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Cross-spectral analysis is recognized as a powerful analytical tool for the analysis of time-varying behavior in a number of disciplines. Applications in business have been limited, however, and the potential usefulness of this new approach to time series analysis has received relatively little attention in advertising. The purpose of this paper is to explain cross-spectral analysis and illustrate the use of this new technique in studying the interaction between advertising and sales. [ABSTRACT FROM AUTHOR]

This article reports the results of a study which examined a very simple phenomenon, the incidence of trips to supermarkets by consumers. Shopping trips were chosen because they are basic to the description of consumer behavior and because there is a growing interest in this area. Several store choice studies [1, 3, 4, 10, 12, 13, 15, 17] using methodologies other than the one employed here have recently appeared. Supermarkets were selected because they are the major recipient of the consumer's available shopping time and shopping dollar. A priori expectations were that the incidence of trips to supermarkets by consumers should be related to consumers' demand for supermarket products and to consumers' available time for shopping, i.e., disposable time. Shopping frequency was believed to be positively related to both. It was also expected that families with little disposable time should display more consistent shopping patterns than families with more disposable time. These expectations stem from empirical evidence and from a simulation analysis of consumer movement [10]. [ABSTRACT FROM AUTHOR]

A red/green equilibrium light is one which appears neither reddish nor greenish (i.e. either uniquely yellow, uniquely blue, or achromatic). A subset of spectral and nonspectral red/green equilibria was determined for several luminance levels, in order to test whether the set of all such equilibria is closed under linear color-mixture operations. The spectral loci of equilibrium yellow and blue showed either no variation or visually insignificant variation over a range of 1-2 log10 unit. There were no trends that were repeatable across observers. We concluded that spectral red/green equilibria are closed under scalar multiplication; consequently they are invariant hues relative to the Bezold-Brücke shift. The additive mixture of yellow and blue equilibrium wavelengths, in any luminance ratio, is also an equilibrium light. Small changes of the yellowish component of a mixture toward redness or greeness must be compensated by predictable changes of the bluish component of the mixture toward greenness or redness. We concluded that yellow and blue equilibria are complementary relative to an equilibrium white; that desaturation of a yellow or blue equilibrium light with such a white produces no Abney hue shift; and that the set of red/green equilibria is closed under general linear operations. One consequence is that the red/green chromatic-response function, measured by the Jameson-Hurvich technique of cancellation to equilibrium, is a linear function of the individual's color-matching coordinates. A second consequence of linear closure of equilibria is a strong constraint on the class of combination rules by which receptor outputs are recoded into the red/green opponent process. © 1974.

A red/green equilibrium light is one which appears neither reddish nor greenish (i.e. either uniquely yellow, uniquely blue, or achromatic). A subset of spectral and nonspectral red/green equilibria was determined for several luminance levels, in order to test whether the set of all such equilibria is closed under linear color-mixture operations. The spectral loci of equilibrium yellow and blue showed either no variation or visually insignificant variation over a range of 1-2 log10 unit. There were no trends that were repeatable across observers. We concluded that spectral red/green equilibria are closed under scalar multiplication; consequently they are invariant hues relative to the Bezold-Brücke shift. The additive mixture of yellow and blue equilibrium wavelengths, in any luminance ratio, is also an equilibrium light. Small changes of the yellowish component of a mixture toward redness or greeness must be compensated by predictable changes of the bluish component of the mixture toward greenness or redness. We concluded that yellow and blue equilibria are complementary relative to an equilibrium white; that desaturation of a yellow or blue equilibrium light with such a white produces no Abney hue shift; and that the set of red/green equilibria is closed under general linear operations. One consequence is that the red/green chromatic-response function, measured by the Jameson-Hurvich technique of cancellation to equilibrium, is a linear function of the individual's color-matching coordinates. A second consequence of linear closure of equilibria is a strong constraint on the class of combination rules by which receptor outputs are recoded into the red/green opponent process. © 1974.

