520 research outputs found
The power inversion adaptive array
After the brief review on adaptive array processing, three
fairly separate topics on the power inversion adaptive array are
treated in this thesis. The first topic is the behaviour of a narrowband
array using the stochastic gradient descent algorithm,
with the environment assumed to rotate at constant velocity in the
sine domain. Conditions for steady state weight deviations and
output power deterioration from optimal values due to the nonstationary
environment are derived and are then used to determine the
maximum scan rate of a radar side-lobe canceller. The second topic
is the jamming rejection capability of a broadband array using tapped
delay line processing. The results obtained are used for designing
the tap spacing and number of taps of the delay lines as
well as assessing, in terms of the number of variable weights, the
relative advantage of the alternative broadband processing method
using several narrowband array processors. The frequency distortions
at various directions introduced by rejecting the jammers are
also studied qualitatively. The third topic is the convergence
behaviour of the broadband array when the stochastic gradient descent
algorithm is employed. Comparison with the alternative broadband processing method is again given. A simple transformation
pre-processor, independent of the external environment and capable
of improving the convergence behaviour of using tapped delay line
processing, is also derived
Inspiral and Plunging Orbits in Kerr-Newman Spacetimes
We present the analytical solutions for the trajectories that spiral and
plunge inward the event horizon along the timelike geodesics of particles
following general non-equatorial paths within Kerr-Newman spacetimes. Our
studies encompass both bound and unbound motions. The solutions can be written
in terms of the elliptical integrals and the Jacobian elliptic functions of
manifestly real functions of the Mino time, and can respectively reduce to the
Kerr, Reissner-Nordstrm, and Schwarzschild black holes in certain
limits of the spin and charge of the black holes. The results can be compared
with some of the known ones restricted in the equatorial plane. These explicit
solutions may find applications such as the black hole accretion.Comment: 28 pages, 9 figure
Regge Closed String Scattering and its Implication on Fixed angle Closed String Scattering
We calculate the complete closed string high energy scattering amplitudes
(HSA) in the Regge regime for arbitrary mass levels. As an application, we
deduce the complete ratios among closed string HSA in the fixed angle regime by
using Stirling number identities. These results are in contrast with the
incomplete set of closed string HSA in the fixed angle regime calculated
previously. The complete forms of the fixed angle amplitudes, and hence the
ratios, were not calculable previously without the input of zero-norm state
calculation. This is mainly due to the lack of saddle point in the fixed angle
closed string calculation.Comment: 10 pages. v2: typos correcte
Butylidenephthalide antagonizes cromakalim-induced systolic pressure reduction in conscious normotensive rats
Merged planning photographs of [284] southern pavilion rubble fill removed to reveal ditch fill and natural; facing west; linked as external references to excavation plan 'Thwing_4-2_excavation_plan.dwg
Performance analysis of interconnected LANs with server/client configuration
Computer Networks and ISDN Systems25121321-133
Biochanin A, a Phytoestrogenic Isoflavone with Selective Inhibition of Phosphodiesterase 4, Suppresses Ovalbumin-Induced Airway Hyperresponsiveness
The present study investigated the potential of biochanin A, a phytoestrogenic
isoflavone of red clover (Triflolium pratense), for use in treating asthma or chronic
obstructive pulmonary disease (COPD). Biochanin A (100 μmol/kg, orally (p.o.))
significantly attenuated airway resistance (RL), enhanced pause (Penh), and increased lung dynamic compliance (Cdyn) values induced by methacholine (MCh) in sensitized and challenged mice. It also significantly suppressed an increase in the number of total inflammatory cells, neutrophils, and eosinophils, and levels of cytokines,
including interleukin (IL)-2, IL-4, IL-5, and tumor necrosis factor (TNF)-α in
bronchoalveolar lavage fluid (BALF) of the mice. However, it did not influence
interferon (IFN)-γ levels. Biochanin A (100 μmol/kg, p.o.) also significantly
suppressed the total and ovalbumin (OVA)-specific immunoglobulin E (IgE) levels in
the serum and BALF, and enhanced the total IgG2a level in the serum of these mice.
The PDE4H/PDE4L value of biochanin A was calculated as >35. Biochanin A did not influence xylazine/ketamine-induced anesthesia. Biochanin A (10~30 μM) significantly reduced cumulative OVA (10~100 μg/mL)-induced contractions in the isolated guinea pig trachealis, suggesting that it inhibits degranulation of mast cells.
In conclusion, red clover containing biochanin A has the potential for treating allergic asthma and COPD
Hesperetin, a Selective Phosphodiesterase 4 Inhibitor, Effectively Suppresses Ovalbumin-Induced Airway Hyperresponsiveness without Influencing Xylazine/Ketamine-Induced Anesthesia
Hesperetin, a selective phosphodiesterase (PDE)4 inhibitor, is present in the traditional Chinese medicine, “Chen Pi.” Therefore, we were interested in investigating its effects on ovalbumin- (OVA-) induced airway hyperresponsiveness, and clarifying its rationale for ameliorating asthma and chronic obstructive pulmonary disease (COPD). Hesperetin was revealed to have a therapeutic (PDE4H/PDE4L) ratio of >11. Hesperetin (10 ~ 30 μmol/kg, intraperitoneally (i.p.)) dose-dependently and significantly attenuated the airway hyperresponsiveness induced by methacholine. It also significantly suppressed the increases in total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL)-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF). It dose-dependently and significantly suppressed total and OVA-specific immunoglobulin E levels in the BALF and serum. However, hesperetin did not influence xylazine/ketamine-induced anesthesia, suggesting that hesperetin has few or no emetic effects. In conclusion, the rationales for ameliorating allergic asthma and COPD by hesperetin are anti-inflammation, immunoregulation, and bronchodilation
- …