Space-time variation of the relative abundance of Limnoperna fortunei in deep zones of São Gonçalo Channel, Rio Grande do Sul, Brazil

This work describes the spatial-temporal variation of the relative abundance and size of Limnoperna fortunei (Dunker, 1857) collected in São Gonçalo Channel through bottom trawl with a 0.5 cm mesh, at depths between 3 and 6 m. The estimative of mean relative abundance (CPUE) ranged from 2,425.3 individuals per drag (ind./drag) in the spring to 21,715.0 ind./drag in the fall, with an average of 9,515.3 ind./drag throughout the year. The estimated mean density of L. fortunei for the deep region of São Gonçalo Channel ranged from 1.2 to 10.3 ind./m², and it was recorded a maximum density of 84.9 ind./m² in the fall of 2008. The method of sampling using bottom trawl enabled the capture of L. fortunei under the soft muddy bottom of the channel, in different sizes ranging from 0.4 to 3.2 cm. This shows that the structure of the L. fortunei adult population under the bottom of the São Gonçalo Channel is composed mostly of small individuals (<1.4 cm), which represent up to 74% of the population collected.

Assemblage of immature Odonata (Insecta, Anisoptera) in streams of the Mato Grosso do Sul State: spatial implications

ABSTRACT This study investigated the assemblages attributes (composition, abundance, richness, diversity and evenness) and the most representative genera of Odonata, Anisoptera at Água Boa and Perobão Streams, Iguatemi River basin, Brazil. Both are first order streams with similar length that are impacted by riparian forest removal and silting. Quarterly samplings were conducted from March to December 2008 in the upper, intermediate and lower stretch of each stream. The Mantel test was used to check the influence of spatial autocorrelation on the Odonata composition. Spatial variations in the composition were summarized by the Principal Coordinates Analysis (PCoA) using Mantel test residuals. The effects of spatial correlation on richness and abundance were investigated by the spatial correlogram of Moranʼs I coefficients. The most representative genera in each stream were identified by the Indicator Value Method. The spatial variations in the attributes of the assemblages were assessed using analysis of variance of null models. We collected 500 immature individuals of 23 genera and three families. Among the attributes analyzed only the composition and abundance showed significant spatial differences, with the highest mean abundance found in the Perobão Stream. Miathyria and Zenithoptera were the indicator genera of the Água Boa Stream and Erythrodiplax, Libellula, Macrothemis, Progomphus and Tramea were the indicator genera of the Perobão Stream.

Influência de elementos climáticos na mortalidade de cidades brasileiras

In this paper, preliminary to a series of investigations that the A. has the purpose to make about the influence of climatic factors particularly upon the prevalence of the most important acute infectious diseases in Brazil, he raises the question whether such factors do affect in this country the total death rates, as it is reasonable to suppose, according to what has been observed in temperate zones of northern and southern hemispheres. The inclusion of absolute humidity among other climatic factors to be dealt with seems justifiable according to Rogers and Stallybrass. Owing to scarcety of reliable data the A. was obliged to limit to a five-years period (1940-1944) the complete proposed investigation, which includes seven of the most important cities, scattered throughout the brazilian territory, from north to south - Belém, recife, Salvador, Rio, S. Paulo, Curitiba and Porto Alegre. Reference is made to their normal climatic conditions and monthly death-rates variations with their mean values and standard deviations. In a first part dealing with seasonal variations only for purposes of comparison, he points out that in there tropical cities of Brazil, without very clear seasonal differentiation, the curve of general mortality reached its highest point in austral autumn season and the remaining four (including Rio near the tropic) in the spring, with the exception of Curitiba, where the peak coincided with the summer season. He shows how such important causes of deaths, as diarrheas, common respiratory diseases and tuberculosis, whose seasonal distribution for each one of the seven cities is referred, may explain such seasonal variations. On a second part, a study is made of the general mortality distribution by four-months periods selected in accordance respectively with the highest or lowest values of rainfall and of mean temperature and humidity during period 1940-1944. Finally he compares the monthly waves of such climatic factors and the corresponding waves of total death - rates and finds through correlation coefficients 17 significant values with respect to their standard errors. Variations in the death - rates seemed to be perhaps more closely and uniformly associated with variations of mean humidity, as is indicated by coefficients ranging from + 0.3 to 0.6.

