Showing papers by "University of Illinois at Chicago published in 1986"
TL;DR: In predicting the development of fears, and possibly other anxiety disorders, it may be more important to know what the person thinks will happen as a result of becoming anxious than how often the person actually experiences anxiety.
2,954Â citations
TL;DR: Results are consistent with a function for P-glycoprotein as an energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells.
1,914Â citations
Book•
01 Jan 1986TL;DR: In this article, a model for Ductile Fracture under Uniaxial Stress and Fracture Under MultiaxiaXial Stress is presented. But the model does not consider the effect of fatigue on the model.
Abstract: 1 - Introduction.- 2 - Creep and Fracture under Uniaxial Stress.- 3 - Creep and Fracture under Multiaxial Stress.- 4 - Crack Growth under Creep Conditions.- 5 - Damage Model for Ductile Fracture.- 6 - Fatigue Damage.- References.- Notations.
1,570Â citations
727Â citations
TL;DR: Evidence is presented that multidrug-resistant sublines of human KB carcinoma cells, selected for resistance to either colchicine, vinblastine, or Adriamycin (doxorubicin), display amplification of two different DNA sequences homologous to the hamster mdr gene, suggesting that the mdr1 gene is involved inMultidrug resistance in human cells.
Abstract: The ability of tumor cells to develop simultaneous resistance to structurally different cytotoxic drugs constitutes a major problem in cancer chemotherapy. It was previously demonstrated that multidrug-resistant Chinese hamster cell lines contain an amplified, transcriptionally active DNA sequence designated mdr. This report presents evidence that multidrug-resistant sublines of human KB carcinoma cells, selected for resistance to either colchicine, vinblastine, or Adriamycin (doxorubicin), display amplification of two different DNA sequences homologous to the hamster mdr gene. Segments of the human mdr DNA sequences, designated mdr1 and mdr2, have been cloned. mdr1 sequences were amplified in all of the highly drug-resistant sublines and were expressed as a poly(A)+ RNA species of 4.5 kilobases that was detected in the resistant cells but not in the parental cell line. No expression of mdr2 sequences was detected. mdr2 sequences were coamplified with mdr1 in some of the multidrug-resistant sublines and, in two independently derived cell lines, underwent very similar rearrangements. The data suggest that the mdr1 gene is involved in multidrug resistance in human cells.
682Â citations
TL;DR: Results suggest that increased expression of mdr1 mRNA is a common mechanism for multidrug resistance in human cells and that Activation of the m dr1 gene by mutations or epigenetic changes may precede its amplification during the development of resistance.
Abstract: The development of simultaneous resistance to multiple structurally unrelated drugs is a major impediment to cancer chemotherapy. Multidrug resistance in human KB carcinoma cells selected in colchicine, vinblastine, or Adriamycin is associated with amplification of specific DNA sequences (the multidrug resistance locus, mdr1). During colchicine selection resistance is initially accompanied by elevated expression of a 4.5-kilobase mdr1 messenger RNA (mRNA) without amplification of the corresponding genomic sequences. During selection for increased levels of resistance, expression of this mRNA is increased simultaneously with amplification of mdr1 DNA. Increased expression and amplification of mdr1 sequences were also found in multidrug-resistant sublines of human leukemia and ovarian carcinoma cells. These results suggest that increased expression of mdr1 mRNA is a common mechanism for multidrug resistance in human cells. Activation of the mdr1 gene by mutations or epigenetic changes may precede its amplification during the development of resistance.
592Â citations
499Â citations
TL;DR: In this paper, a developmental theory is presented to account for the relation between increased exposure to media violence and increased aggressive behavior, and it is argued that the effect of media violence on individual differences in aggression is primarily the result of a cumulative learning process during childhood.
