Bt transgenic crops do not have favorable effects on resistant insects

Sayyed et al. (Ecology Letters (2003) 6: 167–169) hypothesized that insecticidal Bacillus thuringiensis (Bt) toxins produced by transgenic crops could have nutritionally favorable effects that increase the fitness of resistant insects eating such crops. This idea was based on increased pupal weight of resistant larvae of diamondback moth, Plutella xylostella (L.), fed leaf discs treated externally with a Bt toxin. We summarize evidence from diamondback moth and other pests showing that the Bt toxins in transgenic crops do not enhance performance of resistant insects. Aside from a few notable exceptions in which performance of resistant insects did not differ between Bt and non-Bt crops, Bt crops had adverse affects on resistant insects. Abbreviation: / Bt: Bacillus thuringiensi

Canada\u27s Oldest Old: A Population Group which is Fast Growing, Poorly Apprehended and at Risk from Lack of Appropriate Services

The future of population aging in industrialised countries, including Canada, will be driven not by lower fertility but by extensions in life expectancy. Declining mortality will have the most effect on the oldest age groups. In this context, Peter Laslett’s (1989) ideas on rethinking traditional approaches to the life cycle are fundamental. He argues that we need to move from three stages of life to four: childhood; adulthood; then the new third age lasting from retirement until old age, which becomes the fourth age (or the oldest-old). This report examines the present and future characteristics of the oldest old, and the public policies needed to ensure their well-being. The Canadians in this oldest age group are a distinct population, which will come to represent an increasingly important component of the population. This new demographic reality needs to be taken into consideration in designing structures that will meet the associated challenges. The arrival, rapid and in large numbers, of Baby Boomers into these advanced ages will generate new dynamics in the society that need to be studied. Given the changes in behaviours and the health status of the oldest people today, it is vitally important to continue to design policies that take into account the characteristics of the aged in the populations of today and of tomorrow. Key is to continue to develop policies which will enable older people to remain independent for as long as possible, and to base policies on the degree of independence rather than simple age thresholds. The promotion of healthy and positive attitudes towards older people will also contribute to good relations among generations

Policy Brief No. 20 - The Oldest Old: A New Reality in Canada\u27s Population

Canadians aged 85 and over (the oldest old) form a distinct group which is destined to grow as a proportion of the country’s population. This is a demographic reality which needs to be taken into account in policy making

Policy Brief No. 21 - An Increasing Age at Retirement May Amplify Socioeconomic Inequalities

Population ageing raises questions about the sustainability of the public pillars of the retirement income system and about inter-generational equity. In response to this, a number of countries have raised the normal retirement age in an attempt to reduce projected future expenditures on their state pension system. In this context, private savings and later retirement represent the best ways of avoiding a major fall in living standards when retiring. Increased life expectancy at age 65 appears to justify this policy trend. But there are substantial differences in life expectancy and healthy life expectancy between people of different socioeconomic status, and these seem to be widening. There is a danger that in the name of inter-generational equity, we will in fact be moving towards increased social inequality among the pensioners of the future