A whole-ecosystem experiment reveals flow-induced shifts in a stream community.

The growing threat of abrupt and irreversible changes to the functioning of freshwater ecosystems compels robust measures of tipping point thresholds. To determine benthic cyanobacteria regime shifts in a potable water supply system in the tropical Andes, we conducted a whole ecosystem-scale experiment in which we systematically diverted 20 to 90% of streamflow and measured ecological responses. Benthic cyanobacteria greatly increased with a 60% flow reduction and this tipping point was related to water temperature and nitrate concentration increases, both known to boost algal productivity.

[Unmet health care needs in Brazil: an investigation about the reasons for not seeking health care].

Herein, unmet health care needs, defined by the authors as the situation when an individual feels the need but does not seek healthcare, are studied from the data of the health questionnaires of the 1998, 2003 and 2008 rounds of the National Household Sampling Survey (Pnad). From 1998 to 2008, the percentage of the population with healthcare needs during the two weeks prior to the interview did not change, remaining at around 17%, whilst the share with unmet healthcare needs fell from 3.5% to 2.