8,351 research outputs found
Hydroxyethyl-starch use and PBM. a necessary update to the italian national guidelines
Hydroxyethyl-starch use and PBM a necessary update to the italian national guideline
Optimal boundary control of a viscous Cahn-Hilliard system with dynamic boundary condition and double obstacle potentials
In this paper, we investigate optimal boundary control problems for
Cahn-Hilliard variational inequalities with a dynamic boundary condition
involving double obstacle potentials and the Laplace-Beltrami operator. The
cost functional is of standard tracking type, and box constraints for the
controls are prescribed. We prove existence of optimal controls and derive
first-order necessary conditions of optimality. The general strategy, which
follows the lines of the recent approach by Colli, Farshbaf-Shaker, Sprekels
(see the preprint arXiv:1308.5617) to the (simpler) Allen-Cahn case, is the
following: we use the results that were recently established by Colli, Gilardi,
Sprekels in the preprint arXiv:1407.3916 [math.AP] for the case of
(differentiable) logarithmic potentials and perform a so-called "deep quench
limit". Using compactness and monotonicity arguments, it is shown that this
strategy leads to the desired first-order necessary optimality conditions for
the case of (non-differentiable) double obstacle potentials.Comment: Key words: optimal control; parabolic obstacle problems; MPECs;
dynamic boundary conditions; optimality conditions. arXiv admin note:
substantial text overlap with arXiv:1308.561
Bank Competition, Asset Allocations and Risk of Failure: An Empirical Investigation
This study is an empirical investigation of theoretical predictions concerning the impact of bank competition on bank risk and asset allocations. Recent work (Boyd, De NicolĂČ and Jalal, 2009, BDNJ henceforth) predicts that as competition in banking increases, the loan-to-asset ratio will rise (under reasonable assumptions), but the probability of bank failure can either increase or decrease. However, the probability of bank failure will fall if and only if borrowersâ response to take on less risk as loan rates decline is sufficiently strong. We test these predictions using two samples with radically different attributes. With both, we find that banksâ probability of failure is negatively and significantly related to measures of competition. We also find that as competition intensifies, borrower risk decreases and the loan-to-asset ratio increases. These results are consistent with the predictions of the BDNJ model.
Problems Affecting Labor
Much experimental work has been devoted in comparing the folding behavior of proteins sharing the same fold but different sequence. The recent design of proteins displaying very high sequence identities but different 3D structure allows the unique opportunity to address the protein-folding problem from a complementary perspective. Here we explored by â-value analysis the pathways of folding of three different heteromorphic pairs, displaying increasingly high-sequence identity (namely, 30%, 77%, and 88%), but different structures called G A (a 3-α helix fold) and G B (an α/ÎČ fold). The analysis, based on 132 site-directed mutants, is fully consistent with the idea that protein topology is committed very early along the pathway of folding. Furthermore, data reveals that when folding approaches a perfect two-state scenario, as in the case of the G A domains, the structural features of the transition state appear very robust to changes in sequence composition. On the other hand, when folding is more complex and multistate, as for the G Bs, there are alternative nuclei or accessible pathways that can be alternatively stabilized by altering the primary structure. The implications of our results in the light of previous work on the folding of different members belonging to the same protein family are discussed
Direction-Dependent Polarised Primary Beams in Wide-Field Synthesis Imaging
The process of wide-field synthesis imaging is explored, with the aim of
understanding the implications of variable, polarised primary beams for
forthcoming Epoch of Reionisation experiments. These experiments seek to detect
weak signatures from redshifted 21cm emission in deep residual datasets, after
suppression and subtraction of foreground emission. Many subtraction algorithms
benefit from low side-lobes and polarisation leakage at the outset, and both of
these are intimately linked to how the polarised primary beams are handled.
