354 research outputs found

    Holomorphic Supercurves and Supersymmetric Sigma Models

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    We introduce a natural generalisation of holomorphic curves to morphisms of supermanifolds, referred to as holomorphic supercurves. More precisely, supercurves are morphisms from a Riemann surface, endowed with the structure of a supermanifold which is induced by a holomorphic line bundle, to an ordinary almost complex manifold. They are called holomorphic if a generalised Cauchy-Riemann condition is satisfied. We show, by means of an action identity, that holomorphic supercurves are special extrema of a supersymmetric action functional.Comment: 30 page

    X-ray-provoked non-Mendelian transgenerational oncodeterminants

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    Cancer is the most important risk of radiation exposure. There is a definite lack of suitable test systems, human epidemiological data are only available for certain radiation types, especially not for charged particles. We use the Xiphophorus model which is genetically well characterized. As a prelude to experiments with heavy ions we report here on results obtained with x-rays to establish the necessary baseline for future studies. Apart from this direct aim we hope to obtain also a better insight in the genetical determination of cancer formation

    Compactness for Holomorphic Supercurves

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    We study the compactness problem for moduli spaces of holomorphic supercurves which, being motivated by supergeometry, are perturbed such as to allow for transversality. We give an explicit construction of limiting objects for sequences of holomorphic supercurves and prove that, in important cases, every such sequence has a convergent subsequence provided that a suitable extension of the classical energy is uniformly bounded. This is a version of Gromov compactness. Finally, we introduce a topology on the moduli spaces enlarged by the limiting objects which makes these spaces compact and metrisable.Comment: 38 page

    The critically ill patient after hepatobiliary surgery

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    BACKGROUND: We analyzed the causes and results of utilization of critical care services in the special care unit in patients after surgical procedures performed by the hepatobiliary surgical service during a 23-month period. RESULTS: Thirty-two of 537 patients (6.0%) required postoperative admission to the special care unit. Twenty-one patients were admitted directly from operating room or from recovery room because of inability to wean from ventilator (n = 10), hypovolemic shock (n = 4), myocardial ischemia or infarction (n = 2), sepsis (n = 2), upper gastrointestinal bleeding (n = 2), and acute renal failure (n =1). Eleven postoperative patients were admitted from floor care for respiratory failure (n = 4), cardiac dysrhythmia or infarction (n = 4), sepsis (n = 2), and upper gastrointestinal bleeding (n = 1). Thirty-eight per cent of patients (n = 12) admitted to the special care unit after surgery died. By multivariate analysis, total postoperative stay in the special care unit that was greater than median total duration of stay of 4.5 days was the only independent predictor of mortality (P = 0.041). CONCLUSIONS: Respiratory failure was the predominant component of all complications after hepatobiliary surgery. No clinically useful predictors of eventual outcome could be identified

    A large sample study of spin relaxation and magnetometric sensitivity of paraffin-coated Cs vapor cells

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    We have manufactured more than 250 nominally identical paraffin-coated Cs vapor cells (30 mm diameter bulbs) for multi-channel atomic magnetometer applications. We describe our dedicated cell characterization apparatus. For each cell we have determined the intrinsic longitudinal, \sGamma{01}, and transverse, \sGamma{02}, relaxation rates. Our best cell shows \sGamma{01}/2\pi\approx 0.5 Hz, and \sGamma{02}/2\pi\approx 2 Hz. We find a strong correlation of both relaxation rates which we explain in terms of reservoir and spin exchange relaxation. For each cell we have determined the optimal combination of rf and laser powers which yield the highest sensitivity to magnetic field changes. Out of all produced cells, 90% are found to have magnetometric sensitivities in the range of 9 to 30 fTHz. Noise analysis shows that the magnetometers operated with such cells have a sensitivity close to the fundamental photon shot noise limit

    Optical Magnetometry

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    Some of the most sensitive methods of measuring magnetic fields utilize interactions of resonant light with atomic vapor. Recent developments in this vibrant field are improving magnetometers in many traditional areas such as measurement of geomagnetic anomalies and magnetic fields in space, and are opening the door to new ones, including, dynamical measurements of bio-magnetic fields, detection of nuclear magnetic resonance (NMR), magnetic-resonance imaging (MRI), inertial-rotation sensing, magnetic microscopy with cold atoms, and tests of fundamental symmetries of Nature.Comment: 11 pages; 4 figures; submitted to Nature Physic
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