Showing papers by "University of Wisconsin-Madison published in 1974"
TL;DR: The results suggest that tissue GSH-Px can be used as an indicator of animal Se status, but other factors such as age, sex, and dietary vitamin E may have to be considered.
Abstract: Experiments were conducted with male rats to quantitate the relation ship between dietary selenium (Se) intake and the amount of the enzyme glutathione peroxidase (GSH-Px) in erythrocytes and liver. Weanling male rats were fed torula yeast-based diets with 0, 0.05, 0.1, 0.5, 1.0, or 5.0 ppm Se supplemented as sodium selenite. Liver GSH-Px fell to undetectable levels (<1% of that found in the weanling rats) within 24 days in the O ppm Se group; feeding 0.1 ppm Se, or greater, caused liver GSH-Px to increase above that found in the weanling rats. The erythrocyte GSH-Px response to lack of dietary Se was somewhat smaller in magnitude and more gradual; however, only 21% of initial erythrocyte GSH-Px activity remained in the unsupplemented group after 66 days. Increased dietary Se resulted in corresponding increases of erythrocyte GSH-Px activity. Resupplementing with 0.1, 0.5, or 5.0 ppm Se elevated the depressed erythrocyte GSH-Px levels of the deficient rats. Increased dietary Se provided for both faster elevation, and higher maximal GSH-Px activity which in all cases was achieved 60 to 90 days after resupplementation. The results suggest that tissue GSH-Px can be used as an indicator of animal Se status, but other factors such as age, sex, and dietary vitamin E may have to be considered. Lack of GSH-Px in livers of Se-deficient rats may explain the liver necrosis observed when the diet is also deficient in vitamin E and sulfur-containing amino acids. J. Nutr. 104: 580-587,
1,103 citations
TL;DR: This article empirically assesses the relationship between power and the sources of power in a channel of distribution that has a well-defined power source: the franchisor-franchisee channel.
Abstract: This article empirically assesses the relationship between power and the sources of power in a channel of distribution that has a well-defined power source: the franchisor-franchisee channel. In ad...
880 citations
TL;DR: In this paper, the authors deal with questionnaires tapping fears of snakes, spiders, mutilation, and public speaking, and find consistent distribution characteristics of the scales across several samples.
728 citations
TL;DR: The conventional interacting group is compared with nominal and delphi groups in terms of the quantity of ideas generated and perceived satisfaction of participants as mentioned in this paper, where the nominal group was compared with the delphi group.
Abstract: The conventional interacting group is compared with nominal and delphi groups in terms of the quantity of ideas generated and perceived satisfaction of participants. On an applied fact-finding prob...
715 citations
TL;DR: While the unique characteristics of the industrial salesman's role has stimulated much recent research, this uniqueness requires the development and use of occupation-specific measurement instrumen... as discussed by the authors, the authors
Abstract: While the unique characteristics of the industrial salesman's role has stimulated much recent research, this uniqueness requires the development and use of occupation-specific measurement instrumen...
593 citations
TL;DR: The posteromedial barrel subfield in the rat is a special region of the barrel field in which the barrels are arranged in five rows and are larger than elsewhere and are filled with small neurons nearly throughout the thickness of layer IV.
Abstract: The cytoarchitecture of layer IV of SmI neocortex of the rat has been studied in sections parallel and perpendicular to layer IV. The neurons of layer IV are arranged into discrete multicellular units, called barrels, which we have previously described in both mouse and rat. Using the barrels as markers, it is possible to outline precisely a cytoarchitectonic field—the barrel field—which (1) is confined to SmI. (2) has a consistent appearance from hemisphere to hemisphere, and (3) contains at least 220 barrels. A special region of the barrel field has been identified—the posteromedial barrel subfield (PMBSF)—in which the barrels are arranged in five rows and are larger than elsewhere. However, in contrast to other barrels in the rat barrel field and to the barrels that make up the PMBSF in the mouse, the PMBSF barrels in the rat are filled with small neurons nearly throughout the thickness of layer IV.
From experimental evidence, it has been possible for the first time to establish consistent homologies between small groups of neocortical neurons in layer IV. The most surprising finding is that homologous barrels in the PMBSF of two closely related species, the rat and the mouse, have such a different cytoarchitectonic appearance. On the basis of this observation, we suggest that a careful study of these PMBSF barrels in the mouse, the rat and other species may provide a clue to understanding how neocortical neuronal circuits of varying complexity are assembled.
458 citations
TL;DR: It is found that changes in the direction of flagellar rotation indeed constitute the basis of chemotaxis: addition of attractants causes counter clockwise (CCW) rotation, whereas repellents causeClockwise (CW) rotation.
