282 research outputs found

    Detecção de Cryptosporidium sp. em fezes não diarréicas de crianças, em uma escola de educação infantil de São Paulo, Brasil

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    O protozoário Cryptosporidium sp. tem sido detectado com freqüência em fezes de crianças com diarréia persistente. Este trabalho teve como objetivo investigar um surto de criptosporidiose, em uma escola de educação infantil, que atende crianças de classe média alta, de 0 a seis anos de idade. O surto foi detectado a partir de amostras fecais não diarréicas encaminhadas ao Instituto Adolfo Lutz através da rede de saúde pública. Das 64 crianças 13 (20,3%) apresentaram oocistos de Cryptosporidium nas fezes, examinadas pelo método de Kinyoun, sendo sete crianças com um ano de idade, três com dois anos de idade e três, com três anos de idade. Dos 23 adultos examinados, apenas uma mulher de 22 anos, com possível imunocomprometimento, foi positiva. Aspectos epidemiológicos e clínicos foram investigados por meio de questionários, ressaltando-se que o surto ocorreu em período muito seco.The protozoan Cryptosporidium sp. has been frequently detected in faeces from children with persistent diarrhoea. This work achieved to investigate an outbreak of cryptosporidiosis, in a day care center, attending children of high socio-economic level, between 0 and six years old. The outbreak was detected through the network of public health, when stool samples, not diarrhoeic, were examined at the Parasitology Service of the Adolfo Lutz Institute. Among the 64 examined children, 13 (20.3%) showed oocysts of Cryptosporidium sp. in the faeces examined by Kinyoun technique: seven children one year old, three, two years old and three, three years old. Among the 23 examined adults, only a 22 years old woman, possibly having an immunocomprometiment, was positive. Clinical and epidemiological aspects were investigated by questionnaires, highlighting the occurrence of the outbreak in a very dry period

    Esquistossomose mansônica no município de Pedro de Toledo (São Paulo, Brasil) onde Biomphalaria tenagophila é hospedeiro intermediário: I - Prevalência na população humana

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    Due to the scarce information about the epidemiological features of schistosomiasis in which the vector is Biomphalaria tenagophila, an investigation was carried in Pedro de Toledo in 1980 where such peculiarity is observed. Stool examinations (Kato-Katz method) were performed in 4,741 individuals (22.8% positive to Schistosoma mansoni eggs) of this 583 had previously received chemoterapy and 4,158 remainders, untreated. The schistosomiasis prevalence in those two groups where respectively 31.7% and 21.6%. Epidemiological investigation showed that 83.6% were autochthonous cases from the studied area: the autochthonous prevalence rate, and the intensity of infection in the untreated autochthonous cases were higher in males than in females; the intensity in the latter untreated group was low, 58.5 eggs/g feces (geometric mean). Moreover, according to the age groups the intensity of infections correlated well (r s = 0.745) with the prevalence rates. Schistosomiasis was verified to occur mostly during the leisure time and by the use of water streams for housework in rural zone. Only 0.4% out of 1,137 snails was positive for S. mansoni cercariae, apparently unchanged from the 1978 study when the human prevalence was 12.0%. The studied area presented differences and similarities in relation to the other Brazilian areas were the main intermediate host is B. glabrata.Devido à escassez de dados epidemiológicos sobre esquistossomose mansônica onde Biomphalaria tenagophila é vetor foi desenvolvido em 1980 o presente trabalho, no município paulista de Pedro de Toledo. Foram examinadas fezes de 4741 pessoas (Método de Kato-Katz) com prevalência de 22,8%; entre essas, 583 foram tratadas para a endemia anteriormente e 4158 não medicadas; as prevalências nos dois grupos for ram, respectivamente, 31,7% e 21,6%. Por investigação epidemiológica constatou-se que 83,6% dos casos foram autóctones da área estudada. Prevalência dos autóctones e intensidade de infecção nos portadores autóctones não tratados foram maiores no homem do que na mulher; a intensidade no último grupo foi baixa: 58,5 ovos/ g de fezes (média geométrica). De acordo com grupos etários, se correlacionaram bem (r s = 0,745) as intensidades de infecção e as prevalências. A infecção ocorreu, na zona rural, principalmente, durante lazer e trabalho doméstico. Somente 0,4% de 1137 moluscos foram positivos para Schistosoma mansoni. Esse índice foi, aparentemente, o mesmo em estudo de 1978 quando a prevalência humana era de 12,0%. A área estudada apresentou diferenças e semelhanças epidemiológicas em relação às áreas onde B. glabrata é o principal hospedeiro intermediário

    Charge Deficiency, Charge Transport and Comparison of Dimensions

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    We study the relative index of two orthogonal infinite dimensional projections which, in the finite dimensional case, is the difference in their dimensions. We relate the relative index to the Fredholm index of appropriate operators, discuss its basic properties, and obtain various formulas for it. We apply the relative index to counting the change in the number of electrons below the Fermi energy of certain quantum systems and interpret it as the charge deficiency. We study the relation of the charge deficiency with the notion of adiabatic charge transport that arises from the consideration of the adiabatic curvature. It is shown that, under a certain covariance, (homogeneity), condition the two are related. The relative index is related to Bellissard's theory of the Integer Hall effect. For Landau Hamiltonians the relative index is computed explicitly for all Landau levels.Comment: 23 pages, no figure

    Molecular complexity determines the number of olfactory notes and the pleasantness of smells

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    One major unresolved problem in olfaction research is to relate the percept to the molecular structure of stimuli. The present study examined this issue and showed for the first time a quantitative structure-odor relationship in which the more structurally complex a monomolecular odorant, the more numerous the olfactory notes it evokes. Low-complexity odorants were also rated as more aversive, reflecting the fact that low molecular complexity may serve as a warning cue for the olfactory system. Taken together, these findings suggest that molecular complexity provides a framework to explain the subjective experience of smells

    Semantic Knowledge Influences Prewired Hedonic Responses to Odors

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    Background Odor hedonic perception relies on decoding the physicochemical properties of odorant molecules and can be influenced in humans by semantic knowledge. The effect of semantic knowledge on such prewired hedonic processing over the life span has remained unclear. Methodology/Principal Findings The present study measured hedonic response to odors in different age groups (children, teenagers, young adults, and seniors) and found that children and seniors, two age groups characterized by either low level of (children) or weak access to (seniors) odor semantic knowledge, processed odor hedonics more on the basis of their physicochemical properties. In contrast, in teenagers and young adults, who show better levels of semantic odor representation, the role of physicochemical properties was less marked. Conclusions/Significance These findings demonstrate for the first time that the biological determinants that make an odor pleasant or unpleasant are more powerful at either end of the life span
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