Effects of early post-mortem pH and temperature on beef tenderness

The tenderness of loin steaks, prepared from beef sides after chilling, is strongly influenced by muscle temperature in the first 3 h after slaughter. Maintenance of about 37°C within the Longissimus muscle during this time, whether by heavy fat cover or by ambient-temperature manipulation, results in appreciable tenderness enhancement. Early post-mortem muscle pH (which varies over a wide range) also affects tenderness significantly; provided early and exceptionally fast chilling does not induce cold shortening, slow glycolysis promotes tenderness. Low-frequency (2 Hz) electrical stimulation, which accelerates glycolysis but causes negligible tissue disruption, significantly toughens the loin; in its normal mode (50–60 Hz), therefore, stimulation produces its desirable tenderising effect mainly—and perhaps solely—by fibre fracture.     

Study of water behaviour of chemically treated flax fibres-based composites: A way to approach the hydric interface

Silane (Si) and styrene (S) treatments were applied on flax fibres in order to improve their adhesion with a polyester resin and to increase their moisture resistance. The water sorption and permeation kinetics of the composites were correlated with the water sorption behaviour of untreated and treated fibres. An increase of the water barrier effect was observed in treated fibres-based composites in comparison with untreated ones. This was related to the shift-down of water solubility and to a decrease of the water diffusivity in treated fibre-based composites. In the case of (S) treatment, the presence of styrene increased the moisture resistance of the treated fibres and made compatible the fibres and the matrix. In the case of (Si) treatment, a good hydric fibre/matrix interface was obtained due to crosslinking reactions and hydrogen bonding between water molecules and free hydroxyl groups of (Si) treated fibres. In order to interpret water permeation behaviour of composite films, a simple illustrated model is suggested and represented by a schematic view.     

Distance-Ranked Connectivity Compression of Triangle Meshes

We present a new, single-rate method for compressing the connectivity information of a connected 2-manifold triangle mesh with or without boundary. Traditional compression schemes interleave geometry and connectivity coding, and are thus typically unable to utilize information from vertices (mesh regions) they have not yet processed. With the advent of competitive point cloud compression schemes, it has become feasible to develop separate connectivity encoding schemes that can exploit complete, global vertex position information to improve performance. Our scheme demonstrates the utility of this separation of vertex and connectivity coding. By traversing the mesh edges in a consistent fashion, and using global vertex information, we can predict the position of the vertex that completes the unprocessed triangle attached to a given edge. We then rank the vertices in the neighborhood of this predicted position by their Euclidean distance. The distance rank of the correct closing vertex is stored. Typically, these rank values are small, and the set of rank values thus possesses low entropy and compresses very well. The sequence of rank values is all that is required to represent the mesh connectivity—no special split or merge codes are necessary. Results indicate improvements over traditional valence-based schemes for more regular triangulations. Highly irregular triangulations or those containing a large number of slivers are not well modelled by our current set of predictors and may yield poorer connectivity compression rates than those provided by the best valence-based schemes.     

A new method for correcting axial dispersion in GPC

In this paper, a new method for correcting GPC results in order to take into account the axial dispersion of a given set of columns is proposed. The idea is to evaluate the different average molecular weights and the polydispersity for a given elution volume. In order to do so, one needs only to know the efficiency of the set of columns and the different derivatives at a given point of the chromatogram. Some possible applications of this method are reviewed mainly for the characterization of polydispersity and for the determination of the viscosity law if one uses the universal calibration.     

Characterization of unsaturated polyester resin cured with styrene

In this work, the curing kinetic of an unsaturated polyester resin, mixed with styrene as curing agent, was studied by means of diffential scanning calorimetry (DSC) and infrared (IR) spectroscopy. Investigations were made in situ during curing and post-curing periods. The enthalpy (ΔH_cop) characterizing the styrene homopolymerization and its copolymerization with the polyester chains was determined from isothermal DSC investigations. The residual enthalpy (ΔH_res) was determined from nonisothermal DSC measurements. We find that the quantity (ΔH_res + ΔH_cop) depends on the curing temperature (T_iso). Styrene homopolymerization and/or copolymerization lead to characteristic bonds modifications. The variations of the most characteristic bonds versus curing duration were studied from Fourier transform IR investigations. The data allow the determination of a relationship between transformation rate and curing duration using a time constant (τ) characteristic of each reaction involved during the liquid to solid-state transformation. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 695–703, 1998     

Water diffusion in unsaturated polyester films. Effect of plasticization on the glass transition

Water diffusion through Unsaturated Polyester Resin (UPR) is investigated. From differential scanning calorimetry, we observe that the plasticization effect due to water sorption leads to large variations of T_g and is a reversible phenomenon. The transport of water through the polymer is characterized with a new instrument developed in our laboratory which shows that the water transport deviates from Fickian behavior. It is found that the diffusion coefficient is not a constant and experimental data are in good agreement with D = D_oe^γC where γ is a plasticization coefficient.     

Detecting Intention Through Motor-Imagery-Triggered Pupil Dilations

Human–computer interaction systems that bypass manual control can be beneficial for many use cases, including users with severe motor disability. We investigated pupillometry (inferring mental activity via dilations of the pupil) as an interaction method because it is noninvasive, easy to analyse, and increasingly available for practical development. In 3 experiments we investigated the efficacy of using pupillometry to detect imaginary motor movements of the hand. In Experiment 1 we demonstrated that, on average, the pupillary response is greater when the participant is imagining a hand-grasping motion, as compared with the control condition. In Experiment 2 we investigated how imaginary hand-grasping affects the pupillary response over time. In Experiment 3 we employed a simple classifier to demonstrate single-trial detection of imagined motor events using pupillometry. Using the mean pupil diameter of a single trial, accuracy rates as high as 71.25%, were achieved. Implications for the development of a pupillometry-based switch and future directions are discussed.     

The importance of market interdependencies in modeling energy systems - The case of the European electricity generation market

The analysis of complex electricity generation systems such as the European one require large scale models based on extensive databases of the relevant infrastructures. Such models are increasingly used to assist policymaking by developing scenarios to investigate the impact of certain policies on generation capacities, investments and prices. The continuing liberalization and interconnection of energy markets thereby requires the considerations of multiple interdependencies with other markets. Most models, however, do not take this into account. This paper develops and applies a large scale electricity investments and dispatch and natural gas market dispatch model to highlight the importance of recognizing interdependencies between power generation and the gas market. In an exemplary analysis, it is demonstrated that seasonal gas price patterns resulting from temperature-dependent household gas demand have a significant impact on the competitiveness of gas-fired power stations in competition with other technologies. Spatially, we show that competitive cost-based gas prices would lead to a relocation of such plants closer to the sources of natural gas.     

Expanding the small molecular toolbox to study big biomolecular machines

Ion channels are transmembrane protein complexes that are found in virtually all cells. They fulfill a crucial physiological function by facilitating communication between and within cells. Consequently, impaired channel function, e.g. due to mutations, often has profound physiological effects. Their central role in cell-to-cell communication makes ion channels formidable drug targets, albeit their transmembrane nature often hampers efforts to obtain high resolution structures and hence impedes drug discovery. Decades of electrophysiology and molecular biology studies have made critical contributions to our understanding of ion channel structure and function. Small organic compounds, acting as either agonist or antagonist, have played vital roles in such studies and in recent years these molecular tools have become more sophisticated. Decorated with fluorescent, photoaffinity and/or affinity tags small molecular tools enable imaging, binding site mapping and isolation of biomolecular targets. Here, some of the methodologies employed in the context of ion channels are discussed and highlighted with representative examples.