Electromyography of the reticulum, abomasum and duodenum in dairy cows with left displacement of the abomasum

Electromyographic (EMG) recordings of the reticulum, abomasal corpus, pyloric antrum and duodenum of six dairy cows with left displacement of the abomasum (LDA) were made in order to substantiate abomasal atony as a prerequisite to abomasal displacement. EMG recordings were made when LDA was present as well as when absent. Mean values were determined in five of six cows for the maximum peak or amplitude, mean peak values, peak-to-peak interval and count of the electrical response activity (ERA) for each 15 min segment of the waveform recordings. Segments containing phase III migrating myoelectric activity were not analysed. LDA positive periods were compared to LDA negative periods in each cow. The 6 h period (transition period) prior to the diagnosis of LDA was analysed separately. Paired t-tests were applied to group values with statistical significance established at the P = 0.05 level. There was a significant decrease in the ERA count during the LDA positive periods in the abomasal corpus (-1.40% to -7.88%, P = 0.0217) and in the pyloric antrum (-2.05% to -11.98%, P = 0.0430). A corresponding significant increase occurred in the peak-to-peak interval. During the transition period spike activity in the duodenum increased 0.5% to 48.31% (P = 0.0474) and the peak-to-peak interval was significantly decreased. No extended periods of atony were observed in the abomasum during this study.     

A Lagrangian approach to the non-causal inverse dynamics of flexible multibody systems: The three-dimensional case

This paper addresses the problem of end-point trajectory tracking in flexible multibody systems through the use of inverse dynamics. A global Lagrangian approach is employed in formulating the system equations of motion, and an iterative procedure is proposed to achieve end-point trajectory tracking in three-dimensional, flexible multibody systems. Each iteration involves firstly, a recursive inverse kinematics procedure wherein elastic displacements are determined in terms of the rigid body co-ordinates and Lagrange multipliers, secondly, an explicit computation of the inverse dynamic joint actuation, and thirdly, a non-recursive forward dynamic analysis wherein generalized co-ordinates and Lagrange multipliers are determined in terms of the joint actuation and desired end-point co-ordinates. In contrast with the recursive methods previously proposed, this new method is the most general since it is suitable for both open-chain and closed-chain configurations of three-dimensional multibody systems. The algorithm yields stable, non-casual actuating joint torques and associated Lagrange multipliers that account for the constraint forces between flexible multibody components.     

Inverse dynamics of spatial open-chain flexible manipulators with lumped and distributed actuators

This article addresses the problem of inverse dynamics for three-dimensional flexible manipulators with both lumped and distributed actuators. A recursive procedure is presented for computing the lumped inverse dynamic torques and the distributed piezoelectric actuator inputs for simultaneously tracking a prescribed end-point trajectory and reducing induced vibrations in the manipulator. The procedure sequentially solves for the non-causal inverse dynamic torques and piezoelectric voltages applied to each link in the manipulator, starting from the last element in the chain and proceeding to the base element. The method allows trajectory tracking wherein controllability of the structural vibrations is assured in all possible configurations through the use of only one motor at each intermediate joint and three motors at the ground. Numerical simulation shows that the elastic vibrations can be reduced significantly through the use of distributed actuators while at the same time satisfying the trajectory tracking requirement through the use of inverse dynamics. © 1994 John Wiley & Sons, Inc.     

Circannual morphometric investigations of the rat suprachiasmatic nucleus after pinealectomy, ganglionectomy and thyroidectomy

With the advent of combinatorial chemistry a new paradigm is evolving in the field of drug discovery. The approach is based on an integration of chemistry, high-throughput screening and automation engineering. The chemistry arm is usually based on solid-phase synthesis technology as the preferred approach to library construction. One of the most powerful of the solid-phase methods is encoded split synthesis, in which the reaction history experience by each polymeric bead is unambiguously recorded. This split-and-pool approach, employing chemically robust tags, was used to construct a 85,000-membered dihydrobenzopyran library.     

Geometrically non‐linear damage interface based on regularized strong discontinuity

The contribution of this paper concerns the fracture modelling of an interface with a fixed internal material surface in the context of geometrically non‐linear kinematics. Typical applications are composite laminates and adhesive/frictional joints in general. In the model development, a key feature is the concept of regularized strong discontinuity, which provides a regular deformation gradient within the interface. The deformation gradient within the interface is formulated in a multiplicative structure with a continuous part and a discontinuous part, whereby the interface deformation is interpreted as a transformation between the material damaged configuration and the actual spatial configuration. In analogy with the continuum formulation of hyper‐inelasticity, a constitutive framework is defined for the relation between the induced material traction and the displacement jump vector, which are defined on the material damaged interface configuration. Within this framework, a simple, but yet still representative, model for the delamination problem is proposed on the basis of a damage–plasticity coupling for the interface. The model is calibrated analytically in the large deformation context with respect to energy dissipation in mode I so that a predefined amount of fracture energy is dissipated. The paper is concluded with a couple of numerical examples that display the properties of the interface. Copyright © 2002 John Wiley & Sons, Ltd.     