The photo‐induced cell division in single‐celled protonemata of the fern Adiantum capillus‐veneris was studied. When the protonemata were exposed to monochromatic light at 50 nm intervals between 350 and 750 nm, irradiations in the blue and near‐ultraviolet regions effectively induced cell division, while wavelengths longer than 550 nm showed no such effect. As reciprocity between duration and intensity was observed within the range of incident energy used, the action spectrum for the frequency of the photo‐induced cell divisions 24 h after irradiation was determined between 360 and 510 nm at 10 nm intervals. Furthermore, the previously known effect of phytochrome on the timing of the cell division was minimized by a short exposure to red light given immediately after the monochromatic irradiation. The resulting action spectra showed a peak in the neighborhood of 460 nm with shoulders and another peak in the near‐ultraviolet region. [ABSTRACT FROM AUTHOR]

Methods for automatic recordings of action spectra for partial reactions of photosynthesis are previously described. The present paper elaborates one of the descriptions and gives results from measurements. The method is based upon the recordings of changes in the absorption of certain dyes, which are used as electron acceptors or electron donors to photosynthetic reactions in illuminated chloroplasts or photosynthetic lamellae. By measuring the transmission changes continuously during a wavelength sweep of actinic light, which is corrected for equal numbers of light quanta at different wavelengths, an approximate integrated action spectrum of the selected partial reaction is obtained. A computer program gives the action spectrum after taking the first derivative of the curve and correcting it for changes with time in the rate of the dye reduction (oxidation) and the reverse reactions. The action spectrum for photoreduction of 2,6-dichlorophenol indophenol and cytochrome c by spinach chloroplasts has a peak at about the same wavelength as the absorption spectrum (677-680 nm). Details in the curves are observed at 650, 663, 673 and possibly at 695 nm. The action spectrum for mammalian cytochrome c oxidation by PSI particles of Anacystis nidulans has a peak at 683 nm (absorption spectrum at 679 nm). Shoulders are observed at 665, 677, 700, and 715 nm. [ABSTRACT FROM AUTHOR]

Low-temperature (77°K) fluorescence and absorption spectra have been determined for whole cells and photosystem I particles of Anacystis nidulans grown in iron-supplied or iron-deficient inorganic media. Iron deficiency induces a decrease of F720 relative to F685 and F695 in the fluorescence spectra of both whole cells and photosystem I particles. This change is correlated to a reduction of preferentially the long wavelength absorbing fraction of chlorophyll a. The relative fluorescence intensity at 755 nm is increased by iron deficiency. No significant effects of culture-age are found in the ratio between the three fluorescence bands (F685 : F695: F720) of iron-supplied A. nidulans. [ABSTRACT FROM AUTHOR]

The phenylalanine-specific tRNAPhe from 13-day-old chick embryo muscle was purified. Its fluorescent and hydrophobic Y+ base was excised by mild acid treatment and characterized chromatographically and by its ultraviolet absorption and fluorescent spectra. The compound obtained after removal of the Y+ base from chick embryo tRNAPhe was characterized. 1. Chick embryo t RNAPhe looses by the removal of the Y+ base its phenylalanine acceptor capacity. 2. In this state it has a reduced sedimentation coefficient of 2.8 S. a low Tm value (22 °C), only rudimentary hyperchromicity, but unchanged electrophoretic properties. 3. The compound obtained after removal of the Y+ base from chick embryo tRNAPhe regains normal melting behaviour and phenylalanine acceptor capacity when exposed to special renaturation conditions. 4. The Km of the renatured form is 0.25 × 10-6 M and V = 220 pmol × min-1 × ml-1 as compared tO Km = 0.11 × 10-6 M and V = 370 pmol x min-1 × ml-1 for the native chick embryo tRNAPhe. [ABSTRACT FROM AUTHOR]

Complexes of cytochrome c and of an undecapeptide of the protein have been studied by means of Mössbauer spectroscopy in order to obtain information concerning the active heme site. The variation &the quadrupole splitting with the temperature pewits an evaluation of the distortions from octahedral symmetry around the iron ion in the heme group, and also an estimation of the spin-orbit constant. The effect of the different ligands such as CN-, F-, imidazol, etc., is discussed. [ABSTRACT FROM AUTHOR]

The effect of calcium ions on steroid-induced difference spectra of cytochrome P-450, and on pregnenolone formation, has been studied in rat adrenal mitochondria. In the presence of phosphate, addition of calcium chloride to suspensions of these mitochondria resulted in an increase in the inverted type-I difference spectrum induced by pregnenolone or methylandrostenediol and a disappearance of the type I spectrum induced by 25-hydroxycholesterol. The difference in the inverted type I spectrum between mitochondria from ether-stressed animals and those given cycloheximide was abolished. Cholesterol side-chain cleavage was increased, providing an NADPH generator was used as source of reducing equivalents. The difference in side-chain cleavage activity between mitochondria from ether-stressed animals and those given cycloheximide, was maintained. In the absence of phosphate, addition of calcium chloride again resulted in a loss of the type I difference spectrum induced by 25-hydroxycholesterol, but this time there was almost no change in the inverted type I spectrum induced by pregnenolone in mitochondria from rats subjected to ether anaesthesia, and the change in cycloheximide-treated rats was only about 50% of the change in the 25-hydroxycholesterol-induced difference spectrum. These observations are interpreted in terms of interconversions of the various forms of cytochrome P-450 associated with side-chain cleavage proposed to exist in intact adrenal mitochondria. Factors such as bovine serum albumin and EDTA, which increase respiratory control in these mitochondria, also stimulate cholesterol side-chain cleavage activity, as do magnesium ions, but without altering the magnitude of the steroid-binding spectra.

