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Biomedical subjects

A Walsh

Publications and source records attributed to A Walsh.

At least 19 recordsLinked to original sources
PubMed2006

Electronic origins of structural distortions in post-transition metal oxides: experimental and theoretical evidence for a revision of the lone pair model.

Structural distortions in post-transition metal oxides are often explained in terms of the influence of sp hybrid "lone pairs." Evidence is presented here showing that this model must be revised. The electronic structures of prototypically distorted alpha-PbO and alpha-Bi2O3 have been measured by high-resolution x-ray photoemission and soft x-ray emission spectroscopies. In contrast with the expectations of the lone pair model, a high density of metal 6s states is observed at the bottom of the valence band. The measurements are consistent with the results of density functional theory calculations.

Journal Article↗
PubMed2006

Temperature dependence of the optical transition energies of carbon nanotubes: the role of electron-phonon coupling and thermal expansion.

Tunable Raman spectroscopy is used to measure the optical transition energies Eii of individual single wall carbon nanotubes. Eii is observed to shift down in energy by as much as 50 meV, from -160 to 300 degrees C, in contrast with previous measurements performed on nanotubes in alternate environments, which show upshifts and downshifts in Eii with temperature. We determine that electron-phonon coupling explains our experimental observations of nanotubes suspended in air, neglecting thermal expansion. In contrast, for nanotubes in surfactant or in bundles, thermal expansion of the nanotubes' environment exerts a nonisotropic pressure on the nanotube that dominates over the effect of electron-phonon coupling.

Journal Article↗
PubMed2006

Human Vero cytotoxigenic Escherichia coli (VTEC) O157 infection linked to birds.

Vero cytotoxin-producing Escherichia coli O157 (VTEC O157) infections are a threat to public health. VTEC O157 has been isolated from gulls but evidence of transmission to humans from birds has not been reported. We recount an incident of VTEC O157 infection affecting two sibling children who had no direct contact with farm animals. An outbreak control team was convened to investigate the source of infection, its likely mode of transmission, and to advise on control measures. Human and veterinary samples were examined and the human isolates were found to be identical to an isolate from a sample of bird (rook) faeces. Cattle, rabbit and environmental samples were negative. This report provides evidence that birds may act as intermediaries for human infection with VTEC O157.

Animals↗
PubMed2005

Full-genome RNAi profiling of early embryogenesis in Caenorhabditis elegans.

A key challenge of functional genomics today is to generate well-annotated data sets that can be interpreted across different platforms and technologies. Large-scale functional genomics data often fail to connect to standard experimental approaches of gene characterization in individual laboratories. Furthermore, a lack of universal annotation standards for phenotypic data sets makes it difficult to compare different screening approaches. Here we address this problem in a screen designed to identify all genes required for the first two rounds of cell division in the Caenorhabditis elegans embryo. We used RNA-mediated interference to target 98% of all genes predicted in the C. elegans genome in combination with differential interference contrast time-lapse microscopy. Through systematic annotation of the resulting movies, we developed a phenotypic profiling system, which shows high correlation with cellular processes and biochemical pathways, thus enabling us to predict new functions for previously uncharacterized genes.

Animals↗
PubMed2004

School based youth health nurses' role in assisting young people access health services in provincial, rural and remote areas of Queensland, Australia.

