Effect of high‐density lipoprotein on oocyte maturation and bovine embryo development in vitro

High‐density lipoprotein (HDL) is the main lipoprotein in the follicular fluid, and it has anti‐inflammatory, antioxidant and cryoprotectant properties. The anti‐inflammatory potential and antioxidant potential are derived from its lipid composition, especially the apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1). The aim of this study was to evaluate the effect of HDL during in vitro maturation (IVM) on oocyte maturation and early bovine embryo development. For this, cumulus–oocyte complexes (COCs) were obtained from bovine ovaries collected at a local slaughterhouse. COCs (n = 2,250) were allocated into three groups (n = 50 COCs/group) according to the addition of HDL protein (HDL‐P) during IVM for 22 hr: 0 (control), 50 and 150 mg/dl. After IVM, COCs were inseminated (in vitro fertilization) and cultivated for 7 days. Total cholesterol concentration, total protein, triglycerides and ApoAI concentrations on IVM medium increased proportionally to HDL‐P addition. However, PON1 activity was not detected in any treatment. The addition of HDL‐P did not affect nuclear maturation rate, endogenous reactive oxygen species and glutathione levels in COCs (p > 0.05). The highest HDL‐P concentration (150 mg/dl) decreased cleavage and blastocyst rate (p < 0.05). Moreover, the HDL‐P 150 mg/dl group had lower cellular count/blastocyst than the 50 mg/dl group (p < 0.05). However, the addition of HDL‐P did not affect relative gene expression of evaluated genes. In conclusion, the complex HDL/ApoAI obtained from human plasma, in the absence of PON1 activity during in vitro oocyte maturation, decreased initial embryo development.     

Effect of using Acacia mearnsii tannin extract as a feed additive on nutritional variables and productive performance in dairy cows grazing a temperate pasture

This study was carried out to evaluate the impact of including Acacia mearnsii tannin extract (TA) as a feed additive on nutrition and productive performance of dairy cows grazing a high‐quality temperate pasture and receiving supplementation with a concentrate feedstuff. Fourteen multiparous Holstein cows were assigned to either of the following treatments: concentrate without or with 20 g TA/kg dry matter (DM). Concentrate intake accounted for 32% of the total DM intake. Tannin addition increased the herbage DM intake by 22% (p < .05). There was no effect of TA inclusion on milk yield, milk composition, milk nitrogen (N) excretion, milk and plasma urea‐N concentration, urinary excretion of total N, urea‐N, and purine derivatives. However, TA inclusion increased the N intake and retention, total N excretion in manure, fecal N to urine N ratio, and decreased the dietary N efficiency for milk production and the percentage of ingested N excreted in urine (p < .05). In conclusion, supplementing dairy cows grazing a high‐quality temperate pasture with a concentrate containing 20 g TA/kg DM showed the potential of decreasing the proportion of ingested N excreted in urine without affecting the productive performance.     

Sedation and Pain Management with Intravenous Romifidine−Butorphanol in Standing Horses

The objective of this study was to determine the sedation, analgesia, and clinical reactions induced by an intravenous combination of romifidine and butorphanol in horses. The study was conducted on six saddle horses weighing 382 to 513 kg (mean ± SD; 449 ± 54 kg) and aged 6 to 14 years. The horses each underwent three treatments: intravenous romifidine 0.1 mg/kg body weight (RM; mean dose, 4.5 mL); intravenous butorphanol 0.05 mg/kg body weight (BT; mean dose, 2.4 mL); and intravenous romifidine 0.1 mg/kg body weight plus butorphanol 0.05 mg/kg body weight (RMBT; mean dose, 7.0 mL). The order of treatments was randomized. Heart rate, arterial pressure, respiratory rate, rectal temperature, sedation, and analgesia were measured at two times before treatments, 15 minutes apart (times –15 and 0) and at 5, 10, 15, 30, 45, 60, 75, 90, 120, 150, and 180 minutes after drug administration. The onset of sedation was approximately 5 minutes after intravenous injection of RM and RMBT, whereas BT did not present this effect. The duration of complete sedation was approximately 60 minutes for RMBT and approximately 35 minutes for RM. The RMBT treatment provided 30 minutes and the RM treatment 20 minutes of complete analgesia. Heart rate decreased significantly (P < .05) from basal values in the RM and RMBT treatments. Only RM caused significant decreases (P < .05) in the respiratory rate. Arterial pressure did not change significantly (P > .05) in any treatment. Intravenous administration of a romifidine−butorphanol combination to horses resulted in longer duration of sedation and analgesia than administration of romifidine or butorphanol alone. These effects probably resulted from a synergistic effect of the two drugs.     

