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L Morris

Publications and source records attributed to L Morris.

At least 73 records · Page 4Linked to original sources
PubMed1998

Female voice communications in high level aircraft cockpit noises--part II: vocoder and automatic speech recognition systems.

BACKGROUND: The intelligibility of female and male speech is equivalent under most ordinary living conditions. However, due to small differences between their acoustic speech signals, called speech spectra, one can be more or less intelligible than the other in certain situations such as high levels of noise. Anecdotal information, supported by some empirical observations, suggests that some of the high intensity noise spectra of military aircraft cockpits may degrade the intelligibility of female speech more than that of male speech. METHODS: In an applied research study, the intelligibility of female and male speech was measured in several high level aircraft cockpit noise conditions experienced in military aviation. RESULTS: In Part I, (Nixon CW, et al. Aviat Space Environ Med 1998; 69:675-83) female speech intelligibility measured in the spectra and levels of aircraft cockpit noises and with noise-canceling microphones was lower than that of the male speech in all conditions. However, the differences were small and only those at some of the highest noise levels were significant. Although speech intelligibility of both genders was acceptable during normal cruise noises, improvements are required in most of the highest levels of noise created during maximum aircraft operating conditions. These results are discussed in a Part I technical report. This Part II report examines the intelligibility in the same aircraft cockpit noises of vocoded female and male speech and the accuracy with which female and male speech in some of the cockpit noises were understood by automatic speech recognition systems. The intelligibility of vocoded female speech was generally the same as that of vocoded male speech. No significant differences were measured between the recognition accuracy of male and female speech by the automatic speech recognition systems. The intelligibility of female and male speech was equivalent for these conditions.

Adult↗
PubMed1997

Comparison of two question sequences for assessing pregnancy intentions.

Unintended pregnancies can have serious health, social, and economic consequences. Such pregnancies may be unwanted (a baby is not wanted at any time) or mistimed, yet wanted (a baby is wanted eventually). Intended pregnancies are those conceived when desired. Reproductive health survey respondents' understanding of these concepts and validity of survey results may be affected by question order and wording. Using a randomized crossover design, National Survey of Family Growth (NSFG) and Demographic and Health Survey (DHS) intendedness questions were asked in a 1993 survey of Arizona women aged 18-44 years. Of 2,352 ever-pregnant respondents, 25% gave discordant responses to DHS and NSFG questions about the most recent pregnancy. Age, marital status, household income, education, parity, time since pregnancy, and outcome of pregnancy were significantly predictive of discordant responses. DHS and NSFG questions yielded similar prevalence estimates of intendedness and wantedness; but young, unmarried respondents gave more "mistimed" responses on whichever question was asked later. Classifying pregnancies as intended, mistimed, or unwanted may be a problem for women who have not decided on lifetime reproductive preferences. Approaches to improving survey validity include addressing ambivalence, clarifying the definition of "unwanted," and, for young, unmarried women, not attempting to classify unintended pregnancies as mistimed or unwanted.

Adolescent↗
PubMed1997

Amphetamine-induced locomotor stereotypy in rats is reduced by a D1 but not a D2 antagonist.

Amphetamine produces locomotor stereotypy (repetitive routes of locomotion) in an open field. In this research we tested the ability of the D1 antagonist SKF 83566 and the D2 antagonist sulpiride to block the locomotor stereotypy produced by 2 mg/kg amphetamine. SKF 83566 decreased amphetamine-induced locomotor stereotypy; sulpiride had no consistent effect on amphetamine-induced locomotor stereotypy. There was no evidence that either antagonist potentiated the effect of the other.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1997

Osteopathia striata with cranial sclerosis: highly variable phenotypic expression within a family.

We report a four-generation family, with five individuals affected by osteopathia striata with cranial sclerosis (OS-CS). The family illustrates the wide spectrum of gene expression in this autosomal dominant condition. Of particular note is the unusually severe expression in the proband, who exhibits virtually all of the reported associations of the syndrome. Proximal osteolysis of the fibula and congenital urological abnormalities, in the proband, and holoprosencephaly sequence, in the proband's sister, have not previously been described in the syndrome.

Abnormalities, Multiple↗
PubMed1997

Improvement in outcome of children with Wilms' tumour in South Australia over the last 30 years.

