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Showing papers by "University of Missouri published in 1983"


Journal ArticleDOI
TL;DR: A comprehensive literature review of techniques used to increase response rates to questionnaires was conducted and conclusions were based on arithmetic combination of 497 response rates found in 93 questionnaires.
Abstract: A comprehensive literature review of techniques used to increase response rates to questionnaires was conducted. Conclusions were based on arithmetic combination of 497 response rates found in 93 j...

703 citations


Journal ArticleDOI
TL;DR: This review examines host and microbial iron-acquisition and transport mechanisms in an attempt to stimulate the reader's interest in potential "soft spots" that may be exploited prophylactically and therapeutically.
Abstract: The ability of microorganisms that would like to live in or on mammalian hosts to acquire iron is a critical determinant of the host-parasite interaction. Despite the abundance of iron, its availability to microbes is restricted by the iron-binding and transport systems of the host. The successful commensal or pathogen therefore must express effective systems to compete for its iron. The acquisition of iron is thus essential, although not sufficient, for virulence. This review examines host and microbial iron-acquisition and transport mechanisms in an attempt to stimulate the reader's interest in potential "soft spots" that may be exploited prophylactically and therapeutically.

336 citations


Journal ArticleDOI
TL;DR: Ion-exclusion high-pressure liquid chromatography was used to measure poly-β-hydroxybutyrate in Rhizobium japonicum bacteroids andCrotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm.
Abstract: Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-β-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm. The Aminex-HPLC method provides a rapid and simple chromatographic technique for routine analysis of organic acids. Results of PHB analysis by Aminex-HPLC were confirmed by gas chromatography and spectrophotometric analysis.

287 citations


Journal ArticleDOI
TL;DR: This paper showed that for a personally relevant counterattitudinal issue, a highly credible source can alter persuasibility by increasing a subject's message-relevant thinking, which is consistent with the hypothesis that increasing source credibility can enhance message relevance for subjects who typically do not scrutinize message content.
Abstract: The present study shows that for a personally relevant counterattitudinal issue, a highly credible source can alter persuasibility by increasing a subject's message-relevant thinking. Previous failures to show this effect were probably due to the highly thoughtful nature of typical research subjects, when confronted with involving issues. In the present study, field-dependent and field-independent subjects heard convincing or refutable counterattitudinal speeches given by sources of high or low credibility. Results indicated that subjects who are typically low in differentiation of stimuli (field-dependent subjects) showed differential persuasion to strong and weak arguments only when they were presented by a highly credible source. For subjects who are typically high in propensity to differentiate stimuli (field-independent subjects), the arguments were differentially persuasive for both high and low credible sources. These results are consistent with the hypothesis that increasing source credibility can enhance message-relevant thought for subjects who typically do not scrutinize message content.

282 citations


Journal ArticleDOI
TL;DR: The clinical examination remains crucial in the diagnosis and the natural history of this complex disease process has not been established and this history is needed to identify the course of what may be several important factors that lead to the pathological condition in this disease.
Abstract: We reviewed 127 patients who were operated upon for adult presentation Chiari malformation and made six conclusions: (a) The clinical examination remains crucial in the diagnosis. (b) The surgical anatomy is highly varied. (c) Syrinxes can be missed on preoperative contrast studies. (d) By a conservative grading system, we determined that 46% of the patients improved during long term follow-up. One-quarter deteriorated over the long run in spite of any treatment. (e) The overall results did not differ whether the treatment was plugging of the central canal plus decompression or decompression alone. (f) In patients with progression, plugging of the central canal obtained superior results. A review of the literature shows that the natural history of this complex disease process has not been established. This history is needed to identify the course of what may be several important factors that lead to the pathological condition in this disease.

275 citations


Journal ArticleDOI
TL;DR: Spontaneous, supine kicking in newborn (2- and 4-week-old) infants is described in terms of its temporal structure, interjoint coordination, and muscle activation characteristics as measured by surface electromyography.
Abstract: Spontaneous, supine kicking in newborn (2- and 4-week-old) infants is described in terms of its temporal structure, interjoint coordination, and muscle activation characteristics as measured by surface electromyography. Phasic kick movements shoed a constrained temporal organization in the movement, but not the pause phases. Hip, knee, and ankle joints moved in temporal and spatial synchrony, and all three joints showed a rhythmical or periodic organization over time. EMGs revealed antagonist coactivation at the initiation of the flexor movement, but little or not extensor activity. The dorsal muscles, the gastrocnemius and hamstrings, showed less activity than the ventral pair, tibialis anterior and quadriceps. Burst and onset-to-peak durations were also constrained. As a result of neural mechanisms and biomechanical forces, newborn leg movements are structured muscle synergies. This organization has implications both for newborn functioning and for later development.

