148 research outputs found
Sorovares de Salmonella isolados de humanos no Estado de SĂŁo Paulo, Brasil, 1996-2003
A salmonelose permanece uma importante causa de doença diarrĂ©ica em humanos no Estado de SĂŁo Paulo, Brasil. Nesse estudo foram identificados 3554 isolados de Salmonella de infecções humanas, durante o perĂodo 1996-2003. Entre os 68 diferentes sorovares determinados, S. Enteritidis foi predominante em infecções gastrointestinais e extra-intestinais, responsável por 67.4% de todos os isolados. S. Typhimurium e S. enterica subsp. enterica (4,5,12:i:-) foram mais freqĂĽentemente isolados de crianças com idade de < 1 a 4 anos, em contraste, infecções por S. Enteritidis foram predominantes em pessoas entre 20 e 50 anos. A contĂnua vigilância laboratorial das salmoneloses, incluindo a sorotipagem, tem evidenciado os sorovares de Salmonella causando infecções humanas em nossa área geográfica ao longo do tempo.Salmonellosis remains an important cause of diarrheal illness in humans in SĂŁo Paulo State, Brazil. In this study were identified 3554 Salmonella isolates from human infections, during the period 1996-2003. Among 68 different serovars determined, S. Enteritidis was the most frequent one in gastrointestinal and extra-intestinal infections accounting for 67.4% of all isolates. S. Typhimurium and S. enterica subsp. enterica (4,5,12:i:-) were most frequently isolated from children aged < 1-4 year-old, in contrast, people with S. Enteritidis infections were most likely to be 20-50 year-old. In our geographic area the continued laboratorial surveillance of salmonellosis, including serotyping, has showed the trends in Salmonella serovars causing infections in humans throughout the time
Avaliação do cloreto de benzalcônio no controle da ferrugem (Hemileia vastatrix Berk. & Br.) do cafeeiro (Coffea arabica L.)
Stability conditions for fermionic Ising spin-glass models in the presence of a transverse field
The stability of spin-glass (SG) phase is analyzed in detail for a fermionic
Ising SG (FISG) model in the presence of a magnetic transverse field .
The fermionic path integral formalism, replica method and static approach have
been used to obtain the thermodynamic potential within one step replica
symmetry breaking ansatz. The replica symmetry (RS) results show that the SG
phase is always unstable against the replicon. Moreover, the two other
eigenvalues of the Hessian matrix (related to the diagonal
elements of the replica matrix) can indicate an additional instability to the
SG phase, which enhances when is increased. Therefore, this result
suggests that the study of the replicon can not be enough to guarantee the RS
stability in the present quantum FISG model, especially near the quantum
critical point. In particular, the FISG model allows changing the occupation
number of sites, so one can get a first order transition when the chemical
potential exceeds a certain value. In this region, the replicon and the
indicate instability problems for the SG solution close to all
range of first order boundary.Comment: 15 pages, 4 figures, accepted in Physica
Evidence Of Chemotaxis By Quantitative Measurement Of The Force Vectors Of Trypanossoma Cruzi In The Vicinity Of The Rhodnius Prolixus Midgut Wall Cell
In this work we used a methodology to study chemotaxis of Trypanossoma cruzi (T. Cruzi) in real time using an Optical Tweezers system. Trapped beads were used as a force transducer for measuring forces of the same order of magnitude as typical forces induced by flagellar motion. Optical Tweezers allowed real time measurements of the force vectors, strength and direction, of living parasites under chemical or other kinds of gradients. This seems to be the ideal tool to perform observations of taxis response of cells and microorganisms with high sensitivity to capture instantaneous responses to a given stimulus. We applied this methodology to investigate the T. cruzi under distinct situations: the parasite alone and in the presence of its insect-vector Rhodnius prolixus (R. prolixus). © 2009 SPIE.7400http://www.who.int/tdr/diseases/chagas/diseaseinfo.htmlAnna, B., Carole, A.P., Eukaryotic chemotaxis at a glance (2008) J. Cell Science, 121, pp. 2621-2624Laszlo, K., Chemotaxis: The proper physiological response to evaluate phylogeny of signal molecules (1999) Acta Biol Hung, 50, pp. 375-394Law, A.M.J., Aitken, M.D., Continuous-flow capillary assay for measuring bacterial chemotaxis (2005) Appl. Environ. Microbiol., 71, pp. 3137-3143Khan, S., Jain, S., Reid, G.P., Trentham, D.R., The fast tumble signal in bacterial chemotaxis (2004) Biophys. J., 86, pp. 4049-4058Neuman, K.C., Chadd, E.H., Liou, G.F., Bergman, K., Block, S.M., Characterization of photodamage to escherichia coli in optical traps (1999) Biophys. J., 77, pp. 2856-2863Bleul, C.C., Farzan, M., Choe, H., Parolin, C., Clark-Lewis, I., Sodroski, J., Springer, T.A., The lymphocyte chemoattractant SDF-1 is a ligand for LESTR/fusin and blocks HIV-1 entry (1996) Nature, 382 (6594), pp. 829-833. , DOI 10.1038/382829a0Nagasawa, T., Hirota, S., Tachibana, K., Takakura, N., Nishikawa, S., Kitamura, Y., Yoshida, N., Kishimoto, T., Defects of B-cell lymphopoiesis and bone-marrow myelopoiesis in mice lacking the CXC chemokine PBSF/SDF- 1 (1996) Nature, 382, pp. 635-638Nelson, R.D., Quie, P.G., Simmons, R.L., Spontaneous migration of human polymorphonuclear leukocytes and monocytes, chemotaxis under agarose-new and simple method for measuring chemotaxis and (1975) J. Immunol., 115, pp. 1650-1656Blair, D.F., How bacteria sense and swim (1999) Annu. Rev. Microbiol, 49, pp. 489-522Rao, C.V., Glekas, G.D., Ordal, G.W., The three adaptation systems of bacillus subtilis chemotaxis (2008) Trends Microbiol, 16, pp. 480-487Barros, V.C., Oliveira, J.S., Melo, M.N., Gontijo, N.F., Leishmania amazonensis: Chemotaxic and osmotaxic responses in promastigotes and their probable role in development in the phlebotomine gut (2006) Exp. Parasitol., 112, pp. 152-157Pfeffer, W., (1888) Unters. Botan. Inst., 2, pp. 582-661. , TubingenAdler, J., A method for measuring chemotaxis and use of the method to determine optimum conditions for chemotaxis by escherichia coli (1973) J. Gen. Microbiol., 74, pp. 77-91Alves, C.R., Albuquerque-Cunha, J.M., Mello, C.B., Nogueira, E.S.G.D.N.F., Bourguingnon, S.C., Souza, W.D., Azambuja, P., Gonzalez, M.S., Trypanosoma cruzi: Attachment to perimicrovillar membrane glycoproteins of rhodnius prolixus (2007) Experimental Parasitology, 116, pp. 44-52Fontes, A., Giorgio, S., De Castro Jr., A.B., Neto, V.M., De Pozzo, L.Y., Marques, G.P., Barbosa, L.C., Cesar, C.L., Determination of Femto Newton forces and fluid viscosity using optical tweezers - Application to Leishmania amazonensis (2005) Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 5699, pp. 419-425. , DOI 10.1117/12.586427, 59, Imaging, Manipulation, and Analysis of Biomolecules and Cells: Fundamentals and Applications II
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
Evaluation of the Environmental Toxicity Profile of Shampoos Formulated with Plant Biosurfactants
In developing new cosmetics, a series of steps must be followed until the final product is reached. In general, the process goes through the initial idea and preliminary research before reaching the development of the prototype. After the development of the prototype, several analytical tests are carried out to prove the viability of the product before production on a pilot scale. In the present work, three prototypes of innovative shampoo formulations containing plant extracts, rich in biosurfactants, of Chenopodium quinoa (quinoa), Glycine max (soy) and Malpighia emarginata (acerola) as cleaning agents were analyzed for their environmental toxicity profile. The plant extracts used aimed to reduce the use of toxic synthetic surfactants and to produce safe, renewable and biodegradable formulations, to help solve the challenges related to the damage caused to the environment due to the presence of synthetic surfactants in shampoo formulations and their toxic residues in soils and waters. The toxicity of the formulations was evaluated at a concentration of 1%, and the tests carried out were the phytotoxicity tests through the static test involving seed germination and root elongation of tomato (Solanum lycopersicum) and the Allium cepa L. root growth inhibition test. A toxicity test was also performed using the microcrustacean Artemia salina as a bioindicator. A formulation without the addition of surfactants, another containing only DCG, and a commercially available shampoo, whose acceptability is known, were used as comparative standards. The results showed that the formulations showed reduced or no toxic activity for the environmental bioindicator Artemia salina, for the seeds of S. lycopersicum and for the root growth of Allium cepa L., indicating the biocompatibility and safety of these formulations, thus presenting the potential for future commercialization, for the supply of new biotechnological products with high added value
The PiĂşma lineament, southern Espirito Santo: structural expression and tectonic significance
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