Showing papers by "University of North Carolina at Charlotte published in 1984"

Synthetic control of excited-state properties. Tris-chelate complexes containing the ligands 2,2'-bipyrazine, 2,2'-bipyridine, and 2,2'-bipyrimidine

Abstract: The photophysical and photochemical properties of the series of tris-chelate complexes Ru(bpy)/sub n/(bpyz)/sub 3-n//sup 2 +/, Ru(bpy)/sub n/(bpym)/sub 3-n//sup 2 +/, Ru(bpym)/sub n/(bpyz)/sub 3-n//sup 2 +/, and Ru(bpy)(bpym)(bpyz)/sup 2 +/ (n = 0, 1, 2, 3; bpy = 2,2'-bipyridine, bpyz = 2,2'-bipyrazine, bpym = 2,2'-bipyrimidine) are described. From the results of temperature-dependent lifetime (210-345 K) and room-temperature emission quantum yield measurements have been obtained: (1) k/sub r/ and k/sub nr/, the radiative and nonradiative decay rate constants for the emitting MLCT manifold and (2) kinetic parameters which suggest the intervention of additional excited states. The significant points of the study are the following: (1) trends in k/sub nr/ properties are understandable based on the energy gap law, (2) low-lying dd states strongly influence lifetimes and photochemical instabilities for the complexes Ru(bpyz)/sub 3//sup 2 +/, Ru(bpym)/sub 3//sup 2 +/, Ru(bpy)(bpyz)/sub 2//sup 2 +/, Ru(bpy)(bpym)/sub 2//sup 2 +/, Ru(bpym)(bpyz)/sub 2//sup 2 +/, Ru(bpym)/sub 2/(bpyz)/sup 2 +/, and Ru(bpy)(bpym)(bpyz)/sup 2 +/ at room temperature, and (3) for the complexes Ru(bpy)/sub 2/(bpyz)/sup 2 +/ and Ru (bpy)/sub 2/(bpym)/sup 2 +/ there is no evidence for low-lying dd states and these and/or related mixed-ligand complexes may provide a basis for a new series of photochemicallymore » stable Ru-polypyridyl chromophores.« less

Relative Effects of Two Previewing Procedures on LD Adolescents' Oral Reading Performance.

Abstract: An alternating-treatments design was used to investigate the relative effects of two oral reading previewing procedures: (a) silent: the student reads silently the assigned reading passage prior to reading it aloud, and (b) listening: the teacher reads the assigned selection aloud with the student following along silently prior to the student reading the passage aloud. Five junior-high school learning disabled students, four boys and one girl, participated in the study. In four of five cases results showed that systematic prepractice procedures were related to higher performance levels than was baseline (no prepractice). Differential effects were noted: the listening procedure was related to higher rates of words read correctly than was the silent procedure. The findings are discussed in terms of their implications for research and instructional procedures, especially as these relate to adolescent learners.

Lipid Composition of a Psychrophilic Marine Vibrio sp. During Starvation-Induced Morphogenesis.

Abstract: Qualitative and quantitative changes with time in phospholipids and fatty acids were examined after suspension of cells of a psychrophilic marine bacterium in nutrient-free artificial seawater at 5°C. Viability was maintained throughout the 21-day examination period, with plate counts and acridine orange direct counts indicating a slight increase in cell number. Gravimetric data, however, showed a significant decrease in bacterial biomass during the 3-week study. Levels of ATP per cell also decreased significantly (59%) during the starvation period. Since starvation (resulting in dormancy) is probably the typical physiological state of marine bacteria, estimation of bacterial density in marine waters by using ATP data obtained from log-phase cells is probably inaccurate. Total lipid phosphate decreased (65%) during the starvation period, with phosphatidylethanolamine showing the greatest loss. A large increase (57%) in the neutral lipid fraction was also detected, especially during the first week of starvation. A selective increase in palmitoleate at the expense of myristate was detected in the membrane lipids. The effects of these changes on membrane fluidity and the possible consequences for these cells in the marine environment are discussed.