OBJECTIVE: To evaluate the outcome of children with Wilms' tumour over the last 30 years in South Australia. To compare the outcome of children treated before and after 1982, when standard treatment protocols were introduced. METHODOLOGY: Management approaches, survival rates and side-effects of treatment were identified from case notes. Pathology slides were reviewed to ensure all children were correctly diagnosed with Wilms' tumour. RESULTS: Children treated for Wilms' tumour prior to 1982 had an overall survival rate of 54%. Since 1982 there has been a significant improvement in outcome and the current survival rate is now 85%. Children treated since 1982 have also experienced fewer treatment related side-effects than children treated prior to 1982. CONCLUSIONS: There has been substantial improvement in survival from childhood Wilms' tumour over the past 30 years in South Australia. This is likely to be due to a combination of factors including standardization of treatment, tailoring of treatment to stage and histology, improved perioperative care, enhanced radiological techniques and higher levels of collaboration between relevant specialists.

Child↗
PubMed1997

Managing TMD.

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American Dental Association↗
PubMed1996

Pregnancy, abortion, and birth rates among US adolescents--1980, 1985, and 1990.

OBJECTIVE: To analyze pregnancy, abortion, and birth rates among US adolescent girls in 1980, 1985, and 1990. DESIGN: Retrospective analysis of trends in data on pregnancies, abortions, and births. POPULATION: US adolescent girls aged 13 to 19 years. MAIN OUTCOME MEASURES: Pregnancy, abortion, and birth rates (with and without adjustment for sexual experience) among teenaged girls aged 15 to 19 years and girls under 15 years. RESULTS: Although pregnancy rates among all teenaged girls 15 to 19 years old remained fairly stable from 1980 to 1985, they increased by 9% during the last half of the decade, totaling 95.9 pregnancies per 1000 teenaged girls 15 to 19 years old by 1990. Because rates of sexual experience increased even faster, pregnancy rates among sexually experienced teens aged 15 to 19 actually declined between 1980 and 1990 by approximately 8%. Abortion rates among these teens remained stable during the 1980s, with 35.8 and 36.0 abortions per 1000 in 1980 and 1990, respectively. As with overall pregnancy rates, abortion rates among these sexually experienced teenaged girls declined during the 1980s. Between 1980 and 1985, birth rates among teenaged girls aged 15 to 19 years declined by 4%, but they increased by 18% during the latter half of the decade, totaling 59.9 births per 1000 in 1990. Among these sexually experienced teenagers, birth rates also declined between 1980 and 1985 and then increased over the next 5 years. In 1990, pregnancies and abortions among girls younger than 15 years accounted for only 3% of all adolescent pregnancies and abortions. However, the number of births among these younger adolescents increased by 15% over the decade. In that age group, trends in pregnancy, abortion and birth rates over the decade were similar to those for older teens. However, during the late 1980s, the abortion rate declined and the pregnancy rate remained stable, resulting in a 26% increase in the birth rate. CONCLUSIONS: Despite efforts to reduce adolescent pregnancy in the United States, pregnancy and birth rates for that group continue to be the highest among developed countries. Considering that 95% of adolescent pregnancies are unintended, increased efforts to prevent these pregnancies are warranted.

Abortion, Induced↗
PubMed1996

Effects of crack cocaine on neurocognitive function.

Because crack cocaine appears to have a preferential effect on the metabolic and electrophysiological activity of the frontal and temporal regions of the brain (Pascual-Leone et al., 1991a, 1991b; Volkow, 1992), we hypothesized that cognitive measures of those regions would be impaired in crack cocaine users relative to measures in normal volunteers. We used logistic regression to determine the relationship of cocaine usage to neuropsychological test performance. We compared 38 patients with an average of 3.6 (SD = 2.5) years of crack cocaine use and 24.5 (SD = 28.1) days of abstinence to 54 normal volunteers on a battery of neuropsychological tests. Statistical adjustments were made for the effects of age, education, socioeconomic class, and level of depression. Our findings were mixed with regard to purported measures of executive/frontal functioning, with worse performance associated with cocaine usage on the Booklet Categories Test, but better performance associated on others (number of categories on the Wisconsin Card Sorting Test, Controlled Oral Word Association). Cocaine usage was associated with impairment on measures of spatial, but not verbal memory, confrontation naming, and Trail-making Test, Part B, a measure of perceptual-motor speed and cognitive flexibility. In summary, it appears that continuous crack cocaine use produces a dissociative pattern in neuropsychological test performance with improvement on some measures, but deterioration on others. The permanence of these effects remains to be determined with longitudinal studies.