Abstract: BERG and Anderson1 recently argued from existing evidence that bacteria swim by rotation of their helical flagella. Silver-man and Simon2 have now provided a clear demonstration of this. By means of antibodies specific for flagellar components, they tethered cells to microscope slides or to each other and observed rotation of the cell bodies. The cells were able to stop and to rotate in either direction. It seemed possible, as they proposed2, that cessation, or reversal of flagellar rotation might be involved in bacterial chemotaxis. Accordingly, we used wild-type and chemotaxis-defective mutant cells of Escherichia coli tethered to microscope slides in a manner similar to that of Silverman and Simon2, and stimulated them by sudden increases of chemotactic agents. We found that changes in the direction of flagellar rotation indeed constitute the basis of chemotaxis: addition of attractants causes counter clockwise (CCW) rotation, whereas repellents cause clockwise (CW) rotation.
440 citations
TL;DR: In this article, a business cycle theory based on Schumpeter's model is proposed to explain the effect of technological change on economic growth and cyclical instability in the US economy.
Abstract: Not too many years ago most economists were content to treat the process of technological change as an exogenous variable. Technological change – and the underlying body of growing scientific knowledge upon which it drew – was regarded as moving along according to certain internal processes or laws of its own, in any case independently of economic forces. Intermittently, technological changes were introduced and adopted in economic activity, at which point the economic consequences of inventive activity were regarded as interesting and important – both for the contribution to long-term economic growth and to short-term cyclical instability. Schumpeter, for example, saw the engine of capitalist development as residing in this innovative process in the long run, and at the same time he developed a business cycle theory which centred upon the manner in which the capitalist economy absorbs and digests its innovations. In Schumpeter's model, exogenous technological changes stimulated investment expenditures, the variations of which, in turn, generated cyclical instability. In the years after the Second World War the economist's attitude gradually changed. The vast expenditures on Research and Development made it increasingly obvious that inventive activity was – or could be made to be – responsive to economic needs (or even to noneconomic needs if such needs received sufficient financial support). Clearly much of the search activity of R and D was highly purposive: business firms were looking for new techniques in specific categories of products, they spent much money upon this search, and they were sometimes highly successful. Similarly, government agencies had long directed research into specific problem areas and in some cases had achieved conspicuous successes – as in agriculture.
433 citations
TL;DR: It is concluded that the binding of S17 to 16 S RNA is specific and determined the positions of S15, S16, S17, and S12 in the assembly map and have clarified subsequent interactions depending on these proteins.
428 citations
TL;DR: The overall rate of nucleotide substitution within the primates is again found to be less than the rest of the mammals and the procedure employed provides estimates of the relative time of divergence which correlate well with paleontological dates.
Abstract: The vertebrate evolution of four proteins (6 andβ hemoglobins, cytochromec, and fibrinopeptide A) is examined via a maximum likelihood procedure. The fundamental hypothesis is that the process of nucleotide substitution as revealed by the minimum phyletic distance procedure (Fitch, 1971) is Poisson with a constant time average for each protein. The method allows the simultaneous estimation of the relative times of divergence of all common ancestors while utilizing the information from all four proteins. It also affords the possibility of statistically testing several biologically meaningful hypotheses. The results are the following:
401 citations
TL;DR: This work has surveyed a number of chemicals for their ability to repel Escherichia coli and suggested that each class corresponds to a distinct chemoreceptor.
Abstract: Several methods for detecting or measuring negative chemotaxis are described. Using these, we have surveyed a number of chemicals for their ability to repel Escherichia coli. Although most of the repellents are harmful compounds, harmfulness is neither necessary nor sufficient to make a compound a repellent. The repellents can be grouped into at least nine classes according to (i) competition experiments, (ii) mutants lacking certain of the negative taxes, and (iii) their chemical structure. The specificity of each class was studied. It is suggested that each class corresponds to a distinct chemoreceptor. Generally, non-chemotactic mutants lack both positive and negative chemotaxis, and l-methionine is required for both kinds of taxis. Repellents at very low concentrations are not attractants, and attractants at very high concentrations are not repellents.
TL;DR: Urban and suburban environments, commonly shunned by field ornithologists, provide a special opportunity for studying the formation and regulatory dynamics of avian communities, especially in recently developed areas such as the American West.
Abstract: Urban and suburban environments, commonly shunned by field ornithologists, provide a special opportunity for studying the formation and regulatory dynamics of avian communities, especially in recently developed areas such as the American West. The establishment of cities may be regarded as ecological experiments in which a relatively simple array of novel features and resources (lawns, ornamentals, buildings, telephone lines, traffic, etc.) are rather suddenly introduced into a restricted area from which many of the natural features have been removed. The new synthetic habitats lie open to invasion and colonization by any birds that can reach them, utilize their peculiar constellation of resources, and survive their special hazards. The structure and balance of the new community will reflect not only the nature of these local resources and features but also the interactions
TL;DR: In this paper, it was shown that a supernova rate on the order of 1 per 50 years in the gaseous disk of our Galaxy is sufficient to generate and maintain a mesh of interconnected tunnels containing very low-density gas.