Ediacarian fossils from the Carolina slate belt, Stanly County, North Carolina

Abstract: Discovery of metazoan fossils, comparable to those of the late Precambrian Ediacarian fauna, in the Carolina slate belt, Stanly County, North Carolina, extends the paleobiogeographic range of the Ediacarian fauna into the southern Piedmont of the southeastern United States. These fossils provide paleontologic correlation with parts of the Precambrian Valdai Series of the Vendian System of the Soviet Union, the Nama Group of South-West Africa, and the Pound Quartzite of South Australia. In light of the recent discoveries, North Carolina fossil material previously described as the Middle Cambrian trilobite ? Paradoxides carolinaensis St. Jean, 1973, was re-examined and identified as an element of the late Precambrian Ediacarian fauna.

Suicidal death: social reactions to bereaved survivors.

Abstract: The present investigation examined the reactions of persons to specific individuals who have actually experienced suicidal bereavement. Persons who knew another who had experienced bereavement following a suicidal death were interviewed and their responses were compared with those of persons who knew others bereaved as a result of accident and as a result of natural causes. The impact of the cause of death suggests that suicide is perceived as a more difficult type of death with which to cope; interactions wit survivors of suicidal death are seen as somewhat more stressful. The cause of death may have less of an impact on reactions to the bereaved than research has suggested when the focus is on responses of persons who actually know the survivors.

Effect of Metal Design on Marginal Distortion of Metal-Ceramic Crowns

Abstract: An analysis of residual stress and marginal distortion due to thermal contraction mismatch between metal and ceramic is presented for metal-ceramic crowns. Using dilatometric data, finite element stress analyses were performed on pre-molar crowns designed with chamfer-knife edge, chamfer with collar, shoulder with collar, and shoulder-bevel with collar geometries and a maxillary central incisor crown with a chamfer-knife edge geometry. Calculations were made using combinations of a Ni-Cr alloy or a Au-Pd alloy with each of three porcelain products. Calculated marginal distortions due to crown design and metal-porcelain thermal contraction incompatibility were found to be well below experimental values found in the literature. For the cases studied, the calculated marginal distortions due to metal-porcelain thermal contraction mismatch depend primarily on the metal-porcelain combination and are insensitive to the coping design. However, this study excluded copings which have been extensively ground to thic...

Effects of previewing on the oral reading of mainstreamed behaviorally disordered students.

Abstract: An alternating treatments design was used to investigate the relative effects of two previewing procedures on oral reading: (a) silent previewing, which required the student to read silently the as...

Picture Memory in Older Adults: Effects of Contextual Detail at Encoding and Retrieval

Abstract: In the present study, contextual detail was manipulated in a stimulus set by reproducing cartoon pictures intact or with much of the background obliterated. Young and older adults were presented cartoon slides both with and without contextual detail for study. During recognition, presence or absence of background was crossed factorially with its presence or absence during encoding, and participants indicated whether they recognized the cartoon. Analysis of d' scores indicated that old and young adults evidenced encoding specificity effects of comparable magnitude. Additionally, young people recognized pictures with contextual detail better than pictures without detail, whereas the reverse appeared to be true for older individuals. The implications of these findings with respect to those of Craik and Simon are discussed.

Self-disclosure and its relationship to marital intimacy.

Abstract: Examined the relationship between marital intimacy and self-disclosure from a multidimensional framework within a sample of 10 clinical and 10 nonclinical married couples. The linear combination of various parameters of self-disclosing behavior was able to account for 71.7% (R = .853) of the variance in intimacy ratings derived from a structured interview. Results are discussed in terms of both the role that self-disclosure plays in the development of marital intimacy and its therapeutic benefits and limitations in marital therapy.

