Showing papers by "University of Illinois at Chicago published in 1978"

The Effect of Americanization on the Earnings of Foreign-born Men

Abstract: The earnings of foreign-born adult white men, as reported in the 1970 Census of Population, are analyzed through comparisons with the native born and among the foreign born by country of origin, years in the United States, and citizenship. Differences in the effects of schooling and postschool training are explored. Although immigrants initially earn less than the native born, their earnings rise more rapidly with U.S. labor market experience, and after 10 to 15 years their earnings equal, and then exceed, that of the native born. Earnings are unrelated to whether the foreign born are U.S. citizens.

Asymptotic Theory of Least Absolute Error Regression

Abstract: In the general linear model with independent and identically distributed errors and distribution function F, the estimator which minimizes the sum of absolute residuals is demonstrated to be consistent and asymptotically Gaussian with covariance matrix ω2 Q -1, where Q = lim T -1 X'X and ω2 is the asymptotic variance of the ordinary sample median from samples with distribution F. Thus the least absolute error estimator has strictly smaller asymptotic confidence ellipsoids than the least squares estimator for linear models from any F for which the sample median is a more efficient estimator of location than the sample mean.

Clinical, electrocardiographic and electrophysiologic observations in patients with paroxysmal supraventricular tachycardia.

Abstract: Seventy-nine patients without ventricular preexcitation but with documented paroxysmal supraventricular tachycardia were analyzed. Electrophysiologic studies suggested atrioventricular (A-V) nodal reentrance in 50 patients, reentrance utilizing a concealed extranodal pathway in 9, sinus or atrial reentrance in 7 and ectopic automatic tachycardia in 3. A definite mechanism of tachycardia could not be defined in 10 patients (including 7 whose tachycardia was not inducible). The three largest groups with inducible tachycardias were compared in regard to age, presence of organic heart disease, rate of tachycardia, functional bundle branch block during tachycardia and relation of the P wave and QRS complex during tachycardia. A-V nodal reentrance was characterized by a narrow QRS complex and a P wave occurring simultaneously with the QRS complex during tachycardia. Reentrance utilizing a concealed extranodal pathway was characterized by young age, absence of organic heart disease, fast heart rate, presence of bundle branch block during tachycardia and a P wave following the QRS complex during tachycardia. Sinoatrial reentrance was characterized by frequent organic heart disease, a narrow QRS complex and a P wave in front of the QRS complex during tachycardia. In conclusion, a mechanism of paroxysmal supraventricular tachycardia could be defined in most patients. Observations of clinical and electrocardiographic features in these patients should allow prediction of the mechanism of the tachycardia.

The relation of students' precollege characteristics and freshman year experience to voluntary attrition

Abstract: This study assessed the relative influence on attrition of students' precollege characteristics, their experiences and perceptions of the freshman year, and the interactions of sex, major, and racial or ethnic origin with those experiences and perceptions. A series of stepwise multiple regression analyses indicated that precollege traits are not significantly related to attrition, that integration in the academic systems of the institution may be more important than involvement in the social systems, and that certain interactions between precollege traits and freshman year experiences and perceptions may be the most important. The findings suggest that attrition reduction efforts may need to be focused on what happens to students after they arrive on campus, on academic areas, and perhaps on the development of selective plans designed for different kinds of students.

Student-Faculty Informal Relationships and Freshman Year Educational Outcomes

Abstract: This study investigated the relationship between student-faculty informal relationships and three freshman year educational outcomes. After controlling for the influence of 14 student pre-enrollment characteristics, such as high school academic performance, academic aptitude, personality needs, and expectations of certain aspects of college, eight measures of the frequency and strength of student-faculty informal relationships accounted for statistically significant increases in the variance in freshman year academic performance and self-perceived intellectual and personal development. Partial correlations, controlling for the influence of all pre-enrollment characteristics and all other student-faculty relationship variables, indicated that frequency of student-faculty informal interactions focusing on intellectual or course- related matters had the strongest positive association with academic performance and intellectual development. Interactions for the purpose of discussing students’ career co...

