Characteristics of the interaction between Hsc70 and the transferrin receptor in exosomes released during reticulocyte maturation.

The transferrin receptor (TfR) of reticulocytes is released in vesicular form (exosomes) during their maturation to erythrocytes. The heat shock cognate 70-kDa protein (Hsc70) has been demonstrated to interact with the cytosolic domain of the TfR and could thus trigger the receptor toward this secretion pathway. We investigated the characteristics of the interaction between Hsc70 and the TfR in exosomes with an in vitro binding assay using TfR immobilized on Sepharose beads and purified Hsc70. The results show that Hsc70 binds to exosomal TfR with characteristics expected of a chaperone/peptide interaction. We demonstrated that heat-denatured luciferase competed for in vitro binding, dependent on the nucleotide bound to Hsc70, and that this interaction activates the ATPase activity of Hsc70. Moreover, we used immunosuppressive agents that interact with Hsc70, thus decreasing Hsc70 binding to TfR in our in vitro binding assay and enabling us to assess the role of this interaction in vivo during reticulocyte maturation.

Infant mortality and low birthweight, 1975 to 1995.

OBJECTIVES: This article examines trends in infant mortality and the incidence of low birthweight from 1975 to 1995. DATA SOURCES: The data are from the Canadian Vital Statistics Data Base, compiled from information provided to Statistics Canada by the Vital Statistics Registries in each province and territory. ANALYTICAL TECHNIQUES: Death rates, stillbirth rates, and the incidence of low birthweight were calculated for Canada, the provinces, and territories from 1975 to 1995. To examine the impact of changes in maternal characteristics during the period, the incidence of low birthweight was standardized by age and marital status of mothers, using the 1985 distributions. MAIN RESULTS: The pace of decline in infant and perinatal mortality has slowed in recent years. This slowdown may, at least in part, be attributed to the increase in the incidence of low birthweight. In turn, some of the increase in the incidence of low birthweight is explained by the rising proportions of births to women aged 35 and older and to unmarried women.

Fertility among recent immigrant women to Canada, 1991: an examination of the disruption hypothesis.

PIP: In light of recent findings from the 1991 Canadian census that indicate a change in the historical pattern of lower fertility among immigrant women compared with Canadian-born women, this study examines the disruption hypothesis that the fertility of foreign-born women is depressed during the period immediately following immigration and then shows a temporary increase that declines with longevity of residence in Canada. The "own children" method of analysis was applied to microdata from the long form of the 1991 census to estimate fertility differentials in terms of ratio of children and infants to women of childbearing age. Three categories of place of birth were used: Canada, Europe, and non-Europe. This report considers the advantages and disadvantages of the "own children" methodology (using a ratio of children aged 0-4 years to women of childbearing age) and then reviews the literature on the disruption hypothesis. Possible causes for the increase in immigrant fertility are sought in explanations that point to the increasing proportions of women immigrating from non-European countries, the pronounced decline in fertility among Canadian-born women compared with foreign-born women, and educational differences between recent and long-term immigrants. This analysis of own-infant data (calculating the ratio of infants age 0) validated a disruption of fertility of (1-year) among foreign-born women as a whole but that the disruption was short-lived. The disruption was more evident for non-European-born than for European-born women. The main reason for the observation of higher fertility among recent immigrants than that historically seen was the methodology used. Disruption in fertility may or may not be observed depending upon the definition of years since immigration and whether the "own-children" or the "own-infant" method of analysis is used.^ieng

[Life expectancy and health expectancy by sex, marital status, and socioeconomic status in Canada]. / Esperance de vie et esperance de vie en sante selon le sexe, l'etat matrimonial et le statut socio-economique au Canada.

PIP: "This article presents total life expectancy and health expectancy at age 30 [in Canada] by sex, marital status, and two variables used to define socioeconomic status: level of education and household income. The article shows that: (1) there is a relatively important difference in life expectancy according to marital status, level of education and income; (2) this difference is always greater for men than women; (3) adjusting for health further accentuates this difference, and more so for women than men; and (4) the differences between men and women in mortality and health generally decrease as socioeconomic status increases." (EXCERPT)^ieng

Projecting interregional migration balances within a multiregional cohort-component framework.

