Laser Optical Plankton Counter and Zooscan intercomparison in tropical and subtropical marine ecosystems

Two recently developed instruments, the Laser Optical Plankton Counter (LOPC) and the Zooscan, have been applied to study zooplankton biomass size spectra in tropical and subtropical marine ecosystems off Brazil. Both technologies rely on optical measurements of particles and may potentially be used in zooplankton monitoring programs. Vertical profiles of the LOPC installed in a 200 mu m ring net have been obtained from diverse environmental settings ranging from turbid and nearshore waters to oligotrophic open ocean conditions. Net samples were analyzed on the Zooscan and counted under a microscope. Particle biovolume in the study area estimated with the LOPC correlated with plankton displacement volume from the net samples, but there was no significant relationship between total areal zooplankton biomass determined with LOPC and the Zooscan. Apparently, normalized biomass size spectra (NBSS) of LOPC and Zooscan overlapped for particles in the size range of 500 to 1500 mu m in equivalent spherical diameter (ESD), especially at open ocean stations. However, the distribution of particles into five size classes was statistically different between both instruments at 24 of 28 stations. The disparities arise from unequal flow estimates, from different sampling efficiencies of LOPC tunnel and net for large and small particles, and possibly from the interference of non-zooplankton material in the LOPC signal. Ecosystem properties and technical differences therefore limit the direct comparability of the NBSS slopes obtained with both instruments during this study, and their results should be regarded as complementary.

Prevalence of leptospirosis in dairy goats in the semiarid region of Paraiba state

Higino S.S.S., Alves C.J., Santos C.S.A.B., Vasconcellos S.A., Silva M.L.C.R., Brasil A.W.L., Pimenta C.L.R.M. & Azevedo S.S. 2012. [Prevalence of leptospirosis in dairy goats in the semiarid region of Paraiba state.] Prevalencia de leptospirose em caprinos leiteiros do semiarido paraibano. Pesquisa Veterinaria Brasileira 32(3):199-203. Universidade Federal de Campina Grande, Centro de Saude e Tecnologia Rural, Unidade Academica de Medicina Veterinaria, Av. Universitaria s/n, Patos, PB 58700-970, Brazil. E-mail: sergio.azevedo@pq.cnpq.br This study aimed to determine the prevalence of positive dairy goat herds and seropositive animals for leptospirosis in the semiarid region of Paraiba state, Brazil. Sampling was designed to determine the prevalence of positive herds (foci) and seropositive animals for leptospirosis. A total of 975 serum samples were collected from goats of 110 dairy herds in the Monteiro municipality, Western Cariri microregion of Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) was carried out using 24 Leptospira spp. serovars as antigens. A herd was considered positive when existed at least one seropositive animal. The prevalence of positive herds and seropositive animals were 43.6% (95% CI = 34.2-53.4%) and 8.7% (95% CI = 58.7-12.9%) respectively. The most frequent serovars in goats were Autumnalis (1.74%; 95% CI = 0.97-3.09%), Sentot (1.71%; 95% CI = 0.82-3.52%) and Whitcomb (1.39%; 95% CI = 0.65-2.93%), and by herd, serovars Autumnalis (10.9%; 95% CI = 5.8-18.3%), Whitcomb (8.2%; 95% CI = 3.8-15.0%) and Sentot and Patoc (7.3%; 95% CI = 3.2-13.8%) were the most frequent. It is suggested that leptospirosis is spread in goats in the region, and that there is need to implement control and preventive measures in order to reduce infection and economic losses, and to avoid possible transmission of infection to humans.

Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid

Alves C. J., Alcino J. F., Farias A. E. M., Higino S. S. S., Santos F. A., Azevedo S. S., Costa D. F. & Santos C. S. A. B. 2012. [Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid.] Caracterizacao epidemiologica e fatores de risco associados a leptospirose em ovinos deslanados do semiarido brasileiro. Pesquisa Veterinaria Brasileira 32(6): 523-528. Universidade Federal de Campina Grande, Centro de Sa de e Tecnologia Rural, Unidade Academica de Medicina Veterinaria, Av. Universitaria s/n(o), Patos, PB 58700-970, Brazil. E-mail: clebertja@uol.com.br The aim of this investigation was to determine the herd-level and animal-level prevalence of leptospirosis in sheep from the semiarid of Paraiba State, Northeast Brazil, as well as to identify risk factors. Blood samples were collected from 1,275 sheep from 117 flocks in 19 counties in the Sertao mesoregion, Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) using 24 Leptospira spp. serovars as antigens was carried out. Of the 117 flocks studied 33 (28.20%) presented at least one seropositive sheep, and of the 1,275 animals 69 (5.41%) were seropositive with titers ranging from 100 to 3,200. Reactant serovars were Autumnalis (49.30%), Andamana (27.53%), Sentot (17.39%), Whitcomb (4.34%) and Australis (1.44%). Herd size > 48 sheep (odds ratio = 2.26; 95% CI = 1.33-5.07; p = 0.021) and participation in animal exhibits (odds ratio = 9.05; 95% CI = 0.96-85.71; p = 0.055) were identified as risk factors. The need was suggested for studies on the isolation of the agent, characterization of its pathogenicity and its economic impact on sheep flocks of the region, and sanitary control in sheep agglomerations was recommended.

