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
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
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
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
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
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
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
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
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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