Showing papers by "University of Colorado Boulder published in 1978"
TL;DR: A paper-and-pencil test of spatial visualization was constructed from the figures used in the chronometric study of Shepard and Metzler (1971) as discussed by the authors, which showed substantial internal consistency (Kuder-Richardson 20 =.88), a test-retest reliability (83), and consistent sex differences over the entire range of ages investigated.
Abstract: A new paper-and-pencil test of spatial visualization was constructed from the figures used in the chronometric study of Shepard and Metzler (1971). In large samples, the new test displayed substantial internal consistency (Kuder-Richardson 20 = .88), a test-retest reliability (.83), and consistent sex differences over the entire range of ages investigated. Correlations with other measures indicated strong association with tests of spatial visualization and virtually no association with tests of verbal ability.
2,320 citations
TL;DR: In this article, a model in which there is a supercompact cardinal κ which remains super-compact in any κ-directed closed forcing extension was found, where κ is defined as a cardinal which can not be replaced by any other cardinal.
Abstract: A model is found in which there is a supercompact cardinal κ which remains supercompact in any κ-directed closed forcing extension.
362 citations
TL;DR: PMSF-inhibited chymotrypsin did not occur within 1 week at 25°C at pH 7.0, and stock solutions of PMSF in 100% isopropanol are stable at25°C for months if not longer.
321 citations
TL;DR: Preliminary results suggest that certain upper-respiratory-tract viral infections may affect theophylline metabolism.
290 citations
289 citations
TL;DR: Evidence is presented which suggests that polysaccharides similar to rhamnogalacturonan II are present in the primary cell walls of the three other dicotyledonous plants examined.
Abstract: This paper describes the isolation and characterization of rhamnogalacturonan II, a hitherto unobserved component of the primary cell walls of dicotyledonous plants. Rhamnogalacturonan II constitutes 3 to 4% of the primary cell walls of suspension-cultured sycamore (Acer pseudoplatanus) cells. Rhamnogalacturonan II is a very complex polysaccharide yielding, upon hydrolysis, 10 different monosaccharides including the rarely observed sugars apiose, 2-O-methylxylose, and 2-O-methylfucose. In addition, rhamnogalacturonan II is characterized by the rarely observed glycosyl interconnections of 2-linked glucuronosyl, 3,4-linked fucosyl, and 3-linked rhamnosyl residues. These glycosyl linkages have never previously been detected in primary sycamore cell walls. Evidence is presented which suggests that polysaccharides similar to rhamnogalacturonan II are present in the primary cell walls of the three other dicotyledonous plants examined.
286 citations
TL;DR: In this paper, the authors reviewed the observational evidence on the strength of the coronal magnetic field above active regions and found that the relation 279-01, 1.02 ≲ R/R⊙ ≲ 10 is consistent with all the data to within a factor of about 3.
Abstract: The observational evidence on the strength of the coronal magnetic field above active regions is reviewed. Recent advances in observations and plasma theory are used to determine which data are the more reliable and to revise some earlier estimates of field strength. The results from the different techniques are found to be in general agreement, and the relation 279-01, 1.02 ≲ R/R⊙ ≲ 10 is consistent with all the data to within a factor of about 3.
285 citations
TL;DR: It is suggested that at present double-blind food challenge is an indispensible tool for the unequivocal evaluation of adverse reactions to foods.
Abstract: In order to extend previous investigations of adverse reactions to foods performed at this institution, 68 children, aged 5 mo to 15 yr, were studied. All subjects reported a history of adverse reaction to ingestion of one or more of the 14 foods under study. Sixteen of 43 subjects, 3 yr of age or older, had 22 adverse reactions during 94 food challenges with one or more of the 14 foods. All reactions confirmed were to peanut or other nuts, milk, egg, and soy. Skin testing with 1:20 weight/volume concentrations of food extracts applied by the puncture technique produced a net wheal reaction 3 mm or greater in all subjects 3 yr of age or older in whom double-blind food challenges confirmed the history of adverse reaction. Thirteen of 25 children less than 3 yr of age manifested adverse reactions during 49 food challenges. Skin testing by puncture technique produced a net wheal 3 mm or greater in 9 children less than 3 yr of age in whom food challenge elicited a clinical response within 2 hr. One of 4 subjects less than 3 yr of age in whom the adverse reaction occurred more than 4 hr after food challenge exhibited a wheal to puncture skin test of 3 mm or greater. These studies suggest that at present double-blind food challenge is an indispensible tool for the unequivocal evaluation of adverse reactions to foods.
