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C Macleod

Publications and source records attributed to C Macleod.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of quicklime mixing for the remediation of petroleum contaminated soils.

Quicklime mixing is an established solidification/stabilization technique to improve mechanical properties and immobilise contaminants in soils. This study examined the effects of quicklime mixing on the concentrations and leachability of petroleum hydrocarbon compounds, in two natural soils and on a number of artificial sand/kaolinite mixtures. Several independent variables, such as clay content, moisture content and quicklime content were considered in the study. After mixing the soils with the quicklime, pH, temperature, moisture content, Atterberg limits and concentrations of petroleum hydrocarbon compounds were determined on soil and leachate samples extracted from the treated soils. Significant decreases in concentrations of petroleum hydrocarbon compounds were measured in soils and leachates upon quicklime mixing, which may be explained by a number of mechanisms such as volatilization, degradation and encapsulation of the hydrocarbon compounds promoted by the quicklime mixing. The increase in temperature due to the exothermic hydration reaction of quicklime when in contact with porewater helps to volatilize the light compounds but may not be entirely responsible for their concentration decreases and for the decrease of heavy aliphatics and aromatics concentrations.

Aluminum Silicates↗
PubMed2005

Distribution of Neoparamoeba sp. in sediments around marine finfish farming sites in Tasmania.

Marine sediment samples collected from various sites at 2 Atlantic salmon farms in Tasmania were analysed for the presence of Neoparamoeba sp., an amoeba associated with amoebic gill disease (AGD) in farmed Atlantic salmon. Environmental variables of the sediment layer at each site, including redox potential and sulphide concentration, were measured and the general biological condition assessed by video observation. Sediments and environmental data were collected on 4 occasions at each site over a 12 mo period. Neoparamoeba sp. was detected in populations of amoebae recovered by culture from all sites and in 50% of all sediment samples taken. There was evidence of a seasonal influence on the presence of the amoeba, but this was different at each farm. No Neoparamoeba sp. was recovered from any sites at Farm 1 during the winter of 2002 whereas at Farm 2 this was the case for the summer of 2003. There appeared to be no relationship between the presence of Neoparamoeba sp., salmon farming activities and environmental parameters.

Animals↗
PubMed2005

Optimal scheduling to reduce morbidity of involved field radiotherapy with transplantation for lymphomas: a prospective Australasian Leukaemia and Lymphoma Group Study.

This study evaluated delivery of involved field radiotherapy (IFRT) with transplantation for lymphomas timed to minimise toxicity. Patients transplanted for lymphoma had infradiaphragmatic disease irradiated pre-transplant and supradiaphragmatic disease post transplant. A total of 31 patients were studied, with a median follow-up duration of 4 years. Transplant conditioning was according to clinician preference. In all, 14 patients had pre-transplant abdominopelvic IFRT and 19 had post transplant IFRT (including three who had pre-transplant IFRT). Grade III-IV haematological toxicity from pre-transplant IFRT occurred in three patients and from post transplant IFRT in 10 patients. Pre-transplant IFRT had no effect on haematological recovery post transplant, but was associated with a trend towards increased gastrointestinal toxicity (P = 0.094). Pneumonitis due to post transplant thoracic IFRT occurred in one patient. Two patients failed in involved sites after completion of protocol radiotherapy. One case of myelodysplasia has been reported. As sequenced in this study, IFRT was feasible and produced a low incidence of severe pulmonary and haematological toxicities. Patient selection, field size and radiotherapy dose warrant further study.

Adolescent↗
PubMed2003

Vacuum assisted delivery--the need for caution.

