Showing papers by "University of Kansas published in 1980"

Why Older People Move Theoretical Issues

Abstract: The theory of elderly migration lags well behind the state of empirical knowledge. Further development is needed to integrate present findings and direct future research. The intent of this article...

Gonadal Steroids: Effects on Excitability of Hippocampal Pyramidal Cells

Abstract: Electrophysiological field potentials from hippocampal slices of rat brain show sex-linked differences in response to 1 X 10(-10)M concentrations of estradiol and testosterone added to the incubation medium. Slices from male rats show increased excitability to estradiol and not to testosterone. Slices from female rats are not affected by estradiol, but slices from female rats in diestrus show increased excitability in response to testosterone whereas slices from females in proestrus show decreased excitability.

Congenital hypothalamic hamartoblastoma, hypopituitarism, imperforate anus, and postaxial polydactyly—a new syndrome? Part I: Clinical, causal, and pathogenetic considerations

Abstract: We report on six infants with a neonatally lethal malformation syndrome of hypothalamic hamartoblastoma, postaxial polydactyly, and imperforate anus Some, but not all, patients had laryngeal cleft, abnormal lung lobulation, renal agenesis and/or renal dysplasia, short 4th metacarpals, nail dysplasia, multiple buccal frenula, hypoadrenalism, microphallus, congential heart defect, and intrauterine growth retardation The infants also had hypopituitarism and hypoadrenalism All were sporadic cases, parents were not consanguineous, chromosomes were apparently normal Family histories were unremarkable There was insecticide and/or herbicide exposure in several of the cases, but no exposures were common to all 6 mothers Five of the patients were born within an 8-month period, but all in different geographic locations It is postulated that this is a previously apparently unreported syndrome of presently unknown cause

Perceived usefulness of information: a psychometric examination*

Abstract: The perceived usefulness of information is an important construct for the design of management information systems. Yet an examination of existing measures of perceived usefulness shows that the instruments developed have not been validated nor has their reliability been verified. In this paper a new instrument for measuring two dimensions of perceived usefulness is developed. The results of an empirical study designed to test the reliability and construct validity of this instrument in a capital-budgeting setting are presented.

Genetic variation in social mammals: the marmot model.

Abstract: The social substructure and the distribution of genetic variation among colonies of yellow-bellied marmots, when analyzed as an evolutionary system, suggests that this substructure enhances the intercolony variance and retards the fixation of genetic variation. This result supports a traditional theory of gradual evolution rather than recent theories suggesting accelerated evolution in social mammals.

The Role of Social Isolation in Suicide

Abstract: This paper reviews the literature which relates to the role of social isolation in suicide. Major areas include theories on suicide and social isolation, measures of social isolation, and empirical studies which concern the relationship of social isolation to suicide. Social isolation seems to be related to suicidal behaviors in a direct and fundamental way. Implications for helping contacts and the community are addressed.

The effects of an environmental “enrichment” program on the behavior of institutionalized profoundly retarded children

Abstract: This study determined the effects of procedures designed to "enrich" the physical and social environment of an institutional ward on the "adaptive" and "maladaptive" child, adult, self, and object-directed behaviors of five profoundly retarded ambulatory females. Behavior observed in two treatment conditions, an environment "enriched" with toys and objects and an "enriched" environment coupled with differential reinforcement of adaptive behavior, was compared to behavior occurring in corresponding baseline or "austere" conditions and during a period of noncontingent reinforcement. The results generally revealed: (1) little change in adaptive and maladaptive child and adult-directed behavior across conditions, (2) an overall higher incidence of adaptive object-directed behavior and reduced self-directed maladaptive behavior in each treatment condition from that observed in corresponding control conditions, and (3) the use of an "enriched" environment and differential reinforcement of adaptive behavior resulted in maladaptive self-directed behavior being reduced and adaptive object-directed behavior being icreased beyond that observed in the "enriched" environment alone. These behavioral gains were largely maintained during a follow-up condition by continuing the "enriched" environment and transferring the responsibility for differential reinforcement to direct-care staff.

In vivo language intervention: unanticipated general effects.

