Serologic survey for Leptospira spp. in captive neotropical felids in Foz do Igua?u, Paraná, Brazil

Leptospirosis is a bacterial zoonosis of worldwide distribution and is endemic in tropical countries, where rodents and other wild mammals are abundant and may act as reservoirs. Leptospirosis has become a concern in captive wild animals, due mostly to their exposure to contaminated urine or environment. Although domestic cats (Felis catus) have been reported refractory to leptospirosis, serology and disease in captive wild felids is still unclear. In this study 57 adult, clinically healthy felids, including 1 Geoffroy's cat (Leopardus geoffroyi), 3 jaguarundis (Puma yagouaroundi), 17 margays (Leopardus wiedii), 22 little spotted cats (Leopardus tigrinus), and 14 ocelots (Leopardus pardalis) kept in captivity at the Sanctuary at the Itaipu Binacional hydroelectric power plant (Bela Vista Biological Sanctuary), Foz do Iguacu City, Paraná State, Brazil, were serologically surveyed for the presence of antibodies against 28 serovars of Leptospira spp. by microagglutination test (MAT). Two animals (3.5%) were seropositive: one male ocelot to the serovar Cynopteri (titer 100) and one female margay to Autumnalis (100) and Butembo (200). The captive-born, 5-yr-old ocelot had been solitary housed in an individual cage. The approximately 21-yr-old wild-caught margay was also kept individually. None of the tested animals showed signs ofleptospirosis. During a study conducted 4 yr previously in the same facility, this particular margay also tested positive for the same two serovars, among others. The present study indicates that the felids tested for Leptospira spp. by MAT were exposed to serovars, but did not demonstrate clinical signs of disease. Comparison with a previous study suggests that serovar titers may vary over time and that leptospirosis dynamics remains unclear in wild felids.     

Minimum infusion rate and hemodynamic effects of propofol, propofol-lidocaine and propofol-lidocaine-ketamine in dogs

ObjectiveTo evaluate the effects of a constant rate infusion (CRI) of lidocaine alone or in combination with ketamine on the minimum infusion rate (MIR) of propofol in dogs and to compare the hemodynamic effects produced by propofol, propofol-lidocaine or propofol-lidocaine-ketamine anesthesia.Study designProspective, randomized cross-over experimental design.AnimalsFourteen adult mixed-breed dogs weighing 15.8 ± 3.5 kg.MethodsEight dogs were anesthetized on different occasions to determine the MIR of propofol alone and propofol in combination with lidocaine (loading dose [LD] 1.5 mg kg^?1, CRI 0.25 mg kg^?1 minute^?1) or lidocaine (LD 1.5 mg kg^?1, CRI 0.25 mg kg^?1 minute^?1) and ketamine (LD 1 mg kg^?1, CRI 0.1 mg kg^?1 minute^?1). In six other dogs, the hemodynamic effects and bispectral index (BIS) were investigated. Each animal received each treatment (propofol, propofol-lidocaine or propofol-lidocaine-ketamine) on the basis of the MIR of propofol determined in the first set of experiments.ResultsMean ± SD MIR of propofol was 0.51 ± 0.08 mg kg^?1 minute^?1. Lidocaine-ketamine significantly decreased the MIR of propofol to 0.31 ± 0.07 mg kg^?1 minute^?1 (37 ± 18% reduction), although lidocaine alone did not (0.42 ± 0.08 mg kg^?1 minute^?1, 18 ± 7% reduction). Hemodynamic effects were similar in all treatments. Compared with the conscious state, in all treatments, heart rate, cardiac index, mean arterial blood pressure, stroke index and oxygen delivery index decreased significantly, whereas systemic vascular resistance index increased. Stroke index was lower in dogs treated with propofol-lidocaine-ketamine at 30 minutes compared with propofol alone. The BIS was lower during anesthesia with propofol-lidocaine-ketamine compared to propofol alone.Conclusions and clinical relevanceLidocaine-ketamine, but not lidocaine alone, reduced the MIR of propofol in dogs. Neither lidocaine nor lidocaine in combination with ketamine attenuated cardiovascular depression produced by a continuous rate infusion of propofol.     

Particle arrangement and internal porosity of coarse fragments affect water retention in stony soils

Information about water retention in stony soils lags behind due to methodological difficulties. We applied a new strategy to measure the water retention in soils with coarse fragments (CFs) and to get insights into the effect of CFs porosity on water retention. Water retention at zero, 10, and 150 m suction, bulk density, and the mass fraction of six particle size classes were measured in undisturbed blocks from soils with variable CFs contents, originating from three parent materials. The results showed that some soils contain porous CFs (2–250 mm) with a water holding capacity as high as the fine fraction (<2 mm). The water held in the suction range of 1–150 m in a soil with porous CFs was twice as high as in soils with non-porous CFs. Multilinear regressions revealed that both the water retention capacity at 1 m suction and in the range 1–150 m were more dependent on bulk density than on the fraction of CFs and fine particles. In the soil with porous CFs, there was no correlation between their fraction and soil water retention. These results show that the bulk water retention capacity of soils with CFs is underestimated when not considering the internal porosity of the CFs. A better understanding of the effect of the porosity of CFs on bulk soil porosity and water retention is important to propose suitable pedotransfer functions and refine physically-based hydraulic functions for stony soils.     

