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Background: The Netherlands are lacking reliable empirical data in relation to the development of birth and population prevalence of Down syndrome. For the UK and Ireland there are more historical empirical data available. A theory-based model is developed for predicting Down syndrome prevalence in the Netherlands from the 1950s onwards. It is likewise applied to Ireland and the UK for the purpose of validation. Furthermore, a prediction to 2050 is constructed. Materials and Methods: Maternal age births data in the general population, maternal age related risk of Down syndrome, data on selective terminations of Down syndrome pregnancies and mortality rates (from 35 studies from the 1930s until today) were obtained to create this model. Results: For the Netherlands, nowadays birth prevalence is estimated at 14 per 10 000 with around 275 total annual births. The impact of selective abortion is lower than in the UK. Present Dutch Down syndrome population prevalence is estimated, according to this theory-based model, at 7.7 per 10 000 and the grand total at 12 600 individuals. The prevalence of "older" persons with Down syndrome (over 40 years of age) in the Netherlands will reach a peak in 2010, a doubling compared to 1990, implying an increased demand on medical care and counselling. Validity of this theory-based model was examined by comparison with relevant available empirical data from the three countries. The model shows a good fit with historical empirical research, notably four UK and two Irish population prevalence studies and eight birth prevalence studies. Conclusions: A theory-based model for Down syndrome prevalence provides supplementary data in situations with a lack of empirical material and can be used for understanding and predicting long-term developments.

Attitudes towards social groups that have traditionally been marginalised or discriminated against have changed markedly in Britain over the past three decades. This change is particularly marked in attitudes towards homosexuality and racial diversity which, as public opinion surveys have regularly shown, have become more accepting over time. This change is often attributed to older, less tolerant generations being replaced by young cohorts who are more inclusive and open minded in their attitudes to cultural others. The paper explores this argument by examining trends in people's attitudes towards a variety of minorities, including the said groups, but also immigrants and foreign workers. It starts with a discussion of several perspectives predicting different trends with regards to these attitudes. A distinction is made between optimistic ones (i.e. those anticipating rising levels of tolerance) and pessimistic ones (i.e. those expecting stable or declining levels of tolerance). Subsequently, the paper presents trend analyses and an analysis of age, cohort and period effects to broadly assess the explanatory power of these perspectives. Using these approaches, we find that tolerance towards racial minorities and homosexuality has indeed risen across the board, and that young people are also more accepting of these groups than their parents or grandparents and previous generations of young people. These trends broadly support the optimistic perspectives. However, we also find that prejudice has not disappeared from youth attitudes altogether; for a sizeable minority of youth, it has merely shifted its focus to immigration. Not only have unwelcoming attitudes towards immigrants generally become stronger, young people are not always the most tolerant age group regarding this social group. These findings are thus more in line with the expectations of the pessimistic perspectives. [ABSTRACT FROM AUTHOR]

The article discusses the role of brownfields as sites for mixed use development projects in the U.S. and Great Britain. It describes the barriers to and benefits of brownfield development and discusses the ways in which the U.S. and Great Britain have responded to the need for brownfield development. It analyzes the degree of success experienced by each country in creating mixed use spaces from brownfield sites.

Commercial fishing vessels can be a cost-effective alternative to research vessels for performing towed gear fishery-independent surveys, if catch rates are comparable among commercial vessels and with research vessels. A parallel fishing experiment was conducted off the coast of Wales, United Kingdom, to compare the king scallop (Pecten maximus) catch rates of three commercial vessels using commercial dredges and a research vessel using two types of scientifically modified dredges. The scientific dredges are currently used in the fishery-independent survey of local scallop populations. Size-structured scallop catch-per-unit-effort (CPUE) was compared among vessel-gear combinations. Two similarly sized commercial vessels had generally similar CPUEs, however there were some significant differences with scallop size. A smaller commercial vessel had significantly lower CPUEs for a broad range of scallop sizes. The research vessel dredges had significantly higher CPUE for smaller scallops than the commercial vessels. Vessel size is likely to be driving the differences among commercial vessels and belly ring size is likely to be driving differences among research and commercial dredges. These findings highlight commercial vessel CPUE should not be assumed the same, whilst also showing that vessel size may be the best indicator of catch rate similarity. These results also highlight that changing the fishery-independent vessel and gear to the commercial options trialled here would result in a considerable loss of information about the smaller scallops in the population. These findings will be of interest to fishery scientists or managers using multiple vessels, or considering a change of vessels, for fishery-independent surveys. • Research vessel caught significantly more small scallops than commercial vessels. • Smallest commercial vessel caught significantly less scallops at greater depths. • Two commercial vessels of similar size and engine power had similar catch rates. • Differences in catch rates likely driven by belly ring size and vessel size. • Vessel catch rates should not be assumed to be directly comparable. [ABSTRACT FROM AUTHOR]

Understanding links between habitat characteristics and foraging efficiency helps predict how environmental changes influence populations of top predators. This study examines whether measurements of prey (clupeids) availability varied over stratification gradients, and determined if any of those measurements coincided with aggregations of foraging seabirds (common guillemot Uria aalge and Manx shearwater Puffinus puffinus ) in the Celtic Sea, UK. The probability of encountering foraging seabirds was highest around fronts between mixed and stratified water. Prey were denser and shallower in mixed water, whilst encounters with prey were most frequent in stratified water. Therefore, no single measurement of increased prey availability coincided with the location of fronts. However, when considered in combination, overall prey availability was highest in these areas. These results show that top predators may select foraging habitats by trading-off several measurements of prey availability. By showing that top predators select areas where prey switch between behaviours, these results also identify a mechanism that could explain the wider importance of edge habitats for these taxa. As offshore developments (e.g. marine renewable energy installations) change patterns of stratification, their construction may have consequences on the foraging efficiency of seabirds., (© 2018 The Author(s).)