Abstract: After observing the lack of generalization of language trained in highly structured training sessions using established behavior modification techniques, "incidental teaching" procedures were developed to change the use of specified language behaviors in the natural environment. This paper reports an analysis of the general changes in the language, other than that specifically targeted by the incidental teaching procedures, used by disadvantaged preschool children. The daily language samples of disadvantaged children involved in a previously reported experiment to increase compound sentence usage were reexamined and compared to comparable records of other disadvantaged children and of middle-class children of college parents in order to assess possible general effects of the intervention program. Whereas the language that both groups of comparison children used changed little across the preschool year, the amount of talking by the children in the experimental program increased markedly. Their use of more elaborate vocabulary and more elaborate sentences also increased in direct proportion to the increases in overall language use, such that both language use and language elaboration in the experimental group of children changed from a pattern simlar to the comparison group of disadvantaged children to a pattern similar to the comparison group of middleclass children. It is argued that some general features of the incidental teaching procedure--differentially attending to child overtures and responding relative to the child's selected topic (reinforcer)--contributed to the increase in overall language use beyond the specific language behavior targeted, and that this increase in the probability of children's talking itself resulted in the substantial increases in elaboration seen in the children's spontaneous language. Because, at least in children with fairly well-developed language repertoires, language use is contextually controlled, talking more involves talking in more varied and complex contexts, which inevitably produces the use of more elaborate language.

A Modified Monte-Carlo Simulation Technique for the Evaluation of Error Rate in Digital Communication Systems

Abstract: Digital communication systems are frequently operated over nonlinear channels with memory. The analysis of the performance of these systems is difficult and no complete analytical treatment of the problem has been obtained before. Several recent efforts have been directed toward the computation of error probabilities via Monte-Carlo simulation using a complete system model. These simulations require excessively large sample sizes and are not practical for estimating very low values of error probabilities. This paper presents a modified Monte-Carlo simulation technique for estimating error probabilities in digital communication systems operating over nonlinear channels. An importance-sampling technique is used to modify the probability density function of the noise process in a way to make simulation possible. Theoretical results as well as realistic examples are presented, showing that the number of samples needed for simulation is reduced considerably.

Interaction of vitamin c and iron

Abstract: Food iron is absorbed by the intestinal mucosa from two separate pools of heme and nonheme iron. Heme iron, derived from hemoglobin and myoglobin, is well absorbed and relatively little affected by other foods eaten in the same meal. On the other hand, the absorption of nonheme iron, the major dietary pool, is greatly influenced by meal composition. Ascorbic acid is a powerful enhancer of nonheme iron absorption and can reverse the inhibiting effect of such substances as tea and calcium/phosphate. Its influence may be less pronounced in meals of high iron availability--those containing meat, fish, or poultry. The enhancement of iron absorption from vegetable meals is directly proportional to the quantity of ascorbic acid present. The absorption of soluble inorganic iron added to a meal increases in parallel with the absorption of nonheme iron, but ascorbic acid has a much smaller effect on insoluble iron compounds, such as ferric oxide or ferric hydroxide, which are common food contaminants. Ascorbic acid facilitates iron absorption by forming a chelate with ferric iron at acid pH that remains soluble at the alkaline pH of the duodenum. High cost and instability during food storage are the major obstacles to using ascorbic acid in programs designed to combat nutritional iron deficiency anemia.

Activation of Intestinal Guanylate Cyclase by Heat-Stable Enterotoxin of Escherichia coli: Studies of Tissue Specificity, Potential Receptors, and Intermediates

Abstract: Heat-stable enterotoxin (ST) of Escherichia coli increased guanylate cyclase activity in homogenates of rat and rabbit intestinal mucosa and stimulated intestinal fluid secretion in suckling mice. The ST effect on guanylate cyclase was dose-dependent, occurred without a time lag, and was confined to the particulate fraction. ST activation of guanylate cyclase was tissue-specific; ST did not alter activity of soluble or particulate rat liver, lung, heart, kidney, or cerebral cortex enzyme. The ST activity on guanylate cyclase and secretion was methanol-soluble and alkali-labile, and its effects were not altered by phentolamine, propranolol, or atropine. Monosialoganglioside did not reduce ST-induced secretion. However, indomethacin and butylated hydroxyanisole decreased the ST effect on both guanylate cyclase and secretion. Fluid secretion with ST sppears to result from specific activation of particulate intestinal guanylate cyclase. While adrenergic and cholinergic events are probably not involved in this process, the effects of ST may be mediated through prostaglandin synthesis or oxidative mechnanisms.

