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Research in normal and disordered phonology requires measures of speech production that are biolinguistically appropriate and psychometrically robust. Their conceptual and numeric properties must be well characterized, particularly because speech measures are increasingly appearing in large-scale epidemiologic, genetic, and other descriptive-explanatory database studies. This work provides a rationale for extensions to an articulation competence metric titled the Percentage of Consonants Correct [PCC; Shriberg & Kwiatkowski, 1982; Shriberg, Kwiatkowski, Best, Hengst, & Terselic-Weber, 1986], which is computed from a 5- to 10-minute conversational speech sample. Reliability and standard error of measurement estimates are provided for 9 of a set of 10 speech metric including the PCC. Discussion includes rationale for selecting one or more of the 10 metrics for specific clinical and research needs.

ABSTRACT. Objective. To examine the effects of bronchopulmonary dysplasia (BPD) and very low birth weight (VLBW) on the cognitive and academic achievement of a large sample of 8-year-old children.Methods. Infants who were VLBW and had BPD (n ‫؍‬ 98) or did not have BPD (n ‫؍‬ 75) and term infants (n ‫؍‬ 99) were followed prospectively to age 8. Groups were compared on measures assessing 4 broad areas of functioning: intelligence, achievement, gross motor, and attentional skills. Measures included the Wechsler Intelligence Scale for Children III, the Woodcock Johnson Test of Achievement-Revised, the Bruininks-Oseretsky Test of Motor Proficiency, the Tactual Performance Test (spatial memory), and the Continuous Performance Test (attention). School outcomes were assessed by parent and teacher report, as well as from school records. Groups were comparable on socioeconomic status, sex, and race. The total sample of BPD, VLBW, and term children was compared on all outcome measures. In addition, neurologic risk was assessed in the present sample and included the following: intraventricular hemorrhage, echodense lesions, porencephaly, hydrocephalus, ventriculoperitoneal shunt, meningitis, and periventricular leukomalacia. Individual difference analyses were conducted for neurologically intact children in all 3 groups. Finally, treatment effects were examined by comparing BPD children who had received steroids as part of their treatment with BPD children who had not.Results. The BPD group demonstrated deficits compared with VLBW and term children in intelligence; reading, mathematics, and gross motor skills; and special education services. VLBW children differed from term children in all of the above areas, except reading recognition, comprehension, and occupational therapy. Attentional differences were obtained between BPD and term children only. The BPD group (54%) was more likely to be enrolled in special education classes than VLBW (37%) or term children (25%). In addition, more BPD children (20%) achieved full-scale IQ scores <70, in the mental retardation range, compared with either VLBW (11%) or term (3%) children, with all VLBW children significantly more likely than term children to achieve IQs in the subaverage category. After controlling for birth weight and neurologic problems, BPD and/or duration on oxygen predicted lower performance IQ, perceptual organization, full-scale IQ, motor and attentional skills, and special education placement. The qualitative classification of BPD (present or absent) was a significant predictor for lower scores on measures of applied problems; motor skills; and incidence of speech-language, occupational, and physical therapies. Individual difference analyses were performed to ascertain whether differences between the risk groups were primarily attributable to neurologic complications. Even with the neurologically intact sample of BPD and VLBW children, differences between the term comparison group and both the BPD and VLBW groups were found for many outcome measures. When birth w...

The amounts of cytoplasmic water and of all osmotically significant cytoplasmic solutes were determined for Escherichia coli K-12 grown in 3-(N-morpholino)propane sulfonate (MOPS)-buffered glucose-minimal medium containing 0.5 M NaCl in the presence and absence of the osmoprotectants betaine and proline. The goal of this work is to correlate the effects of osmoprotectants on the composition of the cytoplasm with their ability to increase the growth rate of osmotically stressed cells. At a concentration of 1 mM in the growth medium, betaine increases the growth rate more than does proline; choline, which is converted to betaine by E. coli, appears to have an intermediate effect on growth rate. The accumulation of either betaine or proline reduces the cytoplasmic amounts of K+, glutamate, trehalose, and MOPS (the major cytoplasmic osmolytes accumulated in the absence of osmoprotectants), so that at this external osmolarity the total amount of cytoplasmic solutes is essentially the same in the presence or absence of either osmoprotectant. More betaine than proline is accumulated, so the extent of replacement of cytoplasmic solutes is greater for betaine than for proline. Accumulation of these osmoprotectants is accompanied by a large (20 to 50%) increase in the volume of cytoplasmic water per unit of cell dry weight (Vcyt.). This effect, which appears to result from an increase in the volume of free water, V. (as opposed to water of hydration, or bound water), is greater for betaine than for proline. Taken together, these results indicate that the molar effects of betaine and proline on water activity and on the osmotic pressure of the cytoplasm must be significantly larger than those of the solutes they replace. Biol. 222:281-300, 1991) observed that, in cells grown in the absence of osmoprotectants, both growth rate and Vcyt. decreased, whereas the amount of cytoplasmic K+ (nK+) increased, with increasing external osmolarity. We predicted that the observed changes in nK+ and Vcyto would have large and approximately compensating effects on key proteinnucleic acid interactions of gene expression, and we proposed that Vf was the fundamental determinant of growth rate in osmotically stressed cells. The properties of cells cultured in the presence of betaine and proline appear completely consistent with our previous work and proposals. Accumulation of betaine and, to a lesser extent, proline shifts the set of linked physiological parameters (nK+, Vcyto, growth rate) to those characteristic of growth at lower osmolarity in the absence of osmoprotectants. Models for the thermodynamic basis and physiological consequences of the effect of osmoprotectants on Vcyt. and Vf are discussed.Living cells adapt to osmotic stress by varying the intracellular concentration (i.e., thermodynamic activity) of osmotically active solutes (osmolytes). A variety of organisms accumulate the so-called osmoprotectants betaine and proline to prevent dehydration when placed under the stress of high-osmolarity environments (16,22,43,45,52). ...