INTRODUCTION: People living in rural and remote areas have poorer health and more limited access to health services than those in urban areas. Adolescence, generally a period of optimum health, is fraught with risky health behaviours, increasing morbidity and mortality. Increasingly, mental health problems including depression, alcohol and drug use, suicide, self-harm, sexual health, inappropriate nutrition and physical activity are key areas of adolescent health concern in Queensland, Australia. To address the health and well being needs of young people the School Based Youth Health Nurse (SBYHN) Program was introduced into State high schools in Queensland in 1998. SBYHN responsibilities include individual consultations and health promotion within the high school environment. This study was undertaken to explore the referral role of SBYHN in provincial, rural and remote Queensland and to ascertain the availability of referral services. METHOD: A self-report survey was posted to all SBYHN in Queensland. Forty-four (62%) nurses participated; 27 from provincial, 11 from rural and 6 from remote areas. RESULTS: SBYHN consult with young people in provincial, rural and remote State high schools in the areas of psychological concerns, drug and alcohol concerns and/or abuse, family conflict and/or abuse, sexual and reproductive health, social and isolation concerns and nutritional advice. However, the frequency with which SBYHN reported themselves as an appropriate source for young people to seek assistance from varied from over 90% for areas such as sexual and nutritional advice to approximately 30% for areas such as physical abuse and drug and alcohol abuse. When required by the SBYHN, referral services were locally accessible to young people less than 50% of the time. Access to some referral services was reduced because some young people do not want parental involvement in their health and the service requires parental consent. When referral services were unavailable SBYHN used phone counselling, available generalists, supported and monitored the young people until a service was available, or they accepted this as an aspect of residing outside the metropolitan areas and did the best they could. Sometimes, when a young person was reluctant to attend a recommended service or there was a long wait for an appointment, SBYHN provided ongoing support while endeavouring to persuade attendance at the recommended service. Situations like these, experienced by at least half those studied, place SBYHN in the precarious position of practicing beyond their scope of practice. CONCLUSIONS: Health problems during adolescence can be reduced by ensuring assistance and support are available for young people when and if they require it. Thorough confidential individual consultations are provided by SBYHN and young people are availing themselves of this service. SBYHN are practicing at an advanced level and need to be recognised as such. Additionally, the availability of services in rural and remote regions needs consideration. As rural youth are more vulnerable to a number of health concerns, it is imperative that services are available for them. The issue of parental consent remains a barrier to young people seeking health services and it may be timely for community debate on this issue.

Journal Article↗
PubMed2004

Functional outcome of burst fractures of the first lumbar vertebra managed surgically and conservatively.

We retrospectively reviewed 31 neurologically intact patients with burst L1 fractures. We obtained a follow-up clinical evaluation after a mean of 43 (14-80) months from 26 patients--11 treated surgically and 15 managed non-surgically. Patients were assessed with regard to pain, employment status, recreational activities and overall satisfaction. At final follow-up of 15 patients managed non-surgically, six had little or no pain; 12 had returned to work with six declaring little or no restrictions, and eight had returned to the same level of recreational activity as prior to injury with seven declaring little or no restrictions. Of 11 patients treated surgically, four had little or no pain; seven had returned to work with three declaring little or no restrictions, three had returned to the same level of recreational activity as prior to injury and four declared little or no restrictions. There was no correlation found between vertebral collapse, kyphosis, retropulsion and clinical outcome. Patients who had non-operative management reported a good functional outcome. However, patients who required surgical stabilisation due to different fracture characteristics reported a poorer functional outcome.

Activities of Daily Living↗
PubMed2004

High dose caffeine citrate for extubation of preterm infants: a randomised controlled trial.

OBJECTIVE: To compare two dosing regimens for caffeine citrate in the periextubation period for neonates born at less than 30 weeks gestation in terms of successful extubation and adverse effects. DESIGN: A multicentre, randomised, double blind, clinical trial. SETTING: Four tertiary neonatal units within Australia. PATIENTS: Infants born less than 30 weeks gestation ventilated for more than 48 hours. INTERVENTIONS: Two dosing regimens of caffeine citrate (20 v 5 mg/kg/day) for periextubation management. Treatment started 24 hours before a planned extubation or within six hours of an unplanned extubation. MAIN OUTCOME MEASURE: Failure to extubate within 48 hours of caffeine loading or reintubation and ventilation or doxapram within seven days of caffeine loading. RESULTS: A total of 234 neonates were enrolled. A significant reduction in failure to extubate was shown for the 20 mg/kg/day dosing group (15.0% v 29.8%; relative risk 0.51; 95% confidence interval (CI) 0.31 to 0.85; number needed to treat 7 (95% CI 4 to 24)). A significant difference in duration of mechanical ventilation was shown for infants of less than 28 weeks gestation receiving the high dose of caffeine (mean (SD) days 14.4 (11.1) v 22.1 (17.1); p = 0.01). No difference in adverse effects was detected in terms of mortality, major neonatal morbidity, death, or severe disability or general quotient at 12 months. CONCLUSIONS: This trial shows short term benefits for a 20 mg/kg/day dosing regimen of caffeine citrate for neonates born at less than 30 weeks gestation in the periextubation period, without evidence of harm in the first year of life.

