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The numerical extraction of vortex cores from time-dependent fluid flow attracted much attention over the past decades. A commonly agreed upon vortex definition remained elusive since a proper vortex core needs to satisfy two hard constraints: it must be objective and Lagrangian. Recent methods on objectivization met the first but not the second constraint, since there was no formal guarantee that the resulting vortex coreline is indeed a pathline of the fluid flow. In this paper, we propose the first vortex core definition that is both objective and Lagrangian. Our approach restricts observer motions to follow along pathlines, which reduces the degrees of freedoms: we only need to optimize for an observer rotation that makes the observed flow as steady as possible. This optimization succeeds along Lagrangian vortex corelines and will result in a non-zero time-partial everywhere else. By performing this optimization at each point of a spatial grid, we obtain a residual scalar field, which we call vortex deviation error. The local minima on the grid serve as seed points for a gradient descent optimization that delivers sub-voxel accurate corelines. The visualization of both 2D and 3D vortex cores is based on the separation of the movement of the vortex core and the swirling flow behavior around it. While the vortex core is represented by a pathline, the swirling motion around it is visualized by streamlines in the correct frame. We demonstrate the utility of the approach on several 2D and 3D time-dependent vector fields'.

It is generally accepted that there is a need for standardized antigens in the diagnostic of exogenous allergic alveolitis. For this reason, ten antigens in a pigeon intestinal extract were classified in major, minor and intermediate antigens according to the distribution of specific antibodies in sera of asymptomatic and ill persons by use of crossed immunoelectrophoresis. Using a reference antiserum with antibodies against all ten detected antigens it is possible to prove a reproducible antigen composition in following preparations.

To compare two different sources of bird-antigens (intestinal extracts versus serum dilutions) we performed intracutaneous tests in 79 birdkeepers (34 pigeon-, 20 hen- and 25 budgerigar-keepers) and in nonexposed control persons. The bird-exposed persons were divided into 3 groups: 1. Seropositive patients with extrinsic allergic alveolitis (EAA), 2. seropositive persons without any signs of EAA (sensitized asymptomatics), and 3. exposed seronegative healthy persons. The results of the investigation demonstrate that the early skin-reaction (20 minutes after antigen-application) is nonspecific and do not have any diagnostic value. Most of patients with EAA (65.7%) and 29.6% of sensitized asymptomatics developed a positive 6-hour-(Arthus-) reaction with intestinal extracts, whereas in control groups we have not seen any Arthus reaction. Consequently, we recommend the use of intestinal extracts in the diagnostic procedure of EAA.

Due to their high specificity antibodies reveal possibilities for a detailed analysis of structure and function of eukaryotic ribosomes. By means of specific antibodies against single ribosomal proteins we could (1) localize immunoelectron microscopically certain proteins at the surface of ribosomes and (2) determine their role within protein biosynthesis by the binding of the initiation factor eIF-2 to the small ribosomal subunit. The combination of the results of both methods provides evidence of the localization of the peptidyl-tRNA binding site in the head area of the small subunit of ribosomes.

By combination of ion exchange chromatography, gel filtration, preparative polyacrylamide gel electrophoresis and perchloric acid fractionation 21 proteins of the small ribosomal subunit of rat liver were isolated with a purity of more than 95%. It could be demonstrated by immunological studies that no extensive structural homologies exist between these proteins.

For small subunits of rat liver ribosomes three binding sites for antibodies specific for protein S2 have been proved: one in the head region and the two others in the neck region, suggesting that protein S2 has an elongated structure in the small subunit.