The Effect of Soil Moisture and Cabbage Amendment on the Thermoinactivation of Phytophthora nicotianae

The analysis of the effect of soil water matric potential and temperature regimes on the inactivation of chlamydospores of Phytophthora nicotianae in cabbage amended soils was evaluated using three matric potentials (0, -10, and -30kPa), temperature regimes of 1.5h at 44°C, 5h at 41°C and 8h at 35°C, or 3h at 47°C, 5h at 44°C and 8h at 35°C, with a baseline temperature of 25°C during the rest of the day. The results indicated that survival of P. nicotianae was lowest in saturated soil; and as temperature increased, survival of the pathogen decreased at all soil water matric potentials evaluated. Cabbage amendments can enhance the effect of the heat treatment, further decreasing the pathogen population. The soil water matric potentials evaluated represent optimum levels for the study of thermal inactivation. However, under field conditions lower potentials may be found. Extending the range of soil water matric potentials and the treatment time would allow better comparisons with the field data. There is a clear indication that one irrigation period prior to solarization would provide enough moisture to inactivate the primary inoculum of P. nicotianae in the top soil under field conditions; however, other factors may affect the effectiveness of solarization, reducing or enhancing its potential.     

Measurement of Ovine Pregnancy-Associated Glycoprotein (PAG) During Early Pregnancy in Lacaune Sheep

This study describes ovine pregnancy‐associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi‐purified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG_57+59kDa) and R805 (against ovPAG5_58+61kDa) were used respectively in RIA‐780 and RIA‐805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n = 17) than in non‐pregnant ones (n = 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA‐780 and 14 900 Ci/mmol in RIA‐805. The minimal detection limits for RIA‐780 and RIA‐805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra‐assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA‐780 and 8%, 9% and 5% for RIA‐805. The inter‐assay CV in the same samples were 13%, 12% and 7% for RIA‐780 and 13%, 11% and 5% for RIA‐805. The recovery was higher than 95% in both assays. No cross‐reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA‐780 and RIA‐805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding.     

Porewater dynamics and the formation of iron sulfides in a mangrove ecosystem,Sepetiba Bay,Brazil

Porewater dynamics and the formation of iron sulfides were studied in the Brazilian mangrove. Porewater samples were collected during tidal cycles using in situ equipment and physical–chemical and chemical data were obtained. The advective transport of porewater by tidal currents was found to be more effective between 0 and 5cm depth than below 15cm. The diffusive input of atmospheric oxygen during low tides resulted in oxidation of porewater dissolved sulfides. Thermodynamic considerations identified pyrite as the main iron sulfide forming at this depth, and the amorphous iron hydroxides are probably the main iron source. Below 15cm depth, irregular root distribution underground and benthic faunal bioturbation caused considerable spatial variation in a small scale (20cm). The correlation between alkalinity and total dissolved sulfide suggests that the main pathway for organic matter decomposition is sulfate reduction. Formed in the highly sulfidic diagenetic zone, the dissolved iron went through iron sulfide formation process. Crystalline iron oxides like hematite and magnetite may constitute an important iron source below 15cm, whereas pyrite is still the most probably occurring iron sulfide, according to thermodynamic considerations.     

Pilot clinical study of carmustine associated with a lipid nanoemulsion in combination with vincristine and prednisone for the treatment of canine lymphoma

A lipid nanoemulsion (LDE) resembling low‐density lipoprotein can target malignant tumours. In in vivo and clinical studies, association of chemotherapeutic agents to LDE decreased their toxicity and increased pharmacological action. Here, safety of LDE as carmustine carrier (50 mg m^?2, intravenous) combined with vincristine and prednisone for the treatment of dogs with lymphoma was tested and compared with commercial carmustine with vincristine and prednisone. In five dogs from LDE‐carmustine and six from commercial carmustine, complete remission was achieved (P > 0.05). Partial remission occurred in two dogs from each group. In both groups, the median progression‐free intervals (119 and 199 days) and overall survival times (207 and 247 days) were equal. Neutropenia was observed in both groups, but no other major toxicities occurred. Therefore, no difference was observed between the treatments. LDE‐carmustine was shown to be safe and effective in a drug combination protocol, which encourages larger studies to investigate the use of this novel formulation to treat canine lymphomas.     