Multicomponent Latent Trait Models for Ability Tests.

Abstract: A major research direction for ability measurement has been to identify the information-processes that are involved in solving test items through mathematical modeling of item difficulty. However, this research has had limited impact on ability measurement, since person parameters are not included in the process models. The current paper presents some multicomponent latent trait models for reproducing test performance from both item and person parameters on processing components. Components are identified from item subtasks, in which performance is a logistic function (i.e., Rasch model) of person and item parameters, and then are combined according to a mathematical model of processing on the composite item.

Mands for Verbalization Facilitating the Display of Newly Trained Language in Children

Abstract: Verbalization rates of three children exhibiting moderate to severe language delays were increased through the systematic use of adults' instructions for verbalizations, models for verbalizations, and contingent positive consequences following utterances. Daily samples of each child's speech were collected during freeplay periods in a classroom for language-deficient preschool children. In a multiple-baseline design across children, teachers prompted language usage and provided materials and services following requests and descriptions. The results of the study showed that children's verbalization rates doubled to tripled from their baseline levels when the intervention was introduced. The subjects' vocabulary and complexity of utterances increased, as indicated by cumulative rates of novel words and novel word combinations. The classroom display of newly trained words and grammatical structures also increased.

Flight patterns of foraging bees relative to density of artificial flowers and distribution of nectar.

Abstract: Flight patterns of honeybees (Apis mellifera ligustica) were quantified as the bees foraged among artificial ‘flowers’ for sugar solution (‘nectar’). Bees exhibited considerable directionality on successive flights which minimized repeat visits to flowers and they usually made short flights to nearby flowers, thus minimizing flight time. The change in direction on successive flights between flowers were independent of the number of immediately preceding consecutive rewarding visits but decreased as the number of non-rewarding visits increased. Flight distances were short after visits to rewarding flowers but increased as the number of immediately preceding non-rewarding visits increased. The bees' rate of caloric intake (calories/time) was highest at the floral arrays having the highest density, and it was greater at arrays with clumped nectar-distributions than at those with randomly distributed nectar. These findings are explained in terms of the observed flight patterns.

Lipid barrier to water exchange in reptile epidermis.

Abstract: Extraction of lipids from the shed epidermis of the terrestrial snake Elaphe obsoleta obsoleta increases cutaneous water loss in vitro as much as 15-fold. Partial denaturation of epidermal keratin without lipid extraction increases cutaneous water loss only twofold. Histological observations and thin-layer and gas-liquid chromatography of the lipid extracts indicate a complex mixture of polar and neutral lipids predominantly in the mesos layer of the cornified epidermis. Comparative measurements of cutaneous water loss in other species of snakes and a lizard show that permeabilities differ naturally but are essentially identical after lipid extraction. These findings establish the importance of lipids in the permeability barrier of reptilian skin and suggest that keratin or scale morphology are of nominal importance in limiting water exchange.

Statistical Problems of Fitting Individual Growth Curves

Abstract: A thorough-going longitudinal study of a child’s growth can produce upward of forty observations spaced over the years from birth to maturity. Such a data record is too long and inevitably too noisy (because of measurement error and short-run growth variation) to be interpreted without some sort of condensation and smoothing. The length of the record forces attention to certain critical regions or features of the curve, but the noisiness of the data makes it risky to characterize these regions or features by a few isolated measurements. The only safe approach to interpretation of individual growth data is via a statistical method capable of revealing the essential trend and concisely describing its main features.