260 citations


Book ChapterDOI
TL;DR: In this paper, it was shown that α2 receptors may exist in multiple-affinity states reflecting the ability of the α2 binding-site protein to form a complex with additional membrane proteins that themselves are receptors for the physiological substrates guanosine 5'-triphosphate (GTP), Na+, Mg2+, and possibly Ca2+-calmodulin.
Abstract: Publisher Summary Alpha-1 (α1) receptors by and large appear to occur in a single-affinity state with respect to both agonists and antagonists. By comparison, α2 receptors may exist in multiple-affinity states reflecting the ability of the α2 binding-site protein to form a complex with additional membrane proteins that themselves are receptors for the physiological substrates guanosine 5'-triphosphate (GTP), Na+, Mg2+, and possibly Ca2+-calmodulin. Binding studies have also strongly indicated that α2 receptors in most, if not all, tissues are probably coupled in an inhibitory manner to adenylate cyclase, as has been demonstrated in platelets, adipocytes, and NG 108-15 cells. Nothing is known about the mechanisms of regulation of α1 receptors, although both up- and down-regulations of α1 receptor have been demonstrated. In this regard, the ability to label and study α1 receptors on cells in culture would be particularly useful. With regard to α2 receptors, the number of affinity states that exist and their role in terms of the kinetics of α2-receptor coupling to adenylate cyclase are still not clear.

231 citations


Journal ArticleDOI
TL;DR: The study indicated that wheat/rye translocations can be produced in sufficient numbers to allow the use of this method for the introduction of alien variation into wheat research programs.
Abstract: Several generations of four triticale × wheat populations were cytologically analyzed on a plant-by-plant basis using C-banding. Among 785 karyotyped plants, 195 wheat/rye and 64 rye/rye translocated chromosomes were found, as well as 15 rye chromosomes that were modified by deletion or amplification of telomeric heterochromatin. Most of the translocations involved complete chromosome arms; only a few involved smaller segments of chromosomes. Out of 39 identified wheat/rye translocations, 10 occurred between homoeologous and 29 between non-homoelogous chromosomes, five involved A-genome chromosomes, six B-genome chromosomes and the remaining 28 involved D-genome chromosomes. The study indicated that wheat/rye translocations can be produced in sufficient numbers to allow the use of this method for the introduction of alien variation into wheat research programs. Changes in the C-banding technique used are discussed in detail.

217 citations


Journal ArticleDOI
TL;DR: It is suggested that augmentation of GABA effects is involved in the incoordinating and soporific actions of ethanol, and one factor responsible for genetic differences in ethanol response is sensitivity to GABA; and ethanol tolerance and dependence may be related to decreased sensitivity toGABA.

213 citations


Journal ArticleDOI
TL;DR: This article investigated four possible causal mechanisms underlying the false consensus effect in the context of cigarette smoking and found little support for attributional or conformity-based mechanisms, however, support for both a selective exposure and a motivational explanation was found.
Abstract: The current study investigated four possible causal mechanisms underlying the false consensus effect in the context of cigarette smoking. Little support was found for attributional or conformity-based mechanisms. However, support for both a selective exposure and a motivational explanation was found.

207 citations


Journal ArticleDOI
TL;DR: Intra-abdominal pressure, forced vital capacity (FVC), and forced expiratory volume at 1 sec (FEV1) were measured in 18 stable continuous ambulatory peritoneal dialysis patients maintained on 2-liter exchanges after infusing dialysis solutions in 0.5-liter increments as tolerated.

Journal ArticleDOI
TL;DR: It is shown that rats, mice and four types of monkey display tissue-specific as well as species-specific differences in the extent of methylation of their cytosine residues, and the highly repeated DNA sequence fraction was more methylated than the moderately repetitive or single copy fractions.

Journal ArticleDOI
TL;DR: The secretory-excretory system of C. elegans, reconstructed from serial-section electron micrographs of larvae, is composed of four cells, the nuclei of which are located on the ventral side of the pharynx and adjacent intestine.

