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K MacMillan

Publications and source records attributed to K MacMillan.

At least 19 recordsLinked to original sources
PubMed2006

Assessing the importance of genotype x environment interaction for root traits in rice using a mapping population II: conventional QTL analysis.

Modifying plant root systems is considered a means of crop improvement targeted to low-resource environments, particularly low nutrient and drought-prone agriculture. The identification of quantitative trait loci (QTLs) for root traits has stimulated marker-assisted breeding to this end, but different QTLs have been detected in different populations of the same species, and importantly, in the same population when grown in different experimental environments. The presence of QTL x environment interaction is implicated, and this must be characterised if the utility of the target QTLs is to be realised. Previous attempts to do this suffer from a lack of control over replicate environments and inadequate statistical rigour. The Bala x Azucena mapping population was grown in two replicate experiments of four treatment environments, a control, a low light, a low soil nitrogen and a low soil water treatment. After a 4 weeks growth, maximum root length, maximum root thickness, root mass below 50 cm, total plant dry mass, % root mass and shoot length were measured. A summary of the overall results is presented in an accompanying paper. Here, QTL analysis by composite interval mapping is presented. A total of 145 QTLs were detected, mapping to 37 discrete loci on all chromosomes. Superficial evidence of QTL x E (great difference in LOD score) was tested by single-marker analysis which confirmed QTL x E for five loci representing only five individual trait-loci interactions. Some loci appeared to be stable across environments. Some QTLs were clearly more or less active under low light, low nitrogen or drought. A few notable loci on chromosomes 1, 2, 3, 5, 7 and 9 are briefly discussed. Also discussed are some remaining statistical shortcomings that will be addressed in another companion paper.

Adaptation, Physiological↗
PubMed2006

Assessing the importance of genotype x environment interaction for root traits in rice using a mapping population. I: a soil-filled box screen.

Altering root system architecture is considered a method of improving crop water and soil nutrient capture. The analysis of quantitative trait loci (QTLs) for root traits has revealed inconsistency in the same population evaluated in different environments. It must be clarified if this is due to genotype x environment interaction or considerations of statistics if the value of QTLs for marker-assisted breeding is to be estimated. A modified split-plot design was used where a main plot corresponded to a separate experiment. The main plot factor had four treatments (environments), which were completely randomized among eight trials, so that each treatment was replicated twice. The sub-plot factor consisted of 168 recombinant inbreed lines of the Bala x Azucena rice mapping population, randomly allocated to the seven soil-filled boxes. The aim of the trial was to quantify QTL x environment interaction. The treatments were chosen to alter partitioning to roots; consisting of a control treatment (high-soil nitrogen, high light and high-water content) and further treatments where light, soil nitrogen or soil water was reduced singly. After 4 weeks growth, maximum root length (MRL), maximum root thickness, root mass below 50 cm, total plant dry mass (%), root mass and shoot length were measured. The treatments affected plant growth as predicted; low nitrogen and drought increased relative root partitioning, low-light decreased it. The parental varieties Bala and Azucena differed significantly for all traits. Broad-sense heritability of most traits was high (57-86%). Variation due to treatment was the most important influence on the variance, while genotype was next. Genotype x environment interaction was detected for all traits except MRL, although the proportion of variation due to this interaction was generally small. It is concluded that genotype x environment interaction is present but less important than genotypic variation. A companion paper presents QTL x environment analysis of data.

Chromosome Mapping↗
PubMed2006

Randomised controlled trials of immediate weight-bearing mobilisation for rupture of the tendo Achillis.

We performed two independent, randomised, controlled trials in order to assess the potential benefits of immediate weight-bearing mobilisation after rupture of the tendo Achillis. The first trial, on operatively-treated patients showed an improved functional outcome for patients mobilised fully weight-bearing after surgical repair. Two cases of re-rupture in the treatment group suggested that careful patient selection is required as patients need to follow a structured rehabilitation regimen. The second trial, on conservatively-treated patients, provided no evidence of a functional benefit from immediate weight-bearing mobilisation. However, the practical advantages of immediate weight-bearing did not predispose the patients to a higher complication rate. In particular, there was no evidence of tendon lengthening or a higher re-rupture rate. We would advocate immediate weight-bearing mobilisation for the rehabilitation of all patients with rupture of the tendo Achillis.