The following fluorescence parameters have been investigated: emission and excitation spectra, relative quantum yields, polarization values and lifetimes of the apo- and holoenzyme of lipoamide dehydrogenase. Furthermore, fluorescence perturbation techniques have been used to characterize qualitatively the tryptophan and flavin environment in the protein. Also emission spectra at low temperature have been recorded to examine changes occurring on strong immobilization of the enzyme. From lifetimes and quantum yields of the protein fluorescence it can be concluded that the molecular structures of the two apoenzymes, which can be prepared from this enzyme, are different. The quenched protein fluorescence of the holoenzyme is characterized by a very short fluorescence lifetime due to radiationless energy transfer from tryptophan to flavin. Excitation polarization spectra of flavin and tryptophan fluorescences show that the chromophores are rigidly bound to the protein. Luminescence studies at liquid nitrogen temperatures reveal that the triplet state of the tryptophanyl-residues is not involved in energy transfer to the flavin. Collisional fluorescence quenching with KI shows in the dimeric holoenzyme, in contrast with the free molecules, only a small reduction in fluorescence intensity of tryptophanyl and flavin residues. Charge effects might be responsible for these observations. It can be derived from the experimental results together with the indication that only one of the two tryptophans is transferring its excitation energy to the flavin, that the distance between donor and acceptor is 1.3-1.6 nm.

A study of reaction mechanisms of indole-3-acetate degradation by various peroxidases, in the absence of added hydrogen peroxide, has been performed employing stopped-fow and lowtemperature spectroscopic techniques. At pH 6 and for high [substrate]/[enzyme] ratios, peroxidase compound II is formed and is stable for several minutes. However, this enzyme compound becomes visible only after the transient appearance of ferroperoxidase and of compound III. This reaction process is apparently linked with the formation of 3-methyleneoxindole as the major end-product of indole-3-acetate degradation. On the other hand, when indole-3-acetate and peroxidase in stoichiometric concentrations are mixed at pH 4, only ferroperoxidase and compound III are formed and the process appears to be linked with the production of indole-3-aldehyde. Stopped-flow experiments show that indole-3-acetate is rapidly bound on peroxidase, this rapid binding step being followed by a slow one-electron transfer between indole-3-acetate and peroxidase. This reduction of ferriperoxidase is blocked at low temperature (-20 °C), whereas in these experimental conditions, peroxidation of indole-3-acetate in the presence of added hydrogen peroxide still occurs. Moreover, when compound III reacts with indole-3-acetate at low temperature (-15 °C}, this compound is regenerated as long as oxygen is present in the reaction medium. Neither ferroperoxidase nor compound I appear during this process. Most, if not all of the compound III is formed by oxygenation of the ferrous peroxidase. This compound III can react with an equimolar amount of indole-3-acetate to give ferrous peroxidase and indole-3-aldehyde. Moreover, compound III can react with two indole-3-acetate molecules leading to compound II formatiom. Because only small amounts of the organic peroxide derived from indole-3-acetate are present in the reaction medium, most of the compound II is formed by a two-equivalent reduction of... [ABSTRACT FROM AUTHOR]

