Early acute depletion of lymphocytes in calicivirus-infected adult rabbits

Rabbit Haemorrhagic Disease (RHD) is a lethal infection caused by calicivirus that kills 90% of the infected adult rabbits within 3 days. The calicivirus replicates in the liver and causes a fulminant hepatitis. Most studies on the pathology of RHD have been focused on the fulminant liver disease. This may not be the only mechanism in the pathogenesis of RHD: calicivirus infection may also induce leukopenia in the infected adult rabbits. We show now by flow cytometry analysis that the calicivirus induces an early decrease in B and T cells, in both spleen and liver. The depletion of B and T cells was associated with apoptosis labelled by annexin V. These changes occurred in rabbits before they showed enzymatic evidence of liver damage and persisted after liver transaminase values were very high. We conclude that depletion of lymphocytes caused by the calicivirus infection precedes or attends liver damage. The relative contribution of this lymphocyte depletion for the pathogenesis of the fatal calicivirus infection of rabbits remains to be investigated.     

Effects of methadone on the minimum alveolar concentration of isoflurane in dogs

ObjectiveTo investigate the effects of methadone on the minimum alveolar concentration of isoflurane (ISO_MAC) in dogs.Study designProspective, randomized cross-over experimental study.AnimalsSix adult mongrel dogs, four males and two females, weighing 22.8 ± 6.6 kg.MethodsAnimals were anesthetized with isoflurane and mechanically ventilated on three separate days, at least 1 week apart. Core temperature was maintained between 37.5 and 38.5 °C during ISO_MAC determinations. On each study day, ISO_MAC was determined using electrical stimulation of the antebrachium (50 V, 50 Hz, 10 mseconds) at 2.5 and 5 hours after intravenous injection of physiological saline (control) or one of two doses of methadone (0.5 or 1.0 mg kg^?1).ResultsMean (±SD) ISO_MAC in the control treatment was 1.19 ± 0.15% and 1.18 ± 0.15% at 2.5 and 5 hours, respectively. The 1.0 mg kg^?1 dose of methadone reduced ISO_MAC by 48% (2.5 hours) and by 30% (5 hours), whereas the 0.5 mg kg^?1 dose caused smaller reductions in ISO_MAC (35% and 15% reductions at 2.5 and 5 hours, respectively). Both doses of methadone decreased heart rate (HR), but the 1.0 mg kg^?1 dose was associated with greater negative chronotropic actions (HR 37% lower than control) and mild metabolic acidosis at 2.5 hours. Mean arterial pressure increased in the MET1.0 treatment (13% higher than control) at 2.5 hours.Conclusions and clinical relevanceMethadone reduces ISO_MAC in a dose-related fashion and this effect is lessened over time. Although the isoflurane sparing effect of the 0.5 mg kg^?1 dose of methadone was smaller in comparison to the 1.0 mg kg^?1 dose, the lower dose is recommended for clinical use because it results in less evidence of cardiovascular impairment.     

Aerobic Biological Treatment of Chestnut Processing Wastewater

Chestnut agro-industrial companies consume a high volume of water for washing and processing fruit, generating a large volume of wastewater. This work studied the biodegradation of chestnut processing wastewater through aerobic assays, varying substrate, and biomass concentrations. In general, this wastewater presents a good biodegradability, especially in experiments with relatively low chemical oxygen demand (COD) (0.4 and 0.6?g O₂ L^?1) allowing a COD removal of 85?C90?%. The best results were obtained in the reactor initially loaded with 2?g?L^?1 of biomass and 0.4 or 0.6?g O₂ L^?1 of COD. These experiments also showed high COD removal rates: 4.25 and 3.88?g COD g^?1 volatile suspended solids (VSS) h^?1, respectively. The sedimentation rate, evaluated for different initial values of biomass (1, 2, and 3?g?L^?1), always presented higher values in the experiments with 2 and 3?g?L^?1 of biomass, regardless of the initial COD value used. After comparing different kinetic models (Monod, Contois, and Haldane), it was observed that the Haldane inhibition model satisfactorily describes the COD biodegradation. AQUASIM software allowed calculating the kinetic constant ranges: K _s, 1.59?C6.99?g COD L^?1; ?? _max, 25?C40?g COD g^?1 VSS day^?1; and K _i values, 0.07?C0.11. These kinetic constants corresponds to maximum rates (??*) between 1.48 and 4.25?g COD g^?1 VSS day^?1 for substrate concentrations (S*) from 0.38 to 0.88?g COD L^?1.     

Heavy Metal Accumulation in Plant Species Indigenous to a Contaminated Portuguese Site: Prospects for Phytoremediation

Acid rock drainage (ARD) often contains ferrous iron, sulphate and high concentrations of trace elements detrimental to the environment. Future costs will be enormous if the problem is not treated today. Simple and cost-effective methods for remediation of historical mine sites are therefore desired. In this study, three mine waters were mixed with alkaline ash leachates, and the fate of trace elements from both the mine waters (Cd, Cu, Pb, Zn, Ni and Co) and the ash leachates (Cr and Mo) was studied. Addition of ash water precipitates hydrous ferric oxides (HFO) and hydrous aluminium oxides (HAO) induced trace element sorption and coprecipitation. Composition of the formed HFO/HAO mix determines efficiency of the sorption and the relative order of sorption for different trace elements. Sorption occurred much earlier (often one pH unit or more) in a system with high iron concentrations compared to systems with lower iron concentrations. Removal of cadmium and zinc was low, below pH 8, if the amount of precipitates was low. Using ash for generation of alkaline water may be a problem with regard to chromium and molybdenum. This study shows that it is possible to avoid problems with molybdenum by keeping the final pH around 7, and chromium(VI) from the ash water will be reduced into chromium(III) and precipitated as the hydroxide in the presence of iron(II). Results imply that it is possible to also use fly ashes in alkaline leach beds in order to neutralize ARD followed by precipitation and sorption of trace elements.     