Abstract: A developmental theory is presented to account for the relation between increased exposure to media violence and increased aggressive behavior It is argued that the effect of media violence on individual differences in aggression is primarily the result of a cumulative learning process during childhood Aggressive scripts for behavior are acquired from observation of media violence and aggressive behavior itself stimulates the observation of media violence In both childhood and adulthood, certain cues in the media may trigger the activation of aggressive scripts acquired in any manner and thus stimulate aggressive behavior A number of intervening variables may either mitigate or exacerbate these reciprocal effects If undampened, this cumulative learning process can build enduring schemas for aggressive behavior that persist into adulthood Thus, early childhood television habits are correlated with adult criminality independently of other likely causal factors It is concluded that interventions directed at mitigating the effects of media violence on delinquency and criminality should focus on the preadolescent years
486Â citations
432Â citations
TL;DR: It is shown that human KB carcinoma cells which express the mdr1 gene also express P-glycoprotein, and that cDNAs encoding P- glycoprotein cross-hybridize with m dr1 cDN as, Thus, the mDr1 gene codes for P- Glycoprotein.
417Â citations
TL;DR: This article employed a theoretical model to explain the long-term persistence of students who began their postsecondary education in two-year institutions, finding that academic and social integration had the most consistent pattern of positive direct effects, and much of the influence of student precollege traits was indirect.
Abstract: This paper employs a theoretical model to explain the long-term persistence of students who began their postsecondary education in two-year institutions. The model was estimated on a national sample of 825 students who initially enrolled in 85 two-year institutions in the fall of 1971, and who were followed over a nine-year period. Although there were differences in the factors associated with persistence for men and women, the results tend to confirm the importance of person-environment fit as a salient influence on degree persistence and completion in postsecondary education. Measures of academic and social integration had the most consistent pattern of positive direct effects, and much of the influence of student precollege traits was indirect.
TL;DR: In this article, Orientation to College and Freshman Year Persistence/Withdrawal Decisions. The Journal of Higher Education: Vol. 57, No. 2, pp 155-175.
Abstract: (1986). Orientation to College and Freshman Year Persistence/Withdrawal Decisions. The Journal of Higher Education: Vol. 57, No. 2, pp. 155-175.
TL;DR: In this paper, it was shown that δ is invariant with respect to the orientation of the plane boundary (in the case of half-plane problems), the semi-infinite crack and the crack and interface relative to the materials.
TL;DR: In this article, a method of moments technique for analyzing electromagnetic scattering by arbitrary shaped three-dimensional homogeneous lossy dielectric objects is presented based on the combined field integral equations.
Abstract: The recent development and extension of the method of moments technique for analyzing electromagnetic scattering by arbitrary shaped three-dimensional homogeneous lossy dielectric objects is presented based on the combined field integral equations. The surfaces of the homogeneous three-dimensional arbitrary geometrical shapes are modeled using surface triangular patches, similar to the case of arbitrary shaped conducting objects. Further, the development and extensions required to treat efficiently three-dimensional lossy dielectric objects are reported. Numerical results and their comparisons are also presented for two canonical dielectric scatterers-a sphere and a finite circular cylinder.
TL;DR: This study was undertaken with the hypotheses that glucose values in normal neonates may be different from those previously defined and that neonatal hypoglycemia may need to be redefined.
TL;DR: One can give a strong sense to the idea that a relation does not'reduce' to non-relational properties by saying that a relations does not supervene upon the non relational properties of its relata as discussed by the authors.
Abstract: One can give a strong sense to the idea that a relation does not 'reduce' to nonrelational properties by saying that a relation does not supervene upon the nonrelational properties of its relata. That there are such inherent relations I ca11 the doctrine of relational holism, a doctrine which seems to conflict with traditional ideas about physicalism. At least parts of classical physics seem to be free of relational holism, but quantum mechanics, on at least some interpretations, incorporates the doctrine in an a11 pervasive way.
TL;DR: In this paper, it was predicted that subjective career success is a multi-dimensional construct whose facets can be measured by several factors, and the notion that these dimensions would predict some aspects of career success more accurately for either managers or support personnel was also investigated.
