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C J Johnson

Publications and source records attributed to C J Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1990

School-age children's metalinguistic awareness of grammaticality in verb form.

This study investigated 6-, 7-, and 8-year-old children's ability to monitor grammaticality in the past progressive, perfect progressive, and perfect verb forms. The children achieved a significantly higher rate of accurate judgments monitoring grammatical forms that ungrammatical forms. Age was a significant factor in error identification. Eight-year-olds were substantially better at identifying ungrammatical forms than were their younger schoolmates. Verb form, in conjunction with type of anomaly, significantly varied with respect to ease of identification. Errors of the auxiliary and suffix were easier for children to identify than an adverbial error which required a sentence analysis to determine the incompatibility. The context surrounding ungrammatical verb forms significantly affected monitoring ability. Anomalous forms in unrelated sentences were easier to identify as ungrammatical than anomalous forms in sentences taken from a story the children had just heard. It appears that school-age children prefer to maintain the semantic intent of the message rather than critically search for grammatical errors.

Age Factors↗
PubMed1989

Conversational topics of 4-year-olds.

Young children's ability to participate in conversation has been of particular interest in the study of pragmatic aspects of language. In this study, topics of conversation were investigated by videotaping 10 dyads of 4-year-old children during play. Ten-minute samples were analyzed according to a number of topic-dependent measures. Results revealed that all dyads evidenced some lengthy topics (13-91 utterances). Longer topics were characterized by three text-level functions. Enacting Scenarios, Describing, and Problem Solving. Nevertheless, three fourths of all dialogues were considered relatively short. Generally, partners contributed equally to dialogue, but in some dyads, 1 child dominated initiation. Findings of the study suggest that 4-year-olds are capable of extended participation in dialogue, at least part of the time. Naturalistic play settings may elicit samples of conversation that are representative of preschoolers' ability.

Child, Preschool↗
PubMed1988

A new perspective in evaluating clinical effectiveness: the UWO Clinical Grading System.

To improve assessment of the performance of speech-language pathology students in clinical practicum, faculty and students in the Department of Communicative Disorders at the University of Western Ontario developed a new evaluation instrument, the UWO Clinical Grading System (UWO-CGS). This article reports on the development and field-testing of the UWO-CGS and includes estimates of the instrument's intrasupervisor and intersupervisor reliability. Results of content-related, construct-related, and criterion-related investigations are reported to support the inference that the UWO-CGS is a valid measure of the clinical effectiveness of student speech-language pathologists.

Clinical Competence↗
PubMed1987

Interaction of high density lipoprotein with its receptor on cultured fibroblasts and macrophages. Evidence for reversible binding at the cell surface without internalization.

Cultured extrahepatic cells possess a specific high affinity receptor for high density lipoprotein (HDL) that is induced by cholesterol delivery to cells. Current results suggest that HDL receptors on cultured human fibroblasts and mouse peritoneal macrophages promote reversible binding of HDL to the cell surface without internalization of lipoprotein particles. When 125I-HDL3 was bound to cultured cells at 0 degrees C and then warmed to 37 degrees C after removal of unbound lipoprotein, most of the cell surface-bound HDL was released rapidly (t1/2 = 3 min) into the medium without entering a cellular pool that was inaccessible to digestion by trypsin at 0 degrees C. This lack of internalization of HDL was evident under conditions where internalization of 125I-low density lipoprotein and 125I-transferrin were readily detected. When cells were exposed to 125I-HDL3 at 37 degrees C, only a trace amount of iodinated apoprotein remained associated with cells after treatment of cells with trypsin. Fibroblasts treated with medium containing increasing concentrations of cholesterol exhibited a dose-dependent increase in reversible, trypsin-sensitive binding of 125I-HDL3 at 37 degrees C without an attendant increase in trypsin-resistant binding. These results suggest that reversible binding of HDL to its cell-surface receptor without subsequent endocytosis of receptor-HDL complexes is the mechanism by which HDL receptors facilitate cholesterol transport from cells.

Carrier Proteins↗
PubMed1985

Early language abilities of high-risk infants.

Ten children with a history of prematurity and respiratory distress syndrome (RDS) were matched with 10 full-term controls on the single-word stage of language. Eleven dependent variables probed for qualitative differences between the groups. Measures of receptive language were based on two assessment procedures specifically designed for this study. Expressive language measures were taken from a parent-elicited language sample. Control subjects demonstrated superior performance on all receptive language and child verbosity measures despite their younger age.

Child Language↗
PubMed1985

Automatic blood pressure monitors. A clinical evaluation of five models in adults.

Five automatic blood pressure monitors were evaluated by comparing their values with almost simultaneous blood pressure readings from radial artery catheters. A total of 583 comparisons were made on 48 patients. Statistical analysis was performed on the pooled comparisons of systolic and diastolic pressure for each monitor. Agreement between the pressure measurements was variable between both patients and machines. For systolic pressure, two machines (Copal and Sentron) had correlation coefficients of over 0.9 while for the other machines (Dinamap 845XT, Narco and Vitastat 9001S) the values lay between 0.7 and 0.8. The steepest regression lines were also found with the Copal (0.93) and Sentron (0.86) data, but the other machines had considerably flatter slopes (0.55 to 0.67). The intercepts on the Y axes ranged from +14.1 (Copa) to +50.1 (Dinamap). In clinical use, popularity of the different machines reflected the degree to which the machine reproduced the behaviour of the direct pressure measurement.

Adult↗
PubMed1985

Antigen-specific proliferation of CSF lymphocytes in Lyme disease.

The neurologic manifestations of Lyme disease include meningitis, radiculoneuritis, and cranial neuritis. In two patients, we investigated the proliferative response of CSF and peripheral blood lymphocytes to protein antigens derived from the Lyme disease spirochete. The response of CSF lymphocytes was 5 to 10 times greater than that of peripheral blood lymphocytes. In contrast, in the one patient studied, lectin-induced proliferation was less in CSF than in peripheral blood. These findings show that the CSF of patients with Lyme meningitis is an enriched source of antigen-specific proliferative lymphocytes.

Epitopes↗
PubMed1984

Cancer incidence in an area of radioactive fallout downwind from the Nevada Test Site.

Exposures in southwestern Utah to radioactive fallout (1951 through 1962) from atmospheric nuclear detonations at the Nevada Test Site (NTS) were followed by smaller exposures (1962 through 1979) from venting of underground nuclear detonations. The cancer incidence in a 1951 cohort (4, 125) of Mormon families in southwestern Utah near the NTS was compared with that of all Utah Mormons (1967 through 1975). There were 109 more cases of cancer than expected (288[observed]/179[expected]). Leukemia was most prominent early (1958 through 1966), with 19 cases, five times more than expected (3.6). The excess of leukemia persisted into the later period (1972 through 1980), with 12 cases observed, 3.4 expected. There was an increase in lymphoma. Excess cases of thyroid cancer appeared early and a notable excess appeared later (14/1.7). An excess of breast cancer was noted later (27/14). There were more cancers of the gastrointestinal tract than expected. There was an excess of melanoma (12/4.5), bone cancer (8/0.7), and brain tumors (9/3.9). A subgroup with history of acute fallout effects had a higher cancer incidence. That these cases can be associated with radiation exposures is supported by a comparison between groups of the ratio of cancers of more radiosensitive organs with all other types of cancer.

Adolescent↗