Combat in the Fiddler Crabs Uca Pugilator and U. Pugnax: a Quantitative Analysis

Abstract: The aggressive behavior of two temperate species of fiddler crabs (Uca pugilator and U. pugnax) was studied in the field. Most of the fights wer between Residents (crabs owning burrows) and Wanderers seeking to displace them, though less commonly, fighting occurred between Residents occupying adjacent burrows. Over 400 fights were observed in each species. The two species showed differences in the sequences of acts performed during fights. Uca pugnax also performed two acts never observed in U. pugilator. Wanderers were rarely successful in displacing Residents of the same size or larger, but they won a small percentage of fights when they were larger than the Resident. Uca pugilator Wanderers select Residents that are slightly smaller, but we found no evidence for size selection in U. pugnax. Strongly motivated Wanderers repeatedly performed a key act (Downpush), which was also strongly correlated with successfully displacing Residents. Combat duration and number of acts were not related to temperature, the time of day, or the time in relation to low tide. However, the incidence of fighting increases in the early afternoon. Most of the fights occur within 1-3 hours after low tide. Differences between the species in the tempo and length of fights were observed. An hypothesis, based upon habitat differences and the value of burrows as a resource, is presented to account for these differences. We compared our data to CRANE'S (1967) for U. rapax, a tropical species. There are some important differences between her findings and ours, even though U. pugnax is closely related to U. rapax. We suggest that at least one of her opinions on the significance of aggression in tropical fiddlers is in conflict with evolutionary theory. Some of her other ideas do not apply to temperate species, where climatic factors may be responsible for behavioral convergence. Our data also indicate that the differences and similarities between species are sufficiently provocative to warrant further comparative studies.

Competency-based curriculum development on medical education: an introduction.

Abstract: Competency-based curriculum development in medical education: an introduction , Competency-based curriculum development in medical education: an introduction , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Lithium transport pathways in human red blood cells.

Abstract: In human red cells, Li is extruded against its own concentration gradient if the external medium contains Na as a dominant cation. This uphill net Li extrusion occurs in the presence of external Na but not K, Rb, Cs, choline, Mg, or Ca, is ouabain-insensitive, inhibited by phloretin, and does not require the presence of cellular ATP. Li influx into human red cells has a ouabain-sensitive and a ouabain-insensitive but phloretin-sensitive component. Ouabain-sensitive Li influx is competitively inhibited by external K and Na and probably involves the site on which the Na-K pump normally transports K into red cells. Ouabain does not inhibit Li efflux from red cells containing Li concentrations below 10 mM in the presence of high internal Na or K, whereas a ouabain-sensitive Li efflux can be measured in cells loaded to contain 140 mM Li in the presence of little or no internal Na or K. Ouabain-insensitive Li efflux is stimulated by external Na and not by K, Rb, Cs, choline, Mg, or Ca ions. Na-dependent Li efflux does not require the presence of cellular ATP and is inhibited by phloretin, furosemide, quinine, and quinidine. Experiments carried out in cells loaded in the presence of nystatin to contain either only K or only Na show that the ouabain-insensitive, phloretin-inhibited Li movements into or out of human red cells are stimulated by Na on the trans side and inhibited by Na on the cis side of the red cell membrane. The characteristics of the Na-dependent unidirectional Li fluxes and uphill Li extrusion are similar, suggesting that they are mediated by the same Na-Li countertransport system.

New region of the simian virus 40 genome required for efficient viral transformation

Abstract: Viable mutants of simian virus 40 with deletions in three regions of the virus genome (map coordinates 0.21-0.17, 0.59-0.54, and 0.67-0.74) have been tested for their ability to transform rat fibroblasts to anchorage independence. Only those mutants whose deletions occur between 0.59 and 0.55 in the proximal part of the early region are defective in transforming ability. The most severely defective of these transform with less than one-hundredth the efficiency of wild type. They retain their defect when tested in Chinese hamster lung cells and when infection is initiated with viral DNA instead of intact virions. Complementation for transformation can be observed between these transformation-defective deletions and a simian virus 40 temperature-sensitive A mutant.

Social Relationships and Verbal Interactions of Learning Disabled Children

Abstract: Despite federal regulations which define LD children strictly in terms of intellect and achievement, sensitive observers recognize the social and emotional complications these children face. With increased mainstreaming, the LD child's social skills will be severely tested. Our ability to recognize the nonacademic aspects of LD should provide each child with a more understanding and supportive environment. The series of studies Bryan reviews challenges some stereotypes of the LD child and provides alternative views for teachers and researchers. All readers must recognize that the findings may not represent all LD children, nor does Bryan suggest such. Rather, this work provides an empirical touchstone against which to understand individual pupils and to accomplish increasingly refined experimental work. — G.M.S.A series of research studies is described which investigated the sociometric status, social behavior, and social relationship of learning disabled children in classroom observations and laboratory ...

