Biomedical subjects
Publications and source records attributed to R A Fox.
An expandable metal stent was inserted to relieve bronchial obstruction following lobectomy for localised squamous carcinoma which had not been relieved by bronchoplasty with a Goretex flap. This resulted in substantial improvement in lung function and exercise tolerance for nine months, following which severe inflammation around the stents required residual pneumonectomy.
The aim of this study was to determine whether electrostatic charge on a plastic spacer decreases the delivery of salbutamol from a pressurized metered-dose inhaler (pMDI) and, if so, to find an optimal and practical treatment to remove the charge. Ten single actuations from a salbutamol pMDI were drawn through different Volumatic spacers at a constant flow of 60 L.min-1. The efficacies of different methods of removing charge were tested, including detergent coating of the spacers. A multistage liquid impinger was used to determine the particle size distribution of the output of the pMDI through the Volumatic spacers. The electrostatic charge on the inner surface of the spacers was measured both quantitatively with an electrometer, and qualitatively by the attraction of a thin strip of cellulose membrane to the wall of the spacer. Each experiment was repeated four times. Ionic detergent coating of the spacers removed the charge for at least 24 h. This resulted in an increase of 55-70% in small particle (< 6.8 microns) delivery compared to delivery from new spacers with high charge. We have demonstrated that electrostatic charge plays a major role in the delivery of salbutamol through plastic spacers. Adequate treatment with ionic detergent removes the charge and improves drug delivery.
This paper describes and evaluates a training program for parental educators to teach parenting classes for families with children 1 to 5 years of age. Six staff and parent volunteers from a family resource center participated. Evaluations of the training program showed improved knowledge and increased comfort in teaching parenting classes. Two graduates of the training program led a 10-week series of parenting classes. Parents in their class series (n = 9) significantly reduced their reported use of verbal and corporal punishment, increased their nurturing, and improved their perceptions of their children's behavior. These results were similar to those from a series of similar classes for 15 parents led by a university instructor. Results are discussed in terms of research needs for training qualified parental educators.
A surgical light source has been examined to determine the potential for retinal damage to staff in the operating theatre. It has been shown that under certain circumstances the light source examined can give an irradiance at the cornea which is well in excess of accepted safety standards. Calculation using data on the retinal irradiance required to produce retinal damage indicates that for an accidental exposure at a distance of 500 mm there is a significant possibility of retinal damage. At closer distances the probability of retinal damage is even higher. It is possible that other surgical light sources produce a similar degree of hazard and hospitals should establish suitable safety measures where necessary.
Prior studies have reported that Pb exposure results in enhanced sensitivity to both D1 and D2 dopamine agonists as indicated by left shifts of the dose-effect functions for the discrimination of these agonists from saline in drug discrimination procedures (Cory-Slechta and Widzowski, 1991). To further determine mechanisms of such Pb-induced changes in dopamine system functions, this study evaluated the potential contribution to Pb-induced D1 supersensitivity of:i) synergistic D1-D2 receptor interactions, and ii) the effects of the chronic D1 agonist administration inherent in the drug discrimination procedures themselves. As in Cory-Slechta and Widzowski (1991), rats exposed from weaning to 50 or 150 ppm Pb acetate in drinking water and trained using standard operant drug discrimination procedures to discriminate 6.0 mg/kg of the partial D1 agonist SKF38393 from saline showed greater sensitivity to SKF38393 (left-shifted dose effect curves) than did the 0 ppm group. To determine the role of D1/D2 interactions in this supersensitivity, SKF38393 dose-effect curves of the groups were compared in the presence and absence of a dose of 0.04 mg/kg of the D2 antagonist haloperidol. The impact of the chronic administration of the D1 agonist utilized in drug discrimination training was determined by comparing the dose-effect curves of the groups before and after a 24 day period of discontinuation of drug discrimination training. D1/D2 interactions do not appear to contribute to Pb-induced enhancement of sensitivity to the D1 agonist SKF38393, as it was maintained even in the presence of the D2 antagonist haloperidol. Discontinuation of drug discrimination training resulted in sensitization in control but not Pb-treated rats, a pattern indicative of Pb-induced D1 subsensitivity. These data raise questions about the depletion of dopamine (DA) availability as a mechanism of Pb-induced alterations in DA system function and suggest that Pb-induced D1 supersensitivity may represent altered effects of chronic D1 administration imposed on DA systems modified by Pb exposure per se.
Parenting practices of a representative sample of 1,056 urban mothers with very young children were studied via the Parent Behavior Checklist (Fox, 1994) and the Behavior Screening Questionnaire (Richman & Graham, 1971). Potential determinants of parenting practices were also addressed, including maternal age, marital status, education level, number of children living at home, and family socioeconomic status. Less positive parenting practices concerning nuturing and discipline were found among mothers who were younger, had more than one child living at home, were single, had a lower income level, and had lower educational attainment. These mothers also tended to perceive their children as demonstrating more difficult behavior problems. However, the negative influence of some determinants of parenting practices, such as low income, was found to be moderated by the presence of other determinants, such as more education. The present results provide evidence that multiple determinants influence parenting practices among parents of young children.