Modeling the Diving Behavior of Whales: A Latent-Variable Approach with Feedback and Semi-Markovian Components

Recent years have seen a fast-growing body of literature concerned with the statistical modeling of animal movement in the two horizontal dimensions. On the other hand, there is very little statistical work that deals with animal movement in the vertical dimension. We present an approach that provides an important step in analyzing such data. In particular, we introduce a hidden Markov-type modeling approach for time series comprising the depths of a diving marine mammal, thus modeling movement in the water column. We first develop a baseline Markov-switching model, which is then extended to incorporate feedback and semi-Markovian components, motivated by the observations made for a particular species, Blainville’s beaked whale (Mesoplodon densirostris). The application of the proposed model to the beaked whale data reveals both strengths and weaknesses of the suggested modeling framework. The framework is general enough that we anticipate that it can be used for many other species given minor changes in the model structure.     

Partial Nitritation-Anammox Granules: Short-Term Inhibitory Effects of Seven Metals on Anammox Activity

The inhibitory effect of seven different metals on the specific anammox activity of granular biomass, collected from a single stage partial nitritation/anammox reactor, was evaluated. The concentration of each metal that led to a 50% inhibition concentration (IC₅₀) was 19.3 mg Cu⁺²/L, 26.9 mg Cr⁺²/L, 45.6 mg Pb⁺²/L, 59.1 mg Zn⁺²/L, 69.2 mg Ni⁺²/L, 174.6 mg Cd⁺²/L, and 175.8 mg Mn⁺²/L. In experiments performed with granules mechanically disintegrated (flocculent-like sludge), the IC₅₀ for Cd⁺² corresponded to a concentration of 93.1 mg Cd⁺²/L. These results indicate that the granular structure might act as a physical barrier to protect anammox bacteria from toxics. Furthermore, the presence of an external layer of ammonia oxidizing bacteria seems to mitigate the inhibitory effect of the metals, as the values of IC₅₀ obtained in this study for anammox activity were higher than those previously reported for anammox granules. Additionally, the results obtained confirmed that copper is one of the most inhibitory metals for anammox activity and revealed that chromium, scarcely studied yet, has a similar potential inhibitory effect.     

Chemical and spectroscopic evidence for an FeV-oxo complex

Iron(V)-oxo species have been proposed as key reactive intermediates in the catalysis of oxygen-activating enzymes and synthetic catalysts. Here, we report the synthesis of [Fe(TAML)(O)]- in nearly quantitative yield, where TAML is a macrocyclic tetraamide ligand. Mass spectrometry, M?ssbauer, electron paramagnetic resonance, and x-ray absorption spectroscopies, as well as reactivity studies and density functional theory calculations show that this long-lived (hours at -60 degrees C) intermediate is a spin S = 1/2 iron(V)-oxo complex. Iron-TAML systems have proven to be efficient catalysts in the decomposition of numerous pollutants by hydrogen peroxide, and the species we characterized is a likely reactive intermediate in these reactions.     

