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Several lakes near Wawa (Ontario, Canada) present a rare opportunity for studying rapid chemical and biological recovery from acidification and metal contamination. Surface water pH levels in some of these lakes have increased from 3 to 7 following local sulphur emission reductions and closure of an iron ore sintering plant. We used paleolimnological techniques to track diatom community responses to historical water quality changes in five lakes. Pre-industrial diatom assemblages recorded in lake sediments were dominated by species typical of circumneutral pH levels and were characterized by minimal species compositional change. Following the onset of sintering in 1939, there was a striking shift towards acid- and metal-tolerant Eunotia-dominated species assemblages, sometimes consisting of high quantities of teratological Eunotia valves. Recent dramatic water quality improvements, following first reductions in and then cessation of emissions, were accompanied by decreases in the relative abundance of benthic acid- and metal-tolerant species in the sediment record. However, diatom recovery trajectories did not entirely progress towards predisturbance communities, as the contemporaneous increase in relative abundance of other species was restricted to a few groups. Moreover, diatom responses were not synchronous among cores, with recovery rates influenced by local bedrock and the hydrological regime of each lake. Plusieurs lacs pres de Wawa (Ontario, Canada) fournissent une occasion unique d etudier la recuperation chimique et biologique rapide apres l acidification et la contamination par les metaux. Les valeurs de pH des eaux superficielles de certains de ces lacs ont augmente de 3 a 7 apres les reductions des emissions locales de soufre et la fermeture d une usine de frittage du minerai de fer. Des techniques paleolimnologiques nous ont servi a suivre les reactions de la communaute de diatomees aux changements historiques de la qualite de l'eau dans cinq lacs. Les peuplements de diatomees dans l ere preindustrielle retrouves dans les sediments lacustres sont domines par des especes typiques des valeurs de pH pres de la neutralite et sont caracterises par des changements minimaux dans leur composition specifique. Apres le debut du frittage en 1939, il y a eu un changement marque vers des peuplements d especes domines par les Eunotia tolerants a l'acide et aux metaux, contenant quelquefois de fortes quantites de valves teratologiques d Eunotia. Les ameliorations spectaculaires recentes de la qualite de l'eau, suite a la reduction puis l'arret des emissions, ont ete accompagnees de reductions dans l'abondance relative des especes benthiques tolerantes a l'acide et aux metaux accumulees dans les sediments. Cependant, les trajectoires de recuperation des diatomees n ont pas entierement progresse vers le retablissement des communautes d avant les perturbations, puisque l'accroissement actuel de l'abondance relative des autres especes a ete restreint a quelques groupes. De plus, les reactions des diatomees ne sont pas synchrones dans toutes les carottes de sediments, car les taux de recuperation sont influences par la roche-mere locale et le regime hydrologique de chacun des lacs. [Traduit par la Redaction], Introduction Lake acidification remains a principal environmental concern in North America and other regions, particularly in areas with nonreactive bedrock and shallow soils that provide minimal buffering capacity for lakes. [...]

This study describes the person-centered experience and impact of symptoms and the treatment needs of dementia-related psychosis (DRP) from a patient and care partner perspective. Qualitative interviews and a quantitative survey were used to collect patient experience data from persons with DRP or their care partners. Sixteen participants (1 person with DRP, 15 care partners) completed the qualitative interview; 212 participants (26 persons with DRP, 186 care partners) completed the quantitative survey. The most commonly reported symptoms were visual hallucinations, auditory hallucinations, persecutory delusions, and distortion of senses. The most common impacts were difficulty differentiating what is real from what is not real, increased anxiety, and effects on personal relationships. Current treatments were less than moderately helpful, and the ability to distinguish what is real from what is not real and overall symptom improvement were described as the most important benefits of an ideal treatment. Patient experience data provide insights into urgent therapeutic needs of patients by describing the nature, frequency, and severity of symptoms and the impacts they have on individuals' lives. Patient experience data demonstrate an unmet need for treatments to reduce the symptoms and impacts of DRP. [ABSTRACT FROM AUTHOR]

Author(s): Donald T. Monteith (corresponding author) [1, 11]; John L. Stoddard [2, 11]; Christopher D. Evans [3]; Heleen A. de Wit [4]; Martin Forsius [5]; Tore Høgåsen [4]; Anders Wilander [...]