Catia Reis is a Ph.D. student at the Faculty of Medicine at Lisbon University. Lisbon University is a public research university, one of the largest in Portugal. And the Faculty of Medicine is a top medical school with an established history dating back to the 19th century. 

Catia Reis discusses her interest, and background, in the area of sleep and circadian rhythms. She recounts how her earlier work in marine biology stimulated her interest in sleep deprivation and fatigue, and ultimately deeper into the study of sleep. And her own personal struggles with fatigue, being tired all the time from her work, also piqued her interest in this area of study. 

A circadian rhythm is essentially an approximately 24-hour cycle within the overall physiological processes of animate beings such as animals, plants, fungi, cyanobacteria, etc. In a rigid interpretation, circadian rhythms are known to be endogenously produced, however, they may be regulated by certain external cues as well, such as light from the sun and temperature. Reis explains how melatonin affects shift workers. She explains that this kind of work can be very problematic. Unfortunately, regarding shift workers, their melatonin profile may have trouble realigning properly as they work at night and try to get their sleep during the daytime hours. And a misalignment of one's melatonin profile, and the circadian system, in general, can contribute to fractured, or disturbed daytime sleep. Additionally, it may have a profound impact on their alertness during the night shift and could be a contributing factor to other health problems. Reis discusses in detail how inadequate sleep can affect job performance and she talks about the inherent dangers of being sleep deprived on the job.

The sleep researcher talks about genetics, social behavior, and light, and how they influence our cycle. She provides information on the potential for success in the management of these influencing factors. Light, for example, is a strong signal for our internal clocks. Light therapy might be one way to help shift workers ease their bodies into an adjustment to an irregular schedule. Light has a general alerting effect, and it can aid with shifting sleeping patterns, related to the relative timing of light exposure. In light therapy, individuals will sit very near a light box for a preset period of time. Time of day is critical. Bright light exposure early in one's day and dim light exposure at the end of the day can help shift the internal clock to an earlier position, while exposure to light later in the day may delay the timing of one's internal clock. Therefore, the timing of exposure can assist with shifting their internal clock to accommodate needs for work, etc. 

Reis wraps up by discussing her overall expectations for further research and how there is so much to learn from people as she digs deeper into her research. She underscores the importance of our sleep and talks about some of the areas she wants to explore in her field.