USING A MULTIPLE PRODUCT AND MULTIPLE INPUT APPROACH TO DAIRY PROFIT MAXIMIZATION: A SIMULATION USING OPERATIONS RESEARCH METHODS

Dairy producers generally take a single output/multiple input approach when making production decisions. Under component pricing, with large variance in individual component prices, a multiple output/multiple input approach maximizes profits. This paper applied our approach to the individual farm milk production decision.Livestock Production/Industries, Productivity Analysis,

Grass shrimp Palaemonetes pugio predation on sediment- and stem-dwelling meiofauna: Field and laboratory experiments

Field and laboratory experiments were conducted to clarify the predatory role of Palaemonetes pugio Holthius in salt-marsh benthic communities. Field experiments (cage enclosures using P. pugio as a predator) were conducted on unvegetated mudflat and vegetated-marsh sites. Neither sediment- or stem-dwelling meiofaunal abundances were significantly impacted. Laboratory experiments measured the functional response of P. pugio feeding on suspended harpacticoid copepods, tested the efficiency of P. pugio feeding on harpacticoids in sediments, and measured the predation rate of P. pugio on stem-dwelling meiofauna. Grass shrimp feeding rate on suspended copepods followed a type II functional response, increasing with increasing prey density to a maximum of 59 copepods h-1. When a sediment refuge was available, a 40% decline in the consumption of copepods by P. pugio was noted; this decreased feeding efficiency may contribute to the lack of significant declines in meiofaunal abundances in field enclosures over unvegetated sediment. P. pugio proved to be a highly effective predator on the fauna of Spartina alterniflora stems, significantly reducing abundances of stem-associated meiofauna within 24 h and consuming an estimated 35 meiofauna h-1. The greatest impact was exhibited on the lowest (0 to 6 cm) portion of the stems. These experiments suggest that laboratory experiments are an important aid to help interpret field experiments examining predation on meiofauna, and that Spartina stems, and their epiphytic algae and meiofauna, are important, but largely overlooked, resources in salt-marsh food webs

Priors in quantum Bayesian inference

In quantum Bayesian inference problems, any conclusions drawn from a finite number of measurements depend not only on the outcomes of the measurements but also on a prior. Here we show that, in general, the prior remains important even in the limit of an infinite number of measurements. We illustrate this point with several examples where two priors lead to very different conclusions given the same measurement data.Comment: 7 pages; published in AIP Conference Proceedings 1101: Foundations of Probability and Physics 5, edited by L. Accardi et al, p. 255 (2009

The role of Acyl-CoA oxidase in peroxisome division and longevity in yeast

Acyl-CoA oxidase (Aox) is an enzyme that carries out the first step of Ý-oxidation of free fatty acids in peroxisomes. Here I describe a novel role for Aox in peroxisome biogenesis. I found that the peroxisome becomes competent for division only after it acquires the complete set of matrix proteins involved in lipid metabolism. Overloading the peroxisome with matrix proteins promotes the relocation of Aox from the matrix to the membrane. The binding of Aox to Pex16p, a membrane-associated peroxin required for peroxisome biogenesis, initiates the biosynthesis of phosphatidic acid and diacylglycerol (DAG) in the membrane. The formation of these two lipids and the subsequent transbilayer movement of DAG initiate the assembly of a complex between the peroxins Pex10p and Pex19p, the dynamin-like GTPase Vps1p, and several actin cytoskeletal proteins on the peroxisomal surface. This protein team promotes membrane fission, thereby executing the terminal step of peroxisome division. One of my objectives was to understand what role (if any) Aox and other peroxisomal enzymes of fatty acid oxidation may play in regulating yeast longevity. I found that Aox is an essential component of the protein network controlling the chronological lifespan of yeast placed on a low-calorie diet called calorie restriction (CR). My findings lead to the conlusion that fatty acid oxidation in peroxisomes controls longevity by modulating the rate of ATP synthesis in mitochondria, but not by generating the ROS hydrogen peroxide. Recent studies in Dr. Titorenko's laboratory identified novel small molecules that greatly increase the chronological lifespan of yeast. My experiments with one of these novel anti-aging drugs, a commercially available compound further referred to as "LA", revealed that it extends yeast longevity under CR conditions. My studies aimed at elucidating the molecular mechanisms by which LA increases yeast lifespan revealed that . lack of Aox or any other enzyme of peroxisomal fatty acid oxidation does not impair the anti-aging effect of LA. My findings demonstrated that LA extends yeast longevity by: (1) reducing the damaging effect of ROS on cellular macromolecules; and (2) amplifying the so-called "hormetic" effect of ROS through the activation of stress-protecting and other anti-aging proteins

