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A correction to the article "The Flow of Liquid from a Jet through a Compressible Porous Layer, Part I: Analysis of Methods of Applying a Liquid to Flow through a Porous Layer," by A. Samson is presented.

Immunofluorescent studies of intestinal tissues from young preruminant calves demonstrate the presence of two main populations of immunocytes synthesizing IgA and IgM. These cells had infiltrated the lamina propria of the intestine as early as 4 days of age. There was little evidence of any significant involvement of IgG 1 in intestinal immune synthesis of calves at this age although activity was demon- strable in the ileum and colon of one calf. In general there were more IgG2-synthesizing cells than IgG1, but these were few compared with the main populations at' IgA and IgM cells. Local antigenic stimulus to the intestinal mucosa of young fistulated calves using extracts of heat-killed Gram-negative bacteria produced antibody in the secretions over a period of approximately 3 weeks. A second administration of a similar antigenic dose produced a similar response indicating the requirement for continuous stimuli to maintain a measurable level of antibody secretion. Gel filtration and antiglobulin assays indicated that the antibacterial activity was predominantly associated with IgA and that IgM also played a significant role. Oral administration of bacterial antigens to colostrum-fed calves from 5 to 8 days of age produced a faecal antibody response, indicating that intestinal secretion could be successfully interrelated with the declining passive antibody to maintain an almost continuous level of intestinal antibody in early life. [ABSTRACT FROM AUTHOR]

α-Lactalbumin isolated from human milk was reacted with tetranitromethane in molar excess of 8-32 mol/mol of tyrosine. After gel filtration on Sephadex G-75, followed by chromatographic fractionation using DEAE-Sephadex A-25, three main components were separated, which differed from one another in the extent of nitration. These protein fractions were found to contain, respectively, one and two nitrotyrosine residues, or two nitrotyrosine residues together with one nitrotryptophan. The lactose synthase specifier activity of each of these components was measured and compared with that of unsubstituted α-lactalbumin. Comparison of kinetic parameters showed the chemically modified proteins to be only slightly tess active when tyrosines were the sole residues modified. In sharp contrast the additional nitration of a single tryptophan residue totally abolished the specifying activity of α-lactalbumin. Circular dichroism spectra of the tryptophan derivative revealed some structural alteration when compared with the other two and with the native protein. The conclusion could also be confirmed by using a double-immunodiffusion technique. After hydrolysis of the derivatives with thermolysin, it was possible to localize the substituted residues in the known sequence of human α-lactalbumin. Tyrosine-103 was found to be more easily nitrated than tyrosine-18. These two residues seem, therefore, to be on the outer surface of the molecule and more exposed than tyrosine-36 and tyrosine-50. Some precautions are indicated in the use of tetranitromethane as a nitrating agent on the basis of complex products observed in the nitration of the free amino acids tyrosine and tryptophan and their derivatives. [ABSTRACT FROM AUTHOR]

The changes in pressure, velocity, and energy of a liquid particle emanating from a submerged jet and flowing towards and through a porous medium are predicted. An expression is developed for the volumetric rate of flow of a liquid from a jet entering a porous medium, and the rate is shown to vary less than 20% when the distance from the jet nozzle to the porous medium is doubled. The pressure at any level in a compressible porous medium subjected to an initial uniform flow is determined. The distribution of flow within a layer of wool that is impinged upon by a submerged jet is found to be Gaussian, and photographic evidence shows the spread of the flow as it emerges from the downstream surface. [ABSTRACT FROM AUTHOR]

The effects on the conditions of flow of the surface and configurational properties of the fibres in a compressible porous layer are discussed. The characteristics of a layer of wool are evaluated, and its compressibility is determined. It is shown that, when a liquid of initial uniform pressure flows through a compressible porous medium, the pressure gradient within the medium increases with the distance of flow. The resulting pressure drop is found to depend on a function of the ratio of the downstream to the upstream porosity of the compressible medium. Experimental results are reported for permeable flow through various layers of loose wool; these indicate that, when the flow is disturbed turbulent, the pressure drop through the layers is proportional to the square of the filter velocity. This result is not readily apparent from the graphs of pressure drop against filter velocity because of the compressibility of the fibres. [ABSTRACT FROM AUTHOR]

