121 resultados para Olfactory perception.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Olfactory ensheathing cells (OECs) are specialized glial cells in the mammalian olfactory system supporting growth of axons from the olfactory epithelium into the olfactory bulb. OECs in the olfactory bulb can be subdivided into OECs of the outer nerve layer and the inner nerve layer according to the expression of marker proteins and their location in the nerve layer. In the present study, we have used confocal calcium imaging of OECs in acute mouse brain slices and olfactory bulbs in toto to investigate physiological differences between OEC subpopulations. OECs in the outer nerve layer, but not the inner nerve layer, responded to glutamate, ATP, serotonin, dopamine, carbachol, and phenylephrine with increases in the cytosolic calcium concentration. The calcium responses consisted of a transient and a tonic component, the latter being mediated by store-operated calcium entry. Calcium measurements in OECs during the first three postnatal weeks revealed a downregulation of mGluR(1) and P2Y(1) receptor-mediated calcium signaling within the first 2 weeks, suggesting that the expression of these receptors is developmentally controlled. In addition, electrical stimulation of sensory axons evoked calcium signaling via mGluR(1) and P2Y(1) only in outer nerve layer OECs. Downregulation of the receptor-mediated calcium responses in postnatal animals is reflected by a decrease in amplitude of stimulation-evoked calcium transients in OECs from postnatal days 3 to 21. In summary, the results presented reveal striking differences in receptor responses during development and in axon-OEC communication between the two subpopulations of OECs in the olfactory bulb.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background How accurately do people perceive extreme water speeds and how does their perception affect perceived risk? Prior research has focused on the characteristics of moving water that can reduce human stability or balance. The current research presents the first experiment on people's perceptions of risk and moving water at different speeds and depths. Methods Using a randomized within-person 2 (water depth: 0.45, 0.90 m) ×3 (water speed: 0.4, 0.8, 1.2 m/s) experiment, we immersed 76 people in moving water and asked them to estimate water speed and the risk they felt. Results Multilevel modeling showed that people increasingly overestimated water speeds as actual water speeds increased or as water depth increased. Water speed perceptions mediated the direct positive relationship between actual water speeds and perceptions of risk; the faster the moving water, the greater the perceived risk. Participants' prior experience with rip currents and tropical cyclones moderated the strength of the actual–perceived water speed relationship; consequently, mediation was stronger for people who had experienced no rip currents or fewer storms. Conclusions These findings provide a clearer understanding of water speed and risk perception, which may help communicate the risks associated with anticipated floods and tropical cyclones.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human–wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people's ability to estimate extreme wind speeds and perceptions of their associated risks. Method We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt. Results Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual–perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms. Conclusion These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Working primarily within the natural landscape, this practice-led research project explored connections between the artist's visual and perceptual experience of a journey or place while simultaneously emphasizing the capacity for digital media to create a perceptual dissonance. By exploring concepts of time, viewpoint, duration of sequences and the manipulation of traditional constructs of stop-frame animation, the practical work created a cognitive awareness of the elements of the journey through optical sensations. The work allowed an opportunity to reflect on the nature of visual experience and its mediation through images. The project recontextualized the selected mediums of still photography, animation and projection within contemporary display modes of multiple screen installations by analysing relationships between the experienced and the perceived. The resulting works added to current discourse on the interstices between still and moving imagery in a digital world.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It has been shown that active control of locomotion increases accuracy and precision of nonvisual space perception, but psychological mechanisms of this enhancement are poorly understood. The present study explored a hypothesis that active control of locomotion enhances space perception by facilitating crossmodal interaction between visual and nonvisual spatial information. In an experiment, blindfolded participants walked along a linear path under one of the following two conditions: (1) They walked by themselves following a guide rope; and (2) they were led by an experimenter. Subsequently, they indicated the walked distance by tossing a beanbag to the origin of locomotion. The former condition gave participants greater control of their locomotion, and thus represented a more active walking condition. In addition, before each trial, half the participants viewed the room in which they performed the distance perception task. The other half remained blindfolded throughout the experiment. Results showed that although the room was devoid of any particular cues for walked distances, visual knowledge of the surroundings improved the precision of nonvisual distance perception. Importantly, however, the benefit of preview was observed only when participants walked more actively. This indicates that active control of locomotion allowed participants to better utilize their visual memory of the environment for perceiving nonvisually encoded distance, suggesting that active control of locomotion served as a catalyst for integrating visual and nonvisual information to derive spatial representations of higher quality.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In today’s world of information-driven society, many studies are exploring usefulness and ease of use of the technology. The research into personalizing next-generation user interface is also ever increasing. A better understanding of factors that influence users’ perception of web search engine performance would contribute in achieving this. This study measures and examines how users’ perceived level of prior knowledge and experience influence their perceived level of satisfaction of using the web search engines, and how their perceived level of satisfaction affects their perceived intention to reuse the system. 