"The main themes of the paper are developed in three parts. First, the setting for the study is established by reviewing the foundational theory of multiregional population projections, and by detailing how interregional migration is projected within this approach. Second, we will identify the requirements for making multiregional population projections in Canada and undertake to explain why the conventional approach to projecting interregional migration produces less than satisfactory results. Third, an alternative method for projecting interregional migration is proposed."

Twenty years of marriages.

In 1994, a total of 159,959 marriages were performed in Canada, up only slightly from 159,316 the year before. This small increase had no effect on the crude marriage rate, which remained at 5.5 marriages per 1,000 population. Aside from a brief uptum in the late 1980s, Canada's marriage rate has fallen quite steadily since the early 1970s. The overall decline is also evident when rates are disaggregated by the prior marital status of the bride and groom (single, divorced or widowed). Since 1974, the average ages of brides and grooms have risen about five years to 30.1 and 32.6, respectively. Nonetheless, the peak ages for marriage are the twenties. In this age range, women's marriage rates exceed those of men, but at older ages, men's rates are higher. And at progressively older ages, a growing proportion of grooms have brides at least 10 years their junior. The marriage patterns of Quebec residents differ from those of other Canadians. Quebec residents are much more likely to remain single or live common-law, and if they do marry, they are slightly more likely to divorce. Once divorced or widowed, people in Quebec are less likely than those in the rest of Canada to remarry. This article is based on data compiled by Statistics Canada from marriage registration forms provided by the central Vital Statistics Registry in each province and territory.

Changing fertility patterns, 1974 to 1994.

From 1974 to 1994, the number of children Canadian women are likely to have during their lifetime decreased. This downturn in fertility meant that the annual number of live births rose only slightly during this period, even though it marked the prime childbearing years for the baby-boom generation. As they pursued higher education and employment in the paid workforce, women have postponed childbearing. Consequently, the average age of women giving birth has risen. More than a quarter of women over age 30 who have a baby are first-time mothers. And by starting families later in life, women tend to have fewer children. In addition, largely because of the growing number of common-law relationships, over a quarter of all births are to unmarried women. Using data provided by the provincial and territorial Vital Statistics Registries, this article examines national and provincial/territorial trends in births and fertility from 1974 to 1994.

[Population projections of registered Indians in Canada, 1991-2015]. / Projections de la population des Indiens inscrits du Canada, 1991-2015.

PIP: The indigenous population of Canada comprises the Inuits (once called Eskimos) who live in the far north, the Metis (descendants of Indians and French-Canadians) who tend to live in the prairie provinces, and the Indians. The Ministry of Indian Affairs and North Canada conducted population projections of Indians registered with the Indian Registry of the Department of Indian Affairs and Northern Development using 1975-90 data. The statisticians adjusted for underenumeration and late registration of events. They considered migration, fertility, mortality, and proportion of Indians living on reservations. The size of the registered Indian population has increased greatly, especially since 1985. It has increased 54% compared with 11% for the general Canadian population. Reregistration of about 74,000 Indians accounted for 41% of the increase. The projections indicate that the annual growth rate will fall rapidly between 1990 and 2005. Nevertheless, during this period, the annual growth rate will be much higher than that of the general Canadian population (3.34% vs. 1.1%). The age structure of the registered Indian population will continue to be young, but the proportion of children will decrease from 40% in 1990 to 31% in 2015. The median age of registered Indians will continue to be lower than that of the general population: 1995, 25 vs. 35; 2005, 28 vs. 39; and 2015, 30 vs. 41. Between 1991 and 2015, the 35-64 year old age group will increase. In fact, the proportion of this age group will climb from 56% to 62% between 1990 and 2015. The highest proportion of all registered Indians will continue to live in Ontario (23.2% vs. 1.3-15.2% in 1990; 21.8% vs. 1.2-17.3% in 2015).^ieng

Interprovincial data requirements for local health indicators: the British Columbia experience.

