Evaluation of cardiorespiratory and biochemical effects of ketamine‐propofol and guaifenesin‐ketamine‐xylazine anesthesia in donkeys (Equus asinus)

ObjectivesTo evaluate the cardiorespiratory and biochemical effects of ketamine-propofol (KP) or guaifenesin-ketamine-xylazine (GKX) anesthesia in donkeys.Study designProspective crossover trial.AnimalsEight healthy, standard donkeys, aged 10 ± 5 years and weighing 153 ± 23 kg.MethodsDonkeys were premedicated with 1.0 mg kg^?1 of xylazine (IV) in both treatments. Eight donkeys were administered ketamine (1.5 mg kg^?1) and propofol (0.5 mg kg^?1) for induction, and anesthesia was maintained by constant rate infusion (CRI) of ketamine (0.05 mg kg^?1 minute^?1) and propofol (0.15 mg kg^?1 minute^?1) in the KP treatment. After 10 days, diazepam (0.05 mg kg^?1) and ketamine (2.2 mg kg^?1) were administered for induction, and anesthesia was maintained by a CRI (2.0 mL kg^?1 hour^?1) of ketamine (2.0 mg mL^?1), xylazine (0.5 mg mL^?1) and guaifenesin (50 mg mL^?1) solution. Quality of anesthesia was assessed along with cardiorespiratory and biochemical measurements.ResultsAnesthetic induction took longer in GKX than in KP. The induction was considered good in 7/8 with KP and in 6/8 in GKX. Anesthetic recovery was classified as good in 7/8 animals in both treatments. Xylazine administration decreased heart rate (HR) in both treatments, but in KP the HR increased and was higher than GKX throughout the anesthetic period. Respiratory rate was higher in GKX than in KP. PaO₂ decreased significantly in both groups during the anesthetic period. Glucose concentrations [GLU] increased and rectal temperature and PCV decreased in both treatments. Arterial lactate [LAC] increased at recovery compared with all time points in KP. [GLU] and calcium were higher in GKX than in KP at recovery.Conclusion and clinical relevanceThese protocols induced significant hypoxemia but no other cardiorespiratory or metabolic changes. These protocols could be used to maintain anesthesia in donkeys, however, they were not tested in animals undergoing surgery.     

Antimicrobial ent-pimarane diterpenes from Viguiera arenaria against Gram-positive bacteria

The dichloromethane crude extract from the roots of Viguiera arenaria (VaDRE) has been employed in an antimicrobial screening against several bacteria responsible for human pathologies. The main diterpenes isolated from this extract, as well as two semi-synthetic pimarane derivatives, were also investigated for the pathogens that were significantly inhibited by the extract (MIC values lower than 100 μg mL^− 1). The VaDRE extract was significantly active only against Gram-positive microorganisms. The compounds ent-pimara-8(14),15-dien-19-oic acid (PA); PA sodium salt; ent-8(14),15-pimaradien-3β-ol; ent-15-pimarene-8β,19-diol; and ent-8(14),15-pimaradien-3β-acetoxy displayed the highest antibacterial activities (MIC values lower than 10 μg mL^− 1 for most pathogens). In conclusion, our results suggest that pimaranes are an important class of natural products for further investigations in the search of new antibacterial agents.     

Performance of dual and triple fungicide premixes for managing soybean rust across years and regions in Brazil: A meta-analysis

Soybean rust in Brazil is currently controlled with several commercial fungicide premixes composed of demethylation inhibitors (EPOXiconazole, CYPRoconazole, PROThioconazole, TEBUconazole), quinone-outside inhibitors (AZOXystrobin, TriFLoXystrobin, PYRAclostrobin, PICOxystrobin), and succinate demethylation inhibitors (BENZovindiflupyr, BIXaFen, FLUXapyroxad). Here, we summarize the performance of eight premixes evaluated in 177 cooperative trials conducted in 46 locations across 10 states from 2015 to 2020. All fungicide treatments were sprayed three times starting at R1/R2. Percentage control (, %), from back-transforming meta-analytic estimates of the log of the ratio, ranged from 56.2% (PICO + CYPR) to 76.8% (BIXF + TFLX + PROT). Estimates of mean yield difference (, kg/ha) between fungicide-treated and untreated plots were greatest for BIXF + TFLX + PROT (1,080) followed by PICO + BENZ (1,010), PYRA + EPOX + FLUX (981.5), AZOX + BENZ (910), TFLX + PROT (891), PICO +TEBU (682), TFLX + CYPR (646), and PICO + CYPR (600). Significant declines in both and in as little as 4 years were detected for AZOX + BENZ (35.3%; 550 kg/ha) and PICO + BENZ (15.5%; 359.8 kg/ha). Variance in was reduced by the inclusion of baseline severity as covariate. In trials where baseline disease was ≥70%, yield was 250 kg/ha greater compared to areas with low baseline disease. Disease control and yield response were generally greater in the south-east, where the frequency of profitable scenarios was 30% higher on average than in the north-west. Results of this meta-analysis are critical for supporting decisions during planning of fungicide programmes.     

