Patch artifacts

Polar Cell Systems for Membrane Transport Studies Direct current electrical measurement in epithelia steady-state and transient analysis, 171, 607 impedance analysis in tight epithelia, 171, 628 electrical impedance analysis of leaky epithelia theory, techniques, and leak artifact problems, 171, 642 patch-clamp experiments in epithelia activation by hormones or neurotransmitters, 171, 663 ionic permeation mechanisms in epithelia biionic potentials, dilution potentials, conductances, and streaming potentials, 171, 678 use of ionophores in epithelia characterizing membrane properties, 171, 715 cultures as epithelial models porous-bottom culture dishes for studying transport and differentiation, 171, 736 volume regulation in epithelia experimental approaches, 171, 744 scanning electrode localization of transport pathways in epithelial tissues, 171, 792. 

Fig. 6.2 Cross section of a corroded lead artifact before reduction (left) the different regions are (1) the porous corrosion patch, (2) some metal veins, (3) the metal core and (4) the electrolyte. Time-elapsed optical images (a-h) of the same section (right) during the reduction of the corrosion layer (from [303])...

Figure 3.16 Example of an imaging artifact. Left object consisting of an opaque specimen except for a 12 p,m diameter circular aperture. Right calculated transmission image for a single (nonconfocal) Schwarzschild objective with NA = 0.65 and for k = 6 p,m. Note the dark patch in the center, suggesting the presence of absorbing material inside the hole.

Tears are repaired with Japanese tissue, missing areas are filled in with paper similar to the artifact. Repair paper of specific caliper and tone is made in the leaf caster. Adhesives vary methyl cellulose, wheat paste, or a mixture of polyvinyl alcohol with rice paste. The mixture is most useful because it permits use of a warm tacking iron to hasten the drying process. Where missing areas have been patched, the restorer reconstructs only those lines and colors that are already discernable, lest the work be called an attempt at falsification. 

The metapopulation modeling clearly demonstrates that a relationship exists between patch arrangement, initial population size, and carrying capacity in determining the number and frequencies of discrete outcomes. Changes can lead to new outcomes and alter the probabilities of occurrence. Are these results artifacts of the numerical simulations or can they be expressed in simulated populations and ecological systems ... 

It was shown that the measurement of the absorption spectrum of a single bleb in the microscope spectrophotometer is reproducible and free of artifacts (5,11,12). The absorption spectra of several patch free blebs with different diameters were measured for each preparation. In all cases the fit between spectra and overall extinction coefficient was as good as previously reported (5,11,12)... 

Sometimes strong necrotic reactions are seen and an artifact is suspected. In medicolegal cases, it is recommended that control patches (empty or containing water or petrolatum) should be applied simultaneously and in random order. 

There are three primary differences between MNDO and AMI. The most important is the addition of Gaussian functions to the description of the core-repulsion function (CRF) in AMI that was not present in MNDO. These Gaussian functions were added to adjust the shape of the CRF and to patch MNDO for certain theoretical inadequacies. As such, they have met with mixed success in this role, improving results in some cases, but producing computational artifacts in others. 

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