276 citations
TL;DR: This article found that readers write better summaries of stories for which they have an appropriate schema than for stories without a schema, and that this effect is related to the overall organization of the story and does not lie at the level of single sentences.
Abstract: Experiment I shows that readers write better summaries of stories for which they have an appropriate schema than for stories for which they lack a schema, and that this effect is related to the overall organization of the story and does not lie at the level of single sentences. Raters who judged the quality of the summaries found summaries from stories that corresponded to a familiar story schema more informative than those from stories for which they did not have an appropriate schema, even when the latter accurately summarized the story in question. In Experiment II, sequential recall of a story which deviated in various ways from the subjects’ story schema resulted in poor performance: the stories tended to break up after a chain of five sequential recalls, in contrast to a well‐structured, schema‐based story that was usually recalled quite completely and without serious distortions. It was suggested that a culture‐specific schema aids both in comprehending and reconstructing stories.
264 citations
TL;DR: Freeze-fracture electron microscopy has been used to investigate the size, form, distribution and supramolecular organization of chlorosomes (chlorobium type vesicles) in Chloroflexus aurantiacus J-10fl, a phototrophic, filamentous gliding bacterium.
Abstract: Freeze-fracture electron microscopy has been used to investigate the size, form, distribution and supramolecular organization of chlorosomes (chlorobium type vesicles) in Chloroflexus aurantiacus J-10fl, a phototrophic, filamentous gliding bacterium. The chlorosomes, that appear tightly attached to the cytoplasmic membrane, have the form of flat, elongated sacs with rounded ends, and measure 106±24×32±10×12±2nm. They are randomly distributed, and in most instances their longitudinal axis makes an angle of 30–60° to the filament axis. Each chlorosome consists of a core and an approx. 2 nm thick envelope. The core is filled with rod-shaped elements (approx. 5.2 nm in diameter) made up of globular subunits with a periodicity of approx. 6 nm. The rod elements extend the full length of the chlorosome. The membrane-associated envelope layer is marked by extremely fine striations with a repeating distance of 2.5–3nm, while the envelope layer adjacent to the cytoplasm exhibits no discernable substructure. The margins of the vesicles are delineated by regularly spaced 7 nm particles.
263 citations
TL;DR: Petrographic studies of first-cycle desert alluvium of Cenozoic age in the southwestern United States and northwestern Mexico show that the mineralogy, texture, and chemical composition of the deposits have been changed diagenetically.
Abstract: Petrographic studies of first-cycle desert alluvium of Cenozoic age in the southwestern United States and northwestern Mexico show that the mineralogy, texture, and chemical composition of the deposits have been changed diagenetically. The mineralogy has been changed by addition of mechanically infiltrated clay, partial removal of framework grains of feldspars and ferromagnesian silicates, and precipitation of authigenic potassium feldspar, zeolite, montmorillonite, quartz, hematite, and calcite. The texture has been changed by three processes: (1) infiltration of detrital clay and formation of authigenic montmorillonite, which form interstitial clayey matrix not present in the original sediment, (2) formation of voids where framework grains have been dissolved, and (3) in situ formation of silt and other fine-grained sizes. The chemical composition has been changed by infiltration of clay minerals that are richer in aluminum and lower in alkalis and alkaline earths than the original sediment and by removal in ground water of some of the ions released by dissolution and replacement of framework grains. These changes have significantly increased the mineralogical maturity and decreased the textural maturity of the sediments diagenetically. Four major conclusions are drawn from the studies. (1) Some or all of the diagenetic alterations observed in these deposits probably occurred in many analogous ancient first-cycle alluvial deposits at a comparable time in their history. (2) Prolonged movement of ground water through first-cycle deposits may cause unstable minerals to be removed completely, or nearly so, leaving no direct evidence that they were important original constituents of the deposits. (3) Ancient first-cycle alluvium probably rarely, if ever, has the same mineralogy, texture, or chemical composition that the sediments had when deposited. (4) The present mineralogy, texture, and chemical composition of ancient first-cycle alluvial deposits probably do not accurately reflect lithology and climate in the source area or the nature of depositional currents and other environmental factors in the depositional basin.
TL;DR: Since the selection experiment is replicated, other variables which are found to be reliably different among the high, control, and low lines are likely to be causally related to open-field activity; thus these selected lines of mice may be of use to other investigators.
Abstract: High and low lines resulting from 30 generations of bidirectional selection for open-field activity have nonoverlapping distributions and more than a thirtyfold difference in mean activity. Open-field defecation scores of lowactive lines are approximately 7 times higher than those of high-active lines, substantiating earlier reports of a large, negative genetic correlation between these characters. Since the selection experiment is replicated, other variables which are found to be reliably different among the high, control, and low lines are likely to be causally related to open-field activity; thus these selected lines of mice may be of use to other investigators.