Morphophysiology of forage peanut submitted to different intensities of defoliation on grazing with sheep

Tropical Animal Health and Production - The aim was to monitor the growth, the dry mass accumulation curve, and the structural photosynthetic components of forage peanut pasture, in different...     

BORON UPTAKE AND DISTRIBUTION IN FIELD GROWN CITRUS TREES

In low fertility tropical soils, boron (B) deficiency impairs fruit production. However, little information is available on the efficiency of nutrient application and use by trees. Therefore, this work verified the effects of soil and foliar applications of boron in a commercial citrus orchard. An experiment was conducted with fertigated 4-year-old ‘Valencia’ sweet orange trees on ‘Swingle’ citrumelo rootstock. Boron (isotopically-enriched ¹⁰B) was supplied to trees once or twice in the growing season, either dripped in the soil or sprayed on the leaves. Trees were sampled at different periods and separated into different parts for total B contents and ¹⁰B/¹¹B isotope ratios analyses. Soil B applied via fertigation was more efficient than foliar application for the organs grown after the B fertilization. Recovery of labeled B by fruits was 21% for fertigation and 7% for foliar application. Residual effects of nutrient application in the grove were observed in the year after labeled fertilizer application, which greater proportions derived from the soil supply.     

Inheritance and heritability of resistance to citrus leprosis

ABSTRACT The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor 'Murcott' (Citrus sinensis x C. reticulata) and sweet orange 'Pêra' (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.     

The effects of tank colours on the growth and survival of cuttlefish (Sepia officinalis,Linnaeus 1758) hatchlings and juveniles

The effects of different tank colours (white, yellow sandy and black) on the growth, mortality and biomass production were studied for hatchling and early juvenile cuttlefish. For hatchlings, the use of different colour tanks did not promote differences in growth due to the higher variability (standard deviation) found in the white‐ and sand‐coloured tanks. Black tanks promoted the lowest and highest values for total mortality and biomass respectively. For juveniles, the use of different tank colours promoted different growth (P<0.05), but not mortality. Black tanks promoted the best results in terms of growth and biomass. The results obtained in the present study advise the use of black (or dark colour) tanks in the hatchling and early juvenile stages to reduce the standard deviations associated with growth, mortality and biomass production. This will contribute to minimize problems associated with slow and fast growers and competition.     

Preventative releases of self-limiting Ceratitis capitata provide pest suppression and protect fruit quality in outdoor netted cages

Abstract

The Mediterranean fruit fly, Ceratitis capitata, (Medfly) is considered a key pest of citrus fruit in many countries. Integrated pest management (IPM) approaches are frequently highly dependent on the use of insecticides. Oxitec’s self-limiting (prevents the insects’ offspring from surviving to adulthood) Medfly technology (OX3864A) offers an approach to manage Medfly outbreaks and may offer improved sustainability and economics for area-wide programmes. Netted cages were used to evaluate OX3864A deployed for the first time outdoors as a preventative treatment to suppress wild Medfly. Comparative assessments examined sexual competitiveness, the relative performance of OX3864A releases at both adult and pupal life-stages, and the ability of OX3864A to protect against fruit damage. OX3864A males are as competitive as wild males. Deployment of both adult and pupal life-stages of OX3864A effectively reduce Medfly abundance, resulting in elimination of the target pest populations. OX3864A deployment as adults also demonstrated the beneficial attribute of protecting fruit quality to preserve marketable yield. Data for adult and pupal deployment strategies are encouraging for self-limiting technologies targeting Medfly populations and support a broader evaluation of OX3864A Medfly or further improved self-liming Oxitec strains of Medfly in open settings.     

Agronomic performance and water-use efficiency of F3 soybean populations grown under contrasting base saturation

Most of the Brazilian soils, especially in Cerrado biome, have high acidity and toxic aluminium, making the application of limestone an indispensable technique to obtain high yield in soybean crop. The hypothesis of this study was that contrasting base saturation provides changes in water-use efficiency (WUE) and agronomic traits of soybean populations. Thus, we evaluated the WUE and agronomic performance of F₃ soybean populations under different base saturation levels. Each experiment was conducted in a randomized complete blocks design with three replicates and 10 F₃ populations (P1, P2, P3, P4, P5, P6, P7, P8, P9 and P10) for two crop seasons. Segregating populations were obtained by bulk method. In the first experiment, F₃ populations were evaluated without correction of base saturation (V = 30%), while in the second experiment, limestone was applied three months before sowing to increase base saturation to 60%. The traits evaluated were as follows: calcium, magnesium and potassium contents, water-use efficiency (WUE), plant height, first pod height, main stem diameter and grain yield. Our findings indicate that WUE and agronomic performance of F₃ soybean populations depends on the saturation condition. We identified the P4 and P9 populations as the most promising for use in breeding programmes aiming at higher tolerance to abiotic stress caused by low base saturation in soil.