Achilles Tendon↗
PubMed1999

Relatives' lived experiences of complementary therapies in a critical care department--a phenomenological study.

This phenomenological study examined relatives' lived experiences of complementary therapies in the Department of Critical Care Medicine at Royal Hobart Hospital. Participants in the study, 20 relatives of critically ill patients, were involved in a non-structured, audiotaped interview. Subsequently, transcripts were analysed using a phenomenological transformative process to identify common themes in the text. Study findings suggested four emerging conceptual categories, which with further analysis uncovered the essence of the phenomenon as extending and enriching a caring atmosphere.

Adolescent↗
PubMed1999

Comparison of exercise variables measured during intensity of simulated training to variables at maximal effort in standardbreds.

The heart rate changes during routine training in a group of 8 actively racing Standardbreds were used to simulate the training work on a treadmill (ST) and indices of exercise compared to maximal effort (MAX) on the treadmill. The following parameters were recorded during treadmill work: heart rate, velocity, O2 consumption, respiratory and stride frequency, and stride length. Blood lactate concentrations were measured before and after each work test. Heart rate during simulated training was mean +/- s.d. 87.8 +/- 5.5% heart rate in MAX, one of the 8 horses working < 80% of maximal HR and 2 of the 8 horses working above 90% maximal heart rate. Mean +/- s.d. oxygen consumption during the ST was 75.1% +/- 8.4% MAX, but correlated poorly against percentage heart rate for individual horses (r2 = 0.02). At similar velocities for the ST and MAX, only respiratory frequency differed significantly (P > 0.05), being higher during the ST. Most horses worked at intensities based on heart rate consistent with proposed guidelines of 80-90% of maximal heart rate. However, in 3 of the 8 horses work intensity of insufficient or excessive amounts may have occurred.

Animals↗
PubMed1997

Innovative palliative care in Edmonton.

PROBLEM BEING ADDRESSED: Access to palliative care in Edmonton has been hampered by uneven development, poor distribution of services, and more recently, economic restraints. Family physicians' involvement in palliative care has been hindered by the variety of access points, poor coordination, and inadequate reimbursement for time-consuming and difficult patient care situations. OBJECTIVE OF PROGRAM: To provide high-quality palliative care throughout Edmonton in all settings, with patients able to move easily throughout the components of the program; to lower costs by having fewer palliative care patients die in acute care facilities; and to ensure that family physicians receive support to care for most patients at home or in palliative care units. MAIN COMPONENTS OF PROGRAM: The program includes a regional office, home care, and consultant teams. A specialized 14-bed palliative care unit provides acute care. Family physicians are the primary caregivers in the 56 palliative continuing care unit beds. CONCLUSIONS: This program appears to meet most of the need for palliative care in Edmonton. Family physicians, with support from consulting teams, have a central role. Evaluation is ongoing; an important issue is how best to support patients dying at home.

Alberta↗
PubMed1995

History lessons.

Interest in nursing history has grown in North America over the past two decades, in part because of the increase in feminist and nurse historians, but also because of the realization that nursing history can contribute much to the study of health and social issues.

Historiography↗
PubMed1993

Prevalence and types of birth defects in Ontario swine determined by mail survey.

Preweaning mortality in piglets constitutes a major loss to the swine industry. Congenital defects account for a small but significant proportion of these losses. To implement appropriate strategies to reduce such losses, it is necessary to identify the specific causes and their relative importance. Consequently, a mail survey of swine production in Ontario was carried out to determine the prevalence and types of birth defects. Statistical comparisons of the prevalence of overall defects were made between accurate and estimate records, breeds (cross vs. purebred), size of operation (number of sows) and geographic location. The mean litter size of 11 pigs born per sow was not significantly different for those with accurate versus estimate records, but the difference in the prevalence of defective pigs (live and dead) was significant (accurate 3.1% vs. estimate 4.1%). Splayleg (spraddleleg) was the most common defect. The next four defects for both groups were belly rupture, other rupture, ridglings and other, but not in the same ranking. Purebred and small farm operations (< 25 sows) had a significantly higher prevalence of birth defects for estimated data only. Geographic location had no effect. Further work is required to determine whether recording prevalence of birth defects in Ontario swine will provide a useful monitor of environmental stress. The study provides a baseline for the prevalence and type of defects in Ontario swine.

