Urban growth causes environmental problems such as water contamination which, in turn, affects aquatic organisms and human populations. This work presents a study of an urban stream in Lages, SC, Brazil, hit by continued sewage discharge along part of its course. Through analysis of physicochemical and biological parameters, the water was classified according to the CONAMA Resolution 357/05 and the BMWP’ index. Samples were collected 5 times over one year at 5 sites: 2 sites upstream the area of sewage discharge, 2 sites in the area, and 1 site downstream the area. Dissolved oxygen, temperature, pH, phosphate, colour, and turbidity were the analysed physicochemical parameters. Benthic mocroinvertebrates were utilized for the biologic analyses. The sites upstream the area of sewage discharge presented the highest BMWP’ and diversity indices, highest dissolved oxigen rates, and the lowest concentration of total phosphorus. Water at these sites was ranked class 1. The other sites, in and downstream the area of sewage discharge, presented the lowest dissolved oxygen rates, high total phosphorus and turbidity values, and the lowest diversity and uniformity values. Water at these sites was ranked class 4 (polluted). Data analysis is in agreement with the degree of pollution observed along the stream, which undergoes anthropogenic impacts from source to canalization.

Background: Impaired Baroreflex sensitivity (BRS) may indicate cardiovascular autonomic neuropathy (CAN), which often remains undiagnosed during the initial course of diabetes mellitus. The baroreflex mechanism can be considered negative feedback because of baroreflex delay, the time delay between a change in blood pressure, and the counteracting heart rate response. This work sought to analyze BRS through the sequence method, but establishing delays in checking the RR interval, from 1 to 10 RR intervals lag after systolic blood pressure change. We hypothesized that diabetic patients with subclinical CAN would have a detectable delay in autonomic nervous system activity and that it would differ from other patients. Results: The study included 30 subjects with diabetes mellitus. Eleven patients had established CAN (mean ± SD age 37 ± 8 years), 9 patients had subclinical CAN (age 35 ± 10 years), and 10 patients did not have CAN (age 35 ± 6 years). Indexes related to the delay in response of the BRS were proposed and obtained. The three variables that showed potential to separate patients with and without CAN were highest BRS index, BRS with the largest number of sequences, and lag of the largest number of sequences. Several variables were observed to distinguish between individuals with subclinical and established CAN, including the number of sequences of the highest BRS, lag of the highest BRS, and the highest number of sequences. Conclusions: Thus, analysis of BRS and the reaction delay in the heart rate variability signal may contribute to the detection of CAN in its asymptomatic stage.