ACCURACY OF GRID PRICING: AN EVALUATION USING WHOLESALE VALUES OF FED CATTLE

Grid pricing is one of the beef industry's answers to improving value coordination in fed cattle transactions. This paper constructs individual carcass-level grid and wholesale beef values. These values are used to evaluate the level of value communication that occurs between wholesale and grid values of beef. Furthermore, the values are used to estimate grid premiums/discounts that improve value communication. Results indicate that value coordination could be improved by modifying grid premiums/discounts.Marketing,

Probabilistic models to describe the dynamics of migrating microbial communities

In all but the most sterile environments bacteria will reside in fluid being transported through conduits and some of these will attach and grow as biofilms on the conduit walls. The concentration and diversity of bacteria in the fluid at the point of delivery will be a mix of those when it entered the conduit and those that have become entrained into the flow due to seeding from biofilms. Examples include fluids through conduits such as drinking water pipe networks, endotracheal tubes, catheters and ventilation systems. Here we present two probabilistic models to describe changes in the composition of bulk fluid microbial communities as they are transported through a conduit whilst exposed to biofilm communities. The first (discrete) model simulates absolute numbers of individual cells, whereas the other (continuous) model simulates the relative abundance of taxa in the bulk fluid. The discrete model is founded on a birth-death process whereby the community changes one individual at a time and the numbers of cells in the system can vary. The continuous model is a stochastic differential equation derived from the discrete model and can also accommodate changes in the carrying capacity of the bulk fluid. These models provide a novel Lagrangian framework to investigate and predict the dynamics of migrating microbial communities. In this paper we compare the two models, discuss their merits, possible applications and present simulation results in the context of drinking water distribution systems. Our results provide novel insight into the effects of stochastic dynamics on the composition of non-stationary microbial communities that are exposed to biofilms and provides a new avenue for modelling microbial dynamics in systems where fluids are being transported

Molecular Model of the Contractile Ring

We present a model for the actin contractile ring of adherent animal cells. The model suggests that the actin concentration within the ring and consequently the power that the ring exerts both increase during contraction. We demonstrate the crucial role of actin polymerization and depolymerization throughout cytokinesis, and the dominance of viscous dissipation in the dynamics. The physical origin of two phases in cytokinesis dynamics ("biphasic cytokinesis") follows from a limitation on the actin density. The model is consistent with a wide range of measurements of the midzone of dividing animal cells.Comment: PACS numbers: 87.16.Ka, 87.16.Ac http://www.ncbi.nlm.nih.gov/pubmed/16197254 http://www.weizmann.ac.il/complex/tlusty/papers/PhysRevLett2005.pd

Evidence for magnetic clusters in Ni1−x_{1-x}Vx_{x} close to the quantum critical concentration

The d-metal alloy Ni$_{1-x}$V$_{x}$ undergoes a quantum phase transition from a ferromagnetic ground state to a paramagnetic ground state as the vanadium concentration $x$ is increased. We present magnetization, ac-susceptibility and muon-spin relaxation data at several vanadium concentrations near the critical concentration $x_c \approx11.6$ at which the onset of ferromagnetic order is suppressed to zero temperature. Below $x_c$, the muon data reveal a broad magnetic field distribution indicative of long-range ordered ferromagnetic state with spatial disorder. We show evidence of magnetic clusters in the ferromagnetic phase and close to the phase boundary in this disordered itinerant system as an important generic ingredient of a disordered quantum phase transition. In contrast, the temperature dependence of the magnetic susceptibility above $x_c$ is best described in terms of a magnetic quantum Griffiths phase with a power-law distribution of fluctuation rates of dynamic magnetic clusters. At the lowest temperatures, the onset of a short-range ordered cluster-glass phase is recognized by an increase in the muon depolarization in transverse fields and maxima in ac-susceptibility.Comment: 6 pages, 5 figures, submitted to Proceedings of SCES 201

Assessment of dehydration as a commercial-scale food waste valorization strategy

Using a commercially available dehydration unit, this study aimed to valorize various food waste streams from different sources in the Rochester, New York area. Dehydration of the food waste collected for the study helped reduce the weight of the feedstock by 70–90%, as the incoming waste streams were relatively wet. The output was materially characterized against end uses such as cattle feed, fish feed, and compost. The results demonstrated that, other than fertilizer, the remaining five end uses (compost, fish feed, cattle feed, pyrolysis, and pelletized fuel) were potentially compatible with varying waste feedstocks based on the parameters analyzed. Fish feed in particular was found to be the most compatible end use, as a number of attributes, including protein, fell within the optimal range of values. Pelletized fuel was also determined to be a viable application, as six out of eight sources of dehydrated food waste had higher heating values above the minimum U.S. standard level of 18.61 MJ/kg. Ultimately, this analysis showed that the composition of the food waste needs to be matched to an end-use application and sale of the product for dehydration to be a worthwhile valorization strategy

Some remarks on the visible points of a lattice

We comment on the set of visible points of a lattice and its Fourier transform, thus continuing and generalizing previous work by Schroeder and Mosseri. A closed formula in terms of Dirichlet series is obtained for the Bragg part of the Fourier transform. We compare this calculation with the outcome of an optical Fourier transform of the visible points of the 2D square lattice.Comment: 9 pages, 3 eps-figures, 1 jpeg-figure; updated version; another article (by M. Baake, R. V. Moody and P. A. B. Pleasants) with the complete solution of the spectral problem will follow soon (see math.MG/9906132

The landscape of movement control in locomotion: Cost, strategy, and solution

Features of gait are determined at multiple levels, from the selection of the gait itself (e.g., walk or run) through the specific parameters utilized (stride length, frequency, etc.) to the pattern of muscular excitation. The ultimate choices are determined neurally, but what is involved with deciding on the appropriate strategy? Human locomotion appears stereotyped not so much because the pattern is predetermined, but because these movement patterns are good solutions for providing movement utilizing the machinery available to the individual (the legs and their requisite components). Under different circumstances the appropriate solution may differ broadly (different gait) or subtly (different parameters). Interpretation of the neural decision making process would benefit from understanding the influences that are utilized in the selection of the appropriate solution in any set of circumstances, including normal conditions. In this review we survey an array of studies that point to energetic cost as a key input to the gait coordination system, and not just an outcome of the gait pattern implemented. We then use that information to rigorously define the construct proposed by Sparrow and Newell (1998) where the effects of environment, organism, and task act as constraints determining the solution set available, and the coordination pattern is then implemented under pressure for energetic economy. The fit between the environment and the organism define affordances that can be actualized. We rely on a novel conceptualization of task that recognizes that the task goal needs to be separated from the mechanisms that achieve it so that the selection of a particular implementation strategy can be exposed and understood. This reformulation of the Sparrow and Newell construct is then linked to the proposed pressure for economy by considering it as an optimization problem, where the most readily selected gait strategy will be the one that achieves the task goal at (or near) the energetic minimum

Reef Rescue Marine Monitoring Program: Assessment of terrestrial run-off entering the Reef and inshore marine water quality monitoring using earth observation data. Final report for 2010/11 activities

This report delivers management relevant information of flood events and inshore water quality compliance based on tailored temporal and spatial analysis of remote sensing data, carried out by CSIRO as part of the Reef Rescue Marine Monitoring Program (MMP) from 2005 to 2010