SOIL LOSS FROM EROSION IN THE NEXT 50 YEARS IN KARST REGIONS OF MAYABEQUE PROVINCE,CUBA

To date, neither the method nor diagnostic indices employed in Cuba to evaluate erosion of Red Ferralitic or Ferrasol Rhodic soil in karstic regions has taken into consideration morphogenesis in such geo‐ecosystems or their relationship with erosion, which has led to sequential degradation of the most productive soils in Cuba. We explore the case for considering A + B horizon depth as one of the basic indices for evaluating the severity of erosion. There is no methodology available for estimating the volume of soil lost through karstic absorption forms (dolines). This article forecasts loss of soil cover using a model which estimates losses of 268·52 to 450·52 mm y⁻¹ for future scenarios (periods of 25 and 50 years). A mean loss rate of 1·07 mm y⁻¹ was found in areas cultivated as pastureland during the period from 1986 to 2009, which exceeds the tolerance thresholds proposed by the Universal Soil Loss Equation and the soil formation rates estimated for limestone in Cuba and it is likely there is with a marked tendency for this to increase. These results should be interpreted as a first estimate for setting loss tolerances as there is no similar experience with own data for a more precise definition of the erosion of soil in karstic regions. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhalant anesthetic requirement in cats is animal-dependent

Minimum alveolar concentration (MAC) of an inhalant is an indicator of its anesthetic potency. Individuals vary in their sensitivity to anesthetic agents as demonstrated by different individual MAC values. We hypothesized that individual animal sensitivity would be maintained with different inhalant anesthetics. As part of separate studies, six female DSH cats, aged 24 ± 2.5 (mean ± SD) months and weighing 3.5 ± 0.3 kg, were studied similarly on three separate occasions over a 12‐month period to determine the MAC of isoflurane (ISO), sevoflurane (SEVO), and desflurane (DES), respectively. In each study, chamber induction was followed by orotracheal intubation, and anesthesia was maintained via a nonrebreathing circuit. ECG, pulse oximetry, Doppler systolic blood pressure, end‐tidal gases, and esophageal temperature were monitored. End‐tidal gases were hand‐sampled from a catheter whose tip lay level with the distal end of the ET tube. Gases were analyzed by Raman spectrometry and, for each agent, the analyzer was calibrated with at least three gas standards. MAC was determined in triplicate using standard tail‐clamp technique. Data were analyzed by two‐way anova followed by Tukey's test and significant differences were found. Average MACs (%) for ISO, SEVO, and DES were 1.90 ± 0.18, 3.41 ± 0.65, and 10.27 ± 1.06, respectively. Body temperatures, Doppler systolic blood pressure, and SpO₂ were recorded at the time of MAC determinations for ISO, SEVO, and DES were 38.3 ± 0.3, 38.6 ± 0.1, 38.3 ± 0.35 °C; 71 ± 8, 75 ± 16, 88 ± 12 mm Hg; 99 ± 1, 99 ± 1, 99 ± 1%, respectively. Both the anesthetic agent and the individual cat had significant effects on MAC (p = 0.0001 and 0.0185, respectively). MAC varied between individuals and cats were consistent in their order of sensitivity to inhalant anesthetics across the three agents. Within this group of cats, the relationship of individual MAC to the group MAC for each of the three inhalant agents was maintained. This suggests that any individual may be consistently more or less sensitive to a variety of inhalant agents.     

Calibration of two techniques for estimating herbage mass

Two non-destructive techniques for estimating herbage mass (dry matter yield) were evaluated during the growing season of 1988, from April to September. Samples were collected from four sites, with ten observations made on twenty-five days at each site, giving a total of 612 sample units. Observations were obtained from each unit, either with a plastic rising-plate meter (335) or with a metal rising-plate meter (227). In addition, measurements with a single-probe capacitance meter (Pasture Probe) were also made on all units. The usefulness of the non-destructive methods for predicting the actual yield was evaluated by calibrating them by means of regression on the yield determined by mowing 1·5-m² quadrats, weighing, subsampling and drying the grass. The yield measurements were logarithmically transformed to correct for the proportionality of the residual variance with the mowed dry matter yield. Logarithmic transformation of the sensor measurements improved the linearity of the calibration relationships. The combination of one rising-plate meter and the Pasture Probe resulted in a linear and additive model with a larger adjusted R² than models with just one of these two sensors. The addition of the predictors ‘external moisture’ (e.g. dew), ‘day number after mowing’ and ‘site number’ significantly increased the goodness of fit of many models. In some models addition of the logarithm of the ‘dry matter percentage’ was significant. Other predictors in these models such as “Julian day number” and “grazing” proved not to be significant. The adjusted R²s in the best models for the metal and the plastic discs were 89·7% and 87·3% respectively. The corresponding coefficients of variation were 26·2% and 26·1%. The results show that further research is necessary to refine the techniques or to develop new techniques to estimate the dry matter yield, before the sensors can be usefully integrated into a management system.     

