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Biomedical subjects

R A Fox

Publications and source records attributed to R A Fox.

At least 91 records · Page 5Linked to original sources
PubMed1989

Aging and the influence of contextual contrast on vowel identification.

This study examines possible differences between young and older adult listeners in the effect of contextual contrast on vowel identification using a vowel anchoring procedure. All listeners identified a 7-step [i]-[I] continuum under both an equiprobable control condition and an anchoring condition (in which one endpoint stimulus occurred four times more often than any other single stimulus token). Phoneme boundaries in the anchoring condition shifted toward the anchor endpoint, as expected, for both groups, but there was a significant effect of age when [i] served as the anchor. Evidence of an increase in response bias for older adult listeners was also found.

Adolescent↗
PubMed1989

Motor-motor adaptation: preliminary findings.

This study investigated the relationship between speech perception and speech production. An experimental technique called motor-motor adaptation was devised. Subjects produced a speech token repeatedly (20 to 40 repetitions), then produced a second token one time. These tokens all contained stop consonants and were subsequently analyzed for voice onset time. The results paralleled previous findings using the experimental procedure, perceptuomotor adaptation. The present study supports the notion of a perception-production link.

Adaptation, Physiological↗
PubMed1989

Use of the Adjective Generation Technique to measure effects of training parents.

A modified instruction of the Adjective Generation Technique was used to evaluate the effects of a training program for parents. The modified technique was completed by 12 parents (1 father, 11 mothers) who were asked to describe themselves from their children's perspective, prior to and following the completion of a parents' training program. There was a significant reduction in parents' perceptions of anxiety and a significant increase in favorability.

Adult↗
PubMed1989

Stereotactic radiosurgery.

Stereotactic radiosurgery is the accurate focusing of ionising radiation onto an intracranial target, and was pioneered in Sweden in the early 1950's. It has proven effective in the treatment of arteriovenous malformations, acoustic tumours and many other small brain lesions. In the last decade the commercial availability of a gamma ray system has led to other centres following the work in Stockholm; more recently, various techniques utilising linear accelerators, (LINACs), have been developed. Both types of system necessitated special dosimetry and treatment planning methods for the small, high dose-gradient circular fields. Localization of the lesions requires angiography, computerised tomography (CT) or magnetic resonance imaging (MRI).

Brain Diseases↗
PubMed1989

Comparison of breastfeeding attitudes and practices: low-income adolescents and adult women.

Breastfeeding attitudes and practices of two independent samples of low-income adolescents were compared to a third sample of low-income, adult women. Low-income status was based on subject eligibility for the Special Supplemental Food Program for Women, Infants, and Children (WIC). Breastfeeding attitudes were significantly related to setting, race, and age. Other factors, such as previous exposure to breastfeeding, also influenced breastfeeding attitudes. Breastfeeding rates were 16.7% and 32.4% for the two teen samples, and 35.4% for the sample of adult women. Choice of infant feeding method post delivery was significantly related to intention regarding feeding method during pregnancy. Implications of these findings for health care professionals are discussed.

Adolescent↗
PubMed1988

Use of the tracheostoma valve in the marking of contrastive stress and sentence intonation.

Two proficient tracheoesophageal speakers experienced in use of the tracheostoma valve (TSV) produced a total of 64 examples of "Bev loves Bob." These productions varied with location of contrastive stress, type of sentence intonation, and use of TSV. Thirty-four listeners judged the utterances in terms of stress placement and intonation contour simultaneously. An analysis of variance of the perceptual results indicated that TSV use reduced speaker ability to signal the two suprasegmental features; however, locus of the suprasegmental features, particularly stress placement, appeared to exert a stronger effect.

Female↗
PubMed1988

Role of the area postrema in three putative measures of motion sickness in the rat.

After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.

Animals↗
PubMed1988

Conditioned taste aversion induced by motion is prevented by selective vagotomy in the rat.

The role of the vagus nerve in motion-induced conditioned taste aversion (CTA) was studied in hooded rats. Animals with complete, selective gastric vagotomy failed to form conditioned taste aversion after multiple conditioning sessions in which the conditioned stimulus (a cider vinegar solution) was drunk immediately before a 30-min exposure to vertical axis rotation at 150 degrees/s. Results are discussed with reference to the use of CTA as a measure of motion-induced "sickness" or gastrointestinal disturbance, and, because motion-induced CTA requires that both the vagus nerve and the vestibular apparatus be intact, in light of the possible convergence of vagal and vestibular functions.

Afferent Pathways↗
PubMed1988

A simple method of producing parenchymal renograms using parametric imaging.