Lactate dehydrogenase A4 from possum, chicken, and sardine muscle extracts and lactate dehydrogenase B4 from chicken heart, and sardine muscle extracts have been purified. Specific activity determinations confirmed previous studies showing the A4 isoenzyme to be approximately twice as efficient as the B4 isozyme and fish lactate dehydrogenase A4 to be considerably more active than the corresponding enzyme in warm-blooded animals. Spectrophotometric analyses demonstrated striking similarities in ε2801 mg/ml e a values, which reflected a uniform tryptophan content (5 residues lactate dehydrogenate subunit) in the enzyme, is analyzed. Sheep antisera were prepared against each isoenzyme and used in immunochemical titration experiments to measure the extent of inhibition, precipitation and interaction of the lactate dehydrogenase isozymes by the antisera. Lactate dehydrogenase antibodies differed in their immunochemical specificities according to the nature and source of the antigen. For example, the relative affinities of antiserum to possum A4 isozyme for the enzymes was in the order, possum A4>, chicken A4>, sardine A4..., sardine B4, chicken B4 which compared with the affinities for antichicken B4, chicken B4>, sardine B4... sardine, chicken and possum A4. In contrast to the results of other workers, isozymes A4 and B4 were shown to be immunochemically related. This observation is attributed to the higher degree of sensitivity in recognizing enzyme-antibody interactions using gel zymogram/immunochemical technique. The antisera were also used in investigating the immunochemical properties of isozymes A4, A4', B4, B4' and E4 from trout, and isozymes A4, B4 and C4 from pigeon, kangaroo and rat-tissue extracts. These vertebrate lactate dehydrogenase isozymes shared common antigenic determinants which reflected differing degrees of sequence homology and a common evolutionary origin. [ABSTRACT FROM AUTHOR]

Interactions of sperm whale ferrimyoglobin with the cationic detergent laurylpyridinium chloride in aqueous medium were studied by measurement of spectral changes in the Soret band of the prosthetic group. Spectrophotometric titrations were carried out in 0.02 M sodium phosphate buffer pH 7.1 at 25°C in the concentration ranges of 1 nnM-1 μM myoglobin and up to 10 mM laurylpyridinium chloride and also at various NaCl concentrations, up to 0.5 M. A thermodynamic analysis was carried out assuming in all-or-none interaction between the hemoprotein and the detergent. The apparent stoichiometric coefficients for the association of the detergent with the protein and the average standard free energy changes of the interactions were evaluated. The thermodynamic data obtained correspond to values characteristic for hydrophobic interactions. The dependence of the spectral transition curves on total myoglobin concentration found in the present system enabled an evaluation of equilibria involving dissociation of the prosthetic group from the ferrimyoglobin by the ac~ien of the cationic detergent. Direct experimental evidence obtained for this process by chromatography has been presented previously. This leads to interpretation of the spectral effects observed as a result of association between ferriheme and laurylpyridinium chloride molecules. [ABSTRACT FROM AUTHOR]

Specific interaction between α-NADH and glutamate dehydrogenase is demonstrated by difference spectroscopy, circular dichroism and fluorescence measurements. Quantitative binding studies in the preparative ultracentrifuge yield six identical α-NADH binding sites per oligomer with a dissociation constant of 20 μM. Evidence for six to eight additional, very weak α-NADH binding sites is presented. Excess ADP prevents the binding of α-NADH to the tight binding sites, indicating competition of the two nucleotides. In the enzymatic reaction, α-NADH is inactive as a coenzyme; however, like ADP, it is an activator of the reductive amination reaction of 2-oxoglutarate. α-NADH reduces the self-inhibition of high β-NADH concentrations and thus again parallels the effects caused by ADP. Contrary to β-NADH or β-NADH plus GTP, α-NADH or α-NADH plus GTP does not affect the dissociation-association equilibrium of glutamate dehydrogenase. The results are consistent with the assumption of six binding sites for α-NADH, which are identical with the ADP binding sites and most probably the six non-active β-NADH binding sites. [ABSTRACT FROM AUTHOR]

The interaction of αs1-casein with calcium ions at pH 7.0 has been studied, and it is shown that there is a stepwise increase in the fluorescence of the tryptophan residues of the protein as increasing amounts of Ca2+ are added, leading to eventual precipitation of the calcium-caseinate complex. The first of these steps appears to result from a conformational change induced by Ca2+, without which the protein cannot precipitate. Further steps arise from interaction between protein molecules to produce particles of about 120 nm in diameter, then final aggregation of these particles to give a precipitate. All of these changes result in changes in the fluorescence emission spectra of one or both tryptophan residues in the casein, although most of the change in fluorescence behaviour in the first step of the interaction probably arises from tryptophan-164 in the protein: [ABSTRACT FROM AUTHOR]

