Showing papers by "University of Nebraska–Lincoln published in 1990"

Gender Role Stereotypes, Expectancy Effects, and Parents' Socialization of Gender Differences

Abstract: Gender segregation continues to exist in many activity and occupational domains. This article uses the expectancy effect perspective to analyze the role parents may play in influencing their children to engage in gender role stereotyped activities. It outlines the theoretical bases for such effects, and discusses how to distinguish between accuracy and perceptual bias in parents' gender role differentiated perceptions of their children's competencies and interests. Then it summarizes the results of a series of studies, which show that parents distort their perceptions of their own children in gender role stereotypic activities such as math and sports, that the child's gender affects parents' causal attributions for their children's performance in gender role stereotypic activities, and that these perceptual biases influence the children's own self-perceptions and activity choices. Finally, the article presents a theoretical model of how these processes may occur.

The Iowa Articulation Norms Project and Its Nebraska Replication

Abstract: The purpose of the Iowa Articulation Norms Project and its Nebraska replication was to provide normative information about speech sound acquisition in these two states. An assessment instrument con...

Perceptions of Boredom in Leisure: Conceptualization, Reliability and Validity of the Leisure Boredom Scale

Abstract: This paper describes a theoretically and empirically based conceptualization of the leisure boredom construct. In addition, it reports the secondary analysis of data from three studies (N = 679) fo...

Level of nutrition and visceral organ size and metabolic activity in sheep.

Abstract: Thirty-two crossbred wether lambs (initial live-weight 31 kg) were fed on a diet (metabolizable energy (ME) 12.8 MJ/kg) ad lib. (ADLIB) or restricted to maintain body-weight (MAINT) for a 21 d period. On days 0, 7, 14 and 21, four lambs per treatment were slaughtered, visceral organs weighed and tissues sampled. During the 21 d period, ME intake in ADLIB lambs increased quadratically with an average rate of live-weight gain of 425 g/d. In MAINT lambs, live weight (30 kg) was maintained, and daily ME intake (kJ/kg empty body-weight (EBW)0.75) declined (P less than 0.01) quadratically with time. Weights of liver, stomach and small intestines as a percentage of EBW were increased in ADLIB lambs and decreased by 10-33% in MAINT lambs (treatment x day, P less than 0.01). In vitro liver oxygen consumption was not affected by level of feed intake. Estimates of whole-liver O2 consumption (mmol O2/d per kg EBW) increased in ADLIB lambs and were relatively constant in MAINT lambs. These findings suggest that level of feed intake changes the relative proportion of visceral organs to body mass. In addition, the effect of level of feed intake on changes in the relative contribution of visceral organs to whole-body metabolic rate appears to be primarily a result of differences in organ size rather than tissue-specific metabolic activity.

Severity of liver abscesses and efficiency of feed utilization of feedlot cattle.

Abstract: Relationships of gain, intake, feed efficiency and severity of liver abscesses were evaluated in 12 experiments involving 566 head of individually fed cattle. Concentrate level in the diets ranged from 64 to 95%. In all experiments, livers were scored as unabscessed (0), one or two small abscesses (A-), two to four small active abscesses (A) or one or more large, active abscesses (A+). Based on homogeneity of variances, nine of the experiments were divided into two groups. In one group (four experiments) the incidence of liver abscesses was 32.1% and no significant (P greater than .25) effects of liver abscess severity score on feedlot performance variables were found. In the second group (five experiments), the incidence of liver abscesses was 77.7%. In the second group, liver abscess severity score affected final live weight (P less than .10), hot carcass weight (P less than .0001), dry matter intake (P less than .10), daily gain based on live weight recorded 24 h prior to slaughter (P less than .10), daily gain based on live weight estimated from hot carcass weight with a 62% dressing percentage (P less than .0001), feed efficiency using final live weight estimated from hot carcass weight (P less than .0001) and dressing percentage (P less than .01). In all cases, performance means for cattle with A+ liver scores were the only ones that differed significantly from those of non-abscessed cattle.

Personality Development in Evolutionary Perspective

Abstract: A relationship between personality processes and evolution can be seen when behaviors associated with sexual maturation, mating, and parenting are examined. This article stipulates the types of proximal cues implicated in the shaping of personality variables that become important in the development of the individual's reproductive behavior.