Adult↗
PubMed1996

Disability and health: perceptions of a sample of elderly people.

The background to this work was the expected increase in the proportion of elderly people in the population, giving rise to a greater demand for services at a time of scarcity of healthcare resources. The aims of the study were to investigate disability and health in a sample of elderly people living at home in the community. We wished to obtain detailed information about physical disability and health then to explore individual perceptions of health and disability and, finally, to examine relationships between the objective assessments and individual, subjective perceptions. The results reported here represent only part of the work of a larger study which also investigated the use of health and social services in this sample of elderly people. In-depth interviews were undertaken with a random stratified population sample of 200 elderly people living at home. Analysis of interview data showed that, by use of a multidimensional scale of disability, just over one-third of the sample could be classified as 'disabled'. The mobility status of the sample was, in general, good with only small numbers spending most of their time in a wheelchair. The total sample scored highly on activities of daily living, though those classified as disabled were significantly less independent. The mean number of reported health conditions was less than might have been expected in an elderly population. One-third of the subjects in the sample showed discrepancies between their own assessment of their disability and objective assessments. These discrepancies could partly be explained by a combination of individuals' assessment of their own abilities and their beliefs about factors influencing disability. Measures of disability, or activity associated with daily living, were related to perceptions of health, whereas the number of current health problems was not. The factors which determined perceptions of health or disability were: walking unaided and general levels of activity. Health was perceived in terms of what one could do rather than the presence of current diseases or conditions. The results suggested that when planning treatment for elderly people, physiotherapists and others should consider individual variability in perceptions of disability and health, as well as objective assessments. The importance of locomotion in the value systems of elderly people emphasises the high profile of physiotherapy in the care of elderly people.

Activities of Daily Living↗
PubMed1996

Identification of cell subsets expressing intracytoplasmic cytokines within HIV-1-infected lymph nodes.

OBJECTIVE: To describe the endogenous cytokine profile of HIV-1-infected lymph nodes (LN) and to identify the phenotype of individual cells expressing intracytoplasmic cytokines. DESIGN AND METHODS: Whole LN biopsies were collected from three HIV-seronegative controls and four HIV-1-positive individuals with persistent generalized lymphadenopathy. Three had established infection (Centers for Disease Control and Prevention 1993 criteria, stages A2, C1 and C3) and one was undergoing seroconversion illness. A combination of three methods was used to assess the impact of HIV-1 on LN architecture and endogenous cytokine expression. Immunocytochemistry was used to locate follicular dendritic cells (FDC), interdigitating cells and T and B cells. Reverse transcriptase-polymerase chain reaction was used to assess mRNA for interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-10, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma in collagenase-digested LN cells. Three-colour flow cytometry was used to identify intracytoplasmic cytokine expression within cell subsets. RESULTS: Germinal center (GC) hyperplasia was observed in LN from two patients with established HIV-1 infection, and the third, coinfected with Mycobacterium tuberculosis, showed extensive necrosis. In the patient undergoing seroconversion, there was an extensive FDC network within the expanded and confluent GC which covered expansive areas of the LN. There was varied expression of IL-1 beta, IL-4, IL-6, IL-10 and TNF-alpha mRNA from the four HIV-1-infected LN and the patient undergoing seroconversion showed evidence for a mixed cytokine profile, which also included IL-2 and IFN-gamma. Flow cytometry revealed intracytoplasmic IL-1 beta protein restricted to cells expressing CD19, CD21 and CD38 antigens. CONCLUSIONS: Cytokines were detected in freshly isolated HIV-1-infected LN cells without requiring an exogenous stimulus. Seroconversion was associated with an expanded FDC network within enlarged GC, bounded by defined mantle zones containing B cells. There was diverse cytokine mRNA expression and IL-1 beta protein was restricted to cells expressing B-cell-associated antigens.

Adult↗
PubMed1995

An update on AIDS.

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AIDS Vaccines↗