A group of Spanish- and English-speaking listeners participated in a multidimensional scaling (MDS) study examining perceptual responses to three Spanish and seven English vowels. The vowel stimuli represented tokens of Spanish /i/, /e/, and /a/ and English /i/, /I/, /eI/, /epsilon/, /ae/, /lambda/, and /a/. Each vowel had been spoken by three monolingual talkers of Spanish or English and all possible vowel pairs (405 pairs) were presented to listeners (excluding pairs representing the same vowel category). Thirty monolingual English listeners and thirty native Spanish listeners who had learned English as a second language rated these vowel pairs on a nine-point dissimilarity scale. These perceptual distances were then analyzed using then individual-differences version of ALSCAL. Results demonstrated that the English monolinguals used three underlying dimensions in rating vowels while the Spanish-English bilinguals used just two. The most salient perceptual dimension for both groups distinguished vowel height. However, for the English listeners, this dimension was most significantly correlated with duration and indicated a language-dependent sensitivity to this phonetic feature. The second dimension for the English listeners represented a front-back distinction, while the third reflected a central/noncentral distinction. For the Spanish listeners, the second dimension was less easily interpreted. However, the perceptual data for the Spanish listeners was more interpretable in terms of the distribution of the vowels in the two-dimensional perceptual plane. The vowels were distributed in terms of three separate vowel clusters, each cluster near the location of a Spanish vowel.(ABSTRACT TRUNCATED AT 250 WORDS)
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English monolinguals and native Spanish speakers of English rated the dissimilarity of tokens of two Spanish vowel categories, two English vowel categories, or one Spanish and one English vowel category. The dissimilarity ratings of experienced and inexperienced Spanish subjects did not differ significantly. For both the native Spanish and English subjects, perceived dissimilarity increased as the distance between vowels in an F1-F2 acoustic space increased. This supported the existence of a universal, sensory-based component in cross-language vowel perception. The native English and Spanish subjects' ratings were comparable for pairs made up of vowels that were distant in an F1-F2 space, but not for pairs made up of vowels from categories that were adjacent in an F1-F2 space. The inference that the differential classification of a pair of vowels augments perceived dissimilarity was supported by the results of experiment 2, where subjects rated pairs of vowels and participated in an oddity discrimination task. Triads in the oddity task were made up of tokens of vowel categories that were either adjacent (e.g., /a/-/ae/-/a/) or nonadjacent (e.g., /a/-/i/-/i/) in an F1-F2 space. The native English subjects' discrimination was better than the native Spanish subjects' for adjacent but not nonadjacent triads. The better the Spanish subjects performed on adjacent triads--and thus the more likely they were to have differentially classified the two phonetically distinct vowels in the triad--the more dissimilar they had earlier judged realizations of those two categories to be when presented in pairs. Results are discussed in terms of their implications for second language acquisition.
The selection of appropriate outcome measures is important in evaluating specialized geriatric programs, but how the various measures compare, and which are most appropriate, are matters still largely unexplored. We compared several outcome measures, including goal attainment scaling, to assess their sensitivity to changes in the health status of frail elderly patients admitted to two geriatric medicine wards. GAS is a measurement approach which accommodates multiple individual patient goals, and has a scoring system which allows for comparisons between patients. Forty-five patients (mean age 81 years, 30 females) received comprehensive assessments. GAS yielded a mean 5 goals per patient. The mean gain in the GAS score was 22 points (SD = 7) which was compared with the change in the Barthel Index (r = 0.59), the Functional Independence Measure (r = 0.45), the Physical Self-Maintenance Scale (r = 0.54), the Katz Activities of Daily Living Index (r = 0.49) and the Spitzer Quality of Life Index (r = 0.38). The inter-rater reliability of scoring the GAS follow-up guides was 0.91. Using a relative efficiency statistic, GAS proved more efficient than any other measure. The effect size statistic also demonstrated an increased responsiveness to change of GAS compared with standard measures. GAS is an individualized measurement approach which shows promise as a responsive measure in frail elderly patients.
This study examined age-related differences in the use of dynamic acoustic information (in the form of formant transitions) to identify vowel quality in CVCs. Two versions of 61 naturally produced, commonly occurring, monosyllabic English words were created: a control version (the unmodified whole word) and a silent-center version (in which approximately 62% of the medial vowel was replaced by silence). A group of normal-hearing young adults (19-25 years old) and older adults (61-75 years old) identified these tokens. The older subjects were found to be significantly worse than the younger subjects at identifying the medial vowel and the initial and final consonants in the silent-center condition. These results support the hypothesis of an age-related decrement in the ability to process dynamic perceptual cues in the perception of vowel quality.
Designed a study to develop an instrument, the Parenting Inventory: Young Children (PI), to assess the behaviors and developmental expectations of parents who have a child between 1 and 4 years of age. Item development for the PI occurred within a developmental-environmental theoretical framework and was based on literature reviews and clinical experience. Experts working with parents and/or children and parents of young children established the content validity of the items. The PI was tested with a sample of 1,140 mothers. This sample was representative of the population from which it was drawn, a large urban area, in terms of the sample children's sex and ethnicity. A diverse range of socioeconomic levels were included. The resulting 100-item PI was found to reliably measure three aspects of parenting: Expectations, Discipline, and Nurturing. These factors demonstrated good internal consistency and test-retest reliability. Future research needs relative to the continued development of the PI are addressed.
