Effects of fish removal in the Furnas Lake, Azores

The Furnas Lake is a small volcanic, monomitic and increasingly eutrophised water body. Next to agricultural nutrient inputs, high densities of herbivorous fish are thought to contribute to high levels of turbidity in the lake, through zooplankton consumption and re suspension of the nutrients accumulated in the sediment. According to the alternative state hypothesis a shift from turbid to clear water conditions is favoured by reduction of nutrient concentrations, increased light availability and reduction of planktivorous and benthos-feeding fish stock. To improve water quality in the Furnas Lake, a substantial part of the bottom-feeding fish population (62% of the estimated common carp population, Cyprinus carpio, and 5% of the estimated roach population, Rutilus rutilus) was removed. Effects of fish removal on turbidity and associated trophic state were analysed next to post-manipulation chlorophyll a concentration, zooplankton and macrophytes densities. Results suggest that fish removal was not enough to change lake conditions towards a lasting clear state dominated by macrophytes. Excessive nutrient load, in water and sediments, nutrient input from the lake basin and fish recruitment causing enhanced zooplankton grazing are appointed causes. Any further biomanipulation efforts should be associated to nutrient reduction; and continued monitoring of water quality, fish stock, macrophytes and zooplankton is needed

Sistemas de rotação de culturas com trigo para a região sul do Brasil.

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Evaluation on body weight and its relation with abdominal circumference in the diagnosis of obesity in school students in Cacoal municipality, RO, Brazil

Obesity in school-aged children has reached epidemic levels, which is considered a chronic disease. Researchers have been on alert, given the rising prevalence of obesity in the last few decades. The objective of this study is to evaluate the relation between body weight and abdominal circumference as a predictor for nutritional status in school students from 7 to 12 years of age in the municipality of Cacoal, RO, Brazil. The current study is of a descriptive nature, with cross-sectional and quantitative analysis. The study sample had 482 school students, of both genders, 230 male ones and 252 female ones, divided into school students from the urban and teaching rural teaching areas. Body Mass Index (BMI), abdominal circumference, and body weight were the variants analyzed. Reading with general comprehension strategies. It was possible to notice that 13% of the school students from the rural area were obese. On the other hand, 25% of the school students from the urban area, including both genders, were obese. There was a significant relation in body weight variant versus abdominal circumference in both genders, in the two areas studied. The body weight variant showed a significant relation with abdominal circumference and with body weight index in both genders

The use of BMI and Abdominal Circumference in the Diagnosis of Obesity in Schools: a Systematic Review

To verify body composition or body weight distribution in a more traditional way, isolated body weight or height adjusted weight has been used. In the last 5 years, evaluations have been used to verify the distribution of this fat, where these measures are more preventive to health.The objective of the study was to analyze the studies that indicate the use of BMI and waist circumference as a tool to diagnose obesity. The current study is a systematic review, where it followed the criteria of a systematized review and meta-analysis proposed by the PRISMA protocol. The criteria adopted for the selection of articles were the use of the following variables for obesity: BMI, Circumference of abdomen, relation of C.A with stature and C.A and body weight. After consulting the databases selected to search for articles, 1,846 articles were identified on the topic of interest with the descriptors (obesity in schoolchildren). 410 articles were found on the Scielo platform, 150 articles were found on the Bireme platform. In the Pubmed platform 1,236 articles and finally in the Scopus platform a total of 50 articles. After the exclusion, 16 articles were used for the analysis. The majority of the studies in the area of collective health are concluded, but only the BMI isolated for the diagnosis are indicated as evaluation measures. More recent studies indicate an evolution in the way of evaluating. As can be seen in the sixteen articles analyzed

A studying of solar-ENSO correlation with southern Brazil tree-ring index (1955?1994)

International audienceSolar activity, volcanic aerosol, El Niño-Southern Oscillation and global temperature anomalies effects on Southern Brazil tree growth rings are presented through multiple linear analysis. Linear correlations were made on annual, 10 year running averages and band pass filter. For annual averages, the correlation coefficients were low, and the 10 years running average correlations the coefficient correlations were much higher. The multiple regression of 2 to 5 year band pass filter indicates that 60% of the variance in tree ring index was explained by volcanic eruptions, Southern Oscillation Index and temperature anomalies. The multiple regression of 10 year running averages indicates that 84% of the variance in tree ring index was explained by solar activity and another time series. These results indicate that the effects of solar activity, volcanic eruptions, ENSO and temperature anomalies on tree rings are better seen on long timescales than volcanic eruption, ENSO and temperature anomaly

Tree-ring width wavelet and spectral analysis of solar variability and climatic effects on a Chilean cypress during the last two and a half millennia

International audienceSpectral and wavelet analysis were performed on a tree ring width time series obtained from a 2500 yr old cypress tree (Fitzroya cupressoides) from Costa del Osorno, Chile. The periods for analysis were selected at 95% confidence level. Both periodicities characteristic of solar activity and climatic variations were found in this tree ring width series. The 11 and 22 years solar cycle periods were present in tree ring data with a confidence level above 98%. This indicates the solar modulation of climatic variations is being recorded by the tree ring grown. However wavelet analysis shows that these are present only sparsely. Short-term variations, between 2-5 years, are also present in tree ring data, and are shown by wavelet maps to be a more permanent characteristic. This time scale is a signature of ENSO events. Long-term variations, above 200 years, are also present in tree ring data. The spectral analysis performed in this work shows that this species has the ability to record solar-ENSO variations that seems to be affecting the local environment of tree growth, and also that this region was influenced by ENSO events at least in the past 2500 yr interval covered by this study