The I/T curve coefficient for evaluating changes in neuromuscular excitability after polarized light irradiation - a placebo-controlled randomized trial

Introduction: PILER light affects the sensory and motor excitability of the tissue, and these changes may depend on the color of the filter used in the irradiations. Objective: To evaluate changes in neuromuscular excitability after PILER irradiation with different filters. To evaluate the usefulness of the I/T curve coefficient in neuromuscular excitability test. Material and methods: 60 healthy volunteers assigned to four groups: group v - without filter (n=15), group x - red filter (n=15), group y - blue filter (n=15), group z - placebo (n=15) had biceps brachii irradiated with PILER light. Outcome Measures: I/T curve coefficient for rectangular (■I/T coeff) and triangular (▲I/T coeff) pulses for sensory and motor excitability and the pressure pain threshold (PPT). Results: ■I/T coeff (p=0.0013) and ▲I/T coeff (p=0.0011) for sensory excitability increased significantly in the irradiated group. ■I/T coeff (p=0.0356) and ▲I/T coeff (p=0.0022) increased significantly after blue light irradiation. A significant increase in the▲I/T coeff (p=0.0439) in motor excitability was observed in the irradiated group. ■I/T coeff (p=0.0309) and ▲I/T coeff (p=0.0064) increased significantly after blue light irradiation. Conclusion: PILER light may reduce muscle excitability. Using a blue filter may increase the sensory threshold, and myorelaxation. Further experiments are necessary to confirm the usefulness of the I/T curve coefficient.

The effect of the blue light on the pericarp cell growth and lycopene content of cherry tomato (Solanum lycopersicum var. cerasiforme) fruit

The cherry tomato fruit size depends on the growth of the pericarp which is parenchymal cells. The blue light stimulates the expansion of cotyledon cells, hypocotyl cells and leaf cells. In this study, the cherry tomato fruit was used as a material to investigate the effects of the blue light on the pericarp cells growth in fruit growth stage and lycopene accumulation in fruit growth and ripening stage. After 7 days of the blue light (440, 450 or 460 nm) treatment, pericarp cells growth and physiological, biochemical changes of the pericarp cells of 7-day-old fruit pericarp piece in vitro were analyzed. The lycopene content and some organic compound contents of 42-day-old postharvest fruits treated by the blue light similarly in 7 days and 7, 21-day-old fruit wrapped with blue filter (440-510 nm filtered) in 7 days were measured. The results showed that the 450 nm wavelength blue light the increased pericarp thickness of 7-day-old fruits through the increasement of the pericarp cell diameter. The 460 nm wavelength blue light the increased lycopene content of 42-day-old postharvest fruits. The blue filter treatment increased the sugar total content of 7- day-old fruits and increased the lycopene content of 21-day-old fruits.

Regionalization in the compound eye of Talitrus saltator (Crustacea, Amphipoda)

The crustacean Talitrus saltator is known to use many celestial cues during its orientation along the sea-land axis of sandy shores. In this paper, we investigated the existence of the eye regionalization by morphological, electrophysiological and behavioural experiments. Each ommatidium possesses five radially arranged retinular cells producing a square fused rhabdom by R1-R4 cells; the smaller R5 exist between R1 and R4. The size of R5 rhabdomere is largest in dorsal part and becomes gradually smaller in median and ventral part of the eye. Spectral-sensitivity measurements were recorded from either dorsal or ventral parts of the compound eye to clarify the chromatic difference. Results show that the dorsal part is green and UV-blue dichromatic, whereas the ventral part is UV (390 nm) with a substantial population of 450 nm receptors with the responses in the longer wavelength region. To evaluate the orienting behaviour of individuals, their eyes were black painted either in the dorsal or ventral part, under natural sky or a blue filter with or without the vision of the sun. Results show that animals painted on the dorsal part of their eyes tested under the screened sun were more dispersed and in certain cases their directions deflected than other groups of individuals. Furthermore, sandhoppers subjected to the obscuring of this area met in any case high difficulties in their directional choices. Therefore, our present work indicates the existence of a regionalization of the compound eye of T. saltator.Summary statementThis work provides evidences of the morphological and electrophysiological regionalization of the compound eye and the visual capabilities for behaviour involved in the recognition of the celestial compass orienting factors in crustaceans.

Effects of Photosynthetic Activity Radiation (PAR) on Green Mustard Plant Growth (Brassica rapa var. parachinensis L.)

A research on the effect of photosynthetic active radiation (PAR) on the growth of green mustard plants has been conducted. The radiation source used is sunlight. Samples have been grouped as a sample which treated by red filter (P1), by orange filter (P2), by purple filter (P3), by green filter (P4), by blue filter (P5) and a sample without filter as a control (P0). Each sample consisted of four plants. The planting was carried out using polybags with compost media. Observations were made from the nursery phase to the slow vegetative phase (day 3rd, when all plants had grown shoots until day 63rd of the harvest). Parameters measured include light intensity, plant height and number of leaves. Measurement is done every three days. Also it measured plant biomass on the last day of observation (63rd day). The results showed that the intensity of each sample had an impact on the harvest. The best growth rate is obtained in P2, both in the nursery phase and fast vegetative phase i.e. 0.119 cm/day and 0.194 cm/day, respectively. While the highest growth rate was obtained in the P3 sample, namely the slow vegetative phase (0.035 cm/day). Overall the best planting results were obtained in P2 samples with plant height of 23.18 cm, number of leaves of 12 strands and plant biomass of 33.56 g.