chromosome XIV of Saccharomyces cerevisiae Reveals an Unusually High Number of Overlapping Open Reading Frames

This work is part of the effort for sequencing chromosome XIV of Saccharomyces cerevisiae. Cosmid 14–13b contains a 37·8 kb insert derived from a partial Sau3A digestion of the genome, cloned into the BamHI site of the vector Pou6. The strategy used for sequencing is based on the fragmentation of the whole cosmid by sonication, followed by shotgun sequencing on an Applied Biosystem DNA sequencer. The clones with inserts corresponding to the vector were identified by dot-blot hybridization, without the need of sequencing. The analysis of the DNA sequence reveals 29 open reading frames (ORFs) longer than 300 bases. Nine ORFs are internal to some other ORFs. Similarity searches against DNA and protein data banks show that six ORFs correspond to already known yeast genes (OMP1, PSU1, MLS1, RPC19, DBP2, CYB5) and one ORF matches the sequence of a putative yeast gene (ESBP6). The cosmid sequence has been submitted to the EMBL data bank under Accession Number Z69382.©1997 John Wiley & Sons, Ltd.