In the United Kingdom and Republic of Ireland 10% of all deliveries are vacuum assisted. The vacuum is preferred over forceps because it is easier to perform and associated with less maternal morbidity. It is, however, also associated with subaponeurotic haemorrhage that has an incidence of 6.4 per 1000 vacuum assisted deliveries and a mortality of 23%. Based on a figure of 77,500 births annually in Ireland, North and South, it is possible that as many as 11 neonatal deaths each year may attributable to what is generally considered a safe obstetric intervention. In North America concerns about the safety of vacuum assisted delivery resulted in the issuing of public health advisories in both Canada and the United States. To date such concerns have not been raised in either the United Kingdom or Republic of Ireland. We report a case of fatal subaponeurotic haemorrhage to highlight and bring these concerns to the attention of obstetricians, paediatricians and midwives. We also call for the introduction of a national surveillance in order to assess the true extent of this potentially fatal complication.

Adult↗
PubMed2002

Ambulatory paediatrics: does it work?

To determine whether a paediatric ambulatory assessment service is an effective and acceptable replacement for an inpatient unit. Analysis of hospital paediatric medical admissions. Postal questionnaire survey of local general practitioners. Telephone survey of parents of children who had attended the ambulatory service. Rural General Hospital in Northern Ireland. General practitioners. Parents of children referred to assessment service. Number of paediatric medical hospital admissions from the local area before and after the introduction of an ambulatory assessment service. General practitioner satisfaction levels. Parental satisfaction levels. Since the introduction of the new service in April 1996 there has been a marked progressive reduction in paediatric medical hospital admissions from the local area. By the third year of operation of the ambulatory service (1998/99), a 47% reduction in admissions was recorded, compared to the 1995/96 baseline year. The response rate to the general practitioner questionnaire was 65% (37 of 57) of whom most (31, 84%) found the service beneficial. Of the 37 respondents, 31 had referred patients to the service. The majority of these general practitioners (30, 97%) reported that the service was easy to access, and the same proportion felt that requests for consultation were met promptly. Most felt that feedback was appropriate (29, 94%). A telephone survey of 50 parents showed that most were either very satisfied (38, 76%), or satisfied (11, 22%) with the service. Most parents (41, 82%) felt their child had benefited by not being admitted to hospital. Most (46, 92%) felt they had received adequate information regarding their child's illness. A paediatric ambulatory assessment unit can reduce the number of children admitted to hospital and meet the needs of children, their families and general practitioners.

Ambulatory Care↗
PubMed2001

Evaluating cardiac murmurs; are diagnostic tests helpful?

The detection of an asymptomatic murmur in a child usually results in a referral to a consultant paediatrician. In most cases a chest radiograph (CXR) and electrocardiograph (ECG) are performed as an aid to diagnosis, however the evidence for this is contradictory. A retrospective chart review of children referred with asymptomatic cardiac murmurs in a one-year period was conducted. We wished to determine whether CXR and ECG are useful diagnostic aids. 81 patient charts were reviewed. Of those patients with a clinical diagnosis of pathological murmur all had normal CXR and ECG. Never the less 2 cases were referred for echocardiogram and were found to have structural heart disease. Of those with a clinical diagnosis of innocent murmur most (81%) had a CXR and ECG and in most cases (96%) these were normal. Those cases with abnormal investigations subsequently were shown to have structurally normal hearts on echocardiogram. We conclude that routine use of CXR and ECG in evaluating asymptomatic cardiac murmurs in children is not useful.

Electrocardiography↗
PubMed2000

An epidemiological survey of methicillin-resistant Staphylococcus aureus in a tertiary referral hospital.

