Academic literature on the topic 'Delayed comparison'

The purpose of this study was to determine if a difference exists between mean standard scores of the Peabody Picture Vocabulary Test - Revised (PPVT-R) (Dunn and Dunn, 1981) and the Expressive One- Word Picture Vocabulary Test (EOWPVT) (Gardner, 1979) for children in several diagnostic categories. The subjects used in this study were 45 preschool children ranging in age from 36 to 47 months. These subjects were divided into groups of normal, expressively language-delayed (ELD) and normal children with a history of expressive language delay (HELD).

Five tests were conducted to compare delayed applications of Kerb applied by air with applications made through sprinklers. Applications were made commercially to plots ranging in size from 11 to 18 acres. Broadleaf weed control was better in all tests from the sprinkler applied Kerb than from aerial application. The control of volunteer sudangrass was poor in one test from both types of applications and worse from the sprinkler than the aerial application. It was concluded that applying Kerb though sprinklers to lettuce is effective and often superior to aerial applications.

People use language to communicate their needs and intentions, to express emotions, and to form relationships. It seems likely that a disruption in children's language development would have a negative impact on their social development. There is extensive research that shows that school age children with delayed language are "at risk" for increased maladaptive behaviors (Cantwell and Baker, 1977). Whether this is also true for children in the earliest stages of language development is not yet known. The questions this study sought to answer were: 1) Is there a significant difference in the severity and frequency of maladaptive behaviors seen in language delayed children, children who were "late talkers," or children with normal language? and 2) Is there a significant difference among the three subject groups in terms of which behaviors parents are the most concerned about·?

Imaging of myocardial viability using the delayed enhancement technique currently provides high image contrast between infarcted and normal tissue with the aid of a magnetization prepared fast gradient echo pulse sequence following the administration of an extracellular contrast agent. However, there exists a degree of image contrast variability and subjectivity due to contrast agent kinetics and user-specified imaging parameters. Also, the technique has not been explored at higher field strengths (3T), which offer greater inherent signal-to-noise ratio. The overall goal of this study is to compare magnetic resonance delayed contrast enhancement of myocardial infarction at 1.5T and 3T. The analysis was conducted by first developing a comprehensive mathematical simulation of the imaging sequence, which allowed modification of various imaging parameters. Simulations were performed to optimize the sequence for flip angle and inversion time, as well as to evaluate the influence of other image parameters that affected contrast. These theoretical results were validated experimentally with phantoms. In vivo post-contrast T1 measurements at 1.5T and 3T from normal volunteers (n=10) and patients (n=5) provided more precise input into mathematical optimization simulations. In both populations, longer T1 values were found at 3T compared to 1.5T for normal (pre-contrast: 1.24 .06s vs. 1.07 .05s; post-contrast: 0.34-0.59 vs. 0.33-0.54s, n=15) and infarcted myocardium (pre-contrast: 1.27 .06s vs. 1.04 .06s; post-contrast: 0.25-0.37s vs. 0.23-0.32s, n=5). Corresponding simulations using these T1 values revealed an infarct-to-normal tissue contrast gain at 3T of approximately 25%. In vivo image contrast between infarcted and normal tissue following contrast administration was also higher at 3T by approximately 37%. In conclusion, there was good correlation between mathematical simulations of delayed enhancement and experimental results, enabling parameters to be compared and optimized offline given input T1 values. Although contrast-enhanced viability imaging at 3T suffered from artifacts due to field, RF, and inversion pulse inhomogeneity, these results suggest that 3T offers higher contrast-to-noise ratio than 1.5T for this application.

Five humans were exposed to a matching to sample task in which the delay (range = 0 to 32 seconds) between sample stimulus offset and comparison onset was manipulated across conditions. Auditory stimuli (1” tone) and arbitrary symbols served as sample stimuli for three (S1, S2, S3) and two (S4 and S5) subjects, respectively. Uppercase English letters (S, M, and N) served as comparison stimuli for all subjects. Results show small but systematic effects of the retention interval on accuracy and latency to selection of comparison stimuli. The results fail to show a difference between subjects exposed to auditory and visual sample stimuli. Some reasons for the failure to note a difference are discussed.

The study investigated the effects of correction of learners' grammatical errors on acquisition. Specifically, it compared the effects of timing of correction (immediate versus delayed correction) and manner of correction (explicit versus implicit correction). It also investigated the relative effects of correction of morphological versus syntactic features and correction of developmental early versus developmental late features. Data for the study were collected from 56 intermediate level students of English as a Foreign Language in Iranian university and private language school settings. Each participant was required to read and then retell a written text in their own words during an oral interview with the researcher. During or following the interview the researcher corrected the participants on their grammatical errors implicitly (using recasts) or explicitly (providing metalinguistic information). Individualised tests focusing on the errors that had been corrected were constructed for each participant and administered. Statistical analyses were conducted on the scores the participants received on their individualised tests. Results showed no significant differences for timing of correction. However, significant differences were found for manner of correction. Participants who received explicit correction gained significantly higher scores than those who received implicit correction. This finding lends support to the argument of Schmidt (1994) concerning the role of metalinguistic awareness in language acquisition. Correction of morphological features was found to be more effective than that of syntactic features. It is argued that morphological features are generally learnt as items whereas syntactic features involve system learning. Correction of developmental early features was found to be more effective than correction of developmental late features. This finding lends support to suggestions that corrective feedback (like other types of form-focused instruction) needs to take into account learners' cognitive readiness to acquire features (Pienemann 1984; Mackey 1999). iii Analyses of the interactions between independent variables were also conducted. It was found that explicit correction was more effective for the acquisition of developmental early features and implicit correction was more effective for the acquisition of developmental late features The implications of these results for both second language acquisition and language pedagogy are considered.