Journal ArticleDOI
17 Jun 1983-Science
TL;DR: The possibility that during fetal life circulating estrogens may interact with circulating androgens both in regulating the development of sex differences between males and females and in producing variation in phenotype among males and among females is raised.
Abstract: In the house mouse (Mus musculus), fetuses may develop in utero next to siblings of the same or opposite sex. The amniotic fluid of the female fetuses contains higher concentrations of estradiol than that of male fetuses. Male fetuses that developed in utero between female fetuses had higher concentrations of estradiol in their amniotic fluid than males that were located between other male fetuses during intrauterine development. They were also more sexually active as adults, less aggressive, and had smaller seminal vesicles than males that had developed between other male fetuses in utero. These findings raise the possibility that during fetal life circulating estrogens may interact with circulating androgens both in regulating the development of sex differences between males and females and in producing variation in phenotype among males and among females.

Journal ArticleDOI
TL;DR: Compulsive checkers were found to have a poorer memory for prior actions than non-checkers and were also found to underestimate their ability at distinguishing memories of real and imagined events, a process referred to as reality monitoring.

Journal ArticleDOI
TL;DR: In this paper, a method of implicit weighting is proposed as a way to combine valence and instrumentality while avoiding the questionable procedure of multiplying non-ratio scale variables.

Journal ArticleDOI
TL;DR: Nectar production was significantly correlated with the male component of reproductive fitness, pollinaria removal, but not with the female component, pollinia insertion, since pod production is limited by resource availability rather than the number of pollinia insertions.
Abstract: The causes and reproductive consequences of individual variation in nectar production rates within a population of Asclepias quadrifolia were investigated. Two parameters were correlated with nectar production rate per flower: the root weight of the plant and the number of flowers in the inflorescence (umbel). Nectar production increased with increasing root weight but levelled off after a root size of about 3 g was reached. Nectar production decreased with increasing umbel size, but only for umbels that were greater than average size. A total of 57% of the variance in individual nectar production could be explained by these two variables with root weight accounting for 67% of the explained variance. Root weight is a good indicator of a plant's energetic status, indicating the importance of available energy in determining quantity of nectar produced. About 30% of the energy devoted to flowering is utilized in nectar production. Nectar production was significantly correlated with the male component of reproductive fitness, pollinaria removal, but not with the female component, pollinia insertion. Since pod production is limited by resource availability rather than the number of pollinia insertions, nectar production in A. quadrifolia is most closely associated with the maximization of the male function.

Journal ArticleDOI
TL;DR: The findings suggest that alterations of mesothelium might explain some of the changes in peritoneal transport properties under the conditions of these studies.

Journal ArticleDOI
TL;DR: A survey of university hospital employees found that nursing, laboratory, and housekeeping employees, inhalation therapists and pharmacists are also at high risk for needlestick injuries.

Journal ArticleDOI
TL;DR: A structural model of the relation between fluorescence and chlorophyll organization in Anacystis is supported and a method for studying cytochrome andchlorophyll protein assembly in these membranes is suggested.
Abstract: Cells of Anacystis nidulans strain R2 and of Synechococcus cedrorum were grown in an iron-deficient medium. Iron starvation induced several pronounced effects without influencing the viability of these cells. The phycocyanin and chlorophyll contents of these cells were depressed, and the absorption maxima of membrane-bound chlorophyll was blue-shifted by 5 nanometers. Cells showed a dramatic increase in original and in maximal chlorophyll fluorescence when monitored at room temperature. Low temperature chlorophyll fluorescence revealed a loss in fluorescence at 696 and 716 nanometers; much of the remaining fluorescence emission was at 686 nanometers. These changes suggest an alteration of membrane composition and structure. This was documented by an electrophoretic analysis of iron-deficient membranes. The prominent findings were: (a) large chlorophyll-protein complexes were not observed in iron-deficient membranes, although the chlorophyll-binding proteins were present; (b) the staining of acrylamide gels with 3,3′,5,5′-tetramethylbenzidine plus peroxide indicated that iron deficiency led to a decrease in the quantity of cytochromes. These results support a structural model of the relation between fluorescence and chlorophyll organization in Anacystis. In addition, they suggest a method for studying cytochrome and chlorophyll protein assembly in these membranes.

