Le fait que papa et maman soient ou non mariés au moment de la naissance du premier enfant a-t-il un effet sur les risques d'éclatement de la famille ? Pour répondre à cette question, nous examinons de quelle manière l'évolution des modes de formation des familles au Québec et ailleurs au Canada influence la probabilité qu'ont les familles dites « intactes » de connaître une rupture, et noustentons de décortiquer les mécanismes associés aux risques différents observés entre types d'union et entre régions de résidence.Does the fact of whether or not Mummy and Daddy are married when the first child is born have any effect on the risk of the family's splitting up? To answer this question, we examine how the variable developments in the modes of formation of families in Quebec and elsewhere in Canada influence the probability of so-called "intact" families splitting apart, and we aim at a detailed analysis of the mechanisms connected with the different risks observed between the types of union and between regions of residence

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Deux thèses ont été avancées pour expliquer la baisse de popularité du mariage dans bon nombre de pays occidentaux. Becker soutient que le travail rémunéré des femmes aurait diminué l'attrait du mariage, en réduisant les avantages économiques attendus de cette forme d'union. Mais selon Oppenheimer, c'est la détérioration du statut économique des hommes, plus que la montée de l'emploi féminin, qui serait à l'origine du déclin observé. À l'aide des données de l'Enquête sociale générale sur la famille réalisée par Statistique Canada en 1995, cet article cherche à tester ces deux hypothèses, en examinant l'influence de la précarité en emploi des hommes et des femmes sur leur propension à former une première union ainsi que sur le type d'union choisi. L'hypothèse de Becker se vérifie pour les générations les plus anciennes, et celle d'Oppenheimer permet de mieux comprendre les comportements matrimoniaux des générations plus récentes. Dans les premières, la précarité économique serait associée à une propension plus grande des femmes à se marier ; dans les secondes, elle serait liée à un risque moindre de mariage chez les hommes et à un risque accru de connaître une union libre chez les femmes.Two hypotheses have been put forward to explain the decline in the popularity of marriage in many western countries. Becker maintains that women's access to paid work has made marriage less attractive by reducing the anticipated economic benefits of this type of union. But for Oppenheimer, the decline in the popularity of marriage is due more to the deterioration in men's economic status than to the rise in women's employment. Using data from Statistics Canada's 1995 General Social Survey on the family, this article attempts to test these two hypotheses by looking at the influence of job insecurity on men's and women's likelihood of forming a first union and on the type of union opted for. Becker's hypothesis seems to be borne out for older birth cohorts, whereas Oppenheimer's thesis more effectively explains the matrimonial behaviours observed in younger birth cohorts. In the first case, job insecurity seems to be linked to a greater propensity for women to marry; in the second case, it is associated with a lesser likelihood for men to marry and a greater likelihood for women to cohabit

The anatomy and histology of the female and male internal reproductive organs of the sunflower beetle, Zygogramma exclamationis (F.), are described. The female system consists of a vagina, bursa copulatrix, common oviduct, lateral oviducts, spermatheca, spermathecal accessory gland, and ovaries. Twelve ovaries examined contained from 23 to 32 telotrophic ovarioles, the average being 27.3. The male system consists of a pair of bilobed testes, a pair of accessory glands, vasa deferentia, and an ejaculatory duct which is bifurcated at its anterior end. Three testes examined contained 34, 36, and 37 sperm tubes, respectively. The basic features of the reproductive systems of Z. exclamationis are similar to those of other Chrysomelidae.

About 50% of 1,057 green ash (Fraxinus pennsylvanica) systematically sampled in the Great Plains and Rocky Mountain regions had substantial dieback (>10% of crown branches with dieback), and the average growth ring width during the last 20 years was 2.9 mm. The overall condition of the population was rated fair. Ash yellows phytoplasmas were identified at 102 of 106 sites throughout six U.S. states (North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas) and three Canadian provinces (Alberta, Saskatchewan, Manitoba). These phytoplasmas had not previously been known in Alberta, Saskatchewan, Manitoba, Wyoming, Colorado, or Kansas. Incidence of phytoplasmal detection ranged from 16% in Wyoming to 71% in South Dakota. Incidence varied in the range 41 to 67% across site types and crown dieback classes. Incidence was highest in rural plantings, in trees with the most crown dieback, and in larger diameter trees. No significant relationships were detected between presence of ash yellows phytoplasmas and radial growth rates of trees.