Supplementation of citric acid in plant protein‐based diets for juvenile tambaqui,Colossoma macropomum

We evaluated citric acid supplementation (0, 10, 20, and 30 g/kg) in plant protein‐based diets for juvenile tambaqui, Colossoma macropomum. In Experiment 1, fish (n = 160; 27.56 ± 2.73 g) were distributed in 310 L tanks (n = 16) for 80 days. Zootechnical performance, hematological parameters, and mineral composition (muscle and bones) did not differ significantly (p > .05). The inclusion of citric acid‐reduced pH of diets (p = .001) and stomach (p = .035). In Experiment 2, fish (n = 60; 48.00 ± 1.98 g) were distributed in fecal collection aquaria (200 L) for 21 days. The following were observed: a linear effect for the crude protein (p = .0004) and crude fat (p = .0037) digestibility coefficients; a quadratic effect for crude energy (p = .0037) and dry matter (p = .0004); an optimal supplementation level of 18.5 g/kg. Calcium (p = .0060) and magnesium (p = .0222) showed a linear effect, while phosphorus (p = .0001) had a quadratic effect with the 20 g/kg optimum supplementation level. To conclude, the supplementation of this organic acid in diets does not negatively affect fish nutritional status, health or welfare, and increases nutrient and mineral availability.     

Soil microstructure alterations induced by land use change for sugarcane expansion in Brazil

Land use change (LUC) alters soil structure and, consequently, the functions and services provided by these soils. Conversion from extensive pasture to sugarcane is one of the largest land transitions in Brazil as a result of the growth of the domestic and global demands of bioenergy. However, the impacts of sugarcane expansion on the soil structure under extensive pasture remains unclear, especially when considering changes at the microscale. We investigated whether LUC for sugarcane cultivation impacted soil microstructure quality. Undisturbed soil samples were taken from two soil layers (0–10 and 10–20 cm) under three contrasting land uses (native vegetation—NV, pasture—PA and sugarcane—SC) in three different locations in the central-southern Brazil. Oriented thin sections (30 μm) were used for micromorphological analysis. The total area of pores decreased following the LUC in the following order: NV > PA > SC in both soil layers. The area of large complex packing pores (>0.01 mm²) also decreased with the LUC sequence: NV>PA>SC. Qualitative and semi-quantitative micromorphological analysis confirmed porosity reduction was driven by the decrease in complex packing pores and that biological features decreased in the same LUC sequence as the quantitative parameters. Therefore, LUC for sugarcane expansion reduced microscale soil porosity, irrespectively of soil type and site-specific conditions, indicating that the adoption of more sustainable management practices is imperative to preserve soil structure and sustain soil functions in Brazilian sugarcane fields.     

Nitrogen and Phosphorus Dynamics in the Biofloc Production of the Pacific White Shrimp,Litopenaeus vannamei

A study evaluating nitrogen and phosphorus dynamics was carried out using biofloc technology (BFT) systems employed to raise Litopenaeus vannamei juveniles. The study was carried out for 42 d in three fiberglass tanks with 210 L useful volume with no water exchange. Salinity, temperature, dissolved oxygen, pH, nutrients, suspended solids, and chlorophyll‐a were monitored every 3 d. At the completion of the experiment, the shrimp had absorbed 39.1 and 35.0% of the total nitrogen (N) and phosphorus (P) inputs, respectively, while 39.0% of the N and 34.1% of the P remained in the system in dissolved forms. The dominant process of ammonium immobilization in the system was oxidation by nitrifying bacteria. On Day 42, the nitrate concentration represented more than 80% of the total dissolved inorganic nitrogen in all tanks. However, most of the dissolved nitrogen present in the tanks (80%) was organic. Phosphate and organic nitrogen and phosphorus continuously accumulated in the system throughout the experiment. The removal of these nutrients should be the focus of future studies because they may enhance the growth of harmful algae in tanks and in the water bodies that collect the post‐crop wastewater.     

