962 research outputs found
The Generalised Liar Paradox: A Quantum Model and Interpretation
The formalism of abstracted quantum mechanics is applied in a model of the
generalized Liar Paradox. Here, the Liar Paradox, a consistently testable
configuration of logical truth properties, is considered a dynamic conceptual
entity in the cognitive sphere. Basically, the intrinsic contextuality of the
truth-value of the Liar Paradox is appropriately covered by the abstracted
quantum mechanical approach. The formal details of the model are explicited
here for the generalized case. We prove the possibility of constructing a
quantum model of the m-sentence generalizations of the Liar Paradox. This
includes (i) the truth-falsehood state of the m-Liar Paradox can be represented
by an embedded 2m-dimensional quantum vector in a (2m)^m dimensional complex
Hilbert space, with cognitive interactions corresponding to projections, (ii)
the construction of a continuous 'time' dynamics is possible: typical truth and
falsehood value oscillations are described by Schrodinger evolution, (iii)
Kirchoff and von Neumann axioms are satisfied by introduction of 'truth-value
by inference' projectors, (iv) time invariance of unmeasured state.Comment: 13 pages, to be published in Foundations of Scienc
Transcriptional Regulation of the Human Hepatic Lipase Gene: Relation to Glucose and Lipid Metabolism
Hepatic Lipase (HL; EC 3.1.1.3) is an extracellular glycoprotein with phospholipase A1 and
triacylglycerol hydrolase activity. The human HL protein is encoded by the LIPC gene on
chromosome 15q21. Most of this protein is synthesized in the parenchymal cells of the liver
and secreted into the space of Disse where it binds to heparin sulfate proteoglycans.
Some synthesis of HL was also observed in macrophages. The HL protein is also present in
the steroidogenic adrenal glands, ovaries and, in small amounts, in the testes. By using
heparin, HL protein is displaced from its binding site. Human HL protein is a homodimer, the
monomer has a molecular weight of 65 kDa. In the metabolism of plasma lipoproteins HL
plays an important role; it mediates the conversion of high density lipoprotein subfraction 2
(HDL2) to high density lipoprotein subfraction 3 (HDL3), the conversion of intermediate density
lipoprotein (IDL) to low density l
Planar potential flow on Cartesian grids
Potential flow has many applications, including the modelling of unsteady
flows in aerodynamics. For these models to work efficiently, it is best to
avoid Biot-Savart interactions between the potential flow elements. This work
presents a grid-based solver for potential flows in two dimensions and its use
in a vortex model for simulations of separated aerodynamic flows. The solver
follows the vortex-in-cell approach and discretizes the
streamfunction-vorticity Poisson equation on a staggered Cartesian grid. The
lattice Green's function is used to efficiently solve the discrete Poisson
equation with unbounded boundary conditions. In this work, we use several key
tools that ensure the method works on arbitrary geometries, with and without
sharp edges. The immersed boundary projection method is used to account for
bodies in the flow and the resulting body forcing Lagrange multiplier is
identified as a discrete version of the bound vortex sheet strength. Sharp
edges are treated by decomposing the body-forcing Lagrange multiplier into a
singular and smooth part. To enforce the Kutta condition, the smooth part can
then be constrained to remove the singularity introduced by the sharp edge. The
resulting constraints and Kelvin's circulation theorem each add Lagrange
multipliers to the overall saddle point system. The accuracy of the solver is
demonstrated in several problems, including a flat plate shedding singular
vortex elements. The method shows excellent agreement with a Biot-Savart method
when comparing the vortex element positions and the force
Entangled-state cryptographic protocol that remains secure even if nonlocal hidden variables exist and can be measured with arbitrary precision
Standard quantum cryptographic protocols are not secure if one assumes that
nonlocal hidden variables exist and can be measured with arbitrary precision.
The security can be restored if one of the communicating parties randomly
switches between two standard protocols.Comment: Shortened version, accepted in Phys. Rev.