Caffeine↗
PubMed2004

Guidelines for establishing trials of new tests to diagnose tuberculosis in endemic countries.

Efforts to control tuberculosis are currently hampered by the lack of effective tools for the detection of infected individuals. Although new diagnostic tests are being developed and marketed, there is a paucity of data on the value of new technology for the diagnosis of tuberculosis in endemic regions of the world. Trials of new tools need to be undertaken in appropriate settings and to a high standard. The value of previous studies has frequently been compromised by inadequate study design and poor execution. We offer guidelines to assist in planning trials for new tests for the diagnosis of tuberculosis.

Clinical Trials as Topic↗
PubMed2003

Lumbar Chance fracture associated with use of the lap belt restraint in an adolescent.

The use of the 2-point seat belt or lap belt in motor vehicles, particularly to restrain young rear seat passengers, remains an issue of some concern. The occurrence of lumbar spinal flexion-distraction injuries in lap belt restrained children and adolescents during road traffic accidents is a well known phenomenon, but is still occurring. High velocity paediatric Chance fractures are frequently associated with significant intra-abdominal trauma. We present the case of a Chance fracture sustained by a 15 year old girl, involved in a motor vehicle collision, while wearing a lap belt. We emphasise the need to develop safer seat belt designs for juvenile car passengers.

Accidents, Traffic↗
PubMed2001

Spina bifida occulta in isthmic spondylolisthesis: a surgical trap.

An 11-year-old girl presented with symptomatic grade IIB isthmic type spondylolisthesis, with an elongated pars, confirmed on magnetic resonance imaging (MRI). Posterolateral in situ fusion of L5/S1 was performed. At surgery, a significant bony defect in the posterior aspect of S1 was noted. Awareness of this possible co-existence is paramount if iatrogenic damage to neural elements is to be avoided during surgery.

Child↗
PubMed2001

The beginning of the research stream in family medicine residency program at McMaster University.

BACKGROUND: To examine research background, attitudes, knowledge and skills of family medicine residents with regard to primary care research and to compare residents who elected to participate in the research stream with those who did not. METHODS: Mailed survey of Family Medicine residents at McMaster University in 1998, 70% (52/74) of whom responded. The main outcome measures consisted of research background; attitudes towards primary care research and research activities during residency program; knowledge and skills in applying it in biostatistics, epidemiology, and research design. RESULTS: The vast majority of the residents reported previous research experience and/or some training in epidemiology and biostatistics. Residents in the research stream were more likely to be female and were positive towards primary care research: they were more interested in research, more interested in obtaining more research training while a resident, and placed more importance on developing research early in medical education. The research stream residents had stronger views regarding perceived lack of support staff and lack of time for research. There were no statistically significant differences between the research stream and other residents in terms of research knowledge and skills in applying it. CONCLUSIONS: Attitudes towards research rather than research knowledge or skills seemed to distinguish those selecting to be in our new research stream at the inception.

Attitude of Health Personnel↗
PubMed2001

Queensland public sector nurse executives: job satisfaction and career opportunities.

During the past decade, economic and political forces have caused radical transformations in health care systems resulting in changed circumstances within which nursing executives must function. This paper provides an understanding of nursing executives' roles and responsibilities and the impact changes in the health industry have had on their careers. One hundred and forty-seven (52%) of the 281 nursing executives employed in the Queensland Public Health Sector completed a postal self-administered survey. The findings of this study demonstrate their role has expanded to include not only nursing administration, but also responsibility for financial, human resources, strategic and resource management, staff development and quality improvement. The impact of these role changes has affected the health and well-being of nursing executives, with nearly half reporting increased stress, frustration and irritation. Their workload has increased and some reported deterioration in their health, specifically, exhaustion, fatigue and insomnia. Respondents reported they now have less time to spend with families and friends, which has had a negative impact on family relationships. Overall, nursing executives were satisfied with their current position, the work itself and their relationships with their co-workers, but dissatisfied with organisational aspects, especially the quality of mentorship and opportunities for promotion.