Throughfall,stemflow and interception loss in a mixed white oak forest (Quercus serrata Thunb.)

Throughfall and stemflow measurements in a 60-year-old white oak stand (Quercus serrata Thunb.) were carried out during two periods totalling eleven months, from August to November 1993 and from May to November 1994, in order to clarify the rainfall partitioning of this forest. Troughs and spiral-type stemflow gauges connected to tipping bucket-gauges were used for throughfall and stemflow measurements. Seventy-five storms were analyzed individually. Coefficients of variation for throughfall and stemflow ranged between 5–25% and 20–70% respectively. Partitioning of net rainfall in throughfall and stemflow represent 72% and 10% of the gross rainfall respectively. Multiple regression analyses were carried out to determine the stemflow variability. In was determined that maximum rain intensity was highly correlated with stemflow and this variable explained a further 5.5% of the stemflow variation. Estimates of averaged lag time and drainage after rain cease for stemflow were 290 and 164 min, while estimates for throughfall were 60 and 104 min. respectively. The canopy saturation was estimated from continuous storms and showed a value of 0.6 mm. The trunk storage capacity was estimated at a value of 0.2 mm. The interception loss from the forest canopy was estimated in 18%. Interception loss was heighly correlated with rainfall characteristics such as duration and intensity.     

Antiviral evaluation of plants from Brazilian Atlantic Tropical Forest

The antiviral activity of six medicinal plants from Brazilian Atlantic Tropical Forest was investigated against two viruses: herpes simplex virus type 1 (HSV-1) and poliovirus type 2 (PV-2). Cuphea carthagenensis and Tillandsia usneoides extracts showed the best antiherpes activity. T. usneoides dichloromethane, ethyl acetate and n-butanol extracts, and Lippia alba n-butanol extract showed inhibition of HSV-1, strain 29R/acyclovir resistant. In addition, only L. alba ethyl acetate extract showed antipoliovirus activity. These results corroborate that medicinal plants can be a rich source of potential antiviral compounds.     

Larvicidal,molluscicidal and nematicidal activities of essential oils and compounds from <Emphasis Type="Italic">Foeniculum vulgare</Emphasis>

Plant-based products, namely essential oils (EOs), are environmentally friendly alternatives for the control of disease vectors, hosts and/or parasites. Here, we studied the general toxicity and biopesticidal potential of EOs and phenylpropanoids from Foeniculum vulgare var. vulgare (bitter fennel), a perennial plant well adapted to temperate climates. EO/compound toxicity was tested against a freshwater snail and potential intermediate host of Fasciola hepatica (Radix peregra), a mosquito and former European malaria vector (Anopheles atroparvus) and one of the most damaging plant-parasitic nematodes, the root-knot nematode (Meloidogyne javanica). Lethal concentrations (LC₅₀; LC₉₀) of EOs (infrutescences/stems with leaves) and compounds were calculated by probit analysis. All displayed noteworthy activity against R. peregra adults (LC₅₀ 21–39 µg ml^?1) and A. atroparvus larvae (LC₅₀ 16–56 µg ml^?1). trans-Anethole revealed acute nematicidal activity after 24 and 48 h (LC₅₀ 310 and 249 µg ml^?1, respectively), and estragole (1,000 µg ml^?1) showed some effectiveness against M. javanica hatching and juveniles after 15 days. Plant and EO yields were determined to evaluate the bitter fennel productivity. The chemical composition of the EOs was analyzed by gas chromatography coupled to mass spectrometry. EOs extracted from whole plants, infrutescences and stems with leaves were characterized by estragole-dominant profiles (28–65 %), considerable amounts of phellandrene (10–34 %) and fenchone (6–16 %), and minor trans-anethole contents (1–4 %). Although additional toxicological studies against nontarget organisms are required, our study demonstrates that bitter fennel is a productive source of molluscicides and larvicides, and thus a potential sustainable biological agent to control particular host species, namely freshwater snails and mosquitoes.