Canadian Eskimo permanent tooth emergence timing

To identify the times of emergence of the permanent teeth of Canadian Eskimos (Inuit), 368 children and adolescents were examined. The presence or absence of all permanent teeth except the third molars was recorded and these data subjected to probit analysis. Female emergence times were advanced over males. Generally, the Inuit of both sexes showed statistically significant earlier emergence times than Montreal children, except for the incisors. The present results do not support hypotheses indicating that premature extraction of the deciduous teeth advances the emergence of their succedaneous counterparts. There is some indication the controls of deciduous tooth emergence continue to play some part in emergence of the permanent dentition, especially the first permanent teeth that emerge.     

Canadian experience in cytology proficiency testing

The mandatory Laboratory Proficiency Testing Program (LPTP) of the province of Ontario as applied to cytology laboratories is briefly described. LPTP evaluates reporting of test slides to identify laboratories that have deficiencies. Such laboratories receive an on-site visit, followed by recommendations on means of improvement (especially educational) and subsequent monitoring. Most of the 18 cytology laboratories visited to date have shown an improved level of performance on later tests.     

Changes in the timing of births in Melbourne, Australia

2 10-year marriage cohorts from 2 surveys of married women in Melbourne were compared on their timing of the 1st and 2nd births. The results showed that women who were married in the early 1970s were much more likely to delay their first birth until about the 3rd or 4th year of marriage compared with women who married in the 1960s. This tendency to delay the 1st birth was probably aided by effective contraception, as it coincided with widespread use of the oral contraceptive. There was no difference in the timing of the 2nd birth in relation th the 1st birth between the 2 marriage cohorts. Women who delayed childbearing also preferred smaller families. Indeed, the increase in the % of women delaying childbearing appears to be synonymous with the trend toward the two-child family. Altough the number of married women in the labor force increased significantly from the early to the later cohort, a desire to work was not usually cited as the reason for delaying childbearing. Rather, economic reasons were most frequently mentioned for delaying childbearing.     

Wetland mitigation and compensation: Canadian experience

Since Canada’s accession to the Ramsar Convention on Wetlands in 1981, the nation’s commitment to wetland conservation and management has increased significantly. This includes the adoption of one of the World’s first national wetland conservation policies by the Government of Canada, and the adoption of complementary policy and legislative initiatives by most of the 13 provincial and territorial jurisdictions. Numerous habitat ‘no net loss’ and environmental assessment policies, regulations and guidelines for incorporating mitigation processes into development decisions affecting wetland resources are used throughout Canada. The governments of Canada and six provinces have so far adopted wetland mitigation measures. These are in addition to comprehensive wetland fish and wildlife habitat initiatives, such as the species and habitat joint ventures delivered in Canada through the North American Waterfowl Management Plan by all jurisdictions and numerous non-government partners. This paper examines the current policies, regulations and programs, as well as past implementation experience with wetland mitigation and compensation in Canada.     

Canadian experience with structured clinical examinations.

The use of structured clinical examinations to improve the evaluation of medical students and graduates has become significantly more common in the past 25 years. Many Canadian medical educators have contributed to the development of this technique. The Canadian experience is reviewed from the introduction of simulated-standardized patients and objective-structured clinical examinations to more recent developments and the use of such examinations for licensure and certification.     

The paramedic ambulance: a Canadian experience.

Prehospital critical care provided by specially trained ambulance attendants in New Westminster, BC during a 27-month period was studied. Although the most important benefit of the improved care was the prevention of sudden death in a large proportion of persons with crises due to coronary artery disease, the skills learned to provide basic life support are applicable to a wide variety of other disorders that can result in death before the patient reaches hospital.     

Ruptured uterus in pregnancy: a Canadian hospital's experience.

Between 1966 and 1985, 15 cases of complete rupture of the uterus in pregnancy were identified among 52,854 deliveries at Foothills Provincial General Hospital, Calgary, for an incidence rate of 0.3 per 1000 deliveries. Previous cesarean section (in seven patients) was not the only predisposing factor: a history of dilatation and curettage (in two patients) or laparoscopy (in one) were also implicated. Long, obstructed labour did not appear to be a factor. Rupture also occurred in patients at low risk. The most frequent immediate complication was hypotension, in five patients. The rupture site was repaired in 11 of the patients; the other 4 underwent hysterectomy. Close surveillance and prompt intervention are the keys to good fetal and maternal outcome.     