Hitchhiking: a comparison of linkage and partial selfing

Abstract: Genetic hitchhiking occurs when alleles at unselected loci are changed in frequency because of an association with alleles at a selected locus. This association may be mediated either by linkage or partial selfing (inbreeding) and can affect the gene frequency and gametic disequilibrium at the neutral loci. Hitchhiking from partial selfing (unlinked loci) occurs more quickly than linkage hitchhiking and generally has a greater effect. In addition, partial-selfing hitchhiking can cause increases or changes in sign in gametic disequilibrium between neutral loci. The effects of the two types of hitchhiking with different levels of dominance, zygotic frequencies and number of selected loci are also examined. The general conditions for linkage and partial-selfing hitchhiking are outlined and the implications of hitchhiking are discussed for marker or electrophoretic loci.

A Comparison of Components of Written Expression Abilities in Learning Disabled and Non-Learning Disabled Students at Three Grade Levels.

Abstract: Although written language plays a critical role in academic success, little empirical evidence exists on the normal development of processes involved in producing written products. Even less is known about the writing performance of LD children. This study empirically compared the written products of LD and normal students at three grade levels on The Test of Written Language. Results showed that LD subjects scored significantly lower than normal subjects on most written expression abilities, especially in the mechanical tasks of spelling, punctuation, and word usage.

The effect of postural lean and body congruence on the judgment of psychotherapeutic rapport

Abstract: Naturalistic studies have implicated both forward postural lean and interpersonally congruent limb configurations as nonverbal indices of social rapport, although both variables have been confounded with verbal and other nonverbal concomitants. In the present study direction of postural lean and congruence of body positions were systematically manipulated in each of six 40-second videotaped segments of simulated client-therapist interactions. Participating in the study were 30 male and 30 female undergraduate students, each of whom viewed one of six orders of the segments and rated the level of rapport in each interaction. A 2 × 3 × 2 × 6 analysis of variance on factors of Congruence, Lean, Sex, and Order revealed main effects of the Lean and Congruence variables (p<.001 andp<.05, respectively), and no significant main effects of Sex or Order. Both congruent limbs and forward-leaning postures on the part of the therapist and client were significant contributors to attributions of rapport.

The Search for Uniqueness and Valuation of Scarcity

Abstract: The widespread pressure toward conformity in opinion and behavior in current society has captured the attention of many social scientists. Several recent attempts to integrate diverse perspectives and findings on conformity use social exchange theory (Blau, 1964; Homans, 1961, 1974; Nord, 1969b; Secord & Backman, 1964). While integrative, the social exchange view of conformity neglects some important motives, values, and costs. For instance, our research identifies a need for distinctiveness or “uniqueness,” that is, a need to see oneself as different from one’s peers, as a prevalent determinant of behavior. Thus, the outcomes of pressures to conform may depend upon the degree and nature of competing pressures for uniqueness. Alternatively, the act of conformity may arouse or augment pressure toward the foregone alternative of establishing or maintaining the self-perception of uniqueness. The present chapter develops the latter thesis by reviewing the theory and research on uniqueness and discussing implications for the social exchange view of conformity.

Prior Confessions and Mock Juror Verdicts

Abstract: The present study tested the Supreme Court's assumption that jurors discount a coerced confession as unreliable and do not allow it to influence their decisions In two experiments, subjects read a transcript of a trial in which testimony revealed that the defendant had confessed either on his own accord (no constraint), in response to an offer of leniency (positive constraint), in response to a threat of punishment (negative constraint), or not at all (control group) In Experiment 1, subjects discounted the negatively induced confession However, their estimates of the probability that the defendant committed the crime were increased not only by the unconstrained confession, but by the positively constrained one as well Experiment 2 essentially replicated this pattern for probability-of-commision estimates and verdicts despite the additional finding that the positively constrained confession was in fact perceived as involuntary The potential danger of admitting the latter as evidence was noted and specific recommendations were made