Abstract: Despite popular belief that managers are successful by virtue of their positions, few studies have examined the position-success relationship. In this research, it was predicted that subjective career success is a multi-dimensional construct whose facets can be measured by several factors. Moreover, the phenomenon of career success was tested to see if it would relate to an employee's perception of occupational self-concept and job features. The notion that these dimensions would predict some aspects of career success more accurately for either managers or support personnel was also investigated. The confirming results obtained in this study and their implications for future research as well as practitioners are discussed.
TL;DR: The Eating Self-Efficacy Scale (ESES) as mentioned in this paper is a self-efficacy scale based on the Bandura (1977a) selfefficacy theory and has been used for eating disorders.
Abstract: Following from Bandura's (1977a) self-efficacy theory, an Eating Self-Efficacy Scale (ESES) was developed and its psychometric properties established. Factor analysis of the 25-item scale yielded two reliable factors—one concerned with eating when experiencing negative affect (NA) and the other with eating during socially acceptable circumstances (SAC). The ESES demonstrated good internal consistency, test-retest reliability, and convergent validity. A clinical study using this measure found that increases in ESES scores were significantly related to weight losses among weight loss program participants. A laboratory study using a mood induction procedure found that NA subscale scores predicted food consumption irrespective of whether negative affect was induced. This finding may indicate that people have difficulty accurately discriminating the specific circumstances under which their eating difficulties occur and/or that eating difficulties tend to be global in nature. The significant correlation of the two ESES subscales (r =.39, p <.001) supports these possibilities. The clinical and research utility of the ESES and the implications of the findings are discussed.
TL;DR: This paper corrected the critical values for testing normality reported by Lilliefors (1967) and derived a simple analytic approximation to the upper tail probabilities of his test statistic for probabilities less than.10.
Abstract: Table 1 corrects the critical values for testing normality reported by Lilliefors (1967). The corrected table allows us to derive a simple analytic approximation to the upper tail probabilities of his test statistic for probabilities less than .10. With few exceptions, the approximation is more accurate than Lilliefors's original table.
TL;DR: ER and AEBS assays may be of prognostic significance in the natural history of these tumors and competition studies revealed minimal binding with either DEX, DHT, R5020, and R1881, but partial binding with tamoxifen in cytosol and estradiol in microsomal fractions.
TL;DR: Immunoperoxidase staining of brain sections showed that MAP5 is present in neurons throughout the brain and that in them it is evenly distributed throughout axons, dendrites and cell bodies, which suggests thatMAP5 is particularly important in modulating microtubule function during the formation of neuronal processes.
Abstract: A novel microtubule-associated protein, MAP5, is described, whose chemical properties and cytological distribution distinguish it from other known microtubule-associated proteins (MAPs). Its status as a MAP is indicated by the observations that (i) it co-assembles efficiently with microtubules in vitro, (ii) it is localized on microtubules in brain sections by immunogold staining with monoclonal antibody against MAP5 and (iii) immunoaffinity purified MAP5 stimulates tubulin polymerization. Immunoperoxidase staining of brain sections showed that MAP5 is present in neurons throughout the brain and that in them it is evenly distributed throughout axons, dendrites and cell bodies. In this respect it differs from previously described MAPs (1, 2, 3 and tau) which are differentially compartmentalized in brain neurons. MAP5 is not present in axon terminals, dendritic spines or other synaptic elements. It is present at substantially higher levels in neonatal brain than adult and it is more abundant than either MAP1 or MAP2a up to postnatal day 10. The fall in amount of MAP5, from juvenile to adult levels, is completed between postnatal days 10 and 20. This suggests that MAP5 is particularly important in modulating microtubule function during the formation of neuronal processes.
TL;DR: Evidence is discussed that puts in question the widely held belief that adult mammals, including human beings, can meet all of their arginine needs by endogenous synthesis.