Adult↗
PubMed2001

Brace modification improves aerobic performance in Charcot-Marie-Tooth disease: a single-subject design.

OBJECTIVE: Ankle-foot orthoses (AFOs) can lower energy expenditure in patients with hemiplegia by 10%-13%. Review of the lower motor injury literature reveals insufficient physiologic evidence supporting the use or modification of AFOs in patients with lower motor neuron injury and, specifically, progressive conditions such as Charcot-Marie-Tooth disease. We sought to test the hypothesis that optimal AFOs would improve submaximal aerobic performance and submaximal perceived exertion, while producing no change in maximal aerobic capacity. DESIGN: In an individual with Charcot-Marie-Tooth disease, a single-subject design study was used. An A-B-A design was used, with "A" corresponding to use of the patient's old AFOs and "B" corresponding to the newly prescribed AFOs. The subject underwent treadmill exercise tolerance testing using a modified Balke protocol. Indirect calorimetry was used to measure oxygen consumption per unit time (VO2), and the Borg scale was used to measure perceived exertion. RESULTS: At the same submaximal exercise intensities, VO2, rate-pressure product, and perceived exertion were all reduced when using the modified AFOs. Additionally, these conditions allowed the subject to conduct the treadmill exercise test 20% longer. Maximal VO2 remained constant under all conditions. CONCLUSION: Optimizing the AFO prescription in a patient with Charcot-Marie-Tooth disease can enhance physiologic performance and perceived exertion at submaximal activity levels. Larger controlled trials are necessary to further demonstrate such benefits in patients with progressive neuropathy and other causes of lower motor neuron injury.

Ankle↗
PubMed2001

Brittle diabetes in the elderly.

Severely unstable, or brittle, diabetes can be disruptive to patients, carers and diabetes care teams. The peak age-group for brittle diabetes is 15-30, but there are reports of its occurrence in much older patients. To explore the characteristics and cause of brittle instability perceived by diabetologists in elderly patients we circulated a questionnaire to all UK hospital diabetic clinics for adults. 130 (56%) of 231 replied. Reports were obtained on 55 patients fulfilling our criteria for 'elderly brittle diabetes'--namely, age > or =60 years, on insulin treatment, and experiencing life-disrupting glycaemic instability of any kind associated with frequent or long admissions to hospital. Further information was obtained by a research nurse who visited the relevant clinics. The mean age of patients was 74 years (range 60-89) and 71% were female. The brittleness was classed as mixed glycaemic instability in 22 (44%), recurrent ketoacidosis in 16 (29%) and recurrent hypoglycaemia in 15 (27%). In 2 cases there was insufficient information for classification. The diabetes care team judged the brittleness to have multiple origins in two-thirds of the cases: problems with memory or behaviour were rare, and in only 4 cases was deliberate manipulation of therapy considered a possibility. 84% of the patients were living independently. In younger patients the principal manifestation of brittle diabetes is recurrent ketoacidosis. The present survey, though possibly subject to ascertainment bias, indicates that the patterns of instability and their causation may be different in elderly patients. With the growing use of insulin in the elderly, brittle diabetes is likely to be encountered increasingly often in this age-group.

Aged↗
PubMed2000

Older patients in the acute care setting: rural and metropolitan nurses' knowledge, attitudes and practices.

Many studies reporting nurses' knowledge of and attitudes toward older patients in long-term care settings have used instruments designed for older people. However, nurses' attitudes toward older patients are not as positive as their attitudes toward older people. Few studies investigate acute care nurses' knowledge of and attitudes toward older patients. In order to address these shortcomings, a self-report questionnaire was developed to determine nurses' knowledge of, and attitudes and practices toward, older patients in both rural and metropolitan acute care settings. Rural nurses were more knowledgeable about older patients' activities during hospitalisation, the likelihood of them developing postoperative complications and the improbability of their reporting incontinence. Rural nurses also reported more positive practices regarding pain management and restraint usage. However, metropolitan nurses reported more positive attitudes toward sleeping medications, decision making, discharge planning and the benefits of acute gerontological units, and were more knowledgeable about older patients' bowel changes in the acute care setting.

Acute Disease↗