Novel Regulation of Vegetative Storage Protein Genes.

Abstract: Until recently, storage protein research has been largely restricted to the seed-specific reserve proteins, which provide nutrients to seedlings during their early growth. Their abundance, and the potential for improving seed nutritional quality, were early incentives to investigate seed storage proteins, and they continue to be intensively studied as a plant model for tissue-specific and developmentally regulated genes. Recent research has shown that non-seed tissues also synthesize proteins that are distinct from the seed reserves but have the characteristics of storage proteins. That is, they are expressed abundantly in specific cells, are localized in vacuoles (the progenitors of protein bodies in seeds), and are degraded at a later time for the nutritional needs of other organs. It is perhaps not surprising that vegetative tissues contain reserve proteins since plants assimilate, translocate, and reutilize nutrients extensively throughout their life cycle (for reviews, see Pate, 1980; Simpson, 1986). This review focuses on a soybean vegetative storage protein (VSP) that is particularly important for the temporary storage of nitrogen. Unlike the seed proteins, whose massive accumulation comes at the end of a developmental stage, the VSP genes are highly modulated throughout development according to the immediate need to store surplus nitrogen or amino acids. They are particularly intriguing and attractive for further studies because their expression is enhanced by severa1 different stimuli, including seed pod removal, high nitrogen nutrition, and wounding. Jasmonic acid, a nove1 plant compound and a possible endogenous gene regulator, also induces VSP gene expression. As with their seed counterparts, the VSP genes may be important targets for increasing plant productivity or nutritional quality through genetic engineering.

Fractional processing of sequential bronchoalveolar lavage to separate bronchial and alveolar samples.

Abstract: Bronchoalveolar lavage has been widely used to sample the lower respiratory tract. Most of the material recovered with this technique represents alveolar contents. A number of modifications have been suggested in order to obtain samples relatively enriched for bronchial material. In order to be able to use a standard technique for bronchoalveolar lavage to sample both airways and "routine" alveolar material, a simple modification of the technique as described by Reynolds and Newball was used: five sequential 20-ml aliquots were infused into the lower respiratory tract, and each aliquot was immediately aspirated. The return from the first aliquot was processed separately from the return from the subsequent four aliquots. These last four aliquots were pooled. Analysis of the first aliquot revealed it to be enriched for ciliated epithelial cells when compared with the subsequent aliquots. There were also differences in inflammatory cell composition with the bronchial sample containing relatively more neutrophils and relatively less lymphocytes. Aspiration during transoral bronchoscopy was documented by quantifying salivary amylase in the bronchial and alveolar lavage fluids. It was estimated, however, that the aspiration was not of quantitative significance in the vast majority of subjects studied. Finally, with the technique of fractional processing of bronchoalveolar lavage samples, it was possible to compare the protein concentrations in bronchial and alveolar lavages. Most prominent among the differences was a marked relative enrichment in the bronchial samples for immunoglobulin A. The technique of fractional processing of bronchoalveolar lavage samples provides a simple means to obtain samples enriched for bronchial and alveolar components. This should facilitate analysis of lower respiratory tract specimens in airway disease.

The Impact of At-Large Elections on the Representation of Blacks and Hispanics

Abstract: Political scientists have long been interested in the link between election structures and the representation of interest. Here we examine one such link, that between local election structures and minority representation. Research of the middle and late 1970s revealed that at-large city council election procedures resulted in a dramatic underrepresentation of blacks and some underrepresentation of Hispanics. Now a revisionist position claims that at-large elections no longer have this detrimental effect on minority representation, if needed they ever did. In this paper we examine this controversial link by assessing the impact of at-large and district elections on the representation of blacks and Hispanics using varied methodologies and 1988 data. We find that although at-large elections represent blacks much better than a decade ago, there is still a small gap between the representation afforded by at-large and district systems. On the other hand, the impact of local election structures on Hispanic repre...