Abstract: It is found that a supernova rate on the order of 1 per 50 years in the gaseous disk of our Galaxy is sufficient to generate and maintain throughout the interstellar medium a mesh of interconnected tunnels containing very low-density gas. This tunnel system would have a density of approximately 0.01 per cu cm, a temperature of about 1,000,000 K, very low magnetic field strength, tunnel radii of about 10 pc, and would occupy roughly half the interstellar volume. Such a tunnel network may already have been observed in soft X-ray emission, in ultraviolet absorption of O VI against background stars, in the seemingly chaotic distribution of local H I, and in the stringy appearance of velocity-correlated large-scale H I features.
TL;DR: Chromatids singly and doubly substituted with BrdU acquire differential Giemsa stain affinities after treatment at 88° C for 10 minutes in 1.0 M Na phosphate buffer.
Abstract: Sister chromatid exchanges are sharply demarcated in Giemsa stained metaphase preparations of Chinese hamster ovary cells and human peripheral leukocytes. Chromatids singly and doubly substituted with BrdU acquire differential Giemsa stain affinities after treatment at 88° C for 10 minutes in 1.0 M Na phosphate buffer (pH 8.0).
TL;DR: A controlled study of the audiences of two newspapers with differing content emphases was conducted during the 1972 presidential campaign as discussed by the authors, and the results show only moderate support for the agenda-setting hypothesis; the honesty in government issues, given heavy play in one of the two newspapers, failed to generate much enthusiasm among readers of either paper.
Abstract: The agenda-setting hypothesis asserts that the media have an effect indirectly by choosing certain issues for emphasis, thus making those issues more salient to the audiences. The hypothesis, stated in such general terms, presents formidable conceptual and methodological difficulties that are dealt with in this article. A controlled study of the audiences of two newspapers with differing content emphases was conducted during the 1972 presidential campaign. The results show only moderate support for the agenda-setting hypothesis; the honesty in government issues, given heavy play in one of the two newspapers, failed to generate much enthusiasm among readers of either paper. In addition the results suggest agenda setting is not a broad and unqualified media effect. Predicted differences mainly were restricted to the less involved and less motivated partisans who were heavily dependent on the newspapers for their political news. Finally, the importance of studying issue saliences apart from political attitud...
TL;DR: In this article, a semiquantitative model is proposed to explain the complex molecular orientation distribution, observed in injection moldings of amorphous polymers, incorporating flow and heat transfer mechanisms coupled with molecular theories.
Abstract: A semiquantitative model is proposed to explain the complex molecular orientation distribution, observed in injection moldings of amorphous polymers. The model incorporates flow and heat transfer mechanisms coupled with molecular theories. The orientation in the surface skin is related to steady elongational flow in the advancing front, whereas the orientation in the core is related to the shear flow, behind the front, between two solidyfying layers. Coupled with the elongational and shear-induced orientations, a molecular relaxation process takes place which is determined by the rate of heat transfer. The bead-and-spring macromolecular theory was used to calculate root mean end-to-end distances of macromolecules in the various flow fields, as well as the relaxation process.
TL;DR: In the Gramineae the three C4 groups are distinguished by anatomical and ultrastructural characteristics of bundle-sheath chloroplasts, and the dicotyledonous C4 species examined fall into two groups: those having high NADP-malic enzyme and thoseHaving high NAD- malic enzyme.
Abstract: C4 plants can be divided into three groups based on differences in activities of three decarboxylating enzymes: NADP-malic enzyme, NAD-malic enzyme, and phosphopyruvate carboxykinase.
TL;DR: Parenchymal cells from adult rat liver which had been fully regenerated were isolated and cultured in nonproliferating monolayers in vitro andTyrosine aminotrasferase activity in the cells was elevated when the culture medium was supplemented with hydrocortisone or dexamethasone.
Abstract: Parenchymal cells from adult rat liver which had been fully regenerated were isolated and cultured in nonproliferating monolayers in vitro. The optimum conditions for attachment of these cells to Falcon plastic dishes were determined. When approximately 1.0×105 nuclei per cm2 suspended in Ham's F-12 medium with 0.5 μg of insulin per ml and 25% fetal calf serum were incubated at 37°C for 24 hr, about 50% became attached and contiguous. When the above medium was supplemented with synthetic buffers 2-(N-morpholino) ethanesulfonic acid (MES) andN-tris (hydroxymethyl) methyl-2-aminoethanesulfonic acid (TES), the presence of 15% fetal calf serum also allowed an attachement effiency of 50%. Tyrosine aminotrasferase activity in the cells was elevated when the culture medium was supplemented with hydrocortisone or dexamethasone. The largest increases were observed after 72 hr of culture. Cycloheximide prevented the increase.
