Curves relating flicker frequency (F) to mean critical illumination (I(m)) for threshold response to flickered light, with equal durations of light and no light intervals, and relating illumination (I) to mean critical flicker frequency (F(m)) for the same response, have been obtained from homogeneous data based upon the reactions of dragonfly larvae (Anax junius). These curves exhibit the prop...

To provide a scientific basis for artificial culture, the effects of different breeding densities, feeding cycles, and light environments on the growth regulation of Poecilobdella manillensis were studied. After P. manillensis were cultured at breeding densities of 250 ~ 3250 leeches m-2; feeding cycles of 2 ~ 16 days; and a light environment with noise or a light-free environment without noise...

The retrosplenial cortex supports navigation, with one role thought to be the integration of different spatial cue types. This hypothesis was extended by examining the integration of nonspatial cues. Rats with lesions in either the dysgranular subregion of retrosplenial cortex (area 30) or lesions in both the granular and dysgranular subregions (areas 29 and 30) were tested on cross-modal objec...

Sections from the human somatosensory cortex were observed with a light microscope. The neurons were classified into light and dark ones. The light neurons were slightly stained with thionin, luxol fast blue MBS and azocarmine G (80% of all neurons). The dark neurons were more or less shrunken, and stained intensely with these dyes (20% of all neurons). Double staining with luxol fast blue MBS ...

the circadian variation of the toxicity and nociceptive activity of aminophylline as an important methylxanthine was studied in mice. the animals were housed under controlled light-dark cycles for at least 2 weeks. acute toxicity was determined by ld50. hot-plate test was used for determination of thermal pain threshold. doses of 200, 250, 280 and 340 mg/kg of aminophylline were injected intrap...

PURPOSE To compare changes in anterior segment parameters under light and dark (light-to-dark) conditions among eyes with chronic primary angle-closure glaucoma (CPACG), fellow eyes with confirmed or suspect primary angle-closure (PAC or PACS), and age-matched healthy eyes. METHODS Consecutive patients with CPACG in one eye and PAC/PACS in the fellow eye, as well as age-matched healthy subjec...

PURPOSE Animal studies have indicated that retinal oxygen consumption is greater in dark than light. In this study, oxygen saturation is measured in retinal vessels of healthy humans during dark and light. METHODS The oximeter consists of a fundus camera, a beam splitter, a digital camera and software, which calculates hemoglobin oxygen saturation in the retinal vessels. In the first experime...

introduction: it has been shown that low levels of pigmentation increase susceptibility to noise-induced hearing loss in humans. for this reason, white populations develop more pronounced noise- induced hearing loss in comparison to black populations. similarly, blue-eyed individuals exhibit greater temporary threshold shift than brown-eyed subjects; still, no strong correlation has been verifi...

PURPOSE The authors examined the circadian change of basal pupil size in light-dark entrained normal rabbits and in entrained rabbits with unilaterally decentralized ocular sympathetic nerves. The pattern of the circadian pupillary rhythm was compared with the circadian patterns of intraocular pressure (IOP) and body temperature in the same rabbits. METHODS Adult male New Zealand albino rabbi...