5,235 research outputs found
Effects of Rumen Fill on Intake and Milk Production in Dairy Cows Fed Perennial Ryegrass
Physical limitation often limits dry matter intake (DMI) of high producing cows or cows fed high forage diets. The extent to which DMI is regulated by distention in the rumen depends upon the cow’s energy requirement and filling effects of the diet offered (Allen, 2000). The objective here was to challenge middle lactation dairy cows with rumen fill (rumen inert bulk – RIB) feeding ryegrass fresh cut (indoors) or grazed to determine whether RIB affects intake and milk production
Bound vortex states and exotic lattices in multi-component Bose-Einstein condensates: The role of vortex-vortex interaction
We numerically study the vortex-vortex interaction in multi-component
homogeneous Bose-Einstein condensates within the realm of the Gross-Pitaevskii
theory. We provide strong evidences that pairwise vortex interaction captures
the underlying mechanisms which determine the geometric configuration of the
vortices, such as different lattices in many-vortex states, as well as the
bound vortex states with two (dimer) or three (trimer) vortices. Specifically,
we discuss and apply our theoretical approach to investigate intra- and
inter-component vortex-vortex interactions in two- and three-component
Bose-Einstein condensates, thereby shedding light on the formation of the
exotic vortex configurations. These results correlate with current experimental
efforts in multi-component Bose-Einstein condensates, and the understanding of
the role of vortex interactions in multiband superconductors.Comment: Published in PR
Conditions for non-monotonic vortex interaction in two-band superconductors
We describe a semi-analytic approach to the two-band Ginzburg-Landau theory,
which predicts the behavior of vortices in two-band superconductors. We show
that the character of the short-range vortex-vortex interaction is determined
by the sign of the normal domain - superconductor interface energy, in analogy
with the conventional differentiation between type-I and type-II
superconductors. However, we also show that the long-range interaction is
determined by a modified Ginzburg-Landau parameter , different from
the standard of a bulk superconductor. This opens the possibility for
non-monotonic vortex-vortex interaction, which is temperature-dependent, and
can be further tuned by alterations of the material on the microscopic scale
Structural determinants for NF-Y/DNA interaction at the CCAAT box
The recently determined crystal structures of the sequence-specific transcription factor NF-Y have illuminated the structural mechanism underlying transcription at the CCAAT box. NF-Y is a trimeric protein complex composed by the NF-YA, NF-YB, and NF-YC subunits. NF-YB and NF-YC contain a histone-like domain and assemble on a head-to-tail fashion to form a dimer, which provides the structural scaffold for the DNA sugar-phosphate backbone binding (mimicking the nucleosome H2A/H2B\ue2\u80\u93DNA assembly) and for the interaction with NF-YA. The NF-YA subunit hosts two structurally extended \uce\ub1-helices; one is involved in NF-YB/NF-YC binding and the other inserts deeply into the DNA minor groove, providing exquisite sequence-specificity for recognition and binding of the CCAAT box. The analysis of these structural data is expected to serve as a powerful guide for future experiments aimed at understanding the role of post-translational modification at NF-Y regulation sites and to unravel the three-dimensional architecture of higher order complexes formed between NF-Y and other transcription factors that act synergistically for transcription activation. Moreover, these structures represent an excellent starting point to challenge the formation of a stable hybrid nucleosome between NF-Y and core histone proteins, and to rationalize the fine molecular details associated with the wide combinatorial association of plant NF-Y subunits
Estudo da inoculação de bactérias diazotróficas na variedade de cana-de-açúcar RB92579 em um solo enriquecido com 15 N.
Does the Feeding Behaviour of Dairy Cows Differ When Fed Ryegrass Indoors vs. Grazing?
Dairy cows eating ryegrass ingest smaller boli when grazing than when fed indoors (93 vs. 142 g; Boudon et al., 2004). To investigate whether this difference in bolus affects feeding behaviour of the cows, an automated system (chewing halters) was used to monitor feeding behaviour of cows given ad libitum access to perennial ryegrass in individual feed troughs (indoor feeding, IF) or at pasture (grazing, GR)
Aplicação de bactérias diazotróficas associadas com produtos da linha Agcelence na cultura da cana-de-açúcar.
(Giant) Vortex - (anti) vortex interaction in bulk superconductors: The Ginzburg-Landau theory
The vortex-vortex interaction potential in bulk superconductors is calculated
within the Ginzburg-Landau (GL) theory and is obtained from a numerical
solution of a set of two coupled non-linear GL differential equations for the
vector potential and the superconducting order parameter, where the merger of
vortices into a giant vortex is allowed. Further, the interaction potentials
between a vortex and a giant vortex and between a vortex and an antivortex are
obtained for both type-I and type-II superconductors. Our numerical results
agree asymptotically with the analytical expressions for large inter-vortex
separations which are available in the literature. We propose new empirical
expressions valid over the full interaction range, which are fitted to our
numerical data for different values of the GL parameter
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