Doenças intestinais em cidades brasileiras: associação com elementos climáticos

Enteric fevers and dysenteries showed, during the period 1940-44, a summer prevalence in brazilian cities of the temperate zone. The distribu¬tion of the diseases by four-months periods, selected in acordance with the highest of lowest values of rainfall, mean temperature and absolute humidity induced to suppose that, in those cities, and also in tropical ones, both enteric fevers and dysenteries were closely associated with such climatic factors: enteric fevers mainly with absolute humidity and temperature, and dysenteries with humidity and rainfall. Correlation coefficients, statistically significant, have been obtained comparing monthly waves of climatic factors and corresponding waves of prevalence of the diseases. For enteric fevers, clear associations have been disclosed: with temperature variations in all temperate cities (coefficients ranging from + 0.42 to + 0.75, higher with mean temperature in the previous month) and in two of the four tropical cities (from + 0.26 to ± 0.30); with absolute humidity variations in cities of the first group (from + 0.51 to 0.71) and in the tropical city of Rio ( + 0.26 ± 0.12 and + 0.28 ± 0.12); and also with rainfall variations but only in two temperate cities (from + 0.28 to + 0.64). For dysenteric diseases, in cities of temperate zone similar associations have been found with absolute humidity (values of r, ranging from + 0.32 to + 0.45), with temperature (from + 0.26 to + 0.44); and with rainfall only in Curitiba ( + 0.25 ± 0.12). Recife (tropical city) yielded two significant values : r = — 0.27 ± 0.12 (correlation with mean temperature in the same month) and r = + 0.40 ± 0.11 and -h 0.37 ± 0.11 (between monthly morbidity rates and rainfall, respectively in the same month and in the previous one). Deaths by diarrhea and enteritis, in the cities of the temperate zone, prevailed in spring-summer seasons, also in four-months periods of highest temperature and humidity, for those cities and for the tropical ones, with the exception of Belem in which percentages were identical to those of opposite periods. Still with the exception of Belem, in all cities studied positive correla¬tion coefficients, statistically significant, have been obtained with temperature variations (ranging from + 0.25 to + 0.65 in tropical cities, and from + 0.47 to + 0.76 in temperate zone) and with humidity variations (from + 0.34 to + 0.44 in the first group, and from + 0.43 and + 0.74 in the second) . With rainfall, only Rio (in the tropical region) showed a significant value for r ( + 0.26 ±0:12); similarly in S. Paulo and Curitiba, the values ranged from + 0.46 to + 0.56, while in Porto Alegre there were found — 0.26 ± 0.12 and — 0.32 ± 012, for rainfall variations in the same and previous months.

Temperatura, humidade e pluviosidade nas suas relações com doenças respiratórias, em cidades brasileiras

During the period 1940-44, deaths by respiratory diseases and particularly by influenza and pneumonias prevailed during the winter in brazilian cities of the temperate zone (S. Paulo, Curitiba, Porto Alegre) and, with the exception of Rio de Janeiro, in tropical ones (Belem, Recife, Salvador) particularly during the four-months period of highest absolute humidity. For the first group of cities, negative correlation coefficients, statistically significant, have been uniformly obtained comparing monthly death-rates both with temperature - in the same month and in the previous one (values of r ranging from - 0.36 to - 0.640 - and with similar humidity variations (values of r from - 0.33 to - 0.59); also with rainfall, but only in S. Paulo and Curitiba (values of r from - 0.33 to - 0.61). Such associations have been disclosed irregularly and less frequently for the group of tropical cities: statistically significant values of r, in the death-rates correlations with temperature and humidity variations, have been eventually either positive (Recife, Salvador) or negative (Belem, Rio). Whooping cough showed during the same period a winter incidence in Curitiba and Porto Alegre: the compulsory notification of the disease is not required in S. Paulo, a third one brazilian city of the temperate zone. In the brazilian tropical cities of Belem, Recife, Salvador and Rio, the whooping cough distribution by four-months periods - selected in accordance with the highest or lowest values of rainfall, mean temperature and absolute humidity - induced to suppose that the disease was associated more uniformly with a high rainfall than with a low temperature or a low absolute humidity. However, only a few correlation coefficients statistically significant have been found out: between monthly morbidity rates and mean humidity in the same month and in the previous one in recife (-0.43 and - 0.39), and in Porto Alegre (-0.35 and - 0.46); and between the same rates and temperature variations in this last city (-0.28 and - 0.43).

Intestinal protein absorption in malnourished mice with acute schistosomiasis mansoni

Intestinal protein absorption was studied in undernourished albino Swiss mice with acute schistosomiasis mansoni. Undernutrition was induced by feeding mice with the Regional Basic Diet (RBD) ingested by human populations in Northeast Brazil, an experimental model previously developed in our laboratory. Weaning mice were infected with 40 cercariae and compared to undernourished non-infected mice and/or to infected mice fed a balanced control diet. Apparent and True Protein Absorption Coefficients were determined by nitrogen balance during five consecutive days ending at the 63rd day of the trial (acute phase of murine schistosomiasis). Fecal metabolic nitrogen (FMN) was determined after administration of a non-protein diet and was also calculated through linear regression. Our results showed a reduced protein absorption in non-infected RBD-fed mice as compared to mice fed a casein control diet. Infection with Schistosoma mansoni had apparently no effect on intestinal protein absorption in well-nourished mice. However, infection seemed to interfere with protein absorption in under-nourished animals, since the lowest absorption ratios have been detected among RBD-fed infected mice. A brief discussion is made on the advantages of using the method of linear regression for the determination of FMN.

Comparison between the Counter Immunoelectrophoresis Test and Mouse Neutralization Test for the Detection of Antibodies against Rabies Virus in Dog Sera

The detection of rabies antibodies is extremely valuable for epidemiological studies, determination of immune status in man, animals, and for the diagnosis of the disease. Several serological procedures have been described for this purpose. The present study reports a comparison between counterimmunoelectrophoresis test (CIET) and mouse neutralization test (MNT) in the detection of antibodies against rabies virus from 212 serum samples of vaccinated dogs. The agreement between both techniques was 79.7% and a significative association was demonstrated. The correlation coefficients between MNT and the CIET titers was determined considering 88 samples showing positive results in both techniques [CIET = 2 and MNT = 5 (0.13 IU/ml)] and resulted r² = 0.7926 (p < 0.001). The performance of CIET system was technically simple, cheap and rapid, and thereby it could be useful for serological monitoring of dog vaccination campaigns as well as for individual analysis.

Genetic characterization of morphologically variant strains of Paracoccidioides brasiliensis

Molecular characterization of Paracoccidioides brasiliensis variant strains that had been preserved under mineral oil for decades was carried out by random amplified polymorphic DNA analysis (RAPD). On P. brasiliensis variants in the transitional phase and strains with typical morphology, RAPD produced reproducible polymorphic amplification products that differentiated them. A dendrogram based on the generated RAPD patterns placed the 14 P. brasiliensis strains into five groups with similarity coefficients of 72%. A high correlation between the genotypic and phenotypic characteristics of the strains was observed. A 750 bp-RAPD fragment found only in the wild-type phenotype strains was cloned and sequenced. Genetic similarity analysis using BLASTx suggested that this RAPD marker represents a putative domain of a hypothetical flavin-binding monooxygenase (FMO)-like protein of Neurospora crassa.

Study of the relationship between Aedes (Stegomyia) aegypti egg and adult densities, dengue fever and climate in Mirassol, state of São Paulo, Brazil

The purpose of this study was to examine the relationship between Aedes aegypti egg and adult density indices, dengue fever and climate in Mirassol, state of São Paulo, Brazil, between November 2004-November 2005. Weekly collections of adults and eggs were made using, respectively, manual aspirators and oviposition traps that produced four entomological indices (positivity and average of females and eggs). Weekly incidence coefficients were calculated based on dengue cases. Each week, the data obtained from entomological indices were related to each other, dengue, and climate variables. The first index to show an association with dengue transmission was the female average, followed by female positivity and egg average. Egg positivity did not show a relationship with risk for dengue, but was sensitive to identifying the presence of the vector, principally in dry seasons. The relationship between climatic factors, the vector and the disease found in this study can be widely employed in planning and undertaking dengue surveillance and control activities, but it is a tool that has not been considered by the authorities responsible for controlling the disease. In fact, this relationship permits the use of information about climate for early detection of epidemics and for establishing more effective prevention strategies than currently exist.

Evaluation of buffy coat 16S rRNA PCR, buffy coat culture and whole blood PCR for detection of bacteraemia

The use of Gram type-specific PCR on buffy coat from clinical specimens for the detection of bacteraemia was evaluated for the first time using whole blood culture as the gold standard. In addition, the established buffy coat culture and whole blood PCR were also compared. Gram-positive bacteria belonging to six species and Gram-negative bacteria from 10 species were isolated and identified by culture and detected using broad-range 16S rDNA primers and Gram-specific primers. Data from the three methods all conferred very high sensitivity, specificity, positive and negative predictive values when compared to whole blood culture. The Kappa coefficients of agreement were 0.9819 (buffy coat PCR), 0.9458 (whole blood PCR) and 1.0 (buffy coat culture), which establishes their validity as alternative methods to routine blood culture in detecting bacteraemia. In addition, results showed that there was a direct correlation of WBC counts greater than 12,000 cells per mm³ to the occurrence of bacteraemia as detected by the four methods (p < 0.05).