Influence of low-level laser therapy on vertical jump in sedentary individuals / Influência do laser de baixa potência no salto vertical em indivíduos sedentários / Influência do laser de baixa potência no salto vertical em indivíduos sedentários

Objective To investigate the effects of low intensity laser (660nm), on the surae triceps muscle fatigue and power, during vertical jump in sedentary individuals, in addition to delayed onset muscle soreness. Methods We included 22 sedentary volunteers in the study, who were divided into three groups: G1 (n=8) without performing low intensity laser (control); G2 (n=7) subjected to 6 days of low intensity laser applications; and G3 (n=7) subjected to 10 days of low intensity laser applications. All subjects were evaluated by means of six evaluations of vertical jumps lasting 60 seconds each. In G2 and G3, laser applications in eight points, uniformly distributed directly to the skin in the region of the triceps surae were performed. Another variable analyzed was the delayed onset muscle soreness using the Visual Analog Scale of Pain. Results There was no significant difference in fatigue and mechanical power. In the evaluation of delayed onset muscle soreness, there was significant difference, being the first evaluation higher than the others. Conclusion The low intensity laser on the triceps surae, in sedentary individuals, had no significant effects on the variables evaluated. .

Objetivo Verificar os efeitos do laser de baixa potência (660nm) sobre o tríceps sural na fadiga muscular e na potência, durante o salto vertical, em indivíduos sedentários, além da dor muscular de início tardio. Métodos Foram inclusos no estudo 22 voluntários sedentários, divididos em três grupos: G1 (n=8), sem realização de laser de baixa potência (controle); G2 (n=7), submetido a 6 dias de aplicações de laser de baixa potência; e G3 (n=7), submetido a 10 dias de aplicações de laser de baixa potência. Todos os indivíduos foram avaliados por meio de seis avaliações de saltos verticais, com duração de 60 segundos cada. No G2 e G3, foram realizadas aplicações de laser em oito pontos, distribuídos uniformemente e diretamente na pele, na região de do tríceps sural. Outra variável analisada foi a dor muscular de início tardia, utilizando a Escala Visual Analógica de Dor. Resultados Não houve diferença significativa na fadiga e na potência mecânica. Na avaliação da dor muscular tardia, houve diferença significativa, sendo a primeira avaliação maior do que as demais avaliações. Conclusão A aplicação do laser de baixa potência no tríceps sural, em indivíduos sedentários, não apresentou efeitos significativos nas variáveis avaliadas. .

Photoperiodic effects on activity behaviour in the spiny eel (Macrognathus pancalus).

The study focused on the characteristics of circadian locomotor activity in the spiny eel, M. pancalus, kept under different photoperiodic conditions. Two experiments were conducted. Experiment 1 tested the light intensity dependent effect on circadian rhythmicity of the locomotor activity in spiny eel. Three groups of fish were entrained to 12L:12D conditions for 10 days. Thereafter, they were released to constant conditions for 15 days as indicated below: group 1-DD (0 lux), group 2- LLdim (~1 lux) and group 3-LLbright (~500 lux). The locomotor activity of the fish, housed singly in an aquarium, was recorded continuously with infrared sensors connected to a computer. More than 90% activity of the eels was confined to the dark hours suggesting nocturnal habit. Under constant conditions, the activity in 7/9 fish in group 1, 4/8 in group 2 and 3/8 in group 3, started free running with a mean circadian period of 24.48 ± 0.17 h, 23.21 ± 0.47 h and 25.54 ± 1.13 h in respective groups. Remaining fish in each group became arrhythmic. This suggests that spiny eel can be synchronised to LD cycle and under constant conditions they free run with a circadian period. However, their activity under LL is light intensity dependent; higher the intensity, more disruption in circadian locomotor activity. Experiment 2 was conducted to study the effect of decreasing night length (increasing photoperiod) on circadian locomotor activity. The fish were sequentially exposed to 16D (8L:16D), 12D (12L:12D), 8D (16L:8D), 4D (20L:4D) and 2D (22L:2D) for 10 days in each condition, thereafter, they were released in constant dark (DD= 0lux). The results showed that the duration of night length affects both, the amplitude and duration of locomotor activity. It can be concluded that the spiny eels are nocturnal and that their locomotor activity is under the circadian control and may be influenced by the photoperiod.

Effects of light intensity on circadian activity behaviour in the Indian weaverbird (Ploceus philippinus).

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 (LLdim = 0.3 lux). After two weeks of LLdim, birds were given a 2 h light pulse of 1000 lux at circadian time (CT) 12, 17 and 20, and exposure of LLdim was continued for another two weeks and the activity pattern was monitored. As expected, all birds were entrained under 12L:12D showing dense-activity in the group that was placed under light phase of 1000 lux. Under LLdim birds exhibited circadian activity rhythms with periods longer or shorter than 24 h. Light pulse at CT 12 caused small delay shift in the activity phase, but a larger delay in phase shift occurred when the pulse was given at CT 17. A pulse at CT 20 caused small advanced phase shift. Thus, photoperiodic weaverbird appears to show circadian system regulated behaviour as seen by activity-rest pattern under programmed light cycles.

Long-term effect of prenatal exposure to low level of gamma radiation on neurophysiology of mouse.

Abdominal region of pregnant Swiss mice were exposed to 0.25, 0.35 or 0.50 Gy of gamma radiation on days 11.5, 12.5, 14.5 or 17.5 post coitus (pc). Changes in locomotory activity and learning performance, and hippocampal biogenic amines (noradrenaline, NA; dopamine, DA; 5-hydroxytryptomine, 5-HT; and 5-HTs metabolite 5-hydroxyindolacetic acid, 5-HIAA) were studied at 12 (adult) and 18 months (old) of age. Significant change in locomotory activity and learning performance was observed after exposure to 0.50 Gy at late organogenesis day (11.5 pc), when tested at 12 months of age, but not observed much change at 18 months. Biogenic amines did not show any significant change after any exposure dose at any of the gestation days. It was inferred from the results that gamma irradiation (0.50 Gy) at the late organogenesis (day 11.5 pc) can impair the brain functions in adults when normal faculties are functional.