Physiological and pharmacokinetic responses in neotropical Piaractus mesopotamicus to the essential oil from Lippia sidoides (Verbenaceae) as an anesthetic

International Aquatic Research - The goal of the study was to evaluate Lippia sidoides essential oil as an anesthetic for the tropical fish pacu Piaractus mesopotamicus. The physiological and...     

Stability of Perovskite (MgSiO3) in the Earth's Mantle

Available thermodynamic data and seismic models favor perovskite (MgSiO3) as the stable phase in the mantle. MgSiO3 was heated at temperatures from 1900 to 3200 kelvin with a Nd-YAG laser in diamond-anvil cells to study the phase relations at pressures from 45 to 100 gigapascals. The quenched products were studied with synchrotron x-ray radiation. The results show that MgSiO3 broke down to a mixture of MgO (periclase) and SiO2 (stishovite or an unquenchable polymorph) at pressures from 58 to 85 gigapascals. These results imply that perovskite may not be stable in the lower mantle and that it might be necessary to reconsider the compositional and density models of the mantle.     

Response of tomato (Solanum L. section Lycopersicon Mill.) germplasm to begomovirus inoculation under controlled and field conditions

Ninety-five tomato accessions belonging to the Vegetable Crops Germplasm Bank of the Federal University of Viçosa (BGH-UFV) were evaluated in a protected environment (biolistic inoculation under greenhouse conditions) and in the field (natural infection) for resistance to bipartite begomoviruses present in Brazil. Plants were assessed by the visual evaluation of symptoms, and viral infection was confirmed by non-radioactive molecular hybridization. Univariate statistical analyses and correlations were made between the traits. High and significant correlations were found between the percentages of visual symptoms and of viral replication, with values of 0.67 in the protected environment and 0.60 in the field. We concluded that under the protected environment, the accessions BGH-2144, BGH-2150, BGH-6878 and BGH-6881 displayed resistance to infection. Under field conditions with natural infection, the best results were obtained for the accessions BGH-2080 and BGH-6881. Only the BGH-6881 (Solanum peruvianum L.) accession excelled in both conditions; this resistance was attributed to the presence of the Ty-2 and Ty-3 resistance gene alleles in heterozygosity. In general, all of the accessions selected in both experimental conditions can serve as sources for the development of cultivars tolerant or resistant to the bipartite begomoviruses present in Brazil.     

Biosorption of Toxic Metals by Water Lettuce (<Emphasis Type="Italic">Pistia stratiotes</Emphasis>) Biomass

Adsorption isotherms were constructed to evaluate the potential use of water lettuce (Pistia stratiotes) dry biomass for the biosorption of zinc and cadmium. One gram of dry biomass of this plant was treated with five increasing doses of zinc (1.8, 18, 50, 79, and 105 mg L^?1) and four doses of cadmium (0.01, 0.1, 1, and 10 mg L^?1), for nine collection times (1, 3, 6, 12, 24, 36, 48, 60, and 72 h). The levels of these metals were determined by atomic absorption spectrophotometry. To evaluate changes in the surface morphology of the dry biomass, scanning electron microscopy (SEM) images were taken of the samples subjected to the greatest contamination, and these were compared with the images of the samples without zinc and cadmium (control). The ISOFIT software was used to select the isotherm model that best fit the biosorption of metals by water lettuce dry biomass. The linear model was determined to be the best-fitting isotherm model, because it had the lowest corrected Akaike information criterion (AICc) value and a Akaike weight (AICw) value closest to one, which indicates the high affinity of the biosorbent for the adsorbates evaluated. The results for both metals demonstrated greater than 70% reductions in the concentrations of the metals in the contaminated solutions. The SEM images indicated changes in the morphology of the contaminated biomass, thus demonstrating the biosorption mechanisms and confirming the potential of the dry biomass of this plant for use in the remediation of solutions contaminated with zinc and cadmium.     

Coinfection of Leishmania chagasi with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in cats from an endemic area of zoonotic visceral leishmaniasis

The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302 (9.93%), by serology in 46/302 (15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66 (18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66 (7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p<0.0001), but not with T. gondii (p>0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with FIV, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections.