1,912 research outputs found

    Survey and Trend of Some Zoometric Parameters Correlated to the Growth of Male Subjects of Mediterranean Italian Buffalo for Meat Production

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    In this study was evaluated the presence of hereditary disposition to meat production in Mediterranean Italian buffaloes through the analysis of variation of certain important parameters related to the production of meat, in 40 young subjects having the same age. The parameters studied were: live weight, daily weight gain (DWG), withers height, thoracic circumference and trunk length. These values were investigated by controls every 21 days during the period ofmajor growth of the animals, that is from the 240th day of life up to the attainment of slaughter weight. This work has pointed out that there are significant differences in growth between animals of the same age. The data suggested that hasn't yet been made any selection about the presence of hereditary disposition to meat production in Mediterranean Italian Buffalo

    Detecting extreme mass ratio inspirals with LISA using time-frequency methods II: search characterization

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    The inspirals of stellar-mass compact objects into supermassive black holes constitute some of the most important sources for LISA. Detection of these sources using fully coherent matched filtering is computationally intractable, so alternative approaches are required. In a previous paper (Wen and Gair 2005, gr-qc/0502100), we outlined a detection method based on looking for excess power in a time-frequency spectrogram of the LISA data. The performance of the algorithm was assessed using a single `typical' trial waveform and approximations to the noise statistics. In this paper we present results of Monte Carlo simulations of the search noise statistics and examine its performance in detecting a wider range of trial waveforms. We show that typical extreme mass ratio inspirals (EMRIs) can be detected at distances of up to 1--3 Gpc, depending on the source parameters. We also discuss some remaining issues with the technique and possible ways in which the algorithm can be improved.Comment: 15 pages, 9 figures, to appear in proceedings of GWDAW 9, Annecy, France, December 200

    Facing the LISA Data Analysis Challenge

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    By being the first observatory to survey the source rich low frequency region of the gravitational wave spectrum, the Laser Interferometer Space Antenna (LISA) will revolutionize our understanding of the Cosmos. For the first time we will be able to detect the gravitational radiation from millions of galactic binaries, the coalescence of two massive black holes, and the inspirals of compact objects into massive black holes. The signals from multiple sources in each class, and possibly others as well, will be simultaneously present in the data. To achieve the enormous scientific return possible with LISA, sophisticated data analysis techniques must be developed which can mine the complex data in an effort to isolate and characterize individual signals. This proceedings paper very briefly summarizes the challenges associated with analyzing the LISA data, the current state of affairs, and the necessary next steps to move forward in addressing the imminent challenges.Comment: 4 pages, no figures, Proceedings paper for the TeV Particle Astrophysics II conference held Aug 28-31 at the Univ. of Wisconsi

    6-Methyl-Nitroarachidonate :a novel esterified nitroalkene which potently Inhibits platelet aggregation and exerts cgmp mediated vascular relaxation

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    Postprint.Nitro-fatty acids represent endogenously occurring products of oxidant-induced nitration reactions. We have previously synthesized a four isomers mixture of nitroarachidonic acid, a novel anti-inflammatory signaling mediator. Herein, we synthesized, chemically and biologically characterized for a first time an esterified nitroalkene derived from the nitration of methylarachidonate (AAMet): 6-methyl-nitroarachidonate (6-AAMetNO2). Synthesis was performed by AAMet reaction with sodium nitrite in acidic conditions. Analysis by mass spectrometry (positive ion ESI-MS) showed a [M+H]+ ion of m/z 364, characteristic of AAMetNO2. Fragmentation of this ion yielded a daughter ion at m/z 317, corresponding to the neutral loss of the nitro group ([M+HHNO2]+). Furthermore, IR signal at 1378 cm-1 and NMR data confirmed the structure of a 6-nitro positional isomer. This novel esterified nitroalkene showed to be capable of promoting vascular protective actions including: a) the induction of vasorelaxation via endothelium-independent mechanisms, associated with an increase of smooth muscle cells cGMP levels and b) a potent dosedependent inhibition of human platelet aggregation. We postulate that 6-AAMetNO2 could be a potential drug for prevention of vascular and inflammatory diseases, where the presence of the methyl group may increase its pharmacological potential

    Extreme mass ratio inspiral rates: dependence on the massive black hole mass

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    We study the rate at which stars spiral into a massive black hole (MBH) due to the emission of gravitational waves (GWs), as a function of the mass M of the MBH. In the context of our model, it is shown analytically that the rate approximately depends on the MBH mass as M^{-1/4}. Numerical simulations confirm this result, and show that for all MBH masses, the event rate is highest for stellar black holes, followed by white dwarfs, and lowest for neutron stars. The Laser Interferometer Space Antenna (LISA) is expected to see hundreds of these extreme mass ratio inspirals per year. Since the event rate derived here formally diverges as M->0, the model presented here cannot hold for MBHs of masses that are too low, and we discuss what the limitations of the model are.Comment: Accepted to CQG, special LISA issu

    Forward Modeling of Space-borne Gravitational Wave Detectors

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    Planning is underway for several space-borne gravitational wave observatories to be built in the next ten to twenty years. Realistic and efficient forward modeling will play a key role in the design and operation of these observatories. Space-borne interferometric gravitational wave detectors operate very differently from their ground based counterparts. Complex orbital motion, virtual interferometry, and finite size effects complicate the description of space-based systems, while nonlinear control systems complicate the description of ground based systems. Here we explore the forward modeling of space-based gravitational wave detectors and introduce an adiabatic approximation to the detector response that significantly extends the range of the standard low frequency approximation. The adiabatic approximation will aid in the development of data analysis techniques, and improve the modeling of astrophysical parameter extraction.Comment: 14 Pages, 14 Figures, RevTex

    Optimal filtering of the LISA data

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    The LISA time-delay-interferometry responses to a gravitational-wave signal are rewritten in a form that accounts for the motion of the LISA constellation around the Sun; the responses are given in closed analytic forms valid for any frequency in the band accessible to LISA. We then present a complete procedure, based on the principle of maximum likelihood, to search for stellar-mass binary systems in the LISA data. We define the required optimal filters, the amplitude-maximized detection statistic (analogous to the F statistic used in pulsar searches with ground-based interferometers), and discuss the false-alarm and detection probabilities. We test the procedure in numerical simulations of gravitational-wave detection.Comment: RevTeX4, 28 pages, 9 EPS figures. Minus signs fixed in Eq. (46) and Table II. Corrected discussion of F-statistic distribution in Sec. IV

    The crystal morphology and growth rates of triclinic N-docosane crystallising from N-dodecane solutions

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    A detailed analysis of the crystal morphology of triclinic n-docosane (C22H46) is presented together with a preliminary assessment of the supersaturation-dependence of the growth rates for the predicted (hkl) faces. A methodology to index the experimentally observed crystal faces, based on a combined BFDH and zone axis methodology is defined. Analysis using this methodology yields the morphological indexation of n-docosane to be (001), (112), (102), (010), and (1 - 33) or (130) based on the expected triclinic crystal structure. Crystals of n-docosane growing from supersaturated n-dodecane (C12 H26) solutions, as studied using in-situ optical microscopy, at three different supersaturation (σ) levels 0.01, 0.02 and 0.05, reveal that the crystal morphology changes with increasing in supersaturation, evolving from a habit consistent with a triclinic crystal system to a habit that is perhaps more representative of an orthorhombic structure. Growth rates determined for the (112) and (102) faces as well as for those less dominant faces range between 0.51 and 9.85 mm/s, in good agreement with previously reported data for other organic molecules including n-alkanes
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