The chemical shift of the phosphorus resonance of various nucleotides has been studied as a function of pH in the absence and presence of ribonuclease A. The 31P-signal of the nucleotides shifts upfield upon protonation of the phosphate moiety. Thus titration curves and pK values are obtained when the 31P chemical shift is plotted against the pH value. The titration curves are analyzed in terms of interactions of the phosphate group with the base or ribose moieties of the nucleotide itself or with amino-acid side chains of the active site of ribonuclease A. The chemical shift of the phosphorus magnetic resonance of cytidine 2′-phosphate when this nucleotide is bound to ribonuclease A resembles that of the dianionic form of the free compound. Proton magnetic resonance studies indicated that the histidine residue 119 of ribonuclease A is bound to the phosphate group in enzyme-nucleotide complexes [4]. This is now confirmed, since the apparent pK value of the phosphate group of these complexes is the same as the pK value of histidine.ll9 determined by proton magnetic resonance spectroscopy. Possible arrangements of the hydrogen bonds between the imidazole group of histidine-ll9 and the phosphate group are discussed. From linewidth broadening due to chemical exchange, an average life time of the complex of cytidine 2′-phosphate with ribonuclease A is derived. [ABSTRACT FROM AUTHOR]

A number of peptide substrates of the general structure Ac-Lxn … -Lx2-Lx1-Gly-N'H2, have been synthesized and their α-chymotrypsin-catalyzed hydrolyses studied. The acylation rate constants, k23 (= kcat), and the dissociation constants of the enzyme-substrate complexes, KEA (= Km), have been determined using a modified pH-stat and a numerical method for the acquisition and processing of the data. On the basis of these constants a quantitative relationship between the peptide structure N-terminal to the cleaved bond and reactivity has been determined. The results are shown to be consistent with the enzyme-substrate interaction scheme proposed in 1971 by Segal et al. (Biochemistry 10, 3728). A comparison of the k23/KEA values indicates that the influence of a single structural change on the overall reactivity is virtually independent of the nature of the remainder of the substrate. In addition a comparison of the k23 and KEA values shows that, in general, changes in substrate structure are mainly reflected by changes in k23 rather than in KEA. A few exceptions have been found: KEA or KEA and k28 change when glycine is introduced at the x2 position, when this glycine is replaced by alanine or when alanine is introduced at the x3 position. [ABSTRACT FROM AUTHOR]

The environment of the active site of creatine kinase has been investigated by means of three chromophoric reagents :2-hydroxy-5-nitrobenzyl bromide, 2-methoxy-5-nitrobenzyl bromide and 2-(dansylamino)ethyl monophosphate. 1. The first two reagents are incorporated at the essential thiol groups. The effect of pH on the spectra of the 2-hydroxy-5-nitrobenzyl-labelled creatine kinase suggests that this reagent lies inside the active site near an ionized residue, while the 2-methoxy-5-nitrobenzyl group is apparently exposed to the medium. Conformational changes induced by the binding of different ligands, including nucleotide substrates or anions, produce only perturbations of the 2-hydroxy-5-nitrobenzyl chromophore. 2. The 2-(dansylamino)ethyl monophosphate (which is really an analogue of the nucleotide substrate) interacts with the nucleotide site of creatine and arginine kinases in a relatively hydrophobic environment. [ABSTRACT FROM AUTHOR]

The birth-death theme has fascinated humankind for centuries. It can be discovered in many cultural practices, ranging from childnaming and memorialization rituals to the transmission of political power, and birth-death dynamics have been probed by Hegel, Jung, Freud, and other influential thinkers. Surprisingly little has been done, however, to formulate and test specific hypotheses. This article begins with the simplistic proposition: ‘We fear death—and that is why we reproduce after our kind.’ Exploratory data and some methodological and theoretical considerations are presented, including the concept of a spectrum of death-transcending strategies, fertility being hut one. An understanding of our complex orientations toward both propagation and mortality appears necessary in view of emerging pressures to manipulate population structure and divide one generation from another. [ABSTRACT FROM AUTHOR]

Examines the importance of spectrum analysis on frequency domain regressions. Types of spectral regressions; Determination of the spectral shape of economic variables; Approximation of the filter windows.

Smodingium argutum possesses in its sap a C17-catechol which brings about a dermatitis of poisonivy type. Mass spectrometry shows that American poison ivy, an oriental sumac and Smodingiurn all produce in differing amounts a series of related compounds which are responsible for skin reactions. History, ecology, botany, histology and treatment are reviewed. [ABSTRACT FROM AUTHOR]

A conference paper on the the structure of apatites and atomic substitutions is presented. It discusses the presence of atoms in teeth and provides details about the arrangement and characteristics of these atoms. Spectroscopic techniques and diffraction techniques are used to study the packing and bonding of atoms.

Presents an article which aimed to compute estimates of the spectra and cross-spectrum from a realization of a bivariate time series by averaging the periodogram over neighbouring frequencies.