Numerical Solution Scheme for Local Nonsimilarity Boundary-Layer Analysis

Abstract: In the analysis of boundary layers by the local nonsimilarity solution method, the central task is the numerical solution of a set of simultaneous ordinary differential equations. The current method of solving these equations is forward integration in conjunction with a shooting method for determining certain of the starting values for the integration. This approach has been found to be less and less effective as the number of simultaneous equations increases. The numerical solution scheme described here is able to deal effectively with the multiequation systems encountered in local nonsimilarity boundary-layer analysis. It employs integrated forms of the governing differential equations. The key feature of the integrated forms is that they already satisfy the boundary conditions. With these equations, initial, almost arbitrary guesses of the profiles are refined automatically until convergence is attained. For concreteness, the description of the scheme is illustrated by a nonsimilar natural con...

Social Interactions of Learning Disabled Children

Abstract: Efforts to mainstream learning disabled children may require educators to consider social adjustment variables as much as academic factors in remedial programing. As in their previous work, Bryan and Bryan found learning disabled children to be less popular than their peers. This study delineates the behavioral basis of attitudinal rejection of learning disabled children by their classmates. The verbal communication habits of learning disabled children are found to be a major factor in their social rejection. Learning disabled children emit and receive more rejection statements than nondisabled classmates.

Public Health Measures and Mortality in U.S. Cities in the Late Nineteenth Century

Abstract: In this paper we examine the decline in mortality rates by cause of death in U.S. cities during the last decade of the. 19th century. Causes of death are grouped according to their probable relationship to specific public health measures. The reduction which occurred in the death rates from some diseases, e.g., typhoid and diarrheal diseases, can probably be attributed in part to the provision of sewers and waterworks. Large declines also occurred in the death rates from tuberculosis and diphtheria, but the relationship between the declines in these diseases and public health practices designed to combat them is more ambiguous. We therefore conclude that public health measures had some impact on the decline in mortality, but that these measures do not provide a complete explanation of the mortality decline.

Stimulation of fetal hemoglobin synthesis in baboons by hemolysis and hypoxia

Abstract: Fetal hemoglobin (Hb F) levels in the peripheral blood of baboons (Papio cynocephalus) increased from an average value of 0.78% to 18.1% during the recovery phase from phenylhydrazine-induced hemolytic anemia. A similar increase was observed in animals exposed to hypobaric hypoxia. Large individual variations in the maximal Hb F levels were observed which could not be correlated with the ages of the animals. Reinduction of hemolysis in two fully recovered animals resulted in Hb F levels that were of similar magnitude as in the preceding episode, suggesting the possibility of genetically determined individual variations in the rate of Hb F synthesis under the same conditions of erythropoietic stimulation. Reticulocytes from the animals subjected to hemolysis of hypobaric hypoxia synthesized similar absolute quantities of Hb F in vitro. The results of the present studies indicate that the physiological switch from the synthesis of Hb F to that of Hb A during ontogeny can be reversed in adult nonhuman primates by conditions of erythropoietic stress known to be associated with high erythropoietin levels. These findings open the possibility that Hb F synthesis in adult humans may be therapeutically modulated in individuals who might benefit from increased levels of Hb F, such as patients with sickle cell anemia.

Maximum-energy-release-rate criterion applied to a tension-compression specimen with crack

Abstract: The title problem is studied by using the explicit asymptetic analysis presented in the accompanying paper. The asymptotic analysis indicates that the very basic problem is a semi-infinite L-shaped crack governed by a single integral equation. This equation is discretized to a system of complex algebraic equations and solved by a standard HARWELL subroutine. It is found that the maximum-energy-release-rate criterion has two branches, one for tensile loads and one for compressive loads. Our numerical results indicate that the maximum energy-release rate is always associated with maximum K1 and K2=0, where K1 and K2 are the stress-intensity factors at the fractured tip. Thus, the well-known K-G relation valid for crack-parallel propagation also holds for non-crack-parallel propagations. This conclusion is, however, purely numerical.

Refractive errors of retinitis pigmentosa patients.

