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Sightings and migration patterns of 65 bean and 65 white-fronted geese are reported. These geese were tagged and serologically screened. 19 of the 53 birds sighted had serologic evidence of Newcastle Disease. The migration patterns of the wild geese provided further evidence that the main resting and wintering sites of migratory waterfowl are likely to be important for the inter- and intraspecies transmission of avian diseases.
A method of construction of combinational self-checking units with detection of all single faults
(1999)
A necessary adjustment of protocol for use of DPC Coat-a-Count Total Testosterone assay with saliva
(1999)
Prostaglandin E(2) receptors (EP-Rs) belong to the family of heterotrimeric G protein-coupled ectoreceptors with seven transmembrane domains. They can be subdivided into four subtypes according to their ligand-binding and G protein-coupling specificity: EP1 couple to G(q), EP2 and EP4 to G(s), and EP3 to G(i). The EP4-R, in contrast to the EP3beta-R, shows rapid agonist-induced desensitization. The agonist-induced desensitization depends on the presence of the EP4-R carboxyl-terminal domain, which also confers desensitization in a G(i)-coupled rEP3hEP4 carboxyl-terminal domain receptor hybrid (rEP3hEP4-Ct-R). To elucidate the possible mechanism of this desensitization, in vivo phosphorylation stimulated by activators of second messenger kinases, by prostaglandin E(2), or by the EP3-R agonist M&B28767 was investigated in COS-7 cells expressing FLAG-epitope-tagged rat EP3beta-R (rEP3beta-R), hEP4-R, or rEP3hEP4- Ct-R. Stimulation of protein kinase C with phorbol-12-myristate-13-acetate led to a slight phosphorylation of the FLAG- rEP3beta-R but to a strong phosphorylation of the FLAG-hEP4-R and the FLAG-rEP3hEP4-Ct-R, which was suppressed by the protein kinase A and protein kinase C inhibitor staurosporine. Prostaglandin E(2) stimulated phosphorylation of the FLAG- hEP4-R in its carboxyl-terminal receptor domain. The EP3-R agonist M&B28767 induced a time- and dose-dependent phosphorylation of the FLAG-rEP3hEP4-Ct-R but not of the FLAG-rEP3beta-R. Agonist-induced phosphorylation of the FLAG- hEP4-R and the FLAG-rEP3hEP4-Ct-R were not inhibited by staurosporine, which implies a role of G protein-coupled receptor kinases (GRKs) in agonist-induced receptor phosphorylation. Overexpression of GRKs in FLAG-rEP3hEP4-Ct-R- expressing COS-7 cells augmented the M&B28767-induced receptor phosphorylation and receptor sequestration. These findings indicate that phosphorylation of the carboxyl-terminal hEP4-R domain possibly by GRKs but not by second messenger kinases may be involved in rapid agonist-induced desensitization of the hEP4-R and the rEP3hEP4-Ct-R.
Alvin A. Liberman
(1999)
1. The plankton dynamics of Ace Lake, a saline, meromictic basin in the Vestfold Hills, eastern Antarctica was studied between December 1995 and February 1997. 2. The lake supported two distinct plankton communities; an aerobic microbial community in the upper oxygenated mixolimnion and an anaerobic microbial community in the lower anoxic monimolimnion. 3. Phytoplankton development was limited by nitrogen availability. Soluble reactive phosphorus was never limiting. Chlorophyll a concentrations in the mixolimnion ranged between 0.3 and 4.4 mu g L-1 during the study period and a deep chlorophyll maximum persisted throughout the year below the chemo/oxycline. 4. Bacterioplankton abundance showed considerable seasonal variation related to light and substrate availability. Autotrophic bacterial abundance ranged between 0.02 and 8.94 x 10(8) L-1 and heterotrophic bacterial abundance between 1.26 and 72.8 x 10(8) L-1 throughout the water column. 5. The mixolimnion phytoplankton was dominated by phytoflagellates, in particular Pyramimonas gelidicola. P. gelidicola remained active for most of the year by virtue of its mixotrophic behaviour. Photosynthetic dinoflagellates occurred during the austral summer, but the entire population encysted for the winter. 6. Two communities of heterotrophic flagellates were apparent; a community living in the upper monimolimnion and a community living in the aerobic mixolimnion. Both exhibited different seasonal dynamics. 7. The ciliate community was dominated by the autotroph Mesodinium rubrum. The abundance of M. rubrum peaked in summer. A proportion of the population encysted during winter. Only one other ciliate, Euplotes sp., occurred regularly. 8. Two species of Metazoa occurred in the mixolimnion; a calanoid copepod (Paralabidocera antarctica) and a rotifer (Notholca sp.). However, there was no evidence of grazing pressure on the microbial community. In common with most other Antarctic lakes, Ace Lake appears to be driven by 'bottom-up' forces.
Asymptotic comparison of the critical values of step-down and step-up multiple comparison procedures
(1999)
Biodegradation of chitosan
(1999)
Broadband operation of a gain-switched Ti:sapphire laser for measurements with the coherence radar
(1999)
Changing functionality of surfaces by directed self-assembly using oligonucleotides - the oligo-tag
(1999)
Chromosomal assignment of the human gene for endosarcomeric cytoskeletal M-protein (MYOM2) to 8p23.3
(1999)
Clinical findings and parameter of stress and regeneration in powers before world championships
(1999)
Communicative Style
(1999)
Equilibrium constants and thermodynamic parameters for the complexation of nickel(II) and cobalt(II) by noncyclic, monocyclic and bicyclic ligands in acetonitrile have been determined by calorimetric titrations. The donor atoms and the ring size of the ligands play an important role for the stabilities of the complexes formed. An increasing number of nitrogen atoms in the crown ether favours complex formation. The number of nitrogen donor atoms of the macro- cyclic ligands examined has a direct influence on the values of the reaction enthalpies. Keywords: Complex formation; crown ethers; azacrown ethers; thiacrown ethers; cryptands; acetonitrile
Concluding observations
(1999)
If an atom is able to exhibit macroscopic dark periods, or electron shelving, then a driven system of tow atoms has three types of these fluorescence types as a simple and easily accessible indivator of cooperative effects. As an examble, we study two dipole-interacting V systems by simulation techniques. We show that the durations of the two types of light periods exhibit marked sepatation-dependent oscillations and that they vary in phase with the real part of the dipole-dipole coupling constant.
Criteria of talent in sport
(1999)
Decomposing American History as Cultural Analysis: Rosmarie Waldrop's SHORTER AMERICAN MEMORY
(1999)