A multiplex PCR for the detection of Brucella spp. and Leptospira spp. DNA from aborted bovine fetuses

Bovine brucellosis and leptospirosis are important causes of bovine abortion around the world. Both diseases can be serologically diagnosed, but many factors may cause false positive and negative results. Direct methods based on bacteriological isolation are usually employed, but they are difficult, time consuming and dangerous. Monoplex polymerase chain reaction (PCR) have been successfully described for the detection of Brucella spp. and Leptospira spp. Aiming at improvement in the direct diagnosis, a multiplex PCR (mPCR) for the detection of these agents in aborted bovine fetuses is described. The detection threshold of the mPCR was evaluated in experimentally contaminated bovine clinical samples using a conventional proteinase K/SDS or a boiling-based extraction protocols. The mPCR was applied to two groups of clinical samples: 63 episodes of bovine abortion and eight hamsters experimentally infected with Leptospira interrogans serovar pomona. Adopting microbiological isolation as reference, the test showed a sensitivity of 100% in both groups of clinical samples. Seven samples collected from bovine fetuses were Brucella spp. culture negative but showed positive results in mPCR. Regarding Leptospira spp. detection, similar results were observed in three bovine clinical samples. All hamsters infected with Leptospira were positive in both microbiological culture and mPCR. The boiling extraction protocol showed better results in some clinical samples, probably by the removal of PCR inhibitors by heat treatment. The high sensitivity, simplicity and the possibility of detection of both bacteria in a single tube reaction support the use of the mPCR described in the routine diagnosis.     

Estimation of Milk Production in Lactating Sows by Determination of Deuterated Water Turnover in Three Piglets per Litter

The milk intake in piglets from four lactating sows was measured in three 48 h periods, starting on days 3, 10 and 17 of lactation, using the deuterium oxide (D 2 O) dilution technique. The milk intake was estimated from the water turnover in the piglets corrected for the production of metabolic water. The water turnover was estimated from the water dilution space and the fractional turnover of body water, determined by the rate of D 2 O dilution. To determine the magnitude of isotopic recycling, a randomly selected piglet in each litter was not enriched with D 2 O. Milk production of the four lactating sows was also measured by the weigh-suckle-weigh (WSW) method on days 4, 11 and 18 of lactation. The average daily milk production determined by the D 2 O dilution technique (9.91 - 0.69 kg) was higher ( P <0.05) than that determined by the uncorrected WSW method (8.65 - 0.81 kg). Different procedures for selecting piglets were evaluated to obtain the best possible estimation of total milk production from three piglets in each litter. The total milk production of a sow based on three piglets in the litter was obtained from a quadratic model of the relationship between milk intake and daily gain. When the daily gain of all piglets were known the Pearson correlation between milk production determined for the whole litter ( n -1) and only three median piglets was 0.98.     

Geospatial variation of physical attributes and sugarcane productivity in cohesive soils

Precision Agriculture - Sugarcane productivity is highly variable across space, and knowledge about the spatial distribution of soil physical attributes is important to guide management practices...     

Response of in vitro obtained oil palm and interspecific OxG hybrids to inoculation with Phytophthora palmivora

Bud rot (BR) disease caused by Phytophthora palmivora is the most devastating disease in oil palm cultivation in America. Oil palms that survived BR epidemics were found in areas highly devastated by the disease; these palms were introduced into Cenipalma's in vitro micropropagation (cloning programme). A severity scale was developed for in vitro palms from five ortets inoculated with two different P. palmivora isolates. Then, eight ortets of Elaeis guineensis and two ortets of the OxG interspecific hybrid were evaluated in two inoculation trials under chamber growth conditions. The clone performance response was consistent with that reported in the field for the corresponding ortets, and two contrasting ortets, one susceptible (ortet 57) and one resistant (ortet 34) were identified. We monitored and compared defence responses to P. palmivora in the contrasting ortets. An increase in reactive oxygen species (ROS) production after inoculation with the pathogen was observed, with higher accumulation of H₂O₂ in the resistant plants. Catalase (CAT) activity in resistant plants increased after inoculation with the pathogen from 24 hr post‐infection (hpi) and remained high during the observation time. In the susceptible ortets, there was a significant increase on catalase activity only at 48 hpi. Peroxidase (POS) activity increased in clones from both susceptible and resistant ortets, but the increase was much greater in the susceptible ones. Phenylalanine ammonia lyase activity increased in response to inoculation, and these increases were greater in clones of the susceptible ortet than in clones of the resistant ortet.     

Mixed-effect non-linear modelling for diameter estimation along the stem of Tectona grandis in mid-western Brazil

This study evaluated the efficiency of taper functions and the application of mixed-effect modelling for diameter estimation along the stems of Tectona grandis. We sampled 266 trees of Tectona grandis, measuring the diameter at relative heights for volume determination, grouping the data according to three form-factor classes. Six taper functions were fitted, selecting the function with better fit performance. Six taper functions were fitted, selecting the function with better fit performance. The selected function was fitted in its basic formulation, and with the mixed non-linear modelling technique in different scenarios, and for the stem stratified in three portions of the total height. The precision and selection of the adjusted models were evaluated regarding the coefficient of determination, standard error of estimate, the Akaike information criterion, bias, quadratic error and absolute bias. According to the statistical criteria used, the model of Kozak was selected for the adjustments. For diameter estimation, the scenario with two coefficients as random effects provided an accuracy increase of 11.91%, and the mixed non-linear modelling better estimated the stem diameter for the stratified stems. In conclusion, the model of Kozak can be used to describe the stem shape of Tectona grandis, and the mixed-effect non-linear model approach was the best technique to estimate diameter along the stem of Tectona grandis.     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.