The Impact of Comparative Advertising on Levels of Message Involvement

Abstract: This study examines the notion that comparative ads containing direct references to a well-known competitor are inherently more “involving” than noncomparative ads. Utilizing an information-processing perspective, findings indicate that the comparative format elicits higher levels of message involvement/processing activity than the noncomparative format. In addition to perceiving the comparative message as being more relevant, subjects viewing that format paid more attention to, elaborated on, and were able to recall more message points than did subjects exposed to a similar, though noncomparative, ad.

Energy requirements for maintenance of crossbred beef cattle with different genetic potential for milk.

Abstract: Maintenance energy requirements were estimated in two gestation and one lactation feeding trials for three groups of cows All cows in the second gestation trial completed the first gestation and lactation trials The three groups were chosen to represent cattle similar in growth rate and mature size but different in amount of milk provided to their calves The low (L) group included Hereford x Angus, the medium (M) group included Red Poll x Angus and the high (H) group included Milking Shorthorn x Angus cows Cows were individually fed to maintain net body weight (minus gravid uterus for gestation) constant Allowances were made in energy intake for gestation and lactation Cow weights were adjusted to an average condition score in each trial Daily maintenance requirements during gestation were 18% lower than those during lactation The H and M cows required 12% more energy per unit metabolic weight than L cows to maintain body weight during both gestation and lactation Differences in milk production explained 23% of the variation in maintenance requirements, suggesting that important differences exist beyond those associated with milk production potential Repeatabilities of maintenance requirement measurements ranged from 44 to 64 Maintenance requirements for calves under feedlot conditions in the postweaning phase were estimated from data collected from 494 calves, half-sibs and offspring of the cows described previously Energy requirements were 11% higher for the H and M groups than for the L group

Neural networks for bond rating improved by multiple hidden layers

Abstract: The problem of how best to configure and train a network to rate bonds on the basis of financial parameters which characterize corporations is addressed. 126 bond patterns, each with seven financial ratios, were collected. A spectrum of layered neural networks with single or multiple hidden layers was found to easily outperform a bond rating model based on multivariate discriminant analysis, at least when the task was presented as one of separating two noncontiguous classes. These experiments suggest that networks trained with two hidden layers outperform a network having only one hidden layer containing a comparable number of processing elements. Significant advantages arise even when the layers are ordered so that a smaller number of neurons receive their inputs directly from the inputs. This suggests that, for these bond rating data. the problem of mapping from seven features to two classes may have an inherent dimensionality of five or lower. The mapping of the five elements' (or neurons') output of the first layer down to two layers can be performed first. Then there is still an advantage from the use of a subsequent hidden layer to provide another representation of useful classification information

Multi-Member Districts and the Representation of Women: Evidence From Britain and the United States

Abstract: Recent research has suggested a link between multi-member district plurality elections and greater representation of women. Those proposing such a link argue that women may prefer to be candidates in multi-member systems, that their election is facilitated by greater turnover in multi-member systems, and that multi-member systems give voters and party leaders an opportunity to exercise a sort of electoral affirmative action. These possibilities are tested using data on more than 13,000 candidates for office in British and U.S. subnational elections. In general, the link between multi-member plurality systems and women's representation is small and occurs only in some systems. The paper concludes with suggestions for future avenues of exploration of the link between political structure and women's electability.

Homoclinic bifurcation at resonant eigenvalues

Abstract: We consider a bifurcation of homoclinic orbits, which is an analogue of period doubling in the limit of infinite period. This bifurcation can occur in generic two parameter vector fields when a homoclinic orbit is attached to a stationary point with resonant eigenvalues. The resonance condition requires the eigenvalues with positive/negative real part closest to zero to be real, simple, and equidistant to zero. Under an additional global twist condition, an exponentially flat bifurcation of double homoclinic orbits from the primary homoclinic branch is established rigorously. Moreover, associated period doublings of periodic orbits with almost infinite period are detected. If the global twist condition is violated, a resonant side switching occurs. This corresponds to an exponentially flat bifurcation of periodic saddle-node orbits from the homoclinic branch.

Reduction of saliva immunoglobulin levels by swim training.

