Ministry of Agriculture

About: Ministry of Agriculture is a(n) government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topic(s): Quechers & Salmonella. The organization has 1153 authors who have published 1189 publication(s) receiving 14442 citation(s).

New Contributions to the Optics of Intensely Light-Scattering Materials. Part II: Nonhomogeneous Layers*

Abstract: The derived laws apply to layers whose scattering coefficient S and absorption coefficient K vary vertically to the surface of the layer. In the general case the differential equations of the preceding paper [ P. Kubelka , J. Opt. Soc. Am.38, 448 ( 1948)] must be used; the coefficients, however, hitherto constant, now are functions of the distance x from the surface. In the practically important case in which K/S is constant, one may introduce the variable p, such that p≡∫0x(x)dx. One reduces thereby the nonhomogeneous to the previously treated homogeneous case.Transmittance T1,2 and reflectance R1,2 of two nonhomogeneous sheets can be calculated by the following equations: T1,2=T1T21-R1R2, R1,2=R1+T12R21-R1R2,where T1, T2, R1, R2 are the transmittances and reflectances of the single sheets, and R1 represents the reflectance of the first sheet when illuminated in the inverse direction. Analogous formulas for more sheets and formulas relating transmittance, reflectance for specimens upon black, gray or white backing surfaces, and contrast ratio, are derived.It is shown by theory and experiment that reflectance and absorption of a nonhomogeneous specimen depend on the direction of illumination, whereas transmittance does not.

Detection and identification of salmonellas from poultry-related samples by PCR.

Abstract: A polymerase chain reaction (PCR) assay was developed for the generic detection of Salmonella sp. and the identification of S. Enteritidis (SE), S. Gallinarum (SG), S. Pullorum (SP) and S. Typhimurium (ST) in material collected in the field from poultry. The specificity and sensitivity of the assay combined with Rappaport-Vassiliadis selective enrichment broth (PCR-RV) were determined, and field samples were analyzed to verify the validity of the method application. Specificity of the assay was tested using 29 SE, 11 SG, 10 ST and 10 SP strains, along with 75 strains of 28 other Salmonella serovars and 21 strains of other bacterial genera. The assay was 100% specific for Salmonella detection and ST identification. The primer pair for SE, SG and SP also detected S. Berta. PCR detection limits for Salmonella at the genus level were 2 ST, 8 SE, 1.1x10(3) SG and 1.8x10(5) SP cells. At the serovar level, detection limits were 7 ST, 1.2x10(3) SE, 4.4x10(7) SG and 1.8x10(6) SP cells. At the genus level, PCR-RV detected approximately 128% more positive field samples than the standard microbiological techniques and results were ready in 48h instead of 7 days. PCR-RV method is diagnostic of Salmonella at the genus level and ST at the serovar level, although other tests are needed to identify SE, SG and SP to serovar level.

Comparison and evaluation of eight pesticide environmental risk indicators developed in Europe and recommendations for future use

Abstract: Original article can be found at: http://www.sciencedirect.com/science/journal/01678809 Copyright Elsevier B.V. [Full text of this article is not available in the UHRA]

Brucellosis in Brazil.

Abstract: This paper reviews the epidemiology of bovine, swine, ovine, caprine, and canine brucellosis in Brazil. The zoonotic aspects of Brucella infection in Brazil is also discussed. Emphasis is given to the new program for the control of brucellosis in cattle and buffaloes that is likely to provide important insights into the prospects and strategies for controlling brucellosis in developing countries.

Pathogenesis and pathobiology of brucellosis in livestock

Abstract: Summary Brucella species are facultative, intracellular, Gram-negative bacteria with marked tropism for the pregnant reproductive tract of domestic animals. All Brucella species establish persistent infection in the reticuloendothelial system of their natural hosts. The mechanisms of placenta localisation, trophoblast tropism and abortion are poorly understood. A complete picture of the molecular determinants and mechanisms of the cell internalisation process began to emerge only recently. Cyclic β-1,2-glucan is a molecule secreted into the periplasm of Brucella and is required for intracellular Brucella to avoid fusion of the phagosome with lysosomes. The type IV secretion system translocates Brucella effector proteins into host cells and is critical for both survival and replication of Brucella in infected host cells. Some aspects of the pathogenesis and pathobiology of brucellosis in productive domestic animals are discussed in this section.