Relação Parasito-hospedeiro Entre Biomphalaria Amazonica E Schistosoma Mansoni

Biomphalaria amazonica is a planorbid species considered a potential host of Schistosoma mansoni. It is widely distributed in the Neotropical zone, particularly in the North and Centre-West of Brazil and in the North of Bolivia. The aim of the present study was to determine the host-parasite relationship between B. amazonica and S. mansoni (BH and SJ strains). Specimens of B. amazonica and their snail-conditioned water were examined in terms of their ability to attract miracidia. The infectivity of the mollusks was determined by exposing them to 20 miracidia of both strains. Sporocyst development and amebocyte reactions were studied after each mollusk specimen was exposed to 100 miracidia. Although no cercariae were eliminated, specimens of B. amazonica proved capable of attracting 77% of the miracidia they were exposed to. Viable sporocysts with no amebocyte reaction were found 96 hours after the exposure to miracidia. These results indicate the susceptibility of B. amazonica to the BH and SJ strains of S. mansoni, and therefore demonstrate the importance of this planorbid species as a potential vector of the trematode in the areas where it occurs.77

Dirac and Majorana heavy neutrinos at LEP II

The possibility of detecting single heavy Dirac and Majorana neutrinos at LEP II is investigated for heavy neutrino masses in the range $M_N=(\sqrt s/2, \sqrt s)$. We study the process $e^+e^- \longrightarrow \nu_{\ell} \ell q_i \bar q_j$ as a clear signature for heavy neutrinos. Numerical estimates for cross sections and distributions for the signal and the background are calculated and a Monte Carlo reconstruction of final state particles after hadronization is presented.Comment: 4 pages, 8 figure

Efect of bovine milk addition to buffalo's milk on different characteristics of artisanal Marajó "cream cheese" type.

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Comparison of Biomass and Nutrient Dynamics Between an Invasive and a Native Species in a Mediterranean Saltmarsh

Two saltmarsh species, the native Arthrocnemum macrostachyum (AM) and the invasive Spartina densiflora (SD), were compared in terms of monthly variation of above and belowground biomass, and nutrient (N, P, K, Ca, Mg, Mn) concentrations, over 1 year, in Castro Marim saltmarsh, Portugal. Net aboveground primary productivity was also estimated by two different methods. Above and belowground biomass were higher in SD than in AM and there were distinct monthly variations in the two species. Maximum relative growth rate was observed in the October/January period for SD (4.92±0.36 mg g-1 day-1) and in April/July for AM (3.37±1.26 mg g-1 day-1). Whatever the method used, net aboveground primary productivity was higher in SD (2,603 and 2,923 g m-2 yr-1, respectively by the Smalley and the Wiegert and Evans method) than in AM (692 and 1,012 g m-2 yr-1, respectively). The turnover rate for aboveground live biomass of AM was half the value of SD (0.8 yr-1 and 1.7 yr-1, respectively). The N/P ratio in photosynthetic active components and belowground biomass of AM (11 and 13) was higher than in those of SD (7 and 10). Concentrations of K, Ca and Mg in photosynthetic tissues of SD were lower than in AM. Differences observed between study species suggest that S. densiflora has better ability to use resources and to compete with native species

Disinfection with neutral electrolyzed oxidizing water to reduce microbial load and to prevent biofilm regrowth in the processing of fresh-cut vegetables

Product decontamination is one of the most important processes of the hygienic practice in food industries such as Minimally Processed Vegetables (MPV) plants and sodium hypochlorite (NaOCl) solutions are commonly used as a biocide for disinfection. Although it may be corrosive and irritating when compared to alternative biocides, this biocide is frequently applied at high concentrations. This work aims at studying the use of lower concentrations of chlorine by testing neutral electrolyzed oxidizing water (NEOW) as a chlorine-source disinfectant in fresh-cut salad processing. Assays were performed at industrial and laboratory scale. Results showed that lower doses of chlorine from NEOW (30 ppm) are as effective as higher concentrations of the traditional chlorine from NaOCl (80 ppm) in the reduction of total microbial population at industrial scale. Moreover, in laboratory studies, the NEOW chlorine was also more effective in biofilm eradication, as well as a biofilm preventive agent. NEOW can thus be a successful alternative water disinfection technique, reducing the free chlorine concentration needed to sanitize salads, also decreasing water consumption whilst taking into account environmental and food quality impacts