A companion paper includes rationale for the use of 10 metrics of articulation competence in conversational speech (Shriberg, Austin Lewis, McSweeny, & Wilson, 1997). The present paper reports lifespan reference data for these measures using records from a total of 836 3- to 40(+)-year-old speakers with normal and disordered speech. The reference data are subdivided by diagnostic classification based on extensions to an instrument titled the Speech Disorders Classification System (SDCS; Shriberg, 1993). Appendices provide procedural information on the SDCS and statistical rationale for the reference data.

These findings suggest that the phenotype for CAS changes with age. Language disorders persist in these children despite partial resolution of articulation problems. Children with CAS are also at risk for reading and spelling problems.

Speech-sound disorder (SSD) is a complex behavioral disorder characterized by speech-sound production errors associated with deficits in articulation, phonological processes, and cognitive linguistic processes. SSD is prevalent in childhood and is comorbid with disorders of language, spelling, and reading disability, or dyslexia. Previous research suggests that developmental problems in domains associated with speech and language acquisition place a child at risk for dyslexia. Recent genetic studies have identified several candidate regions for dyslexia, including one on chromosome 3 segregating in a large Finnish pedigree. To explore common genetic influences on SSD and reading, we examined linkage for several quantitative traits to markers in the pericentrometric region of chromosome 3 in 77 families ascertained through a child with SSD. The quantitative scores measured several processes underlying speech-sound production, including phonological memory, phonological representation, articulation, receptive and expressive vocabulary, and reading decoding and comprehension skills. Model-free linkage analysis was followed by identification of sib pairs with linkage and construction of core shared haplotypes. In our multipoint analyses, measures of phonological memory demonstrated the strongest linkage (marker D3S2465, P=5.6 x 10(-5), and marker D3S3716, P=6.8 x 10(-4)). Tests for single-word decoding also demonstrated linkage (real word reading: marker D3S2465, P=.004; nonsense word reading: marker D3S1595, P=.005). The minimum shared haplotype in sib pairs with similar trait values spans 4.9 cM and is bounded by markers D3S3049 and D3S3045. Our results suggest that domains common to SSD and dyslexia are pleiotropically influenced by a putative quantitative trait locus on chromosome 3.

In reconstituted vesicles above the lipid phase transition temperature, bacteriorhodopsin (BR) undergoes rotational diffusion about an axis perpendicular to the plane of the bilayer [Cherry, R. J., Muller, U., & Schneider, G. (1977) FEBS Lett. 80, 465]. This diffusion narrows the 13C NMR powder line shape of the BR peptide carbonyls. In contrast, BR in native purple membrane is relatively immobile and exhibits a rigid-lattice powder line shape. By use of the principal values of the rigid-lattice chemical shift tensor and the motionally narrowed line shape from the reconstituted system, the range of Euler angles of the leucine peptide groups relative to the diffusion axis has been calculated. The experimentally observed line shape is inconsistent with those expected for structures which consist entirely of either alpha helix or beta sheet perpendicular to the membrane or beta sheet tilted at angles up to about 60 degrees from the membrane normal. However, for two more complex structural models, the predicted line shapes agree well with the experimental one. These are, first, a structure consisting entirely of alpha1 helices tilted at 20 degrees from the membrane normal and, second, a combination of 60% alpha II helix perpendicular to the membrane plane and 40% antiparallel beta sheet tilted at 10-20 degrees from the membrane normal. The results also indicate that the peptide backbone of bacteriorhodopsin in native purple membrane is extremely rigid even at 40 degrees. The experiments presented here demonstrate a new approach, using solid-state nuclear magnetic resonance (NMR) methods, for structural studies of transmembrane proteins in fluid membrane environments, either natural or reconstituted.(ABSTRACT TRUNCATED AT 250 WORDS)