Over a 30-month period from July 1995 to December 1997, new detections of methicillin-resistant Staphylococcus aureus (MRSA) were prospectively studied in a tertiary referral hospital. The aims of the study were to determine the incidence of colonization of patients admitted to each of the hospital's 39 clinical units and ascertain where each patient had become colonized. Epidemiological information (time to detection, ward movement, admission to other hospitals, data on MRSA isolations in hospital wards) and phage typing were used by the hospital's infection control unit to make this determination. Routine containment procedures included cohorting, flagging and triclosan body washes. Surveillance cultures were collected infrequently. Patients known to be colonized with MRSA were excluded from orthopaedic and haematology wards. During the study period, 995 patients were found to be newly colonized. The incidence of colonization varied from nil to 72 per 1000 admissions, being highest in the main intensive care unit and in services which frequently used that unit. The incidence of colonization in elective orthopaedic surgery (< 1 per 1000) and haematology (3 per 1000) was very low. Determining the place where patients acquired MRSA was made difficult by the high frequency of endemic phage types and frequent patient transfer between wards. Epidemiological data suggested that the main intensive care unit and surgical wards nursing patients with colorectal, urological and vascular diseases were the places where most patients became colonized. MRSA was never acquired by patients nursed in wards which practised an exclusion policy towards patients known to be colonized with MRSA. Our data suggest that in tertiary referral hospitals, where MRSA is not only endemic but frequently imported from other hospitals, it is possible to establish areas where MRSA is never acquired.

Adolescent↗
PubMed1999

A prospective survey of current methicillin-resistant Staphylococcus aureus control measures.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is now endemic in tertiary referral hospitals among the developed world. By prospective survey, the effect of two measures aimed to reduce the spread of MRSA was determined. First, a surgical ward with persistently high levels of MRSA detection was cleaned and renovated. Second, the medical records of all MRSA-colonized patients were electronically flagged, facilitating immediate application of control measures on readmission. METHODS: Data were collected for 995 newly colonized patients admitted between 1 July 1995 and 31 December 1997. Methicillin-resistant Staphylococcus aureus detection was determined before and after implementation of the interventions, along with the likely place of MRSA acquisition and the monthly incidence of MRSA detection for all inpatients. Chi-squared testing with odds ratios and 95% confidence intervals determined associations between the effect of control measures studied and MRSA detection rates. RESULTS: New MRSA detection was 21.6 per 1000 admissions before refurbishment compared with 20.4 per 1000 admissions to the surgical ward after refurbishment. New MRSA detection averaged 6.4 per 1000 hospital admissions before the introduction of record flagging and patient cohorting, compared with 6.2 per 1000 admissions after. CONCLUSION: Neither ward refurbishment, nor introduction of flagging, significantly reduced rates of colonization during the study period. In hospitals that receive MRSA-colonized patients and provide intensive care facilities, spread of MRSA is a major problem. Effective containment demands separate wards for MRSA-colonized and non-colonized patients. The need for such containment should be considered in design of the modern hospital.

Chi-Square Distribution↗
PubMed1999

Inequalities in mortality and illness in Trent NHS Region.

BACKGROUND: The Department of Health is encouraging health authorities to improve health status by tackling health inequalities. We defined ward level spatial health variations in Trent National Health Service Region, England, investigated urban and rural inequalities, and examined the relationship with deprivation, to identify the extent of small area health inequalities and to establish whether a quantifiable difference exists between urban and rural health as affected by deprivation. METHOD: A small area ecological study design was adopted and ward level (n=591) standardized ratios were calculated (population aged <75, n=3,900,000) for specific causes of death and limiting long-term illness. A classification was devised to assess ward health inequalities according to an urban-rural dimension. Deprivation was measured using the Townsend Index and the relationship with mortality and illness was analysed using Pearson product moment correlation. RESULTS: Wide variations in mortality and illness were evident at ward level, being widest for accident mortality (standardized mortality range 0-508). Stroke mortality accounted for the largest proportion of wards with standardized mortality ratios over 125 (36.2 per cent). Relative deprivation correlated strongly with limiting long-term illness (r=0.82) and all-cause mortality (r=0.68) across Trent, and in both urban and rural environments. CONCLUSION: The study set health inequalities within a regional context for Trent as an initiative to coincide with the Government's proposed health strategy for the next few years. Wide health inequalities were evident in Trent and the association between deprivation and health was of a similar magnitude in urban and rural wards. This small area approach allows health authorities access to ward level information in order to inform key debate on tackling health inequalities and distributing resources in relation to need.

Adolescent↗
PubMed1997

Research as intervention within community mental health.

