Circadian (locomotor activity/perching) behaviour of the weaverbird (Ploceus philippinus) under different light intensities was studied. Six groups of birds were subjected to 12L:12D (L = 1000 and 10 lux and D = 0.3 lux) for two weeks, and thereafter released into constant dim illumination (LL(dim) = 0.3 lux). After two weeks of LL(dim), birds were given a 2 h light pulse of 1000 lux at circadi...

Vibrio fischeri possesses two quorum-sensing systems, ain and lux, using acyl homoserine lactones as signaling molecules. We have demonstrated previously that the ain system activates luminescence gene expression at lower cell densities than those required for lux system activation and that both systems are essential for persistent colonization of the squid host, Euprymna scolopes. Here, we ask...

We describe the construction of mini-Tn7-based broad-host-range vectors encoding lux genes as bioluminescent reporters. These constructs can be mobilized into the desired host(s) by conjugation for chromosomal mini-Tn7-lux integration and are useful for localization of bacteria during infections or for characterizing regulation of promoters of interest in Gram-negative bacteria.

A model system based on the Escherichia coli MG1655 (pRecA-lux) Lux-biosensor was used to evaluate the ability of the fermentates of eight probiotic strains to reduce the SOS response stimulated by ciprofloxacin in bacteria and mutagenesis mediated by it. Preliminary attempts to estimate the chemical nature of active components of the fermentates were conducted.

OBJECTIVE Published dosing guidelines for treatment of Seasonal Affective Disorder (SAD) refer to photopic lux, which is not appropriate for short-wavelength light. Short wavelengths are most potent for many non-visual responses to light. If SAD therapy were similarly mediated, standards utilizing lux risk overestimating necessary dose. We investigated antidepressant responses to light using tw...

Objective: The main purpose of this study is to evaluate the visual angle and ambient illumination effects on visual fatigue and performances while viewing from a projected screen for 40 minutes. Methods: Visual angle (16, 24 and 48 min arc of Chinese character height) and ambient illumination (200 and 750 lux) were the independent variables in this study. Change in critical flicker frequency (...

Leaves of rye seedlings (Secale cereale L.) grown in the presence of four chlorosis-inducing herbicides under a low light intensity of 10 lux formed chlorophyll. When segments of such dim-light-grown leaves were exposed to 30,000 lux at either 0 degrees C or 30 degrees C, treatments with aminotriazole or haloxidine (group 1) showed no or only minor changes of their chlorophyll contents. In trea...

Yersinia pestis causes an acute infection known as the plague. Conventional techniques to enumerate Y. pestis can be labor intensive and do not lend themselves to high throughput assays. In contrast, bioluminescent bioreporters produce light that can be detected using plate readers or optical imaging platforms to monitor bacterial populations as a function of luminescence. Here, we describe the...