Characterization of proteins from arthrodial membranes of the lobster, Homarus americanus

A total of six proteins from the abdominal arthrodial membrane (intersegmental membrane) of the lobster, Homarus americanus, were purified and their amino acid sequences were determined by a combination of mass spectrometry and Edman degradation. The proteins are acidic with pI-values close to 4 and they all have molecular masses ≈12 kDa. The sequences of five of the proteins differ in only a few residues, while the sixth protein differs from the others in more than half of the positions. Only little similarity is observed between the sequences of the arthrodial membrane proteins and those of proteins purified from the calcified parts of the exoskeleton of H. americanus. The arthrodial membrane proteins contain the Rebers-Riddiford consensus sequence common in proteins from insect cuticles. Comparison of the complete sequences to the sequences available in databases shows that the lobster membrane proteins are more closely related to proteins from insect pliant cuticles than to proteins derived from cuticles destined for sclerotization. Characteristic features in the protein sequences are discussed, and it is suggested that the various sequence regions have specific roles in determining the mechanical properties of arthrodial membranes.     

Diagnostic accuracy of the neurological upper limb examination I: Inter-rater reproducibility of selected findings and patterns

Background  

We have previously assessed the reproducibility of manual testing of the strength in 14 individual upper limb muscles in patients with or without upper limb complaints. This investigation aimed at additionally studying sensory disturbances, the mechanosensitivity of nerve trunks, and the occurrence of physical findings in patterns which may potentially reflect a peripheral neuropathy. The reproducibility of this part of the neurological examination has never been reported.     

4-Hydroxybenzoylcholine: A natural product present in Sinapis alba

The total fractions of choline esters have been isolated from different parts of Sinapis alba. 4-Hydroxybenzoylcholine has been identified and found to be one of the quantitatively dominating choline esters in seed extracts of S. alba. The identity of the new natural product has been confirmed by comparison with synthetic reference compounds. Several different choline esters are present in this plant but in extracts of seedlings, leaves, and inflorescences they are not so quantitatively dominating as in seeds. The modified ion-exchange technique applied appeared to be an efficient tool in the isolation and separation of choline esters and amines from other types of phenolic plant constituents.     

Radiocarbon wiggle-dating of elm declines in northwest Denmark and their significance

Four elm declines were found in a pollen diagram from a small lake in northwest Denmark. Matching consecutive radiocarbon dates with the dendro-chronological calibration curve indicated a reservoir effect of 120 years, and dates for the four elm declines were obtained (4530, 4130, 3870, 3410 cal B.C.). The occurrence of apophytes (native plants encouraged by human activities) and increased vegetation diversity during the four elm declines indicates human disturbance. The first and second elm declines coincide with traces of early agriculture in northern Germany. The third and fourth elm declines are contemporary with the transitions to the Early Neolithic and the Middle Neolithic Funnel Beaker Culture in Denmark. The possible influence of outbreaks of elm disease is discussed.     

Monitoring harbour seal (Phoca vitulina) in the Danish Wadden Sea

Monitoring of harbour seal (Phoca vitulina) has been carried out in the Danis part of the Wadden Sea during the past 8 years by the Fishery and Maritime Museum. In addition to this, field observations over three breeding seasons have been undertaken. The census shows a steady increase of approx. 14% per yeart. The distribution of the seals in the area can be split up into two different types of haulout localities, and a varied pattern of haulouts is observed during the year. The mass die-off in 1988 is discussed within the framework of the knowledge on the population, and it is recommended that more effort be put into monitoring and population studies of the harbour seal in the entire International Wadden Sea. Presented at the VI International Wadden Sea Symposium (Biologische Anstalt Helgoland, Wattenmeerstation Sylt, D-2282 List, 1–4 November 1988)