Influence of phosphorus on copper sensitivity of fluvial periphyton: the role of chemical, physiological and community-related factors

The influence of eutrophication of fluvial ecosystems (caused by increased phosphorus concentrations) on periphyton Cu sensitivity is explored from a multi-scale perspective, going from the field to the laboratory. The study design included three tiers: a field study including the characterization of land use and the ecological state of the corresponding river sections in the Fluvià River watershed, an experimental investigation performed with natural periphyton from the previously studied stream sites in indoor channels, and finally a culture study in the laboratory. Results showed that differences in copper sensitivity of natural periphyton communities followed the gradient of nutrient concentration found in the field. Results from the culture experiments demonstrated that both, P-conditions during growth and P-content in the media are important factors modulating the toxicological response of algae to Cu. The observations from this study indicate that the ecological effects of metal pollution in rivers might be obscured by eutrophication

Evaluation of the position of lower incisors in the mandibular symphysis of individuals with Class II malocclusion and Pattern II profiles

OBJECTIVES: This study evaluated the position of mandibular incisors in the mandibular symphysis of individuals with Class II malocclusion and Pattern II profiles. METHODS: The sample consisted of 40 Caucasian patients (20 male and 20 female) with Class II malocclusion and Pattern II profile from 10 to 18 years of age (mean age of 12.84 years) who were selected from the records of the School of Dentistry of Universidade de Passo Fundo, Brazil. The linear cephalometric measurements used in this study were Ricketts' 1- AP, Interlandi's line I and Vigorito's 1-VT; and the angular measurement studied was the mandibular plane angle (IMPA). RESULTS: Mandibular incisors of individuals with Class II malocclusion and Pattern II profile tended to be buccally inclined and protruded