TL;DR: In this paper, Reinhardt and Solovay present an expository paper on strong axioms of infinity and elementary embeddings, which is based on a series of lectures on the subject by t(anamori, 1975) and a set of notes circulated thereafter.
TL;DR: This method is now being used routinely for the determination of the concentration and ratios of nucleosides in urine from patients with different types of cancer and in chemotherapy response studies.
TL;DR: If you are one of the people love reading as a manner, you can find the sociobiology debate as your reading material.
Abstract: In wondering the things that you should do, reading can be a new choice of you in making new things. It's always said that reading will always help you to overcome something to better. Yeah, the sociobiology debate is one that we always offer. Even we share again and again about the books, what's your conception? If you are one of the people love reading as a manner, you can find the sociobiology debate as your reading material.
TL;DR: In this article, a number of 4-substituted pyridines were found to be acylation catalysts, the most effective being 4-pyrrolidinopyridine 4 and 1,1,3,3-tetramethyl-4-(4pyridyl)guanidine 8.
TL;DR: Assays using an extreme COOH-terminal ACTH antiserum indicate that the 31K ACTH/endorphin molecule in rat anterior and intermediate pituitary is similar to the pro-ACTH/end Morphin molecule from mousepituitary tumor cells, and sequential immunoprecipitation with ACTH and endorphin antisera demonstrates directly that a single molecule has antigenic determinants for both ACTH
Abstract: Extracts of rat anterior and intermediate-posterior pituitary were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and assayed for immunoactive ACTH and endorphin. In both lobes the major forms of immunoactive ACTH have apparent molecular weights of 31,000 (31K), 20--21K, 14K, and 4.5K, and the major forms of immunoactive endorphin have apparent molecular weights of 31K (coincident with the peak of immunoactive ACTH), 13K (a betaLPH-like peptide), and 3.5K (a beta-endorphin-like peptide). However, the quantitative distribution of immunoactivity among the various forms differs greatly between the lobes. Assays using an extreme COOH-terminal ACTH antiserum indicate that the 31K ACTH/endorphin molecule in rat anterior and intermediate pituitary is similar to the pro-ACTH/endorphin molecule from mouse pituitary tumor cells. A radioimmunoassay that is specific for the NH2-terminal non-ACTH, nonendorphin segment (referred to as 16K fragment) of the mouse pro-ACTH/endorphin molecule was used to assay extracts of rat pituitary. In addition to detecting material at 31K and 20--21K, the 16K fragment radioimmunoassay detects significant amounts of cross-reactive material with an apparent molecular weight of 16K in extracts of both lobes. This result also suggests that the structure and processing of the rat 31K ACTH/endorphin molecule is similar to that of mouse tumor cell pro-ACTH/endorphin. Cell suspensions were prepared from the anterior and intermediate lobes of the rat pituitary and maintained in culture for a 24-h period. The isolated cells from both lobes incorporate [3H] phenylalanine into immunoprecipitable ACTH- and endorphin-containing molecules. By sequential immunoprecipitation with ACTH and endorphin antisera, it is possible to demonstrate directly that a single molecule (31K ACTH/endorphin) has antigenic determinants for both ACTH and endorphin. Significant amounts of 31K ACTH/endorphin are released into the culture medium by isolated anterior lobe and intermediate lobe cells. The isolated intermediate lobe cells synthesize and secrete relatively large amounts of a beta-endorphin-like molecule; the isolated anterior lobe cells secrete significant amounts of both a betaLPH-like molecule and a beta-endorphin-like molecule. These same quantitative differences between anterior and intermediate lobe tissue were observed in immunoassays of extracts of the separated lobes and probably reflect differences in the processing of the common precursor. The isolated anterior lobe cells can be stimulated to release increased amounts of immunoprecipitable ACTH and endorphin by incubation with a cyclic AMP analog and a phosphodiesterase inhibitor.
TL;DR: In this paper, the Eady problem instability is associated with energy transfer both up and down the vertical wavenumber spectrum although energy transfer from small to large three-dimensional wavenumbers may occur over a finite range of the spectrum.
Abstract: Uniform potential vorticity flows are examined. In the quasi-geostrophic system, conservation of total energy and conservation of available potential energy on plane rigid horizontal boundaries imply a restriction on energy exchanges as a result of scale interactions. It is shown that for the Eady problem instability is always associated with energy transfer both up and down the vertical wavenumber spectrum although energy transfer from small to large three-dimensional wavenumbers may occur over a finite range of the spectrum. An inertial theory of two-dimensional turbulence is also presented. The formal analysis, based on Leith's diffusion approximation, predicts two inertial subranges: −5/3 and −1 power dependences on the horizontal wavenumber for available potential energy on horizontal boundaries. In the former range, available potential energy on horizontal boundaries cascades at a constant rate toward higher wavenumbers; in the latter range, the depth-integrated total energy cascades at a c...
