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The present study evaluated the alterations of the oxidative stress markers in adult dogs fed with high levels of PUFA from the mixture of soybean oil enriched with docosahexaenoic acid (DHA) and supplemented with a natural algae-based antioxidant (AOX). Twelve healthy adult (2 years old) Beagle dogs (6 males and 6 females, 11.20 ± 1.92 kg BW), were distributed in 2 completely randomized blocks design and fed with 4 experimental diets coated with 2 lipid sources: saturated (13% bovine tallow) or unsaturated (13% soybean oil enriched with DHA), supplemented or not with 500 mg of AOX for 4 wk, intercalated with a 4-wk adaptation period. Blood samples were collected on days 0, 15, and 30 of each block. Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), sulfhydryl group (SH), protein carbonylation, thiobarbituric acid reactive substances (TBARS), and total reactive antioxidant potential (TRAP) were evaluated in the serum, while GSH-Px, SOD, glutathione S-transferase (GST), catalase (CAT), SH, and TBARS were measured in erythrocytes. There was no significant difference in most of the oxidative markers evaluated. In contrast, GST activity in erythrocytes was greater in the animals that consumed the diets coated with bovine tallow compared to dogs that consumed diets coated with soybean oil enriched with DHA (P < 0.05). Serum from dogs fed on diets supplemented with AOX presented greater TRAP values (P < 0.05). These data demonstrate that the concentrations of unsaturated fatty acids (UNS) used in the diets for dogs were not sufficient to cause large changes in the oxidative status. It was not possible to evaluate the efficiency of the natural antioxidant in maintaining the oxidative balance of the animals as it appears that the oxidative status of the dogs was not challenged by the unsaturated diets. Our findings also suggest that dogs, as descendants from carrion carnivores, may have some natural protection against oxidation. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the effect of full-fat rice bran (FFRB) inclusion in dry diets with and without enzyme blend (EB) supplementation for adult dogs. The diets contained 0, 20, or 40% of FFRB, replacing the equivalent amount of wheat flour (WF). Experiment 1 evaluated the consumption and preference of diets using a simple choice method with 3 comparisons (0 vs. 20, 0 vs. 40, and 20 vs. 40% FFRB). Experiment 2 investigated the effect of EB supplementation on the apparent digestibility coefficients (ADC) of nutrients and GE, fecal characteristics, urinary pH, Ca and P balance, and ME of the diets. In Exp. 1, the results indicated that FFRB included in diets up to 40% did not affect the preference or consumption of food by dogs (P < 0.05). In Exp. 2, increasing levels of FFRB in the diet linearly reduced the ADC of nutrients, GE, and ME (P < 0.05). The addition of EB had no effect on any of the variables examined. Regression analysis enabled estimation of the ADC in FFRB; and ADC of DM, CP, ether extract, GE; and the apparent coefficient of ME were 60.5, 74.8, 88.4, 70.8, and 66.4%, respectively. The inclusion of 20 or 40% FFRB in the diets did not affect urinary pH but caused an imbalance in the Ca and P metabolism when included at 40% (P < 0.05), which could be one of the limitations for greater inclusion of FFRB. The ME of FFRB was estimated to be 3,443 kcal/kg DM. The FFRB appears to be palatable for adult dogs, and although ADC was reduced by 40% FFRB in the diet, this ingredient has the potential for inclusion at 20% of diets for dogs, depending on the other ingredients used to achieve adequate Ca and P balance. The inclusion greater than 20% tends to increase P in the diet and reverse the relationship between Ca and P. [ABSTRACT FROM AUTHOR]

Irazú and Turrialba are a twin volcanic complex that marks a distinct stop in volcanism along the Central America volcanic arc. We present a new traveltime velocity model of the crust beneath Irazú and Turrialba volcanoes, Costa Rica, and interpret it considering the results of previous ambient noise tomographic inversions. Data were acquired by a temporary seismic network during a period of low activity of the Irazú–Turrialba volcanic complex in 2018–2019. Beneath the Irazú volcano, we observe low P -wave velocities (V P = 5 km s−1) and low velocity ratios (V P/ V S = 1.6). In contrast, below the Turrialba volcano, we observe low S -wave velocities (V S = 3 km s−1) and a high V P/ V S (= 1.85) anomaly. We found that locations of low V P and V S anomalies (−15 %) correspond well with shear wave velocity anomalies retrieved from ambient noise tomography. At shallower depths, we observe high V P and V S anomalies (+15 %) located between the summits of the volcanoes. Subvertical velocity anomalies are also observed at greater depths, with high V P and V S anomalies appearing at the lower limits of our models. We propose a complex structure of an intermediate magmatic reservoir, presenting multiphase fluid states of a liquid-to-gas transition beneath Irazú and a juvenile store of magmatic fluid beneath Turrialba, while shallow fluid transport provides evidence of magmatic–hydrothermal interactions. [ABSTRACT FROM AUTHOR]