Recent trends in neonatal mortality: the Canadian experience.

In Canada between 1958 and 1977 the neonatal mortality dropped by more than 50%. the decline was most prominent from 1963 and was almost entirely due to an improvement in neonatal birthweight-specific mortality, which suggests an improvement in perinatal medical care. The timing and pattern of the decline are similar to those reported for the United States. There was a transient increase in the incidence of low and very low birthweight in both countries in the late 1960s. The cause of this increase remains unexplained.     

Education and timing of parenthood among Canadian women: a cohort analysis.

This research examines factors associated with the timing of first birth in Canada, focusing primarily on the role of women's educational attainment. Proportional hazards modelling techniques are applied to data from the 1984 Canadian Fertility Survey (CFS) in order to determine how educational attainment, estimated as close as possible to the date of first birth, influences the timing of first birth and whether the importance of this variable varies according to age cohorts. The results suggest that among a number of variables useful for distinguishing different levels of risk, educational attainment proves to be the most important predictor in the model. Education exerts a substantial positive influence on birth timing for women of all age groups. As expected, moreover, significant cohort differences are also evident, with the greatest to the smallest impact on the risk from the youngest to the oldest cohorts. These clear-cut cohort differences indicate a fundamental change in the effects of education over time, a trend most likely resulting from substantial changes in both the content and social significance of formal schooling during the past few decades.     

Changes in the understory of Canadian southern boreal forest after fire

Abstract. We investigated changes in the composition and abundance of understory species after fire in the southern boreal forest around Lake Duparquet, Québec. Ten plots of 100 m² were sampled in each of eight sites varying in post-fire age from 26 to 230 yr, with 20 1-m² quadrats in each of these 80 plots. Variation in the understory was described by DCA ordination and interpreted as a regeneration succession series. Thickness of the organic layers, stand age and canopy composition were all correlated with vegetational change. This change was not constant throughout succession; some old sites showed an increase in the diversity and abundance of certain pioneer species. This was partly related to openings in the canopy resulting from a major outbreak of spruce budworm, which affected sites dominated by Abies balsamea. The ordinations were performed on both the 100-m² plots and the 1-m² quadrats. Heterogeneity within sites was larger at the 1-m² scale and there was a great deal of overlap in the position of the quadrats in ordination space. At the smaller scale of analysis, stand age and thickness of the organic layers were not correlated with the changes observed in the understory.     

Changes in the forest floor of Canadian southern boreal forest after disturbance

Abstract. The concentrations and contents of organic matter and nutrients in organic deposits on the forest floor were estimated along a 231-yr chronosequence following fire at the southern limit of the boreal forest in eastern Canada. The sampling design was stratified to take into account the variability related to the presence of the principal tree species as well as to the presence of large gaps created by a recent spruce budworm (Choristoneura fumiferana) outbreak. The forest floor showed a steady accumulation of organic matter and total nutrients with time-since-fire and a 50 % decrease in the concentrations of available P and K, but not N (as determined by aerobic incubation). The increase in forest-floor weight was accompanied by an increased storage of available N, Ca and Mg. The availability of N and Ca was more strongly affected by tree species and gaps than by time-since-fire. A high N-availability was observed under Betula papyrifera and in gaps, while high a Ca-availability was found near Populus tremuloides and Thuja occidentalis. In old sites, the forest floor of gaps, created by a recent spruce budworm outbreak, had a necromass similar to that of a young forest, but the low concentrations of available P and K of an old forest.     

Changes in timing, duration, and symmetry of molt of Hawaiian forest birds

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650-1900 m elevation on the Island of Hawaii between 1989-1999 and 2000-2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989-1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000-2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds.     

Therapeutic abortion and its psychological implications: the Canadian experience.

Approximately 9 months after a legal therapeutic abortion, 188 Canadian women were interviewed. One half were single and the rest were married, separated or divorced. They were matched closely for a number of demographic variables with control women who had not had abortions. Neurotic disturbance in several areas of personality functioning was assessed from questionnaire responses. Out of 27 psychological scales, differences between the abortion and control groups were found on only 3: in general, women who had had abortions were more rebellious than control women, abortion tended to be associated with somewhat greater depression in married women, and single women who had had abortions scored higher on the shallow-affect scale. However, all the personality scores were well within the normal range. Perceived social support was strongly associated with favourable psychological reactions after abortion. Use of contraceptives improved greatly after the abortion, when over 90% of women reported using contraceptives regularly.