TL;DR: A sufficient condition is given for a two's complement state variable realization of any order to be free of overflow oscillation, and a simple characterization of the condition isgiven for second-order filters.
Abstract: Most of the literature dealing with overflow oscillation in fixed-point arithmetic digital filters has considered the direct form exclusively. It is possible to eliminate overflow oscillations, regardless of pole locations, by considering more general forms. A sufficient condition is given for a two's complement state variable realization of any order to be free of overflow oscillation. A simple characterization of the condition is given for second-order filters. Among those second-order forms which meet the condition are normal forms, and forms which minimize output roundoff noise.
TL;DR: The origins of this paper lie in a question posed to us by Frank Spitzer who, in fact, ended up solving most of his problem on his own as discussed by the authors, and the question in which Spitzer was interested is what happens if (when d>3) one appropriately rescales the limiting random variable 5700.
Abstract: The origins of this paper lie in a question posed to us by Frank Spitzer who, in fact, ended up solving most of his problem on his own. His problem is the following. Consider an infinite system of independent (^-dimensional branching Brownian motions which at their branching times disappear or double with equal probabilities, and assume that the initial distribution of the system is a Poisson point process. Denote by 5?,(-O, *^0 and r^ oo. The answer is yes if d>3 and no if d — \ or 2 (cf. [2], [4], [6] and for a related situation [3]). The question in which Spitzer was interested is what happens if (when d>3) one appropriately rescales the limiting random variable 5700. To be precise, given tf^>0, define for bounded
TL;DR: A protein from normal uninfected avian cells that is antigenically related to the pp60 src viral protein responsible for transformation by ASV is identified and characterized.
TL;DR: The presence of normal levels of β-galactosidase activity in leukocytes from the mother of the patient indicates that the β-GalactOSidase deficiency is not the primary enzyme defect in this type of patient.
TL;DR: In small groups (five or less individuals) sheep foraging efficiency was poor and interruptions of foraging to scan the environment were frequent, suggesting that these signals cannot be based solely as the result of kin selection.
Abstract: 1.
Several aspects of the foraging behavior of California bighorn sheep (Ovis canadensis californiana) were studied in homogeneous habitats in the interior of British Columbia, Canada. The manner in which an individual sheep foraged was based upon the size of group within which it was found.
2.
In small groups (five or less individuals) sheep foraging efficiency was poor and interruptions of foraging to scan the environment were frequent.
3.
Alarm vocalizations and other conspicuous behaviors tend to alert their neighbors to the presence of disturbances. It appears that these signals cannot be based solely as the result of kin selection.
TL;DR: In this article, child and adult speakers of English, Hungarian, and Italian described nine triplets of pictures whose elements varied along the pragmatic dimension of givenness vs newness, including ellipsis, pronominalization, emphatic stress, the indefinite article, the definite article, and initialization.
TL;DR: The finding of an agonist-specific effect of GTP supports the conclusion that 3H-spiroperidol is binding to functional dopamine receptors in the caudate nucleus.
Abstract: GUANINE NUCLEOTIDES have been shown to regulate the sensitivity of adenylate cyclase to hormones in several systems1–5, including the dopamine-sensitive adenylate cyclase in the caudate nucleus2,4. It has also been reported that in the presence of GTP the affinities of glucagon receptors6, β-adrenergic receptors7,8, prostaglandin E1 receptors9 and opiate receptors10 for agonists are decreased. For β-adrenergic receptors this effect of GTP has been described as ‘agonist-specific’, as it is seen with agonists but not with antagonists7,8. We report here a similar effect of GTP on the ability of dopamine-receptor agonists to compete for 3H-spiroperidol binding sites on rat striatal membranes. The presence of 0.3 mM GTP led to a four-to-fivefold increase in the Kd values for the inhibition of 3H-spiroperidol binding by dopamine-receptor agonists. No changes in Kd values were observed for antagonists. Dopamine-receptor agonists and antagonists have been defined by the stimulation or inhibition of dopamine-sensitive adenylate cyclase in the neostriatum11,12 or by their effects on the canine renal artery13. Controversy exists, however, as to whether binding studies using labelled neuroleptics such as spiroperidol actually measure dopamine receptors. Our finding of an agonist-specific effect of GTP supports the conclusion that 3H-spiroperidol is binding to functional dopamine receptors in the caudate nucleus.