Journal ArticleDOI
TL;DR: Half-sib (HS) matings are useful in the breeding of cross-pollinated sexual perennial forage grasses to evaluate general combining ability of parental clones for synthetic cultivar development, recombine selected entries in recurrent selection programs, and obtain quantitative genetic information.
Abstract: Half-sib (HS) matings, including polycross, topcross, and open-pollination, are useful in the breeding of cross-pollinated sexual perennial forage grasses to evaluate general combining ability of parental clones for synthetic cultivar development, recombine selected entries in recurrent selection programs, and obtain quantitative genetic information. The objective of this paper is to review uses of HS matings in breeding of these forage grasses with emphasis on theoretical aspects related to quantitative genetic analysis. Polycross mating with adequate replications and sufficient isolation is recommended over topcross and open-pollinated mating schemes in generating HS families for quantitative genetic studies. For the estimates of many genetic parameters to be valid, the parents must be a random sample from a random mating population in linkage equilibrium. Precision of the estimates depends on adequante sampling of the population of genotypes and environments used for evaluation. Analyses of variance on HS families and parental clones, and analysis of covariance between parent and offspring provide useful information on additivity of genetic effects and on genotype × environment interactions. Classical, narrow-sense heritability on an individual plant basis can be estimated and used to predict genetic gain from individual (mass) selection, providing that within family variance is estimable. If the forage breeder uses family selection, heritability should be estimated according to the proposed unit of selection. The selection unit must be specified in terms of numbers of replications, years, and locations. Polycross HS family selection can be readily adapted to a population improvement program in forage grass breeding. Narrow-sense heritability can also be estimated by doubling the linear regression coefficient of HS prog eny means on parental means. When HS families and parents are evaluated together in replicated experiments under similar environments, covariance analysis is recommended to remove the genotype × environment interaction covariance and environmental error covariance between parent and offspring, since these nongenetic covariances may result in inflated heritability estimates and misleading expected genetic gains from selection.

Journal ArticleDOI
TL;DR: In this paper, a natural lactic acid fermentation of corn significantly reduced phytate levels and thus increased the amount of Fiske-Subbarow positive phosphorus (free).
Abstract: Natural lactic acid fermentation of corn significantly reduced phytate levels and thus increased the amount of Fiske-Subbarow positive phosphorus (free). Sixteen bacterial strains isolated from a natural lactic fermentation of corn meal had active phytases.

Journal ArticleDOI
TL;DR: The authors review an indepth discussion of the spider, venom, diagnosis, clinical presentation, laboratory findings, treatment, and prevention of Brown recluse spider loxoscelism.
Abstract: The Brown recluse spider has emerged into a potent venomous creature. Loxoscelism and necrotic arachnidism is not an infrequent medical problem. Spiders other than L. reclusa are capable of inflicting painful and persisting necrotic wounds, however, management of the local cutaneous lesions are similar. Systemic complications of loxoscelism appear to be characteristic for spiders of the genus loxosceles. The authors review an indepth discussion of the spider, venom, diagnosis, clinical presentation, laboratory findings, treatment, and prevention. The literature on loxoscelism is contradictory because of the individuality of the reaction. Experience with many patients is the only guide to management of these cases.

Journal ArticleDOI
TL;DR: The anterior sensory ultrastructure of the C. elegans dauer larva was examined in several specimens and compared with that of the second‐stage (L2) larva, which immediately precedes the dauer stage, and comparisons were made with L3, postdauer L4, and adult stages.
Abstract: The anterior sensory ultrastructure of the C. elegans dauer larva was examined in several specimens and compared with that of the second-stage (L2) larva, which immediately precedes the dauer stage. In some instances comparisons were made with L3, postdauer L4, and adult stages. Whereas sensory structures in different nondauer stages closely resemble each other, including the inner labial sensilla, amphids, and deirids. The relative positions of the afferent tips of the two types of inner labial neurons are reversed in the dauer stage compared to the L2 and postdauer L4 stages. Inner labial neuron 1 rather than neuron 2 is more anterior in each of the six sensilla, and neuron 1 has an enlarged tip. The neuron 2 cilia are only one-third as long as those in the L2. Amphidial neurons c, d, g, and i and the amphidial sheath cell are altered in shape or position in the dauer stage. Neurons g and i are displaced posteriorly within the dauer amphidial channel. Neuron d has significantly more microvillar projections than do the d cells in L2, L3, or postdauer L4 larvae. Winglike processes of dauer neuron c form a 200 degrees-240 degrees arc in transverse section, including extensive overlap of the two cells. The arc in an L2 seldom spans more than 100 degrees, and overlap does not occur. While L2 larvae possess two separate bilateral amphidial sheath cells, the left and right sheath cells are often continuous in the dauer larva. Deirid sensory dendrites exhibit a dauer-specific structure and orientation. The tip of each neuron is attached to the body wall cuticle by a substructure not observed in L2 or postdauer L4 stages, and the neurons are oriented parallel to the longitudinal axis of the dauer larva. The deirid sensory terminals are oriented perpendicular to the cuticle in other stages. Reversible alterations in neural structure are discussed in the context of dauer-specific behavior.