Studies of inhibition of rat spermidine synthase and spermine synthase

Abstract: 1. S-Adenosyl-l-methionine, S-adenosyl-l-homocysteine, 5′-methylthioadenosine and a number of analogues having changes in the base, sugar or amino acid portions of the molecule were tested as potential inhibitors of spermidine synthase and spermine synthase from rat ventral prostate. 2. S-Adenosyl-l-methionine was inhibitory to these reactions, as were other nucleosides containing a sulphonium centre. The most active of these were S-adenosyl-l-ethionine, S-adenosyl-4-methylthiobutyric acid, S-adenosyl-d-methionine and S-tubercidinylmethionine, which were all comparable in activity with S-adenosylmethionine itself, producing 70–98% inhibition at 1mm concentrations. Spermine synthase was somewhat more sensitive than spermidine synthase. 3. 5′-Methylthioadenosine, 5′-ethylthioadenosine and 5′-methylthiotubercidin were all powerful inhibitors of both enzymes, giving 50% inhibition of spermine synthase at 10–15μm and 50% inhibition of spermidine synthase at 30–45μm. 4. S-Adenosyl-l-homocysteine was a weak inhibitor of spermine synthase and practically inactive against spermidine synthase. Analogues of S-adenosylhomocysteine lacking either the carboxy or the amino group of the amino acid portion were somewhat more active, as were derivatives in which the ribose ring had been opened by oxidation. The sulphoxide and sulphone derivatives of decarboxylated S-adenosyl-l-homocysteine and the sulphone of S-adenosyl-l-homocysteine were quite potent inhibitors and were particularly active against spermidine synthase (giving 50% inhibition at 380, 50 and 20μm respectively). 5. These results are discussed in terms of the possible regulation of polyamine synthesis by endogenous nucleosides and the possible value of some of the inhibitory substances in experimental manipulations of polyamine concentrations. It is suggested that 5′-methylthiotubercidin and the sulphone of S-adenosylhomocysteine or of S-adenosyl-3-thiopropylamine may be particularly valuable in this respect.

Vinblastine (VLB), bleomycin (BLEO), cis-diamminedichloroplatinum (DDP) in disseminated extragonadal germ cell tumors. A Southwest Oncology Group Study.

Abstract: Nineteen patients considered to have metastatic primary extragonadal germ cell cancer were entered on a Phase II chemotherapy study using as induction therapy a combination of vinblastine (VLB) 12 mg/m2 day 1, bleomycin (BLEO) 15 U/m2 I.V. or I.M. twice weekly, and cis-diamminedichloroplatinum (DDP) 15 mg/m2 days 1–5, with vinblastine and DDP repeated at 28-day intervals for four months. All complete or partial responders were then placed on a maintenance regimen of vinblastine 12 mg/m2 alternating monthly with actinomycin-D 1.5 mg/m2 day 29, and chlorambucil, 10 mg/m2 P.O. days 32–37. There were three complete remissions (CR's), six partial remissions (PR's), and two stable disease. The response rate (CR's + PR's) was 56%; however, the mean duration of response was only two months (range, 1–8 months). Drug toxicity was significant and there was one toxic death. Unlike patients with disseminated testicular cancer, patients with primary metastatic extragonadal germ cell carcinoma appear to do less well on this particular drug regimen. Further investigation using different drug regimens seems necessary.

Stripes do not a zebra make, part i: a cladistic analysis of equus

Abstract: Bennett, D. K. (Department of Systematics and Ecology, The University of Kansas and Museum of Natural History, Lawrence, Kansas 66045) 1980. Stripes do not a zebra make, part I: A cladistic analysis of Equus. Syst. Zool., 29:282-287.-Living and extinct species in Equus have not been reviewed for nearly a century. More than twenty morphological, mostly cranial characters of Equus and Dinohippus are here explained; synapomorphies uniting Equus and Dinohippus and autapomorphies within Equus are discussed. Significant outgroups compared are Dinohippus Quinn, Astrohippus Stirton, and Neohipparion Gidley. Cladistic analysis indicates that Equus is a monophyletic taxon closely related to Dinohippus, and that Equus can reasonably be divided into two (and only two) subgenera, Equus (Equus) and Equus (Asinus), each of which is characterized by a suite of autapomorphic features. The North American fossil record contains close relatives of every living species of equid except E. quagga. An examination of the zoogeographic implications of the cladistic hypothesis here presented indicates a complex pattern of migration from North America to Eurasia during Blancan through late Pleistocene time, and a strong zoogeographic relationship between Africa and North America demonstrated by the equids. [Cladistics; Equus; zoogeography; fossil horses; phylogeny.] The living and extinct species of the genus Equus have not been reviewed