The characteristics of a submerged free turbulent jet are evaluated. The distribution of pressure produced by a free streamline jet impinging on a flat surface is found to be Gaussian. An analysis is made of the distribution of pressure when a submerged plane free turbulent jet impinges on a flat impervious surface, and it is found that the stagnation pressure is negligible beyond twice the width of the jet's nozzle. This is confirmed by evidence from experiments with a water jet in air impinging on a flat plate. [ABSTRACT FROM AUTHOR]

The volumetric rates of flow of a fluid through holes and porous layers when a uniform fluid pressure is applied are compared. An analysis is made of the comparative rates of flow of fluid through holes and porous layers when the application is by uniform pressure and by jets. It is shown that the fluid pressure near a hole located in a porous layer is less than the over-all applied pressure and that this accounts for less flow through the layer near the hole than occurs when the fluid is applied by a jet. [ABSTRACT FROM AUTHOR]

The method by Larsen and Klungsöyr (1964) for the quantitative determination of indole-3-acetaldehyde (IAAld) was modified for the purpose of eliminating the need for filtration after oxidation of the IAAld to indole-3-acetic acid (IAA). The essentials of the modified method are as follows: Samples of IAAld or IAA containing 0.015 to 0.15 μmol (ca. 2.5 to 25 μg) dissolved in peroxide-free ether are evaporated to dryness and redissolved in 1.5 ml 0.02 M Ag2SO4. The oxidation is carried out in dim light by adding 0.5 ml 0.12 N NaOH. After 1.5 min, 2 ml of a modified Salkowski reagent are added. The optical density at 525 nm is read on a spectrophotometer after 75 min. The modified Salkowski reagent consists of 100 ml 0.05 M Fe2 (SO4)3 in 1.5 N H2SO4; 240 ml H2O; and 160 ml conc. H2SO4 (sp. gr. 1.84). O.D. readings are identical for equal samples of IAAld and IAA (the latter used as a standard) up to 0.08 μmol (O.D. = 0.32). Larger quantities of IAAld may be determined when using pure IAAld as a standard, but at 0.20 μmol the O.D. for IAAld is lower than for IAA (0.69 as against 0.72). Indole-3-acetonitrile, tryptophol, indole-3-carboxylic acid, and indole-3-aldehyde all give O.D. values lower than 0.1 when tested at 0.20 μmol under the same conditions as described for IAAld and IAA. [ABSTRACT FROM AUTHOR]

The basic chemical reactions involved in producing a polyurethane foam and some of the secondary reactions are discussed, along with information about raw material preparation and physical testing of the foam. A description of the foam manufacturing and peeling operations, bonding methods and testing of bonded fabrics is included. Analyses of the foams, analytical evaluation of tricots, amount of melt achieved using control foams and fabrics, and an examination of retail garments are given consideration. A novel rating system which was devised to provide objective analyses of washability and drycleanability of the bonded fabrics is discussed in detail. [ABSTRACT FROM AUTHOR]

An attempt has beeti made to purify and characterize the protein atiligens related to autoimmune carditis in the heart extract of albino rats by ammonium sulphate fractionation, molecular sieve gel filtration and polyacrylamide gel electrophoresis. The heart extract of albino rat at pH 70 contains at least nine proteins out of which three are antigenic in rabbits and have been termed as CA 1. II and III. These antigens can be purified by ammonium sulphate fractional precipitation followed by Sephadex G-100 geic filtration. Their molecular weights were 66 (±2)x10*, 2-8 (±0-85)x 10, 4-8 (±-5)xl0 Daltons. A fourth antigen (CA IV) detected is probably polysaccharide. [ABSTRACT FROM AUTHOR]

Normal serum samples from the Australian freshwater catfish Tandanus tandanus possessing ABH-specific haemagglutinating activity, were fractionated using the techniques of gel filtration, ion-exchange chromatography, zone electrophoresis and isoelectric focusing in free solution. The successful isolation of the agglutinins is described and some of the difficulties involved in purifying and studying such 'natural' vertebrate agglutinins are discussed. Reasons against the automatic classification of poikilothermic 'natural' agglutinins as antibodies are advanced. [ABSTRACT FROM AUTHOR]