50 participants from an Australian university participated in the current study, where they performed three search tasks and completed survey questionnaires. A research model was constructed to test the proposed hypotheses. Correlation and regression analyses results indicated a significant correlation between (1) users’ prior level of experience and their perceived level of satisfaction in using the web search engines, and (2) their perceived level of satisfaction in using the systems and their perceived intention to reuse the systems. A theoretical model is proposed to illustrate the causal relationships. The implications and limitations of the study are also discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Driver sleepiness is a major contributor to road crashes. The current study sought to examine the association between perceptions of effectiveness of six sleepiness countermeasures and their relationship with self-reports of continuing to drive while sleepy among 309 drivers after controlling for the influence of age, sex, motivation for driving sleepy, and risk perception of sleepy driving. The results demonstrate that the variables of age, sex, motivation, and risk perception were significantly associated with self-reports of continuing to drive while sleepy and only one countermeasure was associated with self-reports of continuing to drive while sleepy. Further, it was found that age differences in self-reports of continuing to drive while sleepy was mediated by participants’ motivation and risk perception. These findings highlight modifiable factors that could be focused on with interventions that seek to modify drivers’ attitudes and behaviours of driving while sleepy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Emotionally arousing events can distort our sense of time. We used mixed block/event-related fMRI design to establish the neural basis for this effect. Nineteen participants were asked to judge whether angry, happy and neutral facial expressions that varied in duration (from 400 to 1,600 ms) were closer in duration to either a short or long duration they learnt previously. Time was overestimated for both angry and happy expressions compared to neutral expressions. For faces presented for 700 ms, facial emotion modulated activity in regions of the timing network Wiener et al. (NeuroImage 49(2):1728–1740, 2010) namely the right supplementary motor area (SMA) and the junction of the right inferior frontal gyrus and anterior insula (IFG/AI). Reaction times were slowest when faces were displayed for 700 ms indicating increased decision making difficulty. Taken together with existing electrophysiological evidence Ng et al. (Neuroscience, doi: 10.3389/fnint.2011.00077, 2011), the effects are consistent with the idea that facial emotion moderates temporal decision making and that the right SMA and right IFG/AI are key neural structures responsible for this effect.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Prescription medicine samples provided by pharmaceutical companies are predominantly newer and more expensive products. The range of samples provided to practices may not represent the drugs that the doctors desire to have available. Few studies have used a qualitative design to explore the reasons behind sample use. Objective The aim of this study was to explore the opinions of a variety of Australian key informants about prescription medicine samples, using a qualitative methodology. Methods Twenty-three organizations involved in quality use of medicines in Australia were identified, based on the authors' previous knowledge. Each organization was invited to nominate 1 or 2 representatives to participate in semistructured interviews utilizing seeding questions. Each interview was recorded and transcribed verbatim. Leximancer v2.25 text analysis software (Leximancer Pty Ltd., Jindalee, Queensland, Australia) was used for textual analysis. The top 10 concepts from each analysis group were interrogated back to the original transcript text to determine the main emergent opinions. Results A total of 18 key interviewees representing 16 organizations participated. Samples, patient, doctor, and medicines were the major concepts among general opinions about samples. The concept drug became more frequent and the concept companies appeared when marketing issues were discussed. The Australian Pharmaceutical Benefits Scheme and cost were more prevalent in discussions about alternative sample distribution models, indicating interviewees were cognizant of budgetary implications. Key interviewee opinions added richness to the single-word concepts extracted by Leximancer. Conclusions Participants recognized that prescription medicine samples have an influence on quality use of medicines and play a role in the marketing of medicines. They also believed that alternative distribution systems for samples could provide benefits. The cost of a noncommercial system for distributing samples or starter packs was a concern. These data will be used to design further research investigating alternative models for distribution of samples.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis explores the shift in perception of design from a styling and product-focused tool, towards a holistic strategic approach within a small to medium sized manufacturing company. This research is significant because it demonstrates how design tools and approaches can be used within business to translate theory into operational, strategic and cultural outcomes. The outcomes of this research will encourage other businesses to take on similar design-led projects with the ultimate goal of employing design as a means to create a sustainable competitive advantage.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose Food refusal is part of normal toddler development due to an innate ability to self-regulate energy intake and the onset of neophobia. For parents, this ‘fussy’ stage causes great concern, prompting use of coercive feeding practices which ignore a child’s own hunger and satiety cues, promoting overeating and overweight. This analysis defines characteristics of the ‘good eater’ using latent variable structural equation modelling and the relationship with maternal perception of her child as a fussy eater. Methods Mothers in the control group of the NOURISH and South Australian Infants Dietary Intake studies (n=332) completed a self-administered questionnaire - when child was age 12-16 months - describing refusal of familiar and unfamiliar foods and maternal perception as fussy/not fussy. Weight-for-age z-score (WAZ) was derived from weight measured by study staff. Questionnaire items and WAZ were combined in AMOS to represent the latent variable the ‘good eater’. Results/findings Mean age(sd) of children was 13.8(1.3) months, mean WAZ(sd), .58(.86) and 49% were male. The ‘good eater’ was represented by higher WAZ, a child that hardly ever refuses food, hardly ever refuses familiar food, and willing to eat unfamiliar foods (x2/df=2.80, GFI=.98, RMSEA=.07(.03-.12), CFI=.96). The ‘good eater’ was inversely associated with maternal perception of her child as a fussy eater (β=-.64, p<.05). Conclusions Toddlers displaying characteristics of a ‘good eater’ are not perceived as fussy, but these characteristics, especially higher WAZ, may be undesirable in the context of obesity prevention. Clinicians can promote food refusal as normal and even desirable in healthy young children.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Women’s participation in paid employment has become a common scenario even in non-western developing countries. For example in Malaysia, the trend is growing although the traditional gender role remains strong in Malaysian society. Even though working, women are still expected to assume major responsibilities at home. Thus, as opposed to men, women in this society face the challenge to satisfactorily balance work and family. This study was carried out to explore how Malaysian women perceive the meaning of a balanced work-family life. Sampling women teachers, the interview findings revealed that work-family balance was mainly perceived in terms of an individual’s ‘ability to fulfill role obligation’ appropriately in both the work and family domains. A few participants also viewed balance in the context of role satisfaction and role interference. Overall, the results support the assumption in the literature that perceptions of work-family experience are not universal, rather, the construct of work-family balance is culture-specific.