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Using a new concept—the law of the limit to land productivity—this article builds a three (physical, economic, and institutional) worlds’ land-use model with inverse logics of different development stages in a time perspective: before, in, and after the population trap. This model extends the span of the Malthusian population model to history after the Industrial Revolution and makes static proper

Microbial exposure has been indicated as significant in the development of asthma and allergy among children. The aim of the study was to test whether microbial exposure and allergens in the school environment are associated with asthmatic symptoms in pupils. Data on asthmatic symptoms and respiratory infections were collected through a questionnaire survey among 1993 pupils aged 11-15 yr in 10 ra

Galectins are implicated in a large variety of biological functions, many of which depend on their carbohydrate-binding ability. Fifteen members of the family have been identified in vertebrates based on binding to galactose (Gal) that is mediated by one or two, evolutionarily conserved, carbohydrate-recognition domains (CRDs). Variations in glycan structures expressed on glycoconjugates at the ce

To ensure energy to meet needs for economic growth and sustainable development more emphasis should be given to energy efficiency, renewable energy and new technologies for both energy end-use and supply. One key technology is gasification of coal to produce liquid and gaseous fuels, and electricity. The overall conclusion is that there are plausible energy-technology strategies, well within reach

Drawing from ethnographic data from 48 households in four villages in rural Anhui, this study explores how two practices known for upholding son preference are affected by rural–urban out-migration, with a particular focus on the division of labour in agricultural work and patrilocality. The study deploys the concepts of an intergenerational contract and the “unsubstitutability” of sons and finds

The middle Darriwilian delta C-13 excursion (MDICE), one of the least known of the Ordovician delta C-13 excursions, has previously been recorded only from the Middle Ordovician of Baltoscandia. Analysis of many recently collected limestone samples from the Guniutan Formation at two Yangtze Platform localities show elevated delta C-13 values in the same biostratigraphic interval (Microzarkodina oz

Previous studies of mid-Ordovician limestone in Sweden have shown that over a stratigraphic interval representing a few million years there is a two orders-of-magnitude enrichment in fossil L-chondritic meteorites (empty set = 1-21 cm) and sediment-dispersed extraterrestrial chromite (EC) grains (>63 mu m). This has been interpreted as a dramatic increase in the flux of L-chondritic matter to Eart