TL;DR: In this article, the authors employ the theory of weak convergence of cumulative sums to the Wiener Process to obtain large sample theory for cusum tests and study the effect of serial correlation on the performance of the one-sided cusUM test.
Abstract: We employ the theory of weak convergence of cumulative sums to the Wiener Process to obtain large sample theory for cusum tests. These results provide at theoretical basis for studying the effects of serial correlation on the performance of the one-sided cusum test proposed by Page (1955). Particular attention is placed on the first, order auto-regressive and first order moving average models. In order to treat the sequential version of the test, we employ the same Wiener process approximation. This enables us to study the effect of correlation not only on the average run length but, more importantly, on the run length distribution itself. These theoretical distributions are shown to compare quite favorably with the true distribution on the basis of a Monte Carlo study using normal observations. The results on the changes in the shape of the run length distributions show that more than average run length should be considered. Our primary conclusion is that the cusum test is not robust with respect, to dep...
TL;DR: In this article, approximate conditions for genetic polymorphism in temporally and spatially varying environments are presented for loci which are intermediate at the level of fitness or gene function, and the conditions suggest that polymorphism will be more likely in more variable environments while unlikely in constant environments.
Abstract: Approximate conditions for genetic polymorphism in temporally and spatially varying environments are presented for loci which are intermediate at the level of fitness or at the level of gene function. The conditions suggest that polymorphism will be more likely in more variable environments while unlikely in constant environments. Biochemical evidence is presented to justify the assumption of heterozygote intermediacy. Observations on natural populations are cited which substantiate the claim that allozymic polymorphism is primarily due to selection acting on environmental variation in gene function.
TL;DR: In this paper, the authors concluded that there are no significant differences between the sexes in arithmetic achievement before seventh grade, but boys surpass girls after seventh grade in arithmetic reasoning in high school, and that the evidence would suggest to the teacher that boys will achieve higher than girls on tests dealing with mathematical reasoning while the girls will perform higher than boys on tests of computational ability.
Abstract: Are there really sex differences in mathematics achievement? Garai and Scheinfeld (1968), in a review basically of pre-1960 psychological literature, concluded that no significant sex differences were found in computational tasks, but "in arithmetical reasoning and mathematical ability males have consistently been observed to perform better than females as a group [p. 252]." Maccoby (1966, p. 26) in a review including both psychological and educational literature published before 1965 concluded that: (a) girls learn to count at an earlier age; (b) there are no consistent differences in computation throughout the grades; (c) during grade-school years some studies show boys beginning to forge ahead on tests of arithmetical reasoning although a number of studies reveal no difference on this dimension; and (d) boys excel at arithmetic reasoning in high school. Several authors directly related to the mathematics education profession have also drawn conclusions from the reported literature. Glennon and Callahan (1968) state that "the evidence would suggest to the teacher that boys will achieve higher than girls on tests dealing with mathematical reasoning while the girls will achieve higher than boys on tests of computational ability [p. 30]." An equally prestigious review of research (Suydam & Riedesel, 1969, p. 129) states that there are no significant differences between the sexes in arithmetic achievement before seventh grade, but boys surpass girls after seventh grade. Suydam and Weaver stated in 1970: "In general boys scored higher in mathematical reasoning and girls were better in fundamentals, though some conflicting evidence has been presented [p. 4]." Still other studies report no significant achievement differences associated with sex, and most researchers conclude that what little difference exists is not sufficient to influence curriculum decisions. Aiken (1971) states that "sex differences in mathematical abilities are, of course, present at the kindergarten level and undoubtedly earlier [p. 203]." One could conclude from these reviews that although some authors believe the sex difference in mathematical achievement has
TL;DR: In this paper, a logarithmic model for trace element partitioning was further developed for use in describing the behavior of the elements during solidification of the Skaergaard intrusion in order to optimize within limits of uncertainty of measured values, such as bulk composition, zone size, relative proportions of cumulus plus adcumulus minerals, zone mineralogy, and distribution coefficients.
TL;DR: The microtubules of flagella have an intrinsic polarity reflected in their side-arm attachments and in their directionality of growth, as well as a limited extent of proximal addition and growth on the B-tubule.
TL;DR: The multidrug data presented in this report constitute a strong argument for combination drug products whenever multi-drug therapy is indicated.
TL;DR: In this article, the authors established quantitative bounds for the variation of an isolated local minimizer for a general nonlinear program under perturbations in the objective function and constraints, and applied these bounds to establish rates of convergence for a class of recursive nonlinear-programming algorithms.
Abstract: This paper establishes quantitative bounds for the variation of an isolated local minimizer for a general nonlinear program under perturbations in the objective function and constraints. These bounds are then applied to establish rates of convergence for a class of recursive nonlinear-programming algorithms.