The Moderating Role of Work Context in Job Design Research: A Test of Competing Models

Abstract: The article discusses a study which tested the moderating effects of organizational climate on the relationship between job complexity and job satisfaction. Data was collected from nursing service ...

Pain reactions in pregnant women.

Abstract: Reactions to radiant heat stimuli were measured in pregnant women and in a control group of non-pregnant women matched in age. Receiver operating characteristic curve parameters were computed for each of the stages of pregnancy from the 6th month until the postpartum period. When painful stimuli were used, a group by stage of pregnancy interaction was found in the analysis on the response criterion for reporting pain. Pregnant women were found to be significantly more willing to label radiant heat stimuli as painful during the last 2 weeks of pregnancy than during any of the other stages of pregnancy. The control women tested during the same time sequence as the pregnant women showed stable response criteria across the 6 month testing period. There were no group or stage of pregnancy effects evident when the discrimination accuracy measures were analyzed; nor were any effects found with responses to thermal stimuli. The results suggest that the changes in pain reaction associated with pregnancy are based on non-sensory factors that influence the subject's willingness to report pain.

Sex stereotype impacts on competence ratings by children

Abstract: Female and male children, 67 and 114 months of age, provided ratings of perceived relative competence of male and female stimulus persons who were depicted as engaging in sex-stereotyped professions. Ratings for each of eight occupations were made by allocating 10 plastic chips between the two stimulus persons. After the last trial, children also were asked to recall the occupation last paired with a particular stimulus person. Children at each of three age levels rated as more competent the individual whose sex was consistent with the stereotype for the occupational group presented; the degree of differentiation increased with age. Recall was influenced by the consistency of the stimulus person/occupation pairing with the sex stereotype, but was not related to ratings of competence.

Motor units of the primary ankle extensor muscles of the opossum (Didelphis virginiana): functional properties and fiber types.

Abstract: Motor units of the medial gastrocnemius (MG) and the single lateral gastrocnemius/soleus (LG/S) muscles of the opssum (Didelphis virginiana) were found to have uniformly slow contraction times relative to homologous muscles of the cat. Though a broad range of peak tetanic tensions was found among motor units from both muscles, most of the motor units were quite large relative to tension of the whole muscle. Comparison of the relative sizes of motor units showed that those of LG/S are significantly larger and slower than the units of MG. This suggests that the motor units of the two muscles may be differentially recurited during different behaviors. All of the MG and LG/S motor units were highly or moderately resistant to fatigue. Histochemical staining for NADH-diaphorase activity indicated consistently high levels of the enzyme in all of the fibers of both muscles. Apparently, all of the fast motor units consist of fast oxidative/glycolytic (FOG)-type muscle fibers. Our data provide functional evidence that the types of myofibrillar ATPase demonstrated by Brooke and Kaiser ('70), are not necessarily correlated to physiological classification of fiber types as slow oxidative (SO), fast oxidative/glycolytic (FOG), and fast glycolytic (FG) (Peter et al., '72). Perhaps compartmentalization of muscle fiber types may be a first step in the separation of muscles into multiple heads during the evolution of specialization to diverse locomotor habits among the mammals.

Issue Specialization as a Variable in Opinion Assignment on the U.S. Supreme Court

Abstract: Is issue specialization another variable in opinion assignment on the United States Supreme Court? I examined the civil liberties cases of the Warren Court and found that issue specialization was usual and commonplace on the Court. It was present, however, in narrow issues (such as right to counsel) and not in civil liberties in general or even in somewhat broader issues (such as criminal defendant cases). I also discovered that Chief Justice Warren tended to select as issue specialists justices who had the same or similar ideological views as himself.

Necessary conditions for optimality of singular controls

Abstract: The present paper is concerned with the study of controls which are singular in the sense of the maximum principle. We obtain necessary conditions for optimality of singular controls in systems governed by ordinary differential equations. A useful feature of the method considered here is that it can be applied to optimal control problems with distributed parameters.