Indicators based on the registration of vital events are used to determine the health status of populations. The need for these indicators at the regional and community levels has grown with the trend toward decentralization in the delivery of health services. Such indicators are important because they affect funding and the types of service that are provided. Health status indicators tend to be associated with variables such as the level of urbanization or socioeconomic status. According to four indicators-mortality ratios for all causes of death, mortality ratios for external causes of death, infant mortality ratios, and low birth weight live birth ratios-some areas of British Columbia, specifically along the border with Alberta, have relatively good health, although the characteristics of these regions suggest that this should not be the case. However, a much different picture emerges when vital event data registered in Alberta for residents of these areas of British Columbia are considered. This article shows that for adequate health planning and program implementation, some communities need data from neighbouring provinces. It illustrates the effect of incorporating Alberta data into the development of health status indicators for British Columbia. It also suggests that similar adjustments may be necessary for data compiled in other provinces.

Effects of fertility and international migration on changing age composition in Canada.

"This paper analyses the prospects for age distribution in Canada through 2036, based on today's age structure and expected trends in fertility and international migration. Simulating these two demographic components at extreme levels shows that tomorrow's aging is already built into the current age distribution, which is heavily marked by the post-war baby boom and the following persistent baby bust, and that neither fertility nor immigration can be seen as effective adjustment mechanisms for the changing age composition of Canada. Population projections using the component method are applied along with an age-specific growth-rate analysis."

[Aging and education of the Quebec population]. / Vieillissement et scolarisation de la population quebecoise.

"Having projected the composition of the population of the province of Quebec for the years 2011 and 2031 with respect to level of education, the author suggests ways in which an increase in the overall level of scholastic attainment could help Quebec meet the challenge of an aging population. According to him, a better educated population would be more productive and less dependent on public finances when it reached retirement. Such a population would cost less in terms of health care and could, if needed, remain in the labor force past retirement age." (SUMMARY IN ENG AND SPA)

[The demographic exploitation of a unique nominative list: the example of the island of Saint-Barthelemy in 1840]. / Exploitation demographique d'une liste nominative unique: l'exemple de l'ile Saint-Barthelemy en 1840.

PIP: An evaluation of the demographic situation on the island of Saint-Barthelemy in 1840 is presented using census data. Saint-Barthelemy is a small Caribbean island, administratively part of Guadeloupe. Two approaches are used, one based on the age and sex structure of the population, the other on household structure. Both attest to the validity of the census in question.^ieng

[Concerning the use by Statistics Canada of the own-children method to measure current fertility]. / De l'utilisation par Statistique Canada de la methode des propres enfants pour mesurer la fecondite actuelle.

PIP: In countries with satisfactory civil registration data, the own children method offers the possibility of regrouping recent fertility data with other pertinent variables such as education, religion, and income. Statistics Canada applied the method to the 1971 Canadian census to exploit the possibilities and published a bulletin with 6 tables, each of which showed currently married women in 5-year cohorts, the ratio of own children/1000 women, and results according to the birthplace of the woman, the duration of marriage, and educational level, for such factors as the religion, ethnic origin, employment status, educational level, and occupation of the spouse. The most evident biases in the method itself result from census imperfections, mortality which removes mothers and children from observation before the census date, the exclusion of children not living with their mothers, and age misstatement. However, the sample used by Statistics Canada was very highly selected and thus not representative of the general population: women not currently in their 1st marriage, those who had not had a live birth, and women of foreign origin for example were excluded. The selectivity for the various excluding factors varies by age, to a degree which is indeterminable given the data limitations. The method would be more useful in Canada if, in addition to using a more inclusive sample, all women over 15 were questioned about fertility in the census, regardless of marital status, and if a distinction were made between legal and de facto marriage.^ieng