The Escherichia coli uhpT protein catalyzes the active transport of sugar-phosphates by an obligatory exchange mechanism. To examine its transmembrane topology, we isolated a collection of uhpT-phoA fusions encoding hybrid proteins of different lengths from the N terminus of UhpT fused to alkaline phosphatase by using transposon TnphoA. These fusions displayed different levels of alkaline phosphatase activity, although comparable levels of full-length UhpT-PhoA proteins were produced in maxicells of both high-and low-activity fusions. The full-length protein species were unstable and were degraded to the size of the alkaline phosphatase moiety in the case of a high-activity fusion or to small fragments in the case of a low-activity fusion. The enzyme activity present in low-activity fusions appeared to result from export of a small proportion of the fusion protkins to the periplasmic space. Although fusions were not obtained in all predicted extramembranous loops, the deduced topology of UhpT was consistent with a model of 12 membrane-spanning regions oriented with the amino and carboxyl termini in the cytoplasm.
Objective To determine the reliability and validity of a computer-mediated, 50 word intelligibility test designed to be a global measure of severity of speech disability in children with repaired cleft lip and palate (CLP). Design A prospective between group design was used with convenience sampling of patients from a university craniofacial center. Participants Thirty-eight children between the ages of 4 and 9 years. Twenty-two had repaired CLP while 16 had no clefts. Twenty adults served as listeners. Main Outcome Measure(s) Speech intelligibility scores were calculated for repeated administrations of a single-word test based upon the number of correct orthographically transcribed words by 4 groups of 5 listeners per child. Measures of parallel forms, inter-listener, and intra-listener reliability were estimated; measures of construct validity were also determined. Results All measures of reliability were adequate. Parallel forms reliability of the test based upon mean scores from 5 listeners per child was high (r=.97). Thirty-seven of 38 children had differences between forms of 11 percentage points or less. Construct validity of the test was shown by a) significantly lower speech intelligibility scores for children with CLP than controls, and b) a moderately high correlation (r=.79) between intelligibility scores and percent consonants correct for all children. Conclusions A computerized, single-word intelligibility test was described which appears to be a reliable and valid measure of global speech deficits in children with CLP. Additional development of the test may further facilitate standardized assessment of children with CLP.
This paper investigates the possible patterns of anticipatory coarticulation in the speech of young children. Speech samples were elicited from three groups of children between 3 and 6 years of age and one comparison group of adults. The utterances were recorded online in a quiet room environment using high quality microphones and direct analog-to-digital conversion to computer disk. Formant frequency measures (F1, F2, and F3) were extracted from a centralized and unstressed vowel (schwa) spoken prior to two different sets of productions. The first set of productions consisted of the target vowel followed by a series of real words containing an initial CV(C) syllable (voiceless obstruent–monophthongal vowel) in a range of phonetic contexts, while the second set consisted of a series of nonword productions with a relatively constrained phonetic context. An analysis of variance was utilized to determine if the formant frequencies varied systematically as a function of age, gender, and phonetic context. Results will also be discussed in association with spectral moment measures extracted from the obstruent segment immediately following the target vowel. [Work supported by research funding from Brigham Young University.]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.