Currently, countries with the highest human development index (HDI) dominate the production of ecological research. This is problematic because ecology is a discipline that is highly relevant to the challenges facing countries with lower indices. We characterize the full state of current inequity at the authorship and editorial levels, investigating the relative role of gross domestic product (GDP) versus research investment in driving publication patterns. We find that the representation of low HDI countries decreases dramatically from authorship to editorial levels. GDP was the best predictor of publication rate for high HDI countries, whereas research investment was an equal or better predictor for low HDI countries. In light of our results, we propose an alternative model of knowledge sharing and production that emphasizes (a) increasing equity in the communication of ecological science at a global scale, (b) expanding ecology funding in low HDI countries, and (c) prioritizing ecological science in low HDI regions. [ABSTRACT FROM AUTHOR]

SUMMARY Using continuous seismic data from newly available broadband stations in Mexico and Central America we have obtained group and phase velocity maps of fundamental mode Rayleigh wave for the region. These new maps have been calculated for periods between 8 and 60 s from cross-correlations of seismic ambient noise between 100 broadband stations, and stacked for 30 months from 2006 to 2008. The tomographic inversion of the obtained dispersion measurements has been carried out on a 1°× 1° grid, resulting in maps with resolution better than 250 km in the well-sampled regions of the model. For short periods (8-16 s) dispersion maps show good correlation with surface structural features. Low-velocity anomalies correlate with sedimentary basins around the Gulf of Mexico and Colorado embayment. High-velocity anomalies at short periods correlate with mountain ranges and regions of thin, extended crust such as the Gulf of California. Both the lowest and highest group velocity anomalies at these periods reach values of up to 15 per cent. For periods between 25 and 40 s, velocity anomalies are related to variations in crustal thickness and temperature. The most prominent low velocity anomaly correlates with thick crust and high mantle temperatures associated with the Trans-Mexican Volcanic Belt and the Central American volcanic arc. The most remarkable features for longer periods (40-60 s) are the differences between high-velocity anomalies beneath the Mayan block, the Gulf of Mexico and the cratonic part of the United States and low-velocity anomalies beneath the Chortis block and northern Mexico. The long wavelength features of our model agree well with previous global and continental scale studies. However, because of the increased station density of the data set used, we are able to obtain reliable dispersion maps for shorter periods, and to image smaller scale features. [ABSTRACT FROM AUTHOR]

In searching for persistent seizure-induced alterations in brain function that might be causally related to epilepsy, presynaptic transmitter release has relatively been neglected. To measure directly the long-term effects of pilocarpine-induced status epilepticus on vesicular release and recycling in hippocampal mossy fibre presynaptic boutons, we used (i) two-photon imaging of FM1-43 vesicular release in rat hippocampal slices; and (ii) transgenic mice expressing the genetically encoded pH-sensitive fluorescent reporter synaptopHluorin preferentially at glutamatergic synapses. In this study we found that, 1–2 months after pilocarpine-induced status epilepticus, there were significant increases in mossy fibre bouton size, faster rates of action potential-driven vesicular release and endocytosis. We also analysed the ultrastructure of rat mossy fibre boutons using transmission electron microscopy. Pilocarpine-induced status epilepticus led to a significant increase in the number of release sites, active zone length, postsynaptic density area and number of vesicles in the readily releasable and recycling pools, all correlated with increased release probability. Our data show that presynaptic release machinery is persistently altered in structure and function by status epilepticus, which could contribute to the development of the chronic epileptic state and may represent a potential new target for antiepileptic therapies. [ABSTRACT FROM PUBLISHER]