926 resultados para Three-day sickness in cattle
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Attempts were made to study possible effects of the periodontal disease cara inchada (CI) on the cellular immunity of cattle, using adherence-, chemotaxis- and ph-agocytosis-determinations. Adherence of Bacteroides melaninogenicus to bovine granulocytes was significantly decreased in animals with CI. Phagacytosis of B. melaninogenicus by polymorphonuclear granulocytes (PMN) was also decreased in CI-diseased animals. Chemotaxis of the granulocytes appeared to be slightly increased in animals with CI and animals without CI coming from CI-affected herds.
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We present a solitary solution of the three-wave nonlinear partial differential equation (PDE) model - governing resonant space-time stimulated Brillouin or Raman backscattering - in the presence of a cw pump and dissipative material and Stokes waves. The study is motivated by pulse formation in optical fiber experiments. As a result of the instability any initial bounded Stokes signal is amplified and evolves to a subluminous backscattered Stokes pulse whose shape and velocity are uniquely determined by the damping coefficients and the cw-pump level. This asymptotically stable solitary three-wave structure is an attractor for any initial conditions in a compact support, in contrast to the known superluminous dissipative soliton solution which calls for an unbounded support. The linear asymptotic theory based on the Kolmogorov-Petrovskii-Piskunov assertion allows us to determine analytically the wave-front slope and the subluminous velocity, which are in remarkable agreement with the numerical computation of the nonlinear PDE model when the dynamics attains the asymptotic steady regime. © 1997 The American Physical Society.
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The lower bound masses of the ground-state relativistic three-boson system in 1 + 1, 2 + 1 and 3 + 1 spacetime dimensions are obtained. We have considered a reduction of the ladder Bethe-Salpeter equation to the lightfront in a model with renormalized two-body contact interaction. The lower bounds are deduced with the constraint of reality of the two-boson subsystem mass. It is verified that, in some cases, the lower bound approaches the ground-state binding energy. The corresponding non-relativistic limits are also verified.
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Follicle diameters and concentrations of follicular fluid factors were studied in the two largest follicles (F1 and F2) using F1 diameters in increments of 0.2 mm (equivalent to 4 h intervals) and extending from 7.4 to 8.4 mm (12 heifers in each of 6 groups). Changes were compared between follicles using the F2 associated with each F1-diameter group. Diameter deviation began in the 8.2-mm group as indicated by a greater (P < 0.05) diameter difference between F1 and F2 in the 8.4-mm group than in the 8.2-mm group. In the 8.0-mm group, estradiol concentrations began to increase (P < 0.05) differentially in F1 versus F2, and free insulin-like growth factor-1 (IGF-1) began to decrease differentially in F2 (P < 0.06). Combined for F1 and the associated F2, activin-A concentrations increased (P < 0.05) between the 7.6- and 8.2-mm groups and then decreased (P < 0.05). Results supported the hypothesis that estradiol and free IGF-1 concentrations simultaneously become higher in F1 than in the associated F2 by the beginning of diameter deviation. Results did not support the hypothesis that a transient elevation in activin-A is present in F1 but not in the associated F2 at the beginning of the estradiol and IGF-1 changes; instead, a mean transient elevation in activin-A occurred at this time only when data for the two follicles were combined. Comparisons between F1 and F2 also were made by independently grouping F2 and using diameter groups at 0.2-mm increments for F2 as well as for F1. In the diameter groups common to F1 and F2 (7.4, 7.6, 7.8, and 8.0 mm) there was a group effect (P < 0.003) for estradiol involving an increase (P < 0.05) beginning at the 7.6-mm group averaged over F1 and F2. For free IGF-1 concentrations, a fluctuation (a significant increase followed by a significant decrease) occurred independently in F1 between the 7.4-to 7.8-mm groups and independently in F2 between the 7.0- to 7.4-mm groups.
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The three-body recombination coefficient of an ultracold atomic system, together with the corresponding two-body scattering length a, allow us to predict the energy E 3 of the shallow trimer bound state, using a universal scaling function. The production of dimers in trapped Bose-Einstein condensates, from three-body recombination processes, in the regime of short magnetic pulses near a Feshbach resonance, is also studied in line with the experimental observation.
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Objective: To evaluate the effects of simulated aging in bond strength and nanoleakage of class II restorations using three different restorative techniques. Materials and methods: Class II preparations (n = 12) were restored using: FS - composite resin Filtek Supreme Plus (3M/ESPE); RMGIC + FS - resin-modified glass ionomer cement Vitrebond Plus (3M/ESPE) + FS; and FFS + FS - flowable composite resin Filtek Supreme Plus Flowable (3M ESPE) + FS. The teeth were assigned into two groups: Control and Simulated Aging - Thermal/Mechanical cycling (3,000 cycles, 20-80 °C/500,000 cycles, 50 N). From each tooth, two slabs were assessed to microtensile bond strength test (μTBS) (MPa), and two slabs were prepared for nanoleakage assessment, calculated as penetration along the restoration margin considering the penetration length (%) and as the area of silver nitrate particle deposition (μm2). Data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey's post hoc test (p < 0. 05). Results: FS presented the highest μTBS to dentin (22. 39 ± 7. 55 MPa) after simulated aging, while the presence of flowable resin significantly decreased μTBS (14. 53 ± 11. 65 MPa) when compared to no aging condition. Both control and aging groups of RMGIC + FS presented the highest values of silver nitrate penetration (89. 90 ± 16. 31 % and 97. 14 ± 5. 76 %) and deposition area (33. 05 ± 12. 49 and 28. 08 ± 9. 76 μm2). Nanoleakage was not affected by simulated aging. Conclusions: FS presented higher bond strength and lower nanoleakage and was not affected by simulated aging. Use of flowable resin compromised the bond strength after simulated aging. Clinical relevance: The use of an intermediate layer did not improve the dentin bond strength neither reduced nanoleakage at the gingival margins of class II restorations under simulated aging conditions. © 2012 Springer-Verlag.
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The present study provides the first epidemiological data on infection with Babesia bovis in cattle raised in the southwestern Brazilian Amazon. Blood clot samples were filtered through nylon cloth before being submitted to DNA extraction. PCR and nested-PCR were applied to assess the frequency of infection with B. bovis in calves with ages from 4 to 12 months bred in 4 microregions each in the states of Rondônia and Acre. After the DNA was extracted from the samples, the infection in cattle was investigated by amplification of the rap1 gene from B. bovis. The DNA amplification results revealed a frequency of infection with B. bovis of 95.1% (272/286) in the samples from Rondônia and 96.1% (195/203) in those from Acre. The high frequency of B. bovis infection in the animals with ages from 4 to 12 months indicates a situation of enzootic stability in the regions studied. The infection rates are comparable to those detected by immunodiagnostic techniques in other endemic regions of Brazil. © 2012 Elsevier GmbH.
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We consider three-body systems in two dimensions with zero-range interactions for general masses and interaction strengths. The momentum-space Schrödinger equation is solved numerically and in the Born-Oppenheimer (BO) approximation. The BO expression is derived using separable potentials and yields a concise adiabatic potential between the two heavy particles. The BO potential is Coulomb-like and exponentially decreasing at small and large distances, respectively. While we find similar qualitative features to previous studies, we find important quantitative differences. Our results demonstrate that mass-imbalanced systems that are accessible in the field of ultracold atomic gases can have a rich three-body bound state spectrum in two-dimensional geometries. Small light-heavy mass ratios increase the number of bound states. For 87Rb-87Rb-6Li and 133Cs- 133Cs-6Li we find respectively three and four bound states. © 2013 IOP Publishing Ltd.