Effects of Campaign Spending On Local Elections The Charlotte Case

Abstract: Data on Charlotte, Mecklenburg County, N.C. elections held between 1975 and 1980 were collected. The effects of campaign spending, party, sex, race, and incumbency are examined in five types of elections in this single area: nonpartisan school board, single member district primaries, single member district general partisan elections, multiple seat primaries, and multiple seat general partisan elections. Three conclusions are worthy of note: (1) Money is as important in partisan elections as in primaries and school board contests, (2) Campaign spending plays a stronger role in single member district elections and incumbency a stronger role in multiple seat elections, (3) incumbency, party, and campaign spending are not as strongly related to the vote as is suggested by studies that focus on many different constituencies for one office.

Hyperactivity, Learning Disabilities, and Alcohol

Abstract: The United States Food and Drug Administration had issued a warning to women that alcohol consumed during the prenatal period may cause deleterious effects on offspring. The present article examines the professional literature in regard to the history of and research in alcohol consumption by pregnant women. New research findings suggest that maternal alcohol consumption may be the cause for behaviors in children that have led to their being diagnosed as learning disabled. Hyperactivity, short attention span, and emotional lability in children may be the direct result of mothers' drinking during pregnancy. The present paper reaffirms the Food and Drug Administration's warning to pregnant women and potential mothers of the hazards of even mild or moderate drinking during pregnancy and the possible negative effects it may cause on a child's learning and behavior.

Suicide in later life: Some putative causes with implications for prevention

Abstract: Research that has examined factors presumed to cause suicide is reviewed. The roles of physical illness, loss and isolation, sex role differences, economic conditions, attitudes, depression and hopelessness, and life satisfaction are considered. The relevance of these factors to a person-environment interaction perspective is discussed. Baechlor has suggested that suicide is always a solution to a problem and the implications of this fomulation for prevention are discussed. Educational, nontraditional, and policy implications are emphasized.

Triplo-X hermaphrodite of Caenorhabditis elegans: pachytene karyotype analysis, synaptonemal complexes, and pairing mechanisms

Abstract: Pairing of the three X chromosomes in the triplo-X strain of Caenorhabditis elegans occurs at pachytene in a two-by-two fashion such that one bivalent and one univalent are formed. The XX bivalent pairs synchronously with the autosomes and the univalent X remains in a similar chromatic state as the rest of the chromosomal complement. Normal tripartite synaptonemal complexes (SC) are formed between all bivalents. The univalent X lacks a SC and an axial core is not observed. The condensation of the univalent X in the triplo-X is different than in the male where the univalent X is heterochromatic. This real difference in condensation states of the chromatin may explain the fact that the univalent X is maintained in the male line yet it is easily lost in the triplo-X strain.

Negative Effects of Illustrations as Word Cues

Abstract: A multiple baseline across students design was used to investigate the relative effects of illustrations on the acquisition of words in isolation in two settings. Words were taught, using picture cues and no-picture cues, to four elementary school-aged learning disabled students. Results in three of four cases indicated that illustrations wererelated to lower reading performance rates, leading to a conclusion that illustrations interfere with the acquisition of new words in isolation by disabled readers. Results are discussed further in terms of their implications for instruction and research.

Direct Labeling, Tester Expectancy and Delay Maintenance Behavior in Scottish Preschool Children

Abstract: The influence on Scottish preschool children's self-control of labels regarding patience given directly to the children themselves, and of the expectations regarding the children's patience provided to adult testers, was investigated. The children's self-control was assessed in a task in which each child's possession of accumulating candy rewards was made contingent upon the child's stopping of further accumulation. Preschool children directly labeled beforehand as "patient" demonstrated significantly longer delay maintenance than did preschoolers hearing a remark irrelevant to the task. A significant effect of tester expectancy was found, with children not directly labeled as "patient" beforehand being more sensitive to adult expectations than were labeled children.