Integrated ecological risk assessment of pesticides in tropical ecosystems: A case study with carbofuran in Brazil

The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Environ. Toxicol. Chem. 2012;31:437-445. (C) 2011 SETAC

CHARACTERIZATION OF REGOSOLS IN THE SEMIARID REGION OF PERNAMBUCO, BRAZIL

CHARACTERIZATION OF REGOSOLS IN THE SEMIARID REGION OF PERNAMBUCO, BRAZIL Studies on soil characterization in unexplored regions, besides the generation of data banks for the soil classes of the country, also produce scientific information about soil properties, important for the development of good management practices and sustainable land use. One of the main soil classes in the semiarid region of Pernambuco State, the Regosols, cover about 27 % of the state area, and are used mainly for family agriculture. Due to different geological and climatic aspects Regosols with different chemical, physical and mineralogical properties are found in Pernambuco, which were characterized for the semiarid region of the State. Five Regosol profiles were selected in different regions of the State (P1=Sao Caetano; P2=Lagoa do Ouro; P3=Caetes; P4=Sao Joao; P5=Parnamirim). The soils were morphologically characterized and samples collected from all horizons and the bedrock. Routine physical and chemical analyses were carried out for soil classification of all samples and mineralogical analyses of the coarse fractions (gravel and sand) by optical microscopy and of the silt and clay fractions by X ray diffraction (XRD), as well as petrographic analyses of the rock samples. The results showed similarities between the soils, with a low degree of pedogenetic development, varying from medium to very deep, with the horizon sequence A-AC-C-Cr and a sandy to sandy loam texture. In the deeper layers of two profiles (P1 and P5), a solodic character was observed. Organic matter and available phosphorus content were low in all studied soils. Despite the low levels of exchangeable cations, all soil profiles showed high base saturation. The mineralogical composition of gravel, sand and silt fractions consisted, essentially, of quartz, followed by feldspars and mica, supporting the results of the petrographic analysis of the bedrock. Kaolinite was the main clay mineral in all studied profiles and horizons, indicating an important monosialitization process in autochthonous soils of a typical semiarid region. In soil profile P2, at a lower landscape position, smectite minerals were observed, with mixing phases of montmorillonite, beidelite or nontronite, indentified by the Greene-Kelly test in the DRX analysis.

Water transfer from São Francisco river to semiarid northeast of Brazil: technical data, environmental impacts, survey of opinion about the amount to be transferred

The transposition of the São Francisco River is considered one of the greatest engineering works in Brazil of all time since it will cross an extensive agricultural region of continental dimensions, involving environmental impacts, water, soil, irrigation, water payment and other multidisciplinary themes. Taking into account its importance, this subject was incorporated into a discipline of UFSCar (Federal University of São Carlos - Brazil) named "Pollution and Environmental Impacts". It was noted strong reaction against the project, even before the presentation. To allow a critical analysis, the first objective was to compile the main technical data and environmental impacts. The second objective was to detect the three most important aspects that cause reaction, concluding for the following reasons: assumption that the volume of water to be transferred was much greater than it actually is proposed in the project; lack of knowledge about similar project already done in Brazil; the idea that the artificial canal to be built was much broader than that proposed by the project. The participants' opinion about "volume to be transferred" was raised quantitatively four times: 2-undergraduate students; 1-graduate; 1-outside community. The average resulted 14 times larger than that proposed in the project, significant according to t-test. It was concluded that the reaction to water transfer project is due in part to the ignorance combined with a preconceived idea that tend to overestimate the magnitude of environmental impacts.

Molecular epidemiology of animal rabies in the semiarid region of Paraíba, Northeastern Brazil

In the semiarid of the state of Paraíba, the anti-rabies vaccination is not common, most of the local inhabitants who deal with the animals do not know the incidence of the disease in the region. In this study, samples of foxes (Pseudalopex vetulus), insectivorous bats (Molossus molossus), raccoons (Procyon cancrivorous) and domestic animals brains were submitted to the diagnosis of rabies, by using the direct fluorescent antibody technique (d-FAT) and mouse inoculation test (MIT). Of the 581 examined materials, 50 (8.60 %) were positive for d-FAT and 47 (8.09 %) for MIT. From the positive samples for rabies, RNAs were extracted and transformed to cDNA, at the Laboratory of Rabies/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. The phylogenetic characterization of the N gene was performed at the Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade Nihon, Faculdade de Ciências Bioresource, Fujisawa, Kanagawa, Japão. Based on the results of genotyping and phylogenetic analyzes, it is concluded that the epidemiology of rabies is complex in the semiarid of Paraíba, with different viral variants being maintained in domestic dogs, foxes, insectivorous bats and vampire bats. All the isolates examined belong to the genotype I of the genus Lyssavirus and it is possible to state that in the region, foxes are important sylvatic reservoirs of the rabies virus.