Implicit convolution

Using simple ideas from techniques used in the numerical solution of partial differential equations, the concept of implicit convolution is introduced and analysed. Its properties on one-dimensional finite-length signals are first considered. Then, by appealing to the theory of methods of split-operator type, the use of implicit convolution for image enhancement is presented. This product-form approach can easily be extended to images in higher dimensions.     

The ultrastructure of the sheep parotid gland

The sheep parotid is a compound tubular gland; its ultrastructure reflects the function of this gland to secrete large amounts of fluid with very little protein. The cells of the secretory tubules possess extensively folded lateral plasma membranes and a fairly large number of mitochondria. Rapid equilibration of water across the epithelium is assured by the close proximity over large areas of intercellular spaces and the wide secretion canaliculi. Numerous long microvilli extend into the latter. Although secretion granules may be quite numerous, there is evidence that many of these granules are not discharged but undergo degradation by lysosomal enzymes. The intercalated ducts are often dilated but excessive distension is probably prevented by bundles of microfilaments in their epithelial cells.     

Renal lymph protein in the rat

Renal lymph and systemic (posterior) lymph were studied in hydropenic rats. As a consequence of the anatomical arrangement of collecting lymphatics near the kidney, mixed renal and systemic lymph tributaries are situated in such a way that sampling pure renal lymph is difficult. Pure renal lymph contains 1.0 +/- 0.1 g/100 ml total protein with an albumin-to-globulin (A/G) ratio of 2.1 +/- 0.1. Mixed renal and extrarenal lymphatic tributaries contain 3.3 +/- 0.2 g/100 ml total protein with an A/G ratio of 1.8 +/- 0.2. Corresponding values in the plasma are 4.9 +/- 0.2 and 1.2 +/- 0.1 g/100 ml, respectively. Previous studies in which the concentration of renal lymph protein was determined as 30-50% of that in plasma were probably in error due to contamination of renal samples by posterior lymph ducts. The amount of systemic and renal lymph mixing is highly variable from one animal to another. Our renal lymph samples in carefully controlled and prepared Munich-Wistar rats contained a total protein uniformly 20% of that in plasma.     

Screening and confirmatory methods for determining lincomycin residues in animal tissues

Methods for screening and for confirming residues of lincomycin in animal tissues, both sensitive to 0.1 ppm, are described. In the screening technique, residues are extracted, cleaned up by solvent partition, and detected by microbiological plate assay. In the confirmatory technique, residues are cleaned up on an unfunctionalized macroreticular-type resin column, concentrated, chromatographed on thin layer plates, and detected by bioautography. This system was effective in identifying lincomycin in the presence of 20 other antibiotics and chemicals used in the animal health industry.     

Ontogeny of cerebral dominance: Evidence from time-sharing asymmetry in children.

Used a dual-task procedure as a measure of speech lateralization in 151 normal, right-handed, 3–12 yr old children. Ss engaged in unimanual finger tapping with and without concurrent speech. It was hypothesized that if speech is left lateralized, talking should disrupt right-hand tapping (an instance of intrahemispheric interference) more than left-hand tapping (an instance of interhemispheric interference). Results for 2 different verbal tasks show the predicted overall asymmetry but no developmental trend in degree of asymmetry. The data suggest that lateralization is as marked in young children as in older children. About 70% of the Ss showed the predicted effect; there was no significant change in incidence as a function of grade level. Analyses of verbal production indicated that the performance asymmetry could not be attributed to an asymmetrical trade-off between talking and tapping. No sex differences in performance asymmetry were found. The results contradict the traditional model of progressive lateralization but corroborate the developmental invariance frequently observed using perceptual measures of language lateralization. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)