Temporal variation in muscle fibre area,gaping, texture,colour and collagen in triploid and diploid Atlantic salmon (Salmo salar L)

Diploid and triploid Atlantic salmon were reared for 32 months in seawater, from October 1998 to January 2000. During this period of time, four samplings were taken to study differences in quality traits and chemical components in the flesh between diploid and triploid Atlantic salmon. Season was found to be the dominant factor explaining the variation in flesh quality traits in both triploid and diploid fish. Ploidy affected the majority of investigated variables while body size had lesser impact. Triploid Atlantic salmon had fewer small muscle fibres and up to 23% larger mean cross‐sectional muscle fibre area than diploids. Triploids also displayed more gaping, softer fillet texture, lower post mortem end pH, darker (L value) and redder (a value) flesh colour, and more soluble and less insoluble collagen compared with diploid fish. No effect of ploidy was found on crude chemical composition. Furthermore, a negative relationship was found between gaping score and muscle fibre area, and a weak positive correlation was found between fibre density and texture firmness. However, when body size and sampling time was included in the statistical model, this relationship between gaping and fibre area became very weak, and the relationship between texture and fibre area was completely negated. This suggests that intra‐species variation in both texture and gaping is more related to season and body size than to average muscle fibre area size. Copyright © 2004 Society of Chemical Industry     

Rehydration of salt-cured cod using injection and tumbling technologies

Traditional rehydration of salt-cured and dried salt-cured cod (klipfish) is most often carried out in stagnant water for 24–48 h. This process has however been difficult to run in industrial scale due to problems related both to process flow and product quality. The new three-step rehydration method developed in this work includes injection of tap water followed by tumbling in water and tumbling in a 2% NaCl brine. Using the new rapid method whole fillets and loins are rehydrated within 3 h. Similar to traditional rehydration, a weight gain of 33–34% was obtained. A trained sensory panel found significant differences in cohesiveness, after-taste and sour smell between fillets rehydrated with the traditional and the new method. No differences were found concerning 14 other sensory properties or the storage stability of rehydrated samples.     

Investigation of the Mechanisms of Heat Exchanger Corrosion in a Municipal Waste Incineration Plant by Analysis of the Raw Gas and Variation of Operating Parameters

The detailed mechanism of high temperature chlorine corrosion, the dominant cause of corrosion in a municipal solid waste incinerator (MSI), has still to be clarified. Upon its way through the boiler the raw gas is subject to various physical and chemical processes and interactions. Of these, sulfation of chlorides is supposed to have the major impact on chlorine corrosion. The physical and chemical mechanisms of corrosion were investigated at a municipal solid waste incinerator. Both the particulate and gas phases of the flue gas were chemically and physically analyzed during their way through the boiler, at temperatures from close to 1000°C down to 200°C. The raw gas composition was analyzed during normal operation and during the soot blowing cleaning routine. Additionally, operating parameters of the plant were varied, and deposition processes were evaluated with the aim to find out primary measures to reduce corrosion rates. The particle mass concentration exhibits a bimodal size distribution with maxima at approximately 0.5 μ m—growing by duration of travel—and 100 μ m. First results show that sulfation of the particles can be observed upon travel through the boiler and on the fouling. Sulfur-containing additives increased the sulfation of the particles during flight, though not to completion.     

Detection of tropomyosin and determination of proteins in crustacean oils

Tropomyosin is known to be the main allergen in crustaceans and the objective of this study was to investigate if this protein could be detected in commercial crustacean oils from Antarctic krill (Euphausia superba) and the zooplankton Calanus finmarchicus. We also examined the possibility of determining the protein content in the oils by direct amino acid analysis. Western blotting showed that a commercial antibody against shrimp tropomyosin cross-reacted with a protein of similar size in Antarctic krill and C. finmarchicus. The protein tentatively identified as tropomyosin, was also detected in krill oil products, but not in oils from C. finmarchicus. The acetone–heptane method used for extracting proteins in the oils is however not optimal. Other extraction methods should therefore be considered when investigating the presence of allergenic proteins in oils. Direct amino acid analysis on oils should be further explored as a method for determining the total amount of proteins present.