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De Almeida Fagundez D.,Federal University of Pampa | Camara D.F.,Federal University of Pampa | Salgueiro W.G.,Federal University of Pampa | Noremberg S.,Federal University of Pampa | And 5 more authors.
Toxicology Research | Year: 2015

Iron (Fe) is an important metal to organism homeostasis and exists abundantly in the environment. Moderate levels of Fe obtained from food are necessary for normal cell physiology; however, abnormally high levels of Fe may have toxic effects by reducing H2O2 to the highly cytotoxic hydroxyl radical (OH) (Fenton catalysis). Fe is a ubiquitous toxicant to the environment and also widely used in food products; however, its effects on the nervous system are not well understood. Herein, we evaluated the toxic effects of Fe using C. elegans and investigated various parameters in order to contribute to the understanding of Fe-induced toxicity and to validate this model. The Fe LD50 of acute exposure (30 min) was 1.2 mM, and we verified that worms readily take up this metal. Furthermore, sublethal Fe concentrations significantly decreased the worms' lifespan and brood size compared to non-exposed worms. We also observed that animals exposed to Fe had decreased locomotor activity and decreased mechanical sensitivity, suggesting the possible dysfunction of the nervous system. In agreement, we found cholinergic and dopaminergic alterations in the worms. In summary, we suggest that Fe leads to selective neuronal damage, which might be the underlying cause of altered behavior and reproductive defects. © The Royal Society of Chemistry.

Both D.R.,University Federal Of Santa Mariario Grande Do Sul | Matheus S.C.,University Federal Of Santa Mariario Grande Do Sul | Behenck M.S.,University Federal Of Santa Mariario Grande Do Sul
Nutricion Clinica y Dietetica Hospitalaria | Year: 2015

Introduction: The bioelectrical impedance (BI) is a fast, non-invasive and relatively inexpensive technique that can be applied in field situations or clinics. Its cost is ever lower, thus making equipment easy to purchase, but the accuracy of some equipment is still questionable due to the provision of information relating only to fat relative and/or absolute, failing to report values of resistance and/or reactance. Objective: Evaluate the validity of the estimate of the percentage of body fat (%BF) obtained through BI analyzers tetrapolar and bipolar (hand to hand and foot to foot) using the hydrostatic weighing (HW) with a reference technique. Methods: The %BF was measured in 102 men (18 - 30 years), with three equipment BI: Maltron BF-906 (tetrapolar); Omron 306BL (bipolar hand to hand) and Plena Ice (foot to foot) and HW. The accuracy was verified by paired t-test, correlation, standard error of estimate, constant error, total error and residue analysis. Results: The BI hand to hand underestimated and BI foot to foot overestimated significantly (p<0.05) values of %BF. Already tetrapolar BI showed no significant difference, and showed the highest correlation value, lower constant error and total error and the highest percentage of agreement with the HW. Conclusion: The equipment used in this study bipolar BI showed no accuracy to estimate relative body fat. Only IB tetrapolar brand Maltron BF-906 showed validity in determining %BF in the sample.

da Silva R.T.L.,University of Amazon | de Souza L.C.,University of Amazon | Nishijima T.,University Federal Of Santa Mariario Grande Do Sul | Fronza D.,University Federal Of Santa Mariario Grande Do Sul | And 6 more authors.
Journal of Food, Agriculture and Environment | Year: 2015

In order to obtain an equation that permits the estimation of guava leaf area through the dimensional linear parameters of the leaves, a study was conducted in the Polytechnic School of the Universidade Federal de Santa Maria. The guava leaves were collected on four occasions, at 30, 45, 60 and 75 days after pruning. The leaf area was determined by the method of discs. Linear models, linear without intercept, quadratic, cubic and power between leaf area and length or width and its products (Length * Width) were adjusted, and those that had a coefficient of determination less than 0.90 were eliminated. The statistic used to evaluate the performance of models was the Pearson correlation coefficient (r), the determination coefficient (R²), the root mean square error (RMSE), the mean absolute error (MAE), the index d of Willmott and CS index. The models that best fit the data were: the linear, linear without intercept, power and quadratic, considering the relation (Length * Width), as independent variable, and when considering only one dimension, the model power that used the length of the limb leaf was more realistic. © 2015, World Food Ltd. and WFL Publishers. All rights reserved.

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