I.—Richard Avenarius and his general theory of knowledge, empirioicriticsm

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Speed of sound measurements in the evaluation of bone properties in Holstein

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Feasibility of fast-particle channeling in quasicrystals

The feasibility of ion channeling in quasicrystalline structures is investigated in a computer experiment. For this purpose, a quasilattice is constructed by the grid method. As this model crystal shows, in a quasicrystal also the lattice points are arranged in strings and planes and form pronounced axial and planar channels. Their occupation by lattice points is, however, not constant, but exhibits a wide density distribution in contrast to periodic crystals. Manganese atoms were placed at the lattice points and backscattering yield profiles of 750-keV He+ ions were obtained in a channeling computer simulation. Pronounced channeling minima are observed in the profiles for axial as well as planar channeling

Bilateral Polydactyly in a foal

The following case report describes the diagnosis and surgery of bilateral polydactyly of unknown origin in a colt. A 7-month-old Berber colt was referred for cosmetic and curative excision of supernumerary digits. Radiographic examination revealed bilateral polydactyly and well-developed first carpal bones. Surgery consisted of an osteotomy of both second metacarpal bones combined with an amputation of the supernumerary digits. The follow-up at 18 months after surgery revealed a sound horse with an excellent cosmetic outcome

Autologous conditioned plasma as therapy of tendon and ligament lesions in seven horses

This case report describes the intralesional application of autologous conditioned plasma (ACP) in seven horses as treatment of severe tendinitis of the superficial digital flexor tendon, deep digital flexor tendon, or desmitis of the inferior check ligament. Follow-up data of the horses revealed a positive outcome in 10 to 13 months post injury. All horses treated with ACP were either performing in their previous work-load or were back in full training. Further studies with long-term follow-up will have to be performed to support these clinical intermediate-term observations

In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue

Directional migration of transmigrated leukocytes to the site of injury is a central event in the inflammatory response. Here, we present an in vivo chemotaxis assay enabling the visualization and quantitative analysis of subtype-specific directional motility and polarization of leukocytes in their natural 3D microenvironment. Our technique comprises the combination of i) semi-automated in situ microinjection of chemoattractants or bacteria as local chemotactic stimulus, ii) in vivo near-infrared reflected-light oblique transillumination (RLOT) microscopy for the visualization of leukocyte motility and morphology, and iii) in vivo fluorescence microscopy for the visualization of different leukocyte subpopulations or fluorescence-labeled bacteria. Leukocyte motility parameters are quantified off-line in digitized video sequences using computer-assisted single cell tracking. Here, we show that perivenular microinjection of chemoattractants [macrophage inflammatory protein-1alpha (MIP-1alpha/Ccl3), platelet-activating factor (PAF)] or E. coli into the murine cremaster muscle induces target-oriented intravascular adhesion and transmigration as well as polarization and directional interstitial migration of leukocytes towards the locally administered stimuli. Moreover, we describe a crucial role of Rho kinase for the regulation of directional motility and polarization of transmigrated leukocytes in vivo. Finally, combining in vivo RLOT and fluorescence microscopy in Cx3CR1(gfp/gfp) mice (mice exhibiting green fluorescent protein-labeled monocytes), we are able to demonstrate differences in the migratory behavior of monocytes and neutrophils.Taken together, we propose a novel approach for investigating the mechanisms and spatiotemporal dynamics of subtype-specific motility and polarization of leukocytes during their directional interstitial migration in vivo

Ion channeling in T-phase quasicrystals: an investigation by Rutherford backscattering and particle induced X-ray emission

The channeling properties of a T-phase A1 62Cu 20Co 15Si 3 quasicrystal are investigated in a Rutherford backscattering study employing 2 MeV He-ions. Besides axial channeling along the decagonal axis, also planar channeling is observed in planes having the decagonal axis in common and showing the decagonal symmetry of the quasicrystal. Besides a system of main planes, various planes exhibiting only weak channeling properties are observed; they correspond to linear arrangements of vertices in a two-dimensional Penrose grid, demonstrating the close relationship between T-phase quasicrystal and Penrose pattern. Rutherford backscattering (RBS) has also been used to study the decoration of the T-phase structure by Co/Cu- and Al/Si-atoms; in addition, particle induced X-ray emission PIXE served to distinguish between Co- and Cu-atoms. The experimental data are compared with channeling computer simulations on a model T-phase quasicrystal proposed by Steurer and Kuo