4 resultados para Bins.
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Kerodon rupestris (rock cavy, mocó) is an endemic caviidae of Brazilian northeast that inhabits rocky places in the semi arid region. The aim of this study was to characterize the activity/rest rhythm of the rock cavy under 12:12 h LD cycle and continuous light. In the first stage, seven animals were submitted to two light intensities (LD; 250:0 lux and 400:0 lux; 40 days each intensity). In the second stage four males were kept for 40 days in LD (470:<1 lux), for 18 days in LL 470 lux (LL470) and for 23 days in red dim light below 1 lux (LL<1). In the third stage three males were initially kept in LD 12:12 h (450:<1 lux) and after that in LL with gradual increase in light intensity each 21 days (<1 lux LL<1; 10 lux-LL10; 160 lux LL160; 450 lux LL450). In the fourth stage it was analyzed the motor activity of 16 animals in the first 10 days in LD. Motor activity was continuously recorded by passive infrared movement sensors connected to a computer and totaled in 5 min bins. The activity showed circadian and ultradian rhythms and activity peaks at phase transitions. The activity and the rest occurred in the light as well as in the dark phase, with activity mean greater in the light phase for most of the animals. The light intensity influenced the activity/rest rhythm in the first three stages and in the first stage the activity in 400 lux increased in four animals and decreases in two. In the second stage, the tau for 3 animals in LL470 was greater than 24 h; in LL<1 it was greater than 24 h for one and lower for two. In the third stage the tau decreased with the light intensity increase for animal 8. During the first days in the experimental room, the animals did not synchronize to the LD cycle with activity and rest occurring in both phases. The results indicate that the activity/rest rhythm of Kerodon rupestris can be affected by light intensity and that the synchronization to the LD cycle results from entrainment as well as masking probably as a consequence of the action of two or more oscillators with low coupling strength
Resumo:
Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Otherwise, light can act directly on expressed rhythm, without act on the biological oscillators, promoting the masking. Thus, photic stimuli can synchronize the circadian activity rhythm (CAR) by two distinct mechanisms, acting isolated or at a combined way. Among the elements that can influence photic synchronization, the duration and time of photic exposure is pointed out. If in the natural environment the marmoset can choose places of different intensity illumination and is synchronized to light-dark cycle (LD), how the photic synchronization mechanism can be evaluated in laboratory by light self-selection? With objective to response this question, four adult male marmosets were studied at two conditions: with and without sleeping box. The animals were submitted to a LD cycle (12:12/ 350:2 lx) and constant light (LL: 350 lx) conditions in individual cages with an opaque sleeping box, that permitted the light self-selection. At the room, the temperature was 25.6 ºC (± 0.3 ºC) and humidity was 78.7 (± 5%). The motor activity was recorded at 5 min bins by infrared movement sensors installed at the top of the cages. The motor activity profile was distinct at the two conditions: without the sleeping box protection against light, the activity frequency was higher at CT 11-12 (ANOVA; F(3.23) = 62.27; p < 0.01). Also, the duration of the active phase (α) was prolonged of about 1 h (t test, p < 0.05) and the animals showed a significant delay on the activity onset and offset (t test, p < 0.05) and at the acrophase (confidence intervals of 5%) of CAR. In LL, the light continuous exposure prolonged the active phase and influenced the endogenous expression of the circadian activity rhythm period. From the result analysis, it is concluded that the light self-selection can modify several parameters of CAR in marmosets, allowing the study of the synchronization mechanism using the burrow model. Thus, without sleeping box there was a phase delay between the CAR and LD (entrainment) and an increase of activity near lights off (positive masking). Furthermore, in LL, the light continuous exposure modifies α and the endogenous expression of CAR. It is suggested that the light self-selection might be take into account at investigations that evaluate the biological rhythmicity in marmosets
Resumo:
This study reports recommendations for a tactile and graphic wayfinding system aiming to offer more orientability and mobility for visually impaired people (blindness and low vision) at Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN), Parnamirim Campus. It was necessary to focus on visual impaired people and approach concepts like orientation and accessibility at the built environment. In order to provide the comprehension of a complex social phenomenon and preserve the meaningful characteristics of the events, this research has developed a single case study in which elements of Post Occupation Evaluation have been used. Its purpose was to allow not only a technical analysis, but also the user perception about the space in use. The chosen tool to collect the user’s opinions and considerations was the Walk Together Method. The collected and analyzed information has demonstrated that, although Parnamirim Campus has implemented some interventions in relation to the spatial accessibility, they are still not enough to create an environment which arranges safety and autonomy for the visual impaired people and the other ones who attend there. This study suggests that it happened because the engineering interventions at the Campus have been based on Brazilian technical standards NBR 9050:2004, which is proper for the physical impaired people, but it does not offer enough information to respond to all the specific needs demanded by all the classifications of visual impairment.
Resumo:
This study reports recommendations for a tactile and graphic wayfinding system aiming to offer more orientability and mobility for visually impaired people (blindness and low vision) at Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN), Parnamirim Campus. It was necessary to focus on visual impaired people and approach concepts like orientation and accessibility at the built environment. In order to provide the comprehension of a complex social phenomenon and preserve the meaningful characteristics of the events, this research has developed a single case study in which elements of Post Occupation Evaluation have been used. Its purpose was to allow not only a technical analysis, but also the user perception about the space in use. The chosen tool to collect the user’s opinions and considerations was the Walk Together Method. The collected and analyzed information has demonstrated that, although Parnamirim Campus has implemented some interventions in relation to the spatial accessibility, they are still not enough to create an environment which arranges safety and autonomy for the visual impaired people and the other ones who attend there. This study suggests that it happened because the engineering interventions at the Campus have been based on Brazilian technical standards NBR 9050:2004, which is proper for the physical impaired people, but it does not offer enough information to respond to all the specific needs demanded by all the classifications of visual impairment.
