1,872 research outputs found
Cavity optomechanics with stoichiometric SiN films
We study high-stress SiN films for reaching the quantum regime with
mesoscopic oscillators connected to a room-temperature thermal bath, for which
there are stringent requirements on the oscillators' quality factors and
frequencies. Our SiN films support mechanical modes with unprecedented products
of mechanical quality factor and frequency reaching Hz. The SiN membranes exhibit a low optical absorption
characterized by Im at 935 nm, representing a 15 times
reduction for SiN membranes. We have developed an apparatus to simultaneously
cool the motion of multiple mechanical modes based on a short, high-finesse
Fabry-Perot cavity and present initial cooling results along with future
possibilities.Comment: 4 pages, 5 figure
Modeling reverberation mapping data II: dynamical modeling of the Lick AGN Monitoring Project 2008 dataset
We present dynamical modeling of the broad line region (BLR) for a sample of
five Seyfert 1 galaxies using reverberation mapping data taken by the Lick AGN
Monitoring Project in 2008. By modeling the AGN continuum light curve and
H line profiles directly we are able to constrain the geometry and
kinematics of the BLR and make a measurement of the black hole mass that does
not depend upon the virial factor, , needed in traditional reverberation
mapping analysis. We find that the geometry of the BLR is generally a thick
disk viewed close to face-on. While the H emission is found to come
preferentially from the far side of the BLR, the mean size of the BLR is
consistent with the lags measured with cross-correlation analysis. The BLR
kinematics are found to be consistent with either inflowing motions or
elliptical orbits, often with some combination of the two. We measure black
hole masses of for Arp
151, for Mrk 1310, for NGC 5548,
for NGC 6814, and for SBS
1116+583A. The factors measured individually for each AGN are found to
correlate with inclination angle, although not with , ,
or FWHM/ of the emission line profile.Comment: 21 pages, 24 figures, 3 tables, Accepted for publication in MNRAS,
corrected masses for NGC 5548 and NGC 6814 in the abstrac
Properties of an invariant set of weights of perceptrons
In this paper, the dynamics of weights of perceptrons are investigated based on the perceptron training algorithm. In particular, the condition that the system map is not injective is derived. Based on the derived condition, an invariant set that results to a bijective invariant map is characterized. Also, it is shown that some weights outside the invariant set will be moved to the invariant set. Hence, the invariant set is attracting. Computer numerical simulation results on various perceptrons with exhibiting various behaviors, such as fixed point behaviors, limit cycle behaviors and chaotic behaviors, are illustrated
Pro–inflammatory cytokines profiles in Nigerian pregnant women infected with Plasmodium falciparum malaria
AbstractObjectiveTo investigate the pro-inflammatory cytokines profiles in in Nigerian pregnant women infected with Plasmodium falciparum (P. falciparum) malaria.MethodsPeripheral, and placental blood samples were collected from 96 consenting volunteers comprising 76 P. falciparium infected pregnant women and 20 healthy uninfected pregnant women in Ekpoma, Nigeria, and subjected to ELISA for cytokines evaluation.ResultsIncreased serum concentrations of interferon-gamma (IFN-γ) was observed in infected pregnant women than their uninfected counterparts [(31.2±20.9) pg/mL vs (1.8±0.9) pg/mL] and these differences were statistically significant (χ2 = 26.18, P <0.05). The depressed levels of interleukin-12 (IL-12) seen in peripheral blood of the infected pregnant women than the uninfected women [(13.9±3.6) pg/mL vs (28.4±5.28) pg/mL] respectively was not statistically significant (χ2 = 4.96, P >0.05). The interleukin -6 (IL-6) was significantly elevated in infected pregnant women (81.0±26.1 pg/mL) than in the uninfected pregnant women [(25.0±5.0) pg/mL] (χ2 = 29.58, P <0.05). In all, mean cytokines concentration of IL-6, IL-12 and IFN-γ in the placental blood from infected pregnant women were (53.5±23.4) pg/mL, (8.7±6.9) pg/mL and (16.4±4.0) pg/mL, respectively. The multigravidae had a higher haemoglobin level of 10.2 g/dL and birth weight of 3 000 g than the primigrivadae with lower haemoglobin level of 7.5 g/dL and birth weight of 2 430 g.ConclusionsThe elevated IFN-γamong the malarous pregnant women implicates it as the major cytokine mediator in the host responses to systematic P. falciparum malaria in our locality
Do Naked Singularities Form?
A naked singularity is formed by the collapse of a Sine-Gordon soliton in 1+1
dimensional dilaton gravity with a negative cosmological constant. We examine
the quantum stress tensor resulting from the formation of the singularity.
Consistent boundary conditions require that the incoming soliton is accompanied
by a flux of incoming radiation across past null infinity, but neglecting the
back reaction of the spacetime leads to the absurd conclusion that the total
energy entering the system by the time the observer is able to receive
information from the singularity is infinite. We conclude that the back
reaction must prevent the formation of the naked singularity.Comment: 7 pages (21 Kb), PHYZZX. Revised version to appear in Class. & Quant.
Grav. Letts. A discussion of the consistency of the Sine-Gordon model is
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Influential Factors on Korean Casino Visitor’s Gambling Intention: An Application of the Model of Goal-directed Behavior
By examining the perception of responsible gambling strategy this study developed an extended model of goal-directed behavior (EMGB) in the casino visitor’s decision-making process. This study also aimed to compare EMGB with theory of planned behavior (TPB). The results of the EMGB using structural equation modeling (SEM) indicate that “desire” had the strongest relationship with casino visitors’ intention to play casino gambling. The perception of responsible gambling strategy was also found significant (direct) predictor of both desire and behavioral intention as casino visitors had positive image for casino that implemented responsible gambling strategies. Casino managers should consider responsible gambling strategy as one of the important long-term business activities to increase casino visitor’s intention to play casino gambling
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