Journal ArticleDOI
TL;DR: regulation of activities of several membrane-bound enzymes of cholesterol metabolism in which the lipid-transfer protein and cytosolic Z-protein modulate uptake of lower-molecular-weight water-insoluble and water-soluble effectors, respectively, is discussed.

Journal ArticleDOI
TL;DR: The fruits of a decade of research on teaching are discussed in this paper, focusing on time utilization, classroom management, teacher expectations and teacher effectiveness research, and the difficulty of translating these findings into practice is discussed.
Abstract: The fruits of a decade of research on teaching are discussed in this article. The topics focussed on are time utilization, classroom management, teacher expectations and teacher effectiveness research. The difficulty of translating these findings into practice is discussed. It is argued that the complexities and uniqueness of each classroom make it impossible to follow a simple research‐into‐practice model. Research needs to become more integrative — studying teachers, students, and curriculum simultaneously — and the technology to change practice needs to be better developed.

Journal ArticleDOI
TL;DR: Toenails can be useful in epidemiologic studies of selenium and chronic disease because toenails vary in length, clippings from different toes represent different time periods of formation; clippers from all ten toes reflect selenum levels integrated over an extended period.
Abstract: Mounting laboratory and epidemiologic evidence suggests that selenium may be important in the etiology of both cancer and heart disease. We explored the use of hair and nails as indicators of selenium intake by measuring their selenium levels using neutron activation analysis, a highly sensitive and precise nondestructive technique. Levels in duplicate samples of nails, hair, and blood were all reasonably reproducible. However, selenium-containing shampoos severely contaminated some of the hair specimens, suggesting that use of hair in epidemiologic studies could be misleading. The mean selenium level in toenails from South Dakota (a known high selenium area) was 1.17 ppm (1SE = 0.09). This was significantly higher than mean levels from Boston and Georgia (medium selenium intake area) of 0.74 ppm (0.04) and 0.81 (0.03), respectively. The mean selenium level in toenails from New Zealand (low selenium area) was 0.26 (0.02) and these levels did not overlap those of other areas. The South Dakota specimens showed marked familial aggregation, probably reflecting dietary differences. Since toenails vary in length, clippings from different toes represent different time periods of formation; clippings from all ten toes reflect selenium levels integrated over an extended period. As toenails are easily collected, transported, and stored, and reflect longterm intake, they can be useful in epidemiologic studies of selenium and chronic disease.

Journal ArticleDOI
TL;DR: In this paper, an excitonic mechanism of superconductivity based on the presence of impurities is outlined, and generalized Eliashberg equations for the self-energy are derived for both singlet and triplet pairs.
Abstract: To explain the observed diamagnetic anomalies which are coupled with high conductivity in CuCl and CdS samples, an excitonic mechanism of superconductivity based on the presence of impurities is outlined. To formulate the theoretical model on a more fundamental level, four-component field operators have been introduced in analogy to the Nambu formalism. Generalized Eliashberg equations for the self-energy are derived for both singlet and triplet pairs. Numerical model calculations for the effective interaction are presented for different impurity concentrations and different gaps (exciton frequencies). Conjectures for the further development of the theory, together with proposed experiments, conclude this study.


Journal ArticleDOI
TL;DR: It is proposed that asynchronous and asymmetrical maturation of subcortical tracts and/or muscle strength could account for these behavioral shifts in normal human infants.
Abstract: Patterns of interlimb coordination and lateral preference of spontaneous leg kicks were described for 8 normal human infants observed biweekly from 2 to 26 weeks of age. Newborn infants showed a high percentage of alternating movements, which were often supplanted by unilateral movements between 1 and 4 months. Simultaneous (in-phase) kicks matured later than alternating kicks. No consistent lateral preferences were detected. The developmental course was marked by variability and discontinuities within each infant. We propose that asynchronous and asymmetrical maturation of subcortical tracts and/or muscle strength could account for these behavioral shifts.