Abstract: A retinitis pigmentosa (RP) population (268 eyes) had predominantly myopic refractive errors. Whereas 12% of a normal population have myopic refractions, myopia was found in 75% of 268 eyes of RP patients and in 95% of 41 eyes of X-linked RP patients. The spherical errors describe a single-peaked, skewed distribution, with a mean of -1.86 dioptres that is significantly (P less than 0.001) more myopic, by -2.93 D, than that of a normal population. The X-linked genetic group has a spherical mean of -5.51 D that is significantly (P less than 0.01) more myopic than the non-X-linked RP population. This X-linked spherical error distribution may be composed of two separate subdistributions. Astigmatic refractive errors greater than 0.5 D are found in 47% of this RP population, considerably in excess of the 19% of a normal population with such astigmatic errors.

Effects of procainamide on atrioventricular nodal re-entrant paroxysmal tachycardia.

Abstract: Electrophysiological effects of 750 mg i.v. procainamide were studied in 14 patients with dual pathway atrioventricular (A-V) nodal re-entrant paroxysmal tachycardia (PSVT). All patients utilized an A-V nodal slow pathway for antegrade and an A-V nodal fast pathway for retrograde conduction during PSVT. In all 14 patients, procainamide depressed retrograde fast pathway conduction, manifest by increase in mean ± SEM ventricular paced cycle length (CL) producing V-A block from 5 295 ± 25 to 385 ± 17 msec (P < 0.001). Antegrade fast and slow pathway properties were unchanged with procainamide. Eleven of the 14 patients had induction of sustained PSVT before procainamide. Eight of these lost ability to induce or sustain PSVT after procainamide, reflecting depression of retrograde fast pathway conduction with either absence of atrial echoes (4 pts) or induction of nonsustained PSVT, with termination of PSVT occurring after QRS (retrograde block in fast pathway) (4 pts). In three of these 11 patients, sustained PSVT was inducible before and after procainamide (mean CL of 395 ± 38 and 395 ± 40 respectively) (NS). Three patients had induction of nonsustained PSVT before procainamide. In two, induction of sustained PSVT occurred after procainamide due to enhanced antegrade slow pathway conduction, while in the other PSVT remained nonsustained. In conclusion, procainamide inhibited induction of sustained A-V nodal re-entrant PSVT in most patients, reflecting selective depression of retrograde A-V nodal fast pathway conduction. In a minorityof patients, vagolytic effects of procainamide potentiated induction of sustained PSVT.

The appearances of wear on polyethylene--a comparison of in vivo and in vitro wear surfaces.

Abstract: An examination has been made of the wear surfaces of 21 ultra-high-molecular-weight polyethylene components of hip and knee joint prostheses removed from patients. Both light optics and scanning electron microscope systems of examination have been used. The appearances are compared with specimens subjected to two different in vitro wear tests. Surface appearances related to the wear experience have been classified into seven modes. At least four of these are evidences of what may be four different wear mechanisms. Entrapment of bone-cement particles between articulating surfaces is fundamentally extraneous but is seen to generate the most severe wear. In the absence of bone-cement particles, in vivo, wear seems to be mild. Wear in vitro produces similar surface modes but with different relative emphasis.

Four Hundred Consecutive Pars Plana Vitrectomies With the Vitrophage

Abstract: • We performed 400 consecutive pars plana vitrectomies, using the vitrophage. Most patients (68%) showed some degree of visual improvement; only 8% had a decline in visual acuity postoperatively. The major operative complications were controllable bleeding from iris vessels and intravitreal stalks (19%) and retinal tears (2%). No retinal dialysis was noted. The major, early postoperative complications were related to corneal decompensation in 38% of the cases; this persisted beyond two weeks in only 7%. Increased intraocular pressure occurred in 19% and postoperative rubeosis iridis developed in 10% of the diabetic patients. Complications related to rebleeding occurred in 18% of the diabetic patients within the first two weeks, and an additional 9% had late rebleeding. Less frequent complications included one case of endophthalmitis, late retinal detachment in 5%, and phthisis bulbi in 2% of all cases. All complications were considerably more frequent and severe in the diabetic population.

Sum of MMPI scales F, 4, and 9 as a measure of aggression.

Abstract: This study was supported by Grant M1726 from the National Institute of Mental Health, by Contract HSM 42-70-6 from the Surgeon General's Scientific Advisory Committee on Television and Social Behavior, and by the New York State Department of Mental Hygiene. The data analysis was performed with the assistance of the computation center of the University of Illinois at Chicago Circle. For Part 1 of this study, Leopold Wakler was a co-investigator.