157 research outputs found
Estudo experimental de Zygodontomys lasiurus (Rodentia-cricetidae) com cepas de Trypanosoma cruzi
São apresentados resultados em relação a infecção expertmental de Zygodontomys lasiurus (Rodentia-Cricetidae) com duas cepas de T. cruzi isoladas de casos humanos, Y e Berenice, e uma isolada de um triatomíneo silvestre, chamada costalimai. Foram realizados estudos em relação a evolução da parasitemia, duração da patência e prepatência da infecção. Com o objetivo de verificar a agressividade e tropismo tissular das cepas de T. cruzi nesta espécie de roedor, foram também realizados estudos histopatológicos. Os resultados obtidos mostraram que os níveis de parasitemias foram baixos para as três cepas estudadas. A patência da infecção variou de 14 a 16 dias nos animais inoculados com a cepa Y, 26 a 29 dias com a Berenice e 9 a 13 dias com a costalimai. O período prepatente variou de 3 a 5 dias nos animais inoculados com a cepa Y, de 2 a 6 dias com a cepa Berenice e de 6 a 8 dias com a costalimai. As três cepas apresentaram em Z. lasiurus, comprometimento nitidamente muscular, provocando reações leves, moderadas e intensas.Studies on the experimental infection of Zygodontomys lasiurus (Rodentia-Cricetidae) are presented in the current paper. Three strains of T. cruzi were used in the experiments: two, Y and Berenice, were originated from human infection, while the third one was obtained from natural infection in a wild bug Triatoma costalimai. The evolution of the parasitemia was studied and the prepatent and patent periods determined. The tissular tropism and aggressiveness of the strains of T. cruzi were verified through histopathological studies. Results have shown that the parasitemia was always kept at low levels for all the strains. The prepatent period in the infected rodents varied from: 3 to 6 days in the Y strain; 2 to 6 days in the Berenice strain; 6 to 8 in the costalimai strain. The patent period showed the following duration patterns: 14 to 16 days in the Y strain; 26 to 29 in the Berenice strain and 6 to 8 days in the costalimai strain. Tissue damage was predominantly muscular, and the pathological reactions varied from slight to severe
Nonlinear Modulation of Multi-Dimensional Lattice Waves
The equations governing weakly nonlinear modulations of -dimensional
lattices are considered using a quasi-discrete multiple-scale approach. It is
found that the evolution of a short wave packet for a lattice system with cubic
and quartic interatomic potentials is governed by generalized Davey-Stewartson
(GDS) equations, which include mean motion induced by the oscillatory wave
packet through cubic interatomic interaction. The GDS equations derived here
are more general than those known in the theory of water waves because of the
anisotropy inherent in lattices. Generalized Kadomtsev-Petviashvili equations
describing the evolution of long wavelength acoustic modes in two and three
dimensional lattices are also presented. Then the modulational instability of a
-dimensional Stokes lattice wave is discussed based on the -dimensional
GDS equations obtained. Finally, the one- and two-soliton solutions of
two-dimensional GDS equations are provided by means of Hirota's bilinear
transformation method.Comment: Submitted to PR
Spatial distribution and evaluation of risk factors for bovine neosporosis in Rondônia, Brazil
ABSTRACT Neospora caninum is an important worldwide parasite responsible for causing abortion in animals. Due to limited information on the occurrence of infection by this parasite in the state of Rondônia, Brazil, this study aimed to determine the seroprevalence and identify the risk factors associated with the infection in slaughtered cattle, from 19 municipalities distributed in seven microregions of the state. A total of 494 samples were obtained and subjected to anti-N. caninum antibodies, using the Indirect Immunofluorescence Reaction technique. Antibodies were detected in 5.06% (25/494) of the samples, in 30.30% (10/33) of farms, in nine municipalities located in four microregions of Rondônia. Of all the animals analyzed, 4.81% of the females (20/416) and 6.41% of the males (05/78) were seropositive for the parasite, with “abortion in the last 12 months” being considered an important risk factor for the occurrence of infection (OR = 9.54; p = 0.01). The present study points out the prevalence of anti-N. caninum antibodies in 5.06% of slaughtered animals and abortion as the main risk factor associated with infection by N. caninum, thus contributing to the elucidation of the epidemiology of this protozoan in Rondônia, Brazil
Characterization of potential CO2 emissions in agricultural areas using magnetic susceptibility
Considerações sobre as relações entre a análise de citação e a pesquisa científica colaborativa
Determinação do equilíbrio higroscópico e do calor isostérico do bagaço de cana-de-açúcar
Particulate soil organic carbon and stratification ratio increases in response to crop residue decomposition under no-till
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