OBJECTIVE: Goal attainment scaling (GAS) is a measurement approach used extensively in mental health. It accommodates multiple individual patient goals, yet retains mathematical properties allowing comparisons between patients. This study was carried out to investigate the feasibility and measurement properties of GAS in a geriatric care setting. DESIGN: Prospective descriptive study. SETTING: The geriatric restorative care service and geriatric assessment unit at Camp Hill Hospital, a 350-bed tertiary care facility in Halifax, Canada. PATIENTS: Fifteen patients aged 65 to 94 who were consecutively admitted to the two geriatric services (mean age 79 years, mean length of stay 37 days, 9 females). INTERVENTION: Goal Attainment follow-up guides were developed independently for each patient by two geriatricians after a comprehensive assessment of the patient. These guides were later compared to assess level of agreement in goal setting and scale development. A single goal attainment follow-up guide was then developed for each patient by consensus of the two geriatricians. At the end of the follow-up, the guides were scored independently for each patient by one of the geriatricians and by the patient's primary care nurse. MAIN OUTCOME MEASURES: GAS scores were determined on admission and discharge. Each patient also received admission and discharge ratings on the Barthel Index as well as a global rating of outcome (on a subjective 10-point scale) by a geriatrician who was blinded to the Goal Attainment follow-up score. RESULTS: GAS proved feasible, requiring 15-20 minutes to scale an average of six goals per patient. GAS also appears reliable. Of 87 goals, 71 (82%) were identified independently by two geriatricians, and the remainder were determined by consensus. This is also a measure of content validity. The physician-nurse inter-rater reliability was 0.87 (intraclass correlation). Concurrent validity was assessed by correlation with the Barthel Index (r = 0.86) and the global clinical outcome rating (r = 0.82). Content validity was also assessed by comparing our goal areas with those identified in recent consensus reports on geriatric assessment. Of these 13 assessment areas, 12 appeared to be reasonably well covered while one assessment area (sexual problems) was not identified for any of the 15 patients. CONCLUSIONS: GAS appears to be a feasible method of goal setting and outcome evaluation in geriatric care settings, with promising reliability and validity.
Until recently, speech analysis techniques have been built around the all-pole linear predictive model. This study examines the effectiveness of using the perceptual linear predictive method for analyzing nasal consonants. Six speakers (three men and three women) produced 300 CV syllables with initial nasal consonants /m/ and /n/. A threshold-based boundary detection algorithm was developed to extract nasal segments from the CV contexts. Poles of a fifth-order perceptual linear predictive model were calculated and the frequency of the second pole was used to characterize the place of articulation of nasal consonants. Results indicated that the frequency for the second transformed pole was significantly lower for /m/ than for /n/ and was independent of factors such as a vowel context and gender of the speaker. A nasal identification rate of 86% was obtained based on the frequency of the second pole. The use of the perceptual linear predictive method may thus overcome some difficulties associated with analyzing nasal consonants.
The development and use of a two-step word segmentation method for automatic recognition of the speech produced by deaf persons are described in this paper. This method incorporates the segmental and temporal characteristics of deaf speech, particularly the intra- and inter-word pauses, to achieve accurate recognition. In the first step, estimates of word boundaries were obtained by detecting these pauses. In the second step, the word boundaries were determined by matching all possible groupings of speech segments against all reference templates during recognition. This method was applied to recognition of isolated words and connected-speech utterances produced by two deaf speakers. Recognition rates of 93.01 percent and 81.81 percent were obtained in recognizing isolated words and connected speech, respectively.
Selective Internal Radiation Therapy is the intrahepatic arterial injection of microspheres labelled with 90Y. The microspheres lodge in the precapillary circulation of tumor resulting in internal radiation therapy. The activity of the 90Y injected is managed by successive administrations of labelled microspheres and after each injection probing the liver with a calibrated beta probe to assess the dose to the superficial layers of normal tissue. Predicted doses of 75 Gy have been delivered without subsequent evidence of radiation damage to normal cells. This contrasts with the complications resulting from doses in excess of 30 Gy delivered from external beam radiotherapy. Detailed analysis of microsphere distribution in a cubic centimeter of normal liver and the calculation of dose to a 3-dimensional fine grid has shown that the radiation distribution created by the finite size and distribution of the microspheres results in an highly heterogeneous dose pattern. It has been shown that a third of normal liver will receive less than 33.7% of the dose predicted by assuming an homogeneous distribution of 90Y.
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This study evaluated the effectiveness of the STAR Parenting Program, designed specifically for parents with children between the ages of 1 and 5 yr. The 8-hr. program was completed by 35 parents. There was a significant increase in parents' favorability and a significant decrease in anxiety afterwards. Parents also significantly lowered their expectations, reduced the emotionality of their reactions to their child's problem behaviors, and increased their use of time-out and tangible rewards following training. These changes were maintained at a 6-wk. follow-up.