TL;DR: An examination of the relationship between genetic heterozygosity of proteins and morphological variation in natural populations of the killifish, Fundulus heteroclitus, indicates that individuals heterozygous for an enzyme locus are likely to be less morphologically variable than individuals homozygously for that locus.
Abstract: THERE is little consensus among evolutionary biologists on the roles of morphological and protein variation within populations, and little consideration is given to their covariation. Morphological variation is known to be influenced by both the genetics of individuals and the environments in which they develop. Crosses between domesticated strains of plants and animals suggest that highly heterozygous individuals have enhanced developmental homeostasis1, but the implications of this phenomenon for natural populations have not been extensively explored. Reported here is an examination of the relationship between genetic heterozygosity of proteins and morphological variation in natural populations of the killifish, Fundulus heteroclitus. Results indicate that individuals heterozygous for an enzyme locus are likely to be less morphologically variable than individuals homozygous for that locus.
TL;DR: In this article, an elicitor of glyceollin accumulation in soybeans (Glycine max L) has been isolated from a commercially available extract of brewers' yeast, and compositional and structural analysis showed the elicitor to be a glucan containing terminal, 3-, 6-, and 3,6linked glucosyl residues.
Abstract: An elicitor of glyceollin accumulation in soybeans (Glycine max L.) has been isolated from a commercially available extract of brewers' yeast. Yeast is not a known pathogen of plants. The elicitor was isolated by precipitation in 80% (v/v) ethanol followed by column chromatography on DEAE-cellulose, sulfopropyl-Sephadex, and concanavalin A-Sepharose. Compositional and structural analysis showed the elicitor to be a glucan containing terminal, 3-, 6-, and 3,6-linked glucosyl residues. The yeast elicitor stimulates the accumulation of glyceollin in the cotyledons and hypocotyls of soybeans when as little as 15 nanograms or 100 nanograms of the elicitor is applied to the respective tissues. The yeast elicitor is very similar in both structure and absolute elicitor activity to an elicitor isolated from the mycelial walls of Phytophthora megasperma var. sojae, a pathogen of soybeans. These and other results of this laboratory suggest that plants are able to respond to the presence of a wide range of fungi by recognizing, as foreign to the plant, structural polysaccharides of the mycelial walls of the fungi.
TL;DR: The development of IgA antibody to RSV correlated in time with the disappearance of virus from the respiratory tract, consistent with the hypothesis that antibody contributes significantly to cure of infection.
Abstract: Fifty infants younger than six months, hospitalized for infection with respiratory syncytial virus (RSV), were studied by examination of serial samples of nasal secretion. Secretory neutralizing activity was measured by plaque reduction and secretory antibody by indirect fluorescence using conjugated antiserum to human IgA, IgG, or IgM. Secretory neutralizing activity during infection rose or fell fourfold with approximately equal frequency (20% and 26%, respectively). In contrast, levels of IgA antibody to RSV in secretions rose fourfold in 56%--65% of the infants and fell in none. The frequency of such rises in titer of antibody was directly related to age. In individual secretions the correlation between neutralizing activity and IgA antibody to RSV was poor: neutralizing activity was often found in the absence of detectable antibody, and IgA antibody to RSV was often nonneutralizing. Nevertheless, the development of IgA antibody to RSV correlated in time with the disappearance of virus from the respiratory tract. The timing of this secretory response is consistent with the hypothesis that antibody contributes significantly to cure of infection.
TL;DR: In this paper, a fine-mesh net was used to collect feces from Rainbow trout (Salmo gairdneri) after 1, 4, 8, and 16 hours of defecation.
Abstract: Quantitative data are presented on nutrient leaching from fish feces remaining in water for varying periods. Rainbow trout (Salmo gairdneri) were fed a multicomponent diet and feces produced were collected from the trough sediment with a fine-mesh net after 1, 4, 8, and 16 h. Removal of fecal samples from the lowest 2.5 cm of the intestine followed by 1 h water immersion gave digestibility coefficients comparable to those of feces netted from trough sediment at 1-h intervals. This relation suggested that absorption of nutrients was completed before the materials moved into the lower 2.5 cm of intestine. Most leaching of nutrients from feces occurred during the first hour in water. Storage of feces in trough water for 1 h increased digestibility estimates for dry matter, protein, and lipid by 11.5, 10.0, and 3.7 percentage points, respectively. A gradual increase in leaching of nutrients continued up to 4 h, but little or no leaching occurred between 4 and 16 h after defecation. In a second experi...