Abstract: Evidence is discussed that puts in question the widely held belief that adult mammals, including human beings, can meet all of their arginine needs by endogenous synthesis. Arginine, used in synthesis of body proteins, is essential for ammonia detoxification via urea synthesis, which prevents metabolic derangements caused by elevations in tissue ammonia. It is a precursor for polyamine synthesis and is the only source of amidino groups for the formation of creatine, a major source of high energy phosphate for regeneration of ATP in muscle. Arginine at supraphysiologic doses is thymotropic and a secretagogue for hormones that control growth and metabolism. Studies in mature rats show that glucose tolerance, the rate of repletion from severe protein undernutrition and recovery from trauma are significantly accelerated by dietary arginine. Oral or intravenous administration of excessive arginine reverses nitrogen loss and immune suppression after trauma in rats, and healthy human volunteers consuming 30 g of oral supplements or arginine have shown significantly enhanced immunoreactivity of the lymphocytes of their peripheral blood. Calculations based on creatinine excretion show that 0.8 g of protein/kg body weight of the quality supplied by the usual American diet barely provides sufficient arginine for synthesizing the quantity of creatinine excreted daily in the urine of 70-kg adults. Human patients who often consume less than this amount of protein show a decline in creatinine excretion during illness; the decrease suggests that their intake of arginine is less than optimal. Recent studies of intraspecies and interspecies differences in responses to arginine reemphasize that dispensability or indispensability of arginine is a matter of definition and that growth and nitrogen balance data impose significant limitations on the drawing of far-reaching conclusions about the needs for arginine by mammalian adults including humans. Orotic acid excretion, immune responsiveness and circulating hormone levels are measures that should be evaluated for identifying when enhancement of arginine intakes might prove beneficial.
TL;DR: A systematic study of the distribution and metabolism of nitroxide in biological systems provides a reasonably coherent picture of some aspects of the interactions between nitroxides and cells.
TL;DR: In this article, the optimization problem of radar polarimetry is formulated and the method of finding optimal polarizations is modified and extended to non-reciprocal and bistatic cases.
Abstract: Polarization aspects of the radar target scattering problem are reexamined. The optimization problem of radar polarimetry is formulated and Kennaugh's method of finding optimal polarizations is modified and extended to nonreciprocal and bistatic cases. Our approach does not necessitate diagonalization of the target scattering operator and therefore, a change-of-basis is not required. The change-of-polarization-basis is motivated by the comparison of experimental data taken with different antenna sets. Unitary matrix algebra is used to derive proper transformation formulas for scattering operators and bilinear voltage forms.
TL;DR: It is shown that hormones have effects on sexual motivation and behavior in public schools and for both sexes these effects are primarily androgenic in origin and for the most part exert their effects directly rather than through the social interpretation of age and hormone-induced pubertal development.
Abstract: Despite the widespread assumption that hormones stimulate motivation for sexual behavior in adolescence, no published empirical studies have demonstrated this link. In a cross-sectional study of 78 females in the eighth, ninth, and tenth grades in public schools, we show that hormones have effects on sexual motivation and behavior. Comparison with previous results from a parallel sample of males indicates that for both sexes these effects are primarily androgenic in origin and for the most part exert their effects directly rather than through the social interpretation of age and hormone-induced pubertal development.
TL;DR: In a young population without clinical evidence of heart disease, ventricular tachycardia may be the first manifestation of cardiomyopathy, since at least two-thirds of these patients have abnormalities at cardiac catheterization.
Abstract: Since 1974, 24 young patients presenting with ventricular tachycardia and without clinical evidence of heart disease were evaluated and followed. Sixteen patients (67%) were symptomatic. Clinical episodes of ventricular tachycardia were sustained in 18, incessant in four, and nonsustained in two patients. The rate of tachycardia ranged from 130 to 300 beats/min (mean = 200 beats/min). Subtle abnormalities of cardiac size or function were present at cardiac catheterization in 16 of 23 patients (70%). During electrophysiologic studies, spontaneous ventricular tachycardia was present in six patients. The clinical ventricular tachycardia was inducible by programmed stimulation in 13 of 18 patients. The site of origin of tachycardia based on endocardial mapping in 17 patients was the right ventricle in 14, the ventricular septum in one, and indeterminate in two patients. Seventeen patients were treated based on results of short-term drug testing. During a mean follow-up period of 7.5 years, three patients died suddenly; none of these patients were receiving antiarrhythmic medication at the time of death. We conclude that in a young population without clinical evidence of heart disease, ventricular tachycardia may be the first manifestation of cardiomyopathy, since at least two-thirds of these patients have abnormalities at cardiac catheterization. Without treatment mortality in this population may be as high as 13% over an 8 year period. Presently we recommend treatment of ventricular tachycardia in any symptomatic patient, with therapy guided by electrophysiologic and treadmill testing. In addition, we recommend treatment for any asymptomatic patient with exercise-related tachycardia, since this group appears to be at increased risk for sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: In this paper, a study reach of the Calamus River, Nebraska Sand Hills, has a low sinuosity (less than 1.3) and a braiding parameter (Less than 1) and depending on sinusosity, the channel is occupied by alternate bars and point bars, the emergent parts of which form nuclei for midstream bars (islands).