Standard dynamic renography procedures are used to produce time-activity curves for defined regions of interest around the kidneys. Further analysis of the acquired data using Fitted Retention and Excretion Equations (FREE) to determine single kidney glomerular filtration rate (GFR) and kidney transit time is performed at the Royal Marsden Hospital, Sutton. The disadvantage of these methods is that the renal function is assessed for the whole kidney and not on a regional basis. The aim of this study was to use parametric imaging to extend the standard analysis so that the parenchyma could be identified and analysed separately from the collecting system. The parenchyma pixel time-activity curves have shorter time-to-peak (TTP) values than the collecting system. TTP parametric images were used to set limits on the TTP values and thus define the parenchyma pixels. The time-activity curves from the parenchyma were further analysed using FREE to produce parametric images of both GFR and effective blood volume. Finally, the original dynamic data were re-analysed so that time-activity and FREE curves were generated for the parenchyma alone. A study of 15 patients (30 kidneys) showed that the extended analysis indicated parenchymal isotope clearance. By comparing the time-activity and FREE curves of the whole kidney with those from the parenchyma alone, a more useful analysis of parenchymal function was obtained. This proved to be particularly useful for patients with pelvi-ureteric junction (PUJ) obstruction.

Humans↗
PubMed1988

A multidimensional scaling study of esophageal vowels.

A multidimensional scaling experiment was conducted to determine the perceptual structure of 11 American English vowels produced by a competent esophageal speaker. Estimates of perceptual distance among these vowels were obtained using a 9-point similarity/dissimilarity scale and were analyzed using an individual differences scaling algorithm (INDSCAL). A three-dimensional perceptual space was produced. The three perceptual dimensions corresponded to tongue advancement, vowel height, and rhotacization. These three dimensions were then correlated with selected bark scale transformed acoustic vowel measurements. The perceptual dimensions 1-3 corresponded most closely to F3-F2, F1-F0, and F3, respectively. Little difference was found between the perceptual structure of esophageal vowels and laryngeal vowels, although it is suggested that the correlation between some of the acoustic measures (such as F0) and the perceptual dimensions may change as a function of individual speaker differences due to postsurgical capabilities (anatomical and physiological) and/or method of voice restoration.

Aged↗
PubMed1988

Atypical presentation of geriatric infections.

Infection is a common problem in elderly patients, the most common infections being those in the urinary tract and the respiratory tract. In geriatric practice, infection is most frequently seen in combination with many other problems. The geriatric presentation is described in which patients may present with an increased dependency upon care providers due to the development of fresh problems like falls, immobility, confusion, incontinence of urine, and fecal impaction with incontinence. It is important to recognize this presentation and not to miss the diagnosis. It is well recognized that pneumonia is the most frequently missed diagnosis in the elderly. An increase in dependency should not be ignored and attributed to old age. The presence of pathophysiological changes and organ involvement, together with fever, raised white count, or elevated ESR, are strongly supportive of a diagnosis of infection. Once identified, the infection can usually be appropriately treated, resulting in significant improvement in multiple geriatric problems which these patients suffer from.

Accidental Falls↗
PubMed1987

Effect of copper sulphate on the rate of afferent discharge in the gastric branch of the vagus nerve in the rat.

The afferent nerve activity was recorded from a nerve filament isolated from the peripheral cut end of the gastric branch of the vagus nerve. The gastric perfusion of 4 ml of two different concentrations (0.04% and 0.08%) of CuSO4 solution provoked an increase in afferent activity. The stimulating effect of the 0.08% solution was stronger than that of the 0.04% solution, and lasted for a longer period of time. The observations suggest a possible mechanism by which CuSO4 elicits emesis.

Animals↗
PubMed1987

Effect of a geriatric consultation service on management of patients in an acute care hospital.

Elderly patients present particular management challenges. We conducted a randomized clinical trial of the effect of a geriatric consultation service on the management of elderly patients in an acute care hospital. A total of 113 patients aged 75 years or more who met certain criteria were assigned to either receive (57 patients) or not receive (56) care by the service. At the end of their hospital stay the patients were assessed with regard to predetermined outcomes. The patients were followed up for 1 year after discharge to determine death rates and direct health care expenditures. The intervention group showed significantly greater improvement in mental status (p less than 0.01), were receiving fewer medications at discharge (p less than 0.05) and had lower short-term death rates (p less than 0.05) than the control group. A geriatric consultation service can improve the hospital care and health of the elderly.

Aged↗
PubMed1987

The atypical presentation of infection in old age.

A study was designed to determine the incidence of atypical or geriatric presentation of infection in a long-term-care-hospital population of aged veterans. During the 6-month period of surveillance there were 65 instances of functional decline among the 143 veterans, with 50 episodes of infection. Although the symptoms and signs of infection were attenuated in many patients, a diagnosis was reached by careful examination and investigation. The majority of patients had a temperature of at least 38 degrees C in the presence of infection and it is concluded that the afebrile response to infection is rare in this population. During the course of this study the death rate in this institution dropped to about half of what was anticipated, and returned to previous levels following completion of the study. Infection can be recognized at a very early stage despite an atypical geriatric presentation and early treatment reduces morbidity and mortality.

Aged↗
PubMed1987

Prenatal education for pregnant adolescents.

Providing services to pregnant adolescents poses a unique challenge for health professionals. Several programs have emerged tailored specifically to this special population. Prenatal education is an integral component of these programs. This paper describes prenatal education classes offered at Teen Pregnancy Service, including special modifications required to meet the learning needs of participants. Outcome data provided for 66 pregnant teens show significant changes in prenatal knowledge following the class series. Information is included about the teens' backgrounds, their perceptions regarding potential problems infants may experience, and how they remembered being reared by their parents.

Adolescent↗