An appraisal of five methods for the measurement of the fungal population in soil treated with chlorothalonil

An experiment was carried out in a greenhouse with the aim of determining an acceptable method to quantify the fungal population in a soil treated with the fungicide chlorothalonil. Doses of the fungicide ranging from 12 to 96 µg AI g⁻¹ soil were applied and microbial biomass carbon (C), soil ergosterol content, living hyphal length, as well as counts of total and cellulolytic fungi colonies, were measured 1, 2, 3, 4 and 5 weeks after application. At the end of 16 weeks a new evaluation was done using the three first methods. The microbial biomass C was the least sensitive parameter and, on balance, the living hyphal length was the most sensitive parameter for demonstrating effects of chlorothalonil on the fungal population. Some problems related to the efficiency of the ergosterol content and living hyphal length measurements in the evaluation of the effect of the fungicide on the fungal microflora are discussed, as is the need to compare short‐term (0–5 weeks after treatment) with longer‐term (16 weeks) results. © 2000 Society of Chemical Industry     

Method for evaluating the influence of wood machining conditions on the objective characterization and subjective perception of a finished surface

A method for evaluating the influence of the operating parameters of wood machining (planing, sanding) on the quality of a finished surface was established. The influence of each of the operations involved was studied using different strategies. For the planing operation, three levels were established (Level 1, 2 and 3) by determining different values for each of the major process parameters (tool rotation speed, feed speed, depth of cut). For both, surface preparation and polishing, two levels were established with a fixed setup. Finally, as finishing products, two different transparent coatings were selected (water-borne and solvent-borne). The quantitative evaluation of the state of the surface was assessed by means of an artificial vision system for the determination of the pseudo-roughness of wood surfaces. A filtering method based on fast Fourier transforms was applied and it was possible to derive three criteria for evaluating the resulting profile.     

Neutral sugars in melanins synthesized by actinomycetes from Brazilian soils

 Nine actinomycete melanins synthesized under various culture conditions, eight of them by actinomycete samples isolated from Brazilian topsoils under savanna (cerrado) vegetation and one from an ATCC sample, were subjected to a two-step hydrolysis procedure and the sugars released qualitatively and quantitatively determined by capillary gas-liquid chromatography (GLC). Humic acids (HAs) extracted from these soils, analysed previously, were used for comparison. The neutral sugars glucose, galactose, mannose, xylose, arabinose, ribose, rhamnose and fucose and the alcohol sugar inositol were present in varying amounts in most of the melanins analysed. The same sugars were present in the HAs used for comparison, except for ribose. Some qualitative and quantitative differences observed in the two types of macromolecules would be expected, considering their origins. The results indicate that the actinomycete melanins have a qualitative sugar distribution pattern similar to that of the HAs from Brazilian tropical soils and of HAs reported for soils from other climatic regions. The possible participation of actinomycete melanins in the formation of soil humic substances is discussed. Received: 4 April 1997     

Detection of rubber tree orchards infested by Meloidogyne exigua using vegetation indexes obtained from satellite images

New Forests - Hevea brasiliensis natural rubber production is strategic for the world economy. Meloidogyne exigua causes the main root disease in this crop in Brazil. Its early diagnosis allows...     

Distribution patterns and population structure of the blue shark (Prionace glauca) in the Atlantic and Indian Oceans

The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheries from several nations in the Atlantic and Indian Oceans was compiled. Data sets included information on location, size and sex, in a total of 478,220 blue shark records collected between 1966 and 2014. Sizes ranged from 36 to 394 cm fork length. Considerable variability was observed in the size distribution by region and season in both oceans. Larger blue sharks tend to occur in equatorial and tropical regions, and smaller specimens in higher latitudes in temperate waters. Differences in sex ratios were also detected spatially and seasonally. Nursery areas in the Atlantic seem to occur in the temperate south‐east off South Africa and Namibia, in the south‐west off southern Brazil and Uruguay, and in the north‐east off the Iberian Peninsula and the Azores. Parturition may occur in the tropical north‐east off West Africa. In the Indian Ocean, nursery areas also seem to occur in temperate waters, especially in the south‐west Indian Ocean off South Africa, and in the south‐east off south‐western Australia. The distributional patterns presented in this study provide a better understanding of how blue sharks segregate by size and sex, spatially and temporally, and improve the scientific advice to help adopt more informed and efficient management and conservation measures for this cosmopolitan species.