The section of "Chemical Testing and Analysis," focuses on the chemical techniques used in the process of identification and quantitative determination of textile finishes. It presents several techniques used to identify different types of textile finishes such as thin-layer chromatography and ultraviolet spectroscopy for the separation, identification, and quantitative analysis of fluorescent brightening agents (FBAs), hydrolysis, spectroscopic analysis for the identification of easy-care resin finishes and infrared spectroscopy of suitable extracts for flame radiant finishes.

The prototype of fitting polynomials to equally-spaced data—in which the equal-spacing is theoretically precise and the data is accurate to many decimal places—arises in the analysis of band spectra. A hard look at such examples forces us to reexamine our thinking on such diverse issues as: How to formulate such problems, the use of robust/resistant techniques in polynomial regression, which coordinates to use and why, the basic properties of linear least squares, choices in stopping a fit, and improved ways to describe our answers. Our results and attitudes apply rather directly to other situations where we are fitting a sum of functions of a single variable. When two or more different variables, subject to error, blunder, or omission, underlie the carriers to be considered, regression/ fitting problems are likely to need not only the considerations presented here, but others as well. To a varying extent, the same will be true of nonlinear fitting/regression problems. [ABSTRACT FROM AUTHOR]

With increasing use of open-end spinning, it is appropriate to examine the credibility of the many claims of a color difference phenomenon between ring spun and open-end spun yarns after dyeing. While it is apparent that yarns prepared by open-end spinning have physical properties different from conventional ring spun yarns for the same fiber, the practical dyer would not expect variation in dyeability or uptake. However, differences in appearance are obvious, but these obvious differences have not been scientifically explained in the literature. An investigation of the physical and chemical properties of yarn prepared by the two systems reveals that fiber orientation differences in nominally identical yarns markedly affect apparent color. The apparent color differences are explainable, and experiments to measure color yield by reflectance and absorption spectroscopy are described. [ABSTRACT FROM AUTHOR]

An increasing use of spectrophotometric transmittance measurements to determine the relative dye strength of incoming shipments to a standard type has been noted for users of dyes. For many dyes, the results determined from solution measurements are in agreement with those determined by application tests on the intended substrate. The purpose of this paper is to point out the exceptions; i.e., those factors that affect the accuracy and precision of measuring dye concentrations in solution. The solution variables examined are categorized into three groups: group 1—effect of additives, concentration, dissolution aids, hydrogen ion activity and solvents on the absorption spectrum; group 2— effect of dye interaction, fluorescence, irradiation, plating, solution heating and temperature on the absorption spectrum; group 3—effect of hydrolysis, interfering ions, ionic strength, light fading and redox potential on the absorption spectrum. A brief description of each solution variable is included together with suggestions on methods of preparing the colorant solutions to avoid these effects. Illustrations of most of these solution effects on currently available dyes are included. [ABSTRACT FROM AUTHOR]

It has been shown that flame retardant fibers, fiber additives and finishes in fabrics can be identified by their infrared spectra. The rapid and nondestructive multiple internal reflection technique was found to be suitable for the identification of most inherently flame retardant fibers. If the fabric bas an open, coarse surface, the MIR spectrum may be of weak intensity, but it will be sufficient for identifying the fiber present in the fabric. A rapid solvent extraction procedure requiring about 1 min was used for identifying flame retardant fiber additives and finishes in fabrics. The fabric sample was placed on a KRS-5 crystal, 1-2 ml of a suitable solvent was added and the fabric removed after 30 sec. After the solvent evaporated from the crystal, an infrared spectrum of the residual thin film was obtained by the MIR procedure. Infrared spectra were obtained for 14 flame retardant fibers and finishes in fabrics. These spectra can serve as references for future analyses. As additional flame retardant fibers and finishes become commercially available, their infrared spectra can be obtained by these techniques and added to the present file. [ABSTRACT FROM AUTHOR]

The degree of demineralization of the enamel surface was evaluated by means of two different methods, namely by the 32P uptake method, and by determining the calcium release directly, using atomic absorption spectroscopy. The accuracy of the 32P uptake method was assessed. When applied on groups of young and old premolars separately, the 32P uptake method proved to give reliable information about differences between the two groups with respect to the degree of demineralization under equal experimental conditions. For comparison the two methods were used simultaneously in 20 separate tests with varying experimental conditions. The comparison of the results obtained by the two methods showed very good correspondence. [ABSTRACT FROM AUTHOR]