This paper raises some issues for discussion and debate concerning the nature of research within a mental health setting. Research, no matter what form it takes, is always an intervention. Sensitivity to various concerns surrounding research is required of the mental health worker. Participatory research, which is seen as empowering participants, has become popular in mental health programmes. Attention needs to be paid, however, to the meaning of participation and the process of decision-making. Researchers are often uncomfortable with shedding their "objective informer" stance and adopting a position that requires social action. Some of this has to do with the epistemological view taken by the researcher. This paper suggests that the knowledge produced in research is a social construction created in interaction between the researcher and participants and has a multiplicity of potential meanings. The instrumental, conceptual and persuasive uses of research are discussed, and two intervention-type research procedures (needs assessment and evaluation) are critically reviewed. It is concluded that research, as with all other interventions, should be carefully planned, implemented, monitored and evaluated.

Community Mental Health Services↗
PubMed1995

Brain natriuretic peptide: effect on left ventricular filling patterns in healthy subjects.

1. Elevated plasma concentrations of brain natriuretic peptide are found in conditions associated with impaired left ventricular diastolic function. The purpose of this study was to determine whether this peptide actually plays a physiological role in improving myocardial performance in diastole. 2. Nine normal subjects received infusions of brain natriuretic peptide or placebo in a randomized, double-blind, crossover study. Brain natriuretic peptide infusion produced a significant reduction in isovolumic relaxation time (means and 95% confidence interval for difference -10.8 ms, -14.5 to -7.0 ms) (P < 0.01) and significantly increased both the peak E/A velocity (0.54, 0.14-0.94) (P < 0.05) and the E/A time velocity integral (1.09, 0.20-1.98) (P < 0.05). 3. These responses were evident at concentrations of brain natriuretic peptide that produced no associated effects on blood pressure, heart rate or stroke distance. 4. Brain natriuretic peptide infusion in normal subjects significantly reduces isovolumic relaxation time and improves transmitral Doppler flow profiles, suggesting that this peptide may be important in the control of left ventricular diastolic relaxation in man.

Cross-Over Studies↗
PubMed1995

Acute effects of atrial natriuretic peptide on left ventricular diastolic function. a pulsed wave Doppler study in man.

Doppler echocardiographic indices of diastolic function and systemic haemodynamics were studied in response to infusions of atrial natriuretic peptide (0.5, 1, 2, 5 pmol.kg-1.min-1) and placebo (0.9% (w/v) saline) in ten normal male subjects. Compared with placebo, atrial natriuretic peptide infusion produced a significant and dose-related reduction in the isovolumic relaxation time [(mean and 95% CI) -5.9 (-9.2 to -2.6) ms (P < 0.01) at 5 pg.kg-1 min-1] and a significant increase in the ratio between early and late transmitral peak velocities [0.46 (0.02 to 0.89) (P < 0.05) at 5 pg.kg-1 min-1]. No significant changes in heart rate, blood pressure or aortic stroke distance were observed with infusion of atrial natriuretic peptide compared with placebo. These data suggest that pathophysiological plasma concentrations of atrial natriuretic peptide improve diastolic function by increasing the rate of myocardial relaxation.

Adolescent↗
PubMed1989

Vigilance, visual search and attention in an agricultural task.

In a fragile agricultural environment, such as Western Australia (WA), introduced exotic plant species present a serious environmental and economic threat. Skeleton weed, centaurea juncea, a Mediterranean daisy, was accidentally introduced into WA in 1963. It competes with cash crops such as wheat. When observed in the fields, farms are quarantined and mechanised teams search for the infestations in order to destroy them. Since the search process requires attention, visual search and vigilance, the present investigators conducted a number of controlled field trials to identify the importance of these factors in detection of the weed. The paper describes the basic hit rate, vigilance decrement, effect of search party size, effect of target size, and some data on the effect of solar illumination of the target. Several recommendations have been made and incorporated in the search programme and some laboratory studies undertaken to answer questions arising.

Journal Article↗