587 research outputs found
Efeito da cobertura de polietileno sobre a temperatura do solo e produtividade do tomateiro em estufa plástica
The effect of soil mulching with transparent, black, white, and co-extruded white-on-black polyethylene sheets on soil temperature and tomato yield was evaluated in the Subtropical Central Region of the Rio Grande do Sul State, Brazil. The experiment was carried out from August 21, 1994 to December 2, 1994 in a 10m x 25m nonheated plastic greenhouse located at the county of Santa Maria. Highest soil temperatures were obtained under transparent mulch. Maximum amplitude of soil temperature waves was smaller under opaque mulches. Tomato yield was not significantly affected by mulch treatments, however, a tendency of greater yield was observed for opaque mulches as compared to transparent mulch. Among opaque mulches, the highest yield was obtained from white mulches.Este experimento foi conduzido para avaliar o efeito da cobertura do solo com polietileno transparente, preto, branco e co-extruzado branco-preto sobre a temperatura do solo e produtividade do tomateiro no interior de uma estufa plástica, em Santa Maria, Rio Grande do Sul, Brasil. O período experimental foi de 21 de agosto a 02 de dezembro de 1994. Observou-se que a temperatura máxima e média diária do solo foi maior sob polietileno transparente. A amplitude máxima da onda diária de temperatura do solo foi maior nos materiais opacos em relação ao transparente. Não houve diferença estatística na produtividade do tomateiro entre os tratamentos, mas a produtividade média foi maior com plásticos opacos do que com o plástico transparente. Entre os plásticos opacos, a maior produtividade foi obtida nos plásticos brancos, que refletem maior fração da radiação solar global incidente do que o plástico preto
Thermodynamics of Quasi-Particles
We present in this work a generalization of the solution of Gorenstein and
Yang for a consistent thermodynamics for systems with a temperature dependent
Hamiltonian. We show that there is a large class of solutions, work out three
particular ones, and discuss their physical relevance. We apply the particular
solutions for an ideal gas of quasi-gluons, and compare the calculation to
lattice and perturbative QCD results.Comment: 26 pages, 1 figure. To appear in Nuclear Physics
Scalable Production of AAV Vectors in Orbitally Shaken HEK293 Cells.
Adeno-associated virus (AAV) vectors are currently among the most commonly applied for in vivo gene therapy approaches. The evaluation of vectors during clinical development requires the production of considerable amounts of highly pure and potent vectors. Here, we set up a scalable process for AAV production, using orbitally shaken bioreactors and a fully characterized suspension-adapted cell line, HEKExpress. We conducted a proof-of-concept production of AAV2/8 and AAV2/9 vectors using HEKExpress cells. Furthermore, we compared the production of AAV2/9 vectors using this suspension cell line to classical protocols based on adherent HEK293 cells to demonstrate bioequivalence in vitro and in vivo. Following upstream processing, we purified vectors via gradient centrifugation and immunoaffinity chromatography. The in vitro characterization revealed differences due to the purification method, as well as the transfection protocol and the corresponding HEK293 cell line. The purification method and cell line used also affected in vivo transduction efficiency after bilateral injection of AAV2/9 vectors expressing a GFP reporter fused with a nuclear localization signal (AAV2/9-CBA-nlsGFP) into the striatum of adult mice. These results show that AAV vectors deriving from suspension HEKExpress cells are bioequivalent and may exhibit higher potency than vectors produced with adherent HEK293 cells
Thermodynamics of Quasi-Particles at Finite Chemical Potential
We present in this work a generalization of the solution of Gorenstein and
Yang to the inconsistency problem of thermodynamics for systems of
quasi-particles whose masses depend on both the temperature and the chemical
potential. We work out several solutions for an interacting system of quarks
and gluons and show that there is only one type of solution that reproduce both
perturbative and lattice QCD.Comment: 33 pages, 1 figure. Accepted for publication in Nuclear Physics
Cell shape analysis of random tessellations based on Minkowski tensors
To which degree are shape indices of individual cells of a tessellation
characteristic for the stochastic process that generates them? Within the
context of stochastic geometry and the physics of disordered materials, this
corresponds to the question of relationships between different stochastic
models. In the context of image analysis of synthetic and biological materials,
this question is central to the problem of inferring information about
formation processes from spatial measurements of resulting random structures.
We address this question by a theory-based simulation study of shape indices
derived from Minkowski tensors for a variety of tessellation models. We focus
on the relationship between two indices: an isoperimetric ratio of the
empirical averages of cell volume and area and the cell elongation quantified
by eigenvalue ratios of interfacial Minkowski tensors. Simulation data for
these quantities, as well as for distributions thereof and for correlations of
cell shape and volume, are presented for Voronoi mosaics of the Poisson point
process, determinantal and permanental point processes, and Gibbs hard-core and
random sequential absorption processes as well as for Laguerre tessellations of
polydisperse spheres and STIT- and Poisson hyperplane tessellations. These data
are complemented by mechanically stable crystalline sphere and disordered
ellipsoid packings and area-minimising foam models. We find that shape indices
of individual cells are not sufficient to unambiguously identify the generating
process even amongst this limited set of processes. However, we identify
significant differences of the shape indices between many of these tessellation
models. Given a realization of a tessellation, these shape indices can narrow
the choice of possible generating processes, providing a powerful tool which
can be further strengthened by density-resolved volume-shape correlations.Comment: Chapter of the forthcoming book "Tensor Valuations and their
Applications in Stochastic Geometry and Imaging" in Lecture Notes in
Mathematics edited by Markus Kiderlen and Eva B. Vedel Jense
Исследование характеристик ядерных трековых мембран для создания дренажной системы в лечении глаукомы
In this article has been researched possibility of using nuclear track membrane for fluid transport in the implementation and maintenance of the cornea weaklydehydrated state
Probing the Environment with Galaxy Dynamics
I present various projects to study the halo dynamics of elliptical galaxies.
This allows one to study the outer mass and orbital distributions of
ellipticals in different environments, and the inner distributions of groups
and clusters themselves.Comment: 5 pages, 2 figs, to appear in Proc. ESO Workshop, Groups of Galaxies
in the Nearby Universe (5-9 Dec 2005), eds. I. Saviane, V. Ivanov & J.
Borissova (Springer-Verlag
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