Violation of Bell Inequalities as a Violation of Fair Sampling in Threshold Detectors

Photomultiplier tubes and avalanche photodiodes, which are commonly used in quantum optic experiments, are sometimes referred to as threshold detectors because, in photon counting mode, they cannot discriminate the number of photoelectrons initially extracted from the absorber in the detector. We argue that they can be called threshold detectors on more account than that. We point out that their their functioning principle relies on two thresholds that are usually thought unimportant individually in the context of EPR-Bell discussion. We show how the combined effect of these threshold can lead to a significant sampling selection bias in the detection of pairs of pulses, resulting in an apparent violation of Bell inequalities.Comment: 11 pages, 8 figures, FPP5 conference, Vaxjo (Sweden) August 200

On Bell's theorem, quantum communication, and entanglement detection

(A) Bell's theorem rests on a conjunction of three assumptions: realism, locality and ``free will''. A discussion of these assumptions will be presented. It will be also shown that, if one adds to the assumptions the principle or rotational symmetry of physical laws, a stronger version of the theorem emerges. (B) A link between Bell's theorem and communication complexity problems will be presented. This also includes experimental realizations, which surprisingly do not involve entanglement. (C) A new sufficient and necessary criterion for entanglement of general (mixed) states is be presented. It is derived using the same geometric starting point as the inclusion of the symmetry in (A). The set of entanglement identifiers (EI's) emerging via this method contains entanglement witnesses (EW's), but they form only a subset of all EI's. Thus the method is more powerful than the one based on EW's.Comment: 10 pages, for proceedings of Foundations of Probability and Physics-5 at Vaxjo University, Swedish Southeast Academy August 24-27, 200

Is Bell's theorem relevant to quantum mechanics? On locality and non-commuting observables

Bell's theorem is a statement by which averages obtained from specific types of statistical distributions must conform to a family of inequalities. These models, in accordance with the EPR argument, provide for the simultaneous existence of quantum mechanically incompatible quantities. We first recall several contradictions arising between the assumption of a joint distribution for incompatible observables and the probability structure of quantum-mechanics, and conclude that Bell's theorem is not expected to be relevant to quantum phenomena described by non-commuting observables, irrespective of the issue of locality. Then, we try to disentangle the locality issue from the existence of joint distributions by introducing two models accounting for the EPR correlations but denying the existence of joint distributions. We will see that these models do not need to resort explicitly to non-locality: the first model relies on conservation laws for ensembles, and the second model on an equivalence class by which different configurations lead to the same physical predictions.Comment: Extended with new materia

SIC-POVMs and MUBs: Geometrical Relationships in Prime Dimension

The paper concerns Weyl-Heisenberg covariant SIC-POVMs (symmetric informationally complete positive operator valued measures) and full sets of MUBs (mutually unbiased bases) in prime dimension. When represented as vectors in generalized Bloch space a SIC-POVM forms a d^2-1 dimensional regular simplex (d being the Hilbert space dimension). By contrast, the generalized Bloch vectors representing a full set of MUBs form d+1 mutually orthogonal d-1 dimensional regular simplices. In this paper we show that, in the Weyl-Heisenberg case, there are some simple geometrical relationships between the single SIC-POVM simplex and the d+1 MUB simplices. We go on to give geometrical interpretations of the minimum uncertainty states introduced by Wootters and Sussman, and by Appleby, Dang and Fuchs, and of the fiduciality condition given by Appleby, Dang and Fuchs.Comment: Contribution to the Conference "Foundations of Probability and Physics-5", Vaxjo, 200