Animal Husbandry↗
PubMed1990

Palliative care in a cancer center: results in 1984 versus 1987.

We reviewed the charts of 48 consecutive patients treated by our Palliative Care Team (PCT) during 1984 and compared these results with 50 consecutive patients treated during 1987. The composition of the PCT did not change between 1984 and 1987. The median equivalent daily dose of parenteral morphine (MEDD) before referral, after initial treatment by the PCT, and at the maximum prescribed by the PCT were 43 mg, 48 mg, and 96 mg in 1984, respectively, versus 60 mg (p less than 0.03), 60 mg (p less than 0.03), and 120 mg (p less than 0.12) in 1987, respectively. Seventeen of 43 patients were receiving mild narcotics in 1984 versus 7 of 48 patients in 1987 (p less than 0.01). Parenteral narcotics were used initially in 2% of patients in 1984 versus 46% of patients in 1987 (p less than 0.001). Poor pain control after the initial treatment was observed in 42% of patients in 1984 versus 26% in 1987 (p less than 0.01). Our results suggest that patients are being treated more aggressively by their physicians before referral to the PCT in 1987, that our PCT is using more aggressive initial treatment than in 1984, and that, notwithstanding these changes, there is still a significant proportion of patients in whom pain cannot be controlled before death. These results suggest that more research is necessary to better define intractable pain syndromes and develop adequate treatments for them.

Alberta↗
PubMed1989

The Edmonton staging system for cancer pain: preliminary report.

Fifty-six consecutive patients with pain due to cancer were admitted to a prospective study designed to test a clinical staging system for cancer pain. The system classifies patients in stage 1 (good prognosis) to stage 3 (poor prognosis) according to the mechanism of pain, characteristics of pain, previous narcotic exposure, cognitive function, psychological distress, tolerance and past history of drug addiction or alcoholism. During day 1 patients were staged after being seen by one of the investigators. Patients were treated for 21 days, when a final diagnosis of pain control was made. Eighteen of 22 patients in stage 1 achieved good pain control (82%) vs. 2/22 patients in stage 3 (10%; P less than 0.01). Sensitivity, specificity and negative predictive value of the system were 0.75, 0.86 and 0.80, respectively. We conclude that this is a simple and reliable system for clinical staging that can be used for clinical research and management of patients with cancer pain.

Female↗
PubMed1988

Patient-controlled subcutaneous hydromorphone versus continuous subcutaneous infusion for the treatment of cancer pain.

Twenty-five patients with pain due to advanced cancer were randomized to receive patient-controlled sc injections (PCIs) of hydromorphone (HM) versus continuous sc infusion (CSCI) of HM by means of a Pharmacia 5200 pump. Each self-injection of HM during PCI was equivalent to 4 hours of CSCI. After 3 days, a crossover occurred, and patients received the alternate treatment for 3 days. During both phases of the study, patients could request extra doses of HM from their nurses. In 22 patients able to be evaluated, pain intensity (visual analogue, 0-100 mm) at 9:00 a.m. and 4:00 p.m. was 31 +/- 23 and 28 +/- 18 mm, respectively, on PCI versus 28 +/- 18 and 27 +/- 17 mm, respectively, on CSCI [P = not significant (NS)]. The total dose of HM was 168 +/- 197 and 181 +/- 234 mg on PCI and CSCI, respectively (P = NS). No significant difference was found in nausea, drowsiness, or number of hours of sleep. The total number of extra doses of HM was 6 +/- 7 on CSCI versus 2 +/- 3 on PCI (P = .007). At the end of the study, patients chose PCI and CSCI in seven and 10 cases, respectively (P = NS; 5 patients expressed no preference). We conclude that both methods were similar in regard to effectiveness and toxic effects in short-term hospital use.

Female↗