High-resolution freshwater dissolved calcium and pH data layers for Canada and the United States.

Freshwater ecosystems are biologically important habitats that provide many ecosystem services. Calcium concentration and pH are two key variables that are linked to multiple chemical processes in these environments, influence the biology of organisms from diverse taxa, and can be important factors affecting the distribution of native and non-native species. However, it can be challenging to obtain high-resolution data for these variables at regional and national scales. To address this data gap, water quality data for lakes and rivers in Canada and the continental USA were compiled and used to generate high-resolution (10 × 10 km) interpolated raster layers, after comparing multiple spatial interpolation approaches. This is the first time that such data have been made available at this scale and resolution, providing a valuable resource for research, including projects evaluating risks from environmental change, pollution, and invasive species. This will aid the development of conservation and management strategies for these vital habitats.

Egg sharing: an NHS consultant's view.

Fertility services in the UK National Health Service are underfunded and subject to considerable regional variation despite the publication of national evidenced-based guidelines commissioned by the Department of Health. Competition for funding within the NHS makes it unlikely that fertility will ever be fully funded. Novel and imaginative solutions are sought, of which some have already been rejected. Egg sharing could provide a means of increasing the availability of complex assisted conception techniques to a greater number of subfertile couples, who would otherwise be excluded. On the other hand, it would be understandable but unfortunate if healthcare providers view the success of egg sharing as an opportunity to shift the already limited funds to other competing specialties. Egg sharing is readily accepted by many UK couples and provides a dignified solution to two separate clinical problems, without reducing the donor's chances of conceiving or involving complex financial negotiations. Many couples are also comforted by the thought that even if their treatment is ultimately unsuccessful others have also been given a chance.