Abstract: A study reach of the Calamus River, Nebraska Sand Hills, has a low sinuosity (less than 1.3) and braiding parameter (less than 1). Depending on sinuosity, the channel is occupied by alternate bars and point bars, the emergent parts of which form nuclei for midstream bars (islands). Channel migration occurs by bend expansion and translation, downstream and lateral growth of islands, and by chute cutoff.
Channel-bed sediment is mainly medium-grained sand, but gravel and coarser sand sizes occur in thalweg areas adjacent to cutbanks and upstream parts of bars and islands, and finer sands occur on the downstream parts of bars and filling channels. Curved-crested dunes cover most of the channel bed at most flow stages, with ripples restricted to shallow areas near banks. Bed material is mostly large-scale cross-stratified, with small-scale cross-strata interbedded with plant debris occurring in topographically high areas near banks.
Vibracores through channel bars show a basal erosion surface overlain by large-scale cross-stratified sands, in turn overlain by small-scale cross-stratified sand interbedded with plant debris. The overall sequence generally fines upwards, but the large-scale cross-stratified portion either fines upwards, coarsens upwards, or shows little grain size variation. Lithofacies distributions vary spatially within and between bars depending on position in the bar and local channel curvature/width, in a similar way to unbraided rivers elsewhere. Lithofacies of bar deposits are similar to those in the active channel, and the elevations of the basal erosion surface and adjacent channel thalweg correspond closely.
Channels abandoned by chute cutoff are filled progressively from the upstream end, and comprise deposits similar to the downstream parts of bars (i.e. fining upwards). The downstream extremities of channel fills may contain large proportions of peat relative to sand, but little mud due to the paucity of such fine suspended load in the Calamus.
TL;DR: This paper examined the process by which students arrive in graduate school by estimating a causal model incorporating measures of socioeconomic background and undergraduate institutional characteristics and experiences and found that the student's background was found to influence strongly the initial choice of undergraduate institution, but the direct impact of background became nonsignificant as the student progressed through the educational process.
Abstract: This paper examines the process by which students arrive in graduate school by estimating a causal model incorporating measures of socioeconomic background and undergraduate institutional characteristics and experiences. The student's background was found to influence strongly the initial choice of undergraduate institution, but the direct impact of background became nonsignificant as the student progressed through the educational process. However, background variables do affect decisions to enroll in graduate school, although indirectly, through intervening variables. Primary direct influences on graduate school attendance were found from variables associated with the undergraduate experience. Although both academic and social integration are significant for men and women, academic integration has greater influence for men, whereas for women, social integration has a slightly larger effect.
TL;DR: In this article, a constitutive theory for concrete based on the geometry of its mesostructure and the actual kinetics of the microcrack evolution is proposed, which allows for a rational determination of the response in function of the volume fraction of the coarse aggregate, sieving curve, distribution and size of initial defects, relative strengths of the cement and aggregate, etc.
TL;DR: The Genetically Epilepsy-Prone Rat (GEPR) is rapidly gaining support as a model of epilepsy, and the relative potencies of anticonvulsant drugs between the two colonies of GEPRs predict the clinical efficacies of traditional antiepileptic drugs and may be able to predict novel anticonVulsants.