1,656 research outputs found

    The excretion of biuret in the urine of sheep fed biuret

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    The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentation PDF-Format

    The pathological physiology of helminth infestation. lll. Trichostrongylus colubriformis

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    Trials are described in which the reactions of 11 sheep infested with T. colubriformis and 11 uninfected controls were studied in detail. The main findings in the acute disease were anorexia, retention of ingesta in the rumen and abomasum, diarrhoea, a severe hypo-albuminaemia and death 16 to 17 days after infestation. In the chronic disease there was a progressive decrease in feed intake and loss of body weight. Plasma albumin concentration decreased with a rise in plasma gamma globulin concentration later in the disease. A drop in packed red cell volume, haemoglobin concentration, red cell count, total volume of circulating erythrocytes and plasma inorganic phosphate was noted. There was a decrease in protein, phosphate and possibly selenium uptake leading to emaciation, muscular and myocardial atrophy and degeneration and eventually death.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Observability and nonlinear filtering

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    This paper develops a connection between the asymptotic stability of nonlinear filters and a notion of observability. We consider a general class of hidden Markov models in continuous time with compact signal state space, and call such a model observable if no two initial measures of the signal process give rise to the same law of the observation process. We demonstrate that observability implies stability of the filter, i.e., the filtered estimates become insensitive to the initial measure at large times. For the special case where the signal is a finite-state Markov process and the observations are of the white noise type, a complete (necessary and sufficient) characterization of filter stability is obtained in terms of a slightly weaker detectability condition. In addition to observability, the role of controllability in filter stability is explored. Finally, the results are partially extended to non-compact signal state spaces

    Extracting Spatial Information from Noise Measurements of Multi-Spatial-Mode Quantum States

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    We show that it is possible to use the spatial quantum correlations present in twin beams to extract information about the shape of a mask in the path of one of the beams. The scheme, based on noise measurements through homodyne detection, is useful in the regime where the number of photons is low enough that direct detection with a photodiode is difficult but high enough that photon counting is not an option. We find that under some conditions the use of quantum states of light leads to an enhancement of the sensitivity in the estimation of the shape of the mask over what can be achieved with a classical state with equivalent properties (mean photon flux and noise properties). In addition, we show that the level of enhancement that is obtained is a result of the quantum correlations and cannot be explained with only classical correlations

    The impact of deep-sea fisheries and implementation of the UNGA Resolutions 61/105 and 64/72. Report of an international scientific workshop

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    The scientific workshop to review fisheries management, held in Lisbon in May 2011, brought together 22 scientists and fisheries experts from around the world to consider the United Nations General Assembly (UNGA) resolutions on high seas bottom fisheries: what progress has been made and what the outstanding issues are. This report summarises the workshop conclusions, identifying examples of good practice and making recommendations in areas where it was agreed that the current management measures fall short of their target

    Theory of Two-Dimensional Josephson Arrays in a Resonant Cavity

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    We consider the dynamics of a two-dimensional array of underdamped Josephson junctions placed in a single-mode resonant cavity. Starting from a well-defined model Hamiltonian, which includes the effects of driving current and dissipative coupling to a heat bath, we write down the Heisenberg equations of motion for the variables of the Josephson junction and the cavity mode, extending our previous one-dimensional model. In the limit of large numbers of photons, these equations can be expressed as coupled differential equations and can be solved numerically. The numerical results show many features similar to experiment. These include (i) self-induced resonant steps (SIRS's) at voltages V = (n hbar Omega)/(2e), where Omega is the cavity frequency, and n is generally an integer; (ii) a threshold number N_c of active rows of junctions above which the array is coherent; and (iii) a time-averaged cavity energy which is quadratic in the number of active junctions, when the array is above threshold. Some differences between the observed and calculated threshold behavior are also observed in the simulations and discussed. In two dimensions, we find a conspicuous polarization effect: if the cavity mode is polarized perpendicular to the direction of current injection in a square array, it does not couple to the array and there is no power radiated into the cavity. We speculate that the perpendicular polarization would couple to the array, in the presence of magnetic-field-induced frustration. Finally, when the array is biased on a SIRS, then, for given junction parameters, the power radiated into the array is found to vary as the square of the number of active junctions, consistent with expectations for a coherent radiation.Comment: 11 pages, 8 eps figures, submitted to Phys. Rev

    Magnetically geared pseudo direct drive for safety critical applications

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    The paper presents an investigation into the electromagnetic design and performance of a fault-tolerant magnetically geared Pseudo Direct Drive (PDD®) electrical machine for primary flight control surface electromechanical actuation. It is shown that a large number of combinations of high-speed rotor (HSR) pole pairs, pole-piece numbers, and stator slot numbers exist for which a duplex 3-phase fault tolerant configuration can be realized. Furthermore, in addition to facilitating a lower mass solution, it is also shown that a PDD presents a significantly lower inertia referred to the screw, when compared to direct-drive or mechanically geared motor solutions. The findings are validated on a prototype PDD, which has been designed and built to meet the requirements of primary control surface electromechanical actuator
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