Metabolic responses of matrinxã, Brycon amazonicus (Spix & Agassiz, 1829), exposed to environmental nitrite

Nitrite is usually found in aquatic environments where nitrification process occurs. This ion can cause several injuries to aquatic species, particularly fish. Nitrite reacts with haemoglobin yielding the non‐functional methaemoglobin, which leads to many physiological consequences such as functional anaemia and supposed hypoxia. Metabolism of the freshwater teleost matrinxã, Brycon amazonicus, exposed to environmental 0.6 mg L^?1 of nitrite N‐NO₂^? for 96 h was studied, and the fermentative/oxidative preference was gauged. Concentrations of glycogen, glucose, lactate, pyruvate and ammonia, plus the activities of lactate, glutamate and malate dehydrogenase were assayed. The exposure resulted in a metabolic profile that allowed inferring the continuity of oxidative metabolism. Catabolism of amino acids prevailed or was apparently exacerbated by inferred branchial injury and consequent impairment of nitrogen excretion. Moreover, the studied enzymes glutamate dehydrogenase, lactate dehydrogenase and malate dehydrogenase from brain and heart were little affected by nitrite. The expected fermentative metabolism due to the high methaemoglobin formation was not observed.     

Land cover,riparian zones and instream habitat influence stream fish assemblages in the eastern Amazon

The Amazon rainforest has experienced rapid land‐use changes over the last few decades, including extensive deforestation that can affect riparian habitats and streams. The aim of this study was to assess responses of stream fish assemblages to deforestation and land cover change in the eastern Amazon. We expected that percentage of forest in the catchment is correlated with local habitat complexity, which in turn determines fish assemblage composition and structure. We sampled 71 streams in areas with different land uses and tested for relationships between stream fish assemblages and local habitat and landscape variables while controlling for the effect of intersite distance. Fish assemblage composition and structure were correlated with forest coverage, but local habitat variables explained more of the variation in both assemblage composition and structure than landscape variables. Intersite distance contributed to variance explained by local habitat and landscape variables, and the percentage of variance explained by the unique contribution of local habitat was approximately equivalent to the shared variance explained by all three factors in the model. In these streams of the eastern Amazon, fish assemblages were most strongly influenced by features of instream and riparian habitats, yet indirect effects of deforestation on fish assemblage composition and structure were observed even though intact riparian zones were present at most sites. Long‐term monitoring of the hydrographic basin, instream habitat and aquatic fauna is needed to test for potential legacy effects and time lags, as well as assess species responses to continuing deforestation and land‐use changes in the Amazon.     

Mixtures of grasses: An alternative to traditional pasture monocultures in the tropics

A two-year experiment assessed herbage production and above- and below-ground characteristics of a highly productive monoculture (‘BRS Zuri’ guineagrass [Panicum maximum Jacq.]) and two mixtures of three grasses (Mixture 1: ‘BRS Zuri’ guineagrass, ‘BRS Xaraés’ palisadegrass [Brachiaria brizantha Stapf.], and ‘Basilisk’ signalgrass [Brachiaria decumbens Stapf.]; Mixture 2: ‘BRS Quênia’ guineagrass [Panicum maximum Jacq.], ‘Marandu’ palisadegrass [Brachiaria brizantha Stapf.], and ‘BRS Paiaguás’ palisadegrass [Brachiaria brizantha Stapf.]), cultivated in the Brazilian tropical savanna. Mixtures 1 and 2 were subjected to two grazing intensities (removal of 40 or 60% of pre-grazing height) and ‘BRS Zuri’ guineagrass monoculture was defoliated to a single grazing intensity of 50%. Treatments were randomly assigned to fifteen 0.25-ha plots and managed under intermittent stocking by cattle. Herbage accumulation rate was similar among pastures and years (p > .1). The root mass in the tussocks did not differ (p > .1), with mean values ranging between 0.62 to 1.81 kg DM m⁻². Root density in the tussock interspaces was greater in the mixtures (p < .001), regardless of seasons (p = .405) and years (p = .292). The mixtures were dominated by guineagrass (70%) and palisadegrass (30%) at the end of the experiment, with the population of ‘Basilisk’ and ‘BRS Paiaguás’ being completely suppressed throughout the experimental period. Mixing guineagrass and brachiariagrasses can be an alternative to the traditional pastoral systems in the tropics, as it does not compromise herbage production and presents a capacity to produce more roots than a very productive monoculture of ‘BRS Zuri’ guineagrass.