Abstract: Saliva immunoglobulin A (IgA) and cortisol levels were measured in 21 male members of a major midwestern swim team. Saliva samples were collected before and after training sessions four times during the fall season; the training intensity was light, moderate, heavy and during the taper period before a major competitive meet. Saliva IgA levels were decreased after each training session, reaching statistical significance with the moderate training intensity. Over the 3-month training period the pre-session and post-session IgA levels both decreased significantly during the heavy and taper training intensities later in the fall season. Cortisol levels were significantly elevated only after the heavy-intensity training session. The Profile of Mood States (POMS) was used to assess the swimmers' overall mood on each test day. No significant correlations were found between the global POMS score and IgA or cortisol. Also, cortisol and IgA were not significantly correlated except after the light training session. Results from this study indicate that acute bouts of exercise can reduce salivary IgA levels and that chronic exercise of high intensity can reduce the resting levels of IgA. These changes may render the athletes more vulnerable to respiratory infections after exercise and even at rest during the later stages of the competitive season.

Archaeoparasitology in North America.

Abstract: The study of prehistoric parasitism through analysis of coprolites, mummies, skeletons, and latrine soils is rapidly growing. Its development in North America is interdisciplinary and is derived from the fields of physical anthropology, parasitology, and archaeology. The various parasite finds from North America are reviewed. The data show that prehistoric peoples in North America suffered from a variety of parasitic diseases. The validity of the findings are then considered. Although most finds of parasites from prehistoric contexts result from human infections, some finds cannot be verified as such. However, in combination with data from South America, it is clear that prehistoric peoples in the Americas were host to a variety of human parasites, some of which were not previously thought to be present before historic times.

Effects of grain type, roughage level and monensin level on finishing cattle performance.

Abstract: Interactions among grain type (grain sorghum, corn or wheat), roughage level and monensin level were studied in four feedlot trials using pen-fed crossbred yearling cattle. In Trial 1, cattle fed high-moisture corn (HMC) were more efficient (.1537 vs .1406 for gain/feed; P less than .01) than cattle fed dry-rolled grain sorghum (DRGS). As level (0, 3, 6, 9%) of dietary roughage was increased, feed efficiency (gain/feed) decreased (.1566, .1461, .1479, .1382; linear, P less than .01). In Trial 2, a grain type (DRGS; dry-rolled corn, DRC; dry-rolled wheat, DRW) x roughage level interaction was observed for daily gain and feed efficiency. Feed efficiency (gain/feed) was decreased when roughage was added to diets containing DRC (.1608 vs .1750) or DRGS (.1674 vs .1465), but not to the diet containing DRW (.1664 vs .1607). In trial 3, a grain type x roughage level x monensin level interaction (P less than .08) was observed for feed efficiency. The addition of 27.5 mg of monensin per kilogram of the 0% roughage-DRC diet tended to improve feed efficiency (.1633 vs .1531), but the addition of monensin to the 7.5% roughage-DRC diet tended to depress feed efficiency (.1476 vs .1575). The addition of either roughage (.1493 vs .1420) or monensin (.1500 vs .1413) to the DRW diet improved feed efficiency. In Trial 4, cattle fed a combination of 75% DRW and 25% DRC were more efficient (.1618 vs .1591; P less than .06) than cattle fed DRC. As level of roughage (0, 3.75, 7.5%) increased, feed efficiency decreased linearly (.1645, .1599, .1569; P less than .0001). Monensin had no effect on feed efficiency. The value of feeding roughage and monensin was variable both across grain types and within similar grain types.

Mothers' Communication Orientation and Consumer-Socialization Tendencies

Abstract: This study examines parent-child communication patterns and mothers' consumer-socialization tendencies. Results indicate mothers' concept-orientations are related to number of goals, discussing advertising, coviewing, coshopping, children's influence, yielding, and granting children consumer independence. In contrast, socio-orientations are related to limits on children's TV exposure and refusing requests.

Sequence and genetic organization of a Zymomonas mobilis gene cluster that encodes several enzymes of glucose metabolism.

