80 research outputs found
Advanced Full-Text Search Based on Synonyms in Postgres
This paper discusses the advanced full-text search queries based on synonyms that are supported in Chajda, which is a postgres extension and corresponding python library for highly multi-lingual full-text search in postgres. This discussion will include the motivations for using advanced queries based on synonyms, examples of how to use these advanced queries in Chajda, current limitiations of the advanced queries, and performance testing of the advanced queries
Chromophore switch from 11-cis-dehydroretinal (A2) to 11-cis-retinal (A1) decreases dark noise in salamander red rods
Dark noise, light-induced noise and responses to brief flashes of light were recorded in
the membrane current of isolated rods from larval tiger salamander retina before and after
bleaching most of the native visual pigment, which mainly has the 11-cis-3,4-dehydroretinal
(A2) chromophore, and regenerating with the 11-cis-retinal (A1) chromophore in the same
isolated rods. The purpose was to test the hypothesis that blue-shifting the pigment by switching
from A2 to A1 will decrease the rate of spontaneous thermal activations and thus intrinsic
light-like noise in the rod. Complete recordings were obtained in five cells (21âŠC). Based on
the wavelength of maximum absorbance, λmax,A1 =502 nm and λmax,A2 =528 nm, the average
A2 : A1 ratio determined from rod spectral sensitivities and absorbances was âŒ0.74 : 0.26 in
the native state and âŒ0.09 : 0.91 in the final state. In the native (A2) state, the single-quantum
response (SQR) had an amplitude of 0.41±0.03 pA and an integration time of 3.16±0.15 s
(mean±S.E.M.). The low-frequency branch of the dark noise power spectrum was consistent
with discrete SQR-like events occurring at a rate of 0.238±0.026 rodâ1 sâ1. The corresponding
values in the final state were 0.57±0.07 pA (SQR amplitude), 3.47±0.26 s (SQR integration
time), and 0.030±0.006 rodâ1 sâ1 (rate of dark events). Thus the rate of dark events per rod
and the fraction of A2 pigment both changed by ca 8-fold between the native and final states,
indicating that the dark events originated mainly in A2 molecules even in the final state. By
extrapolating the linear relation between event rates and A2 fraction to 0% A2 (100% A1) and
100% A2 (0% A1), we estimated that the A1 pigment is at least 36 times more stable than the A2
pigment. The noise component attributed to discrete dark events accounted for 73% of the total
dark current variance in the native (A2) state and 46% in the final state. The power spectrum of
the remaining âcontinuousâ noise component did not differ between the two states. The smaller
and faster SQR in the native (A2) state is consistent with the idea that the rod behaves as if
light-adapted by dark events that occur at a rate of nearly one per integration time. Both the
decreased level of dark noise and the increased SQR amplitude must significantly improve the
reliability of photon detection in dim light in the presence of the A1 chromophore compared to
the native (A2) state in salamander rods
Velocity and Temperature Profiles for Laminar Magnetohydrodynamic Flow in the Entrance Region of a Plane Channel
Closure to âDiscussions of âThe Development of Free Convection Between Heated Vertical Platesââ (1962, ASME J. Heat Transfer, 84, p. 44)
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