Building on previous contributions from a number of authors, in which
direction-dependent corrections are incorporated into visibility gridding
kernels, we consider the special characteristics of arrays of fixed dipole
antennas operating around 100-200 MHz, looking towards instruments such as the
Square Kilometre Array (SKA) and the Hydrogen Epoch of Reionization Arrays
(HERA). We show that integrating snapshots in the image domain can help to
produce compact gridding kernels, and also reduce the need to make complicated
polarised leakage corrections during gridding. We also investigate an
alternative form for the gridding kernel that can suppress variations in the
direction-dependent weighting of gridded visibilities by 10s of dB, while
maintaining compact support.Comment: 15 pages, 4 figures. Accepted for publication in JA
Speeding up Cylindrical Algebraic Decomposition by Gr\"obner Bases
Gr\"obner Bases and Cylindrical Algebraic Decomposition are generally thought
of as two, rather different, methods of looking at systems of equations and, in
the case of Cylindrical Algebraic Decomposition, inequalities. However, even
for a mixed system of equalities and inequalities, it is possible to apply
Gr\"obner bases to the (conjoined) equalities before invoking CAD. We see that
this is, quite often but not always, a beneficial preconditioning of the CAD
problem.
It is also possible to precondition the (conjoined) inequalities with respect
to the equalities, and this can also be useful in many cases.Comment: To appear in Proc. CICM 2012, LNCS 736
Nitrogen and energy partitioning in two genetic groups of pigs fed low-protein diets at 130 kg body weight
The aim was to evaluate the effect of low-protein (LP) or low-amino acid diets on digestibility, energy and nitrogen (N) utilisation in 2 genetic groups (GG) of pigs (129±11 kg BW). DurocĂLarge White (A) pigs were chosen to represent a traditional GG for ham production, and Danbred Duroc (D) pigs to represent a GG with fast growing rate and high carcass lean yield. Dietary treatments: a conventional diet (CONV) containing 13.2% CP, and two LP diets, one with LP (10.4%) and low essential AA (LP1), the second with LP (9.7%) and high essential AA (LP2). Compared to CONV, LP2 had the same essential AA content per unit feed, while LP1 the same essential AA content per unit CP. Feed was restricted (DMI=6.8% BW0.75). Four consecutive digestibility/balances periods were conducted with 24 barrows, 12 A and 12 D. Metabolic cages and respiration chambers were used. No significant difference between diets was registered for digestibility. Nitrogen excreted: 41.3, 33.4 and 29.0 g/d (P=0.009), for CONV, LP1 and LP2 diets, respectively. Nitrogen retention was similar between the diets. Heat production (HP) was the lowest for LP diets. There was a tendency (P=0.079) for a lower energy digestibility in D group. The D pigs also had a higher HP and hence a lower retained energy in comparison with the A pigs. In conclusion: it is possible to reduce N excretion using very LP diets and LP-low AA diets; Danbred GG have a higher heat production and a lower energy retention than A pigs
How Much Longer Will it Take? A Ten-year Review of the Implementation of United Nations General Assembly Resolutions 61/105, 64/72 and 66/68 on the Management of Bottom Fisheries in Areas Beyond National Jurisdiction
The United Nations General Assembly (UNGA) in 2002 adopted the first in a series of resolutions regarding the conservation of biodiversity in the deep sea. Prompted by seriousconcerns raised by scientists, non-governmental organizations (NGOs) and numerous States,these resolutions progressively committed States to act both individually and through regional fishery management organizations (RFMOs) to either manage bottom fisheries in areas beyond national jurisdiction to prevent significant adverse impacts on deep-sea species, ecosystems and biodiversity or else prohibit bottom fishing from taking place.Ten years have passed since the adoption of resolution 61/105 in 2006, calling on States to take a set of specific actions to manage bottom fisheries in areas beyond national jurisdiction to protect vulnerable marine ecosystems (VMEs) from the adverse impacts of bottom fishing and ensure the sustainability of deep-sea fish stocks. Despite the considerable progress by some RFMOs, there remain significant gaps in the implementation of key elements and commitments in the resolutions. The Deep Sea Conservation Coalition (DSCC) has prepared this report to assist the UNGA in its review in 2016 and to address the following question: How effectively have the resolutions been implemented
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