Abstract: The Zymomonas mobilis genes that encode glucose-6-phosphate dehydrogenase (zwf), 6-phosphogluconate dehydratase (edd), and glucokinase (glk) were cloned independently by genetic complementation of specific defects in Escherichia coli metabolism. The identity of these cloned genes was confirmed by various biochemical means. Nucleotide sequence analysis established that these three genes are clustered on the genome and revealed an additional open reading frame in this region that has significant amino acid identity to the E. coli xylose-proton symporter and the human glucose transporter. On the basis of this evidence and structural analysis of the deduced primary amino acid sequence, this gene is believed to encode the Z. mobilis glucose-facilitated diffusion protein, glf. The four genes in the 6-kb cluster are organized in the order glf, zwf, edd, glk. The glf and zwf genes are separated by 146 bp. The zwf and edd genes overlap by 8 bp, and their expression may be translationally coupled. The edd and glk genes are separated by 203 bp. The glk gene is followed by tandem transcriptional terminators. The four genes appear to be organized in an operon. Such an arrangement of the genes that govern glucose uptake and the first three steps of the Entner-Doudoroff glycolytic pathway provides the organism with a mechanism for carefully regulating the levels of the enzymes that control carbon flux into the pathway.

Pharmacokinetic Drug Interactions with Cyclosporin (Part II)

Abstract: This article reviews the reported pharmacokinetic interactions between cyclosporin and other drugs. Both rifampicin and the majority of anticonvulsants can decrease cyclosporin concentrations to levels that are at or below the limit of detection for most assays. There have been no reports of any interaction between valproic acid and cyclosporin. Other drugs that have been reported to decrease cyclosporin concentration include sulfadimidine and trimethoprim, nafcillin and octreotide. Erythromycin, ketoconazole and some calcium channel blockers have been clearly shown to increase the concentration of cyclosporin. Other less well documented interactions have been reported with other macrolide antibiotics, other azole antifungal drugs, high dose methylprednisolone, metoclopramide, fluoroquinolones, imipenem/cilastatin, oral contraceptives/danazol, sulindac, methyltestosterone, colchicine, acetazolamide, alcohol and cimetidine. Although the most commonly reported mechanism is inhibition of cyclosporin metabolism, there is increasing evidence that erythromycin, metoclopramide and probably other drugs increase the bioavailability of oral cyclosporin. Two calcium channel blockers which have not been reported to interact with cyclosporin are nifedipine and nitrendipine. With increasing use of cyclosporin, the number of drugs reported to interact will rise. Prudent clinicians should monitor the concentration of this agent more frequently when another drug is added or discontinued and cyclosporin dosage should be adjusted when appropriate. Sustained changes in cyclosporin concentration can result in graft rejection (or graft-versus-host disease) or renal toxicity. Further studies are needed to determine the mechanism of most of these interactions.

Environmental influences on soil macroarthropod behavior in agricultural systems

Abstract: Afin de comprendre l'environnement dans lequel vivent les macroartropodes du rat, les principales bases de la physique des sols jouant un role dans la relation des mouvements de ces insectes avec le comportement de recherche des hotes sont examinees (Temperature, humidites, structure du sol). L'importance du comportement dans le controle de ces insectes est discutee

Extraction of Cholesterol and Other Lipids from Dried Egg Yolk Using Supercritical Carbon Dioxide

Abstract: Supercritical carbon dioxide extraction was investigated for removal of cholesterol and lipid components from dried egg yolk. Four different combinations of pressure and temperature were used including 163 atm/40°C, 238 atm/45°C, 306 atm/45°C and 374 atm/55°C. As temperature and pressure were increased, more lipids and cholesterol were removed. Extraction at 306 atm/45°C or 374 atm/55°C removed approximately two-thirds of the cholesterol. Phospholipids and protein were concentrated under the supercritical extraction conditions used. Sponge cake volume was significantly (P < 0.05) improved at extraction conditions of 163 atm/40°C, 238 atm/45°C and 306 atm/45°C, which may have been due to higher phospholipid and protein concentrations. Only extraction at 374 atm/55°C significantly (P < 0.05) impaired emulsion stability of egg yolk.

Fear of crime: An assessment of related factors

Abstract: This study examines the relationship between fear of crime and victimization, gender, age, and selected social factors. Data for the study were obtained from a random sample (n = 1,835) of respondents 15 years of age and over. Separate multiple regression techniques were utilized to assess the effects of predictor variables on fear of crime. The findings revealed that victimization was the most powerful predictor of fear of crime for the total sample and for each subsample. Other significant predictor variables include gender, age and race.