577 research outputs found
Cloreto de potássio na linha de semeadura pode causar danos à soja.
bitstream/item/24735/1/COT200264.pdfDocumento on-line
Detection of ‘long-haired’ Saprolegnia (S. parasitica) isolates using monoclonal antibodies
P. 726-733The ability of five monoclonal antibodies (Mabs) raised against a pathogenic Saprolegnia
parasitica isolate from brown trout to detect and differentiate between isolates with
bundles of long hairs (S. parasitica) and other Saprolegnia species was determined by means
of an indirect immunofluorescence assay. Four of the Mabs used recognized some of the
long-haired S. parasitica isolates but also cross-reacted with other Saprolegnia species without bundles of hairs and with Achlya sp. The other Mab (named 18A6) was able to differentiate between the asexual and most of the sexual isolates in the group of long-haired
S. parasitica isolates, but did not recognize Achlya sp. or the Saprolegnia species without
bundles of hairs, with the exception of S. hypogyna. These results indicate that isolates
with bundles of long hairs are closely related with other members of genus Saprolegnia
and share several antigens. However, Mab 18A6 seems to recognize an epitope that is
expressed mainly in the asexual isolates in the long-haired S. parasitica isolates.S
Absence of squirt singularities for the multi-phase Muskat problem
In this paper we study the evolution of multiple fluids with different
constant densities in porous media. This physical scenario is known as the
Muskat and the (multi-phase) Hele-Shaw problems. In this context we prove that
the fluids do not develop squirt singularities.Comment: 16 page
A maximum principle for the Muskat problem for fluids with different densities
We consider the fluid interface problem given by two incompressible fluids
with different densities evolving by Darcy's law. This scenario is known as the
Muskat problem for fluids with the same viscosities, being in two dimensions
mathematically analogous to the two-phase Hele-Shaw cell. We prove in the
stable case (the denser fluid is below) a maximum principle for the
norm of the free boundary.Comment: 16 page
Incompressible flow in porous media with fractional diffusion
In this paper we study the heat transfer with a general fractional diffusion
term of an incompressible fluid in a porous medium governed by Darcy's law. We
show formation of singularities with infinite energy and for finite energy we
obtain existence and uniqueness results of strong solutions for the
sub-critical and critical cases. We prove global existence of weak solutions
for different cases. Moreover, we obtain the decay of the solution in ,
for any , and the asymptotic behavior is shown. Finally, we prove the
existence of an attractor in a weak sense and, for the sub-critical dissipative
case with , we obtain the existence of the global attractor
for the solutions in the space for any
Breakdown of smoothness for the Muskat problem
In this paper we show that there exist analytic initial data in the stable
regime for the Muskat problem such that the solution turns to the unstable
regime and later breaks down i.e. no longer belongs to .Comment: 93 pages, 10 figures (6 added
Estudio teórico de algunas propiedades termodinámicas de los ácidos grasos obtenidos como destilados en la desodorización de aceites comestibles
Nowadays the feasibility of a change of technology in the deodorization stage of edible vegetable oil refining is being investigated. The proposed technology involves a modification in the composition of the distillates coming from the deodorization stage and their further treatment To design the apparatus which are required by the proposed technology it is necessary to study the physical properties of the distillates. The thermodynamic properties of the fatty acids: palmitic, stearic, oleic and linoleic, which are the principal components produced at the deodorization stage have been studied. The properties that have been studied were those corresponding to the critical point (critical temperature, pressure and volume), the vapour pressure-temperature relation and the latent heat of vaporisation. Different methods to estimate the above mentioned properties and some experimental published data have been compared.Estudio teórico de algunas propiedades termodinámicas de los ácidos grasos obtenidos como destilados en la desodorización de aceites comestibles Actualmente se investiga la viabilidad de un cambio en la tecnología de la desodorización de aceites comestibles que afecta a la composición de los destilados que se obtienen en el proceso y al tratamiento de los mismos. El diseño de los equipos que conlleva este cambio de tecnología requiere el estudio de propiedades físicas de los destilados. Se han estudiado algunas propiedades termodinámicas de los ácidos palmítico, esteárico, oleico y linoleico, componentes mayoritarios resultantes del proceso de desodorización. Las propiedades estudiadas han sido las correspondientes al punto crítico (temperatura, presión y volumen críticos), las curvas de presión de vapor en función de la temperatura y el calor latente de vaporización. Se han recogido distintos métodos de estimación de las mencionadas propiedades y algunos datos experimentales, y se han comparado los resultados obtenidos
The Significance of the Location of Mutations for the Native-State Dynamics of Human Lysozyme
The conversion of human lysozyme into amyloid fibrils is associated with a rare but fatal hereditary form of nonneuropathic systemic amyloidosis. The accumulation of large amounts of aggregated protein is thought to be initiated by the formation of transient intermediate species of disease-related lysozyme variants, essentially due to the loss of global cooperativity under physiologically relevant conditions. Interestingly, all five naturally occurring, amyloidogenic, single-point mutations are located in the β-domain of lysozyme, the region that is predominantly unfolded during the formation of the transient intermediate species. Given the lack of known naturally occurring, amyloidogenic, single-point mutations in the α-domain, we chose three specific mutations to address the effects that location may have on native-state dynamics, as studied by hydrogen-deuterium (HD) exchange experiments analyzed by NMR spectroscopy, and mass spectrometry. We compared the effect of a destabilizing α-domain mutation (I23A) with that of the well-characterized I59T β-domain variant. We also investigated the effect of a mutation that has minor effects on native-state stability at the domain interface (I56V) and compared it with that of a variant with similar stability within the C-helix (I89V). We show that when variants have similar reduced native-state stabilities, the location of the mutation (I23A versus I59T) is crucial to the native-state dynamics, with the α-domain mutation having a significantly lower ability to populate transient intermediate species under physiologically relevant conditions. Interestingly, the mutation at the interface (I56V) has a greater effect in facilitating the formation of transient intermediate species at elevated temperatures compared with the variants containing α-domain mutations, even though this mutation results in only minor changes to the native-state stability of lysozyme. These findings reveal that the location of specific mutations is an important factor in determining the native-state dynamical properties of human lysozyme in the context of its propensity to populate the aggregation-prone transient intermediate species associated with pathogenic amyloid formation.This research was supported by the Biotechnology and Biological Sciences Research Council (BB/E019927/1 to C.M.D., C.V.R., and J.R.K.), the Medical Research Council (E.D.G. and C.M.D.), the Belgian Program of Interuniversity Attraction Poles administered by the Federal Office for Scientific Technical and Cultural Affairs (PAI numbers P6/19 and P7144 to C.M.D. and M.D.), the European Union’s Sixth Framework Program (LSHM-CT-2006-037525 to C.M.D. and M.D.), and Programme grants from the Wellcome Trust and the Leverhulme Trust (C.M.D.). It was also supported by a Korean Government Scholarship for Overseas Studies (M.A.), the Winston Churchill Foundation (C.L.H.), and Boerhinger Ingleheim funds (A.D.). The NMR facility at the Department of Chemistry, University of Cambridge, is supported in part by an EPSRC Core Capability grant (EP/K039520/1)
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