A Geometrical Representation of Entanglement as Internal Constraint
We study a system of two entangled spin 1/2, were the spin's are represented
by a sphere model developed within the hidden measurement approach which is a
generalization of the Bloch sphere representation, such that also the
measurements are represented. We show how an arbitrary tensor product state can
be described in a complete way by a specific internal constraint between the
ray or density states of the two spin 1/2. We derive a geometrical view of
entanglement as a 'rotation' and 'stretching' of the sphere representing the
states of the second particle as measurements are performed on the first
particle. In the case of the singlet state entanglement can be represented by a
real physical constraint, namely by means of a rigid rod.Comment: 10 pages, 3 figures. submitted to International Journal of
Theoretical Physic
Explaining Latent Factor Models for Recommendation with Influence Functions
Latent factor models (LFMs) such as matrix factorization achieve the
state-of-the-art performance among various Collaborative Filtering (CF)
approaches for recommendation. Despite the high recommendation accuracy of
LFMs, a critical issue to be resolved is the lack of explainability. Extensive
efforts have been made in the literature to incorporate explainability into
LFMs. However, they either rely on auxiliary information which may not be
available in practice, or fail to provide easy-to-understand explanations. In
this paper, we propose a fast influence analysis method named FIA, which
successfully enforces explicit neighbor-style explanations to LFMs with the
technique of influence functions stemmed from robust statistics. We first
describe how to employ influence functions to LFMs to deliver neighbor-style
explanations. Then we develop a novel influence computation algorithm for
matrix factorization with high efficiency. We further extend it to the more
general neural collaborative filtering and introduce an approximation algorithm
to accelerate influence analysis over neural network models. Experimental
results on real datasets demonstrate the correctness, efficiency and usefulness
of our proposed method
Supplementary feeding increases nestling feather corticosterone early in the breeding season in house sparrows
Several studies on birds have proposed that a lack of invertebrate prey in urbanized areas could be the main cause for generally lower levels of breeding success compared to rural habitats. Previous work on house sparrows Passer domesticus found that supplemental feeding in urbanized areas increased breeding success but did not contribute to population growth. Here, we hypothesize that supplementary feeding allows house sparrows to achieve higher breeding success but at the cost of lower nestling quality. As abundant food supplies may permit both high-and low-quality nestlings to survive, we also predict that within-brood variation in proxies of nestling quality would be larger for supplemental food broods than for unfed broods. As proxies of nestling quality, we considered feather corticosterone (CORTf), body condition (scaled mass index, SMI), and tarsus-based fluctuating asymmetry (FA). Our hypothesis was only partially supported as we did not find an overall effect of food supplementation on FA or SMI. Rather, food supplementation affected nestling phenotype only early in the breeding season in terms of elevated CORTf levels and a tendency for more variable within-brood CORTf and FA. Early food supplemented nests therefore seemed to include at least some nestlings that faced increased stressors during development, possibly due to harsher environmental (e.g., related to food and temperature) conditions early in the breeding season that would increase sibling competition, especially in larger broods. The fact that CORTf was positively, rather than inversely, related to nestling SMI further suggests that factors influencing CORTf and SMI are likely operating over different periods or, alternatively, that nestlings in good nutritional condition also invest in high-quality feathers
How to play two-players restricted quantum games with 10 cards
We show that it is perfectly possible to play 'restricted' two-players,
two-strategies quantum games proposed originally by Marinatto and Weber having
as the only equipment a pack of 10 cards. The 'quantum board' of such a model
of these quantum games is an extreme simplification of 'macroscopic quantum
machines' proposed by one of the authors in numerous papers that allow to
simulate by macroscopic means various experiments performed on two entangled
quantum objectsComment: 4 pages, 3 figure
Quantum Structures: An Attempt to Explain the Origin of their Appearance in Nature
We explain the quantum structure as due to the presence of two effects, (a) a
real change of state of the entity under influence of the measurement and, (b)
a lack of knowledge about a deeper deterministic reality of the measurement
process. We present a quantum machine, where we can illustrate in a simple way
how the quantum structure arises as a consequence of the two mentioned effects.
We introduce a parameter epsilon that measures the size of the lack of
knowledge on the measurement process, and by varying this parameter, we
describe a continuous evolution from a quantum structure (maximal lack of
knowledge) to a classical structure (zero lack of knowledge). We show that for
intermediate values of epsilon we find a new type of structure, that is neither
quantum nor classical. We apply the model that we have introduced to situations
of lack of knowledge about the measurement process appearing in other regions
of reality. More specifically we investigate the quantum-like structures that
appear in the situation of psychological decision processes, where the subject
is influenced during the testing, and forms some of his opinions during the
testing process. Our conclusion is that in the light of this explanation, the
quantum probabilities are epistemic and not ontological, which means that
quantum mechanics is compatible with a determinism of the whole.Comment: 22 pages, 8 figure
Detection of 'best' positive end-expiratory pressure derived from electrical impedance tomography parameters during a decremental positive end-expiratory pressure trial
Introduction: This study compares different parameters derived from electrical impedance tomography (EIT) data to define 'best' positive end-expiratory pressure (PEEP) during a decremental PEEP trial in mechanically-ventilated patients. 'Best' PEEP is regarded as minimal lung collapse and overdistention in order to prevent ventilator-induced lung injury.Methods: A decremental PEEP trial (from 15 to 0Â cm H2O PEEP in 4 steps) was performed in 12 post-cardiac surgery patients on the ICU. At each PEEP step, EIT measurements were performed and from this data the following were calculated: tidal impedance variation (TIV), regional compliance, ventilation surface area (VSA), center of ventilation (COV), regional ventilation delay (RVD index), global inhomogeneity (GI index), and intratidal gas distribution. From the latter parameter we developed the ITV index as a new homogeneity parameter. The EIT parameters were compared with dynamic compliance and the PaO2/FiO2 ratio.Results: Dynamic compliance and the PaO2/FiO2 ratio had the highest value at 10 and 15Â cm H2O PEEP, respectively. TIV, regional compliance and VSA had a maximum value at 5Â cm H2O PEEP for the non-dependent lung region and a maximal value at 15Â cm H2O PEEP for the dependent lung regio
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