Acacia Aguirre - Academia.edu (original) (raw)
Papers by Acacia Aguirre
Les mauvais dormeurs constituent un modele d'etude de la regulation veille/sommeil chez l'... more Les mauvais dormeurs constituent un modele d'etude de la regulation veille/sommeil chez l'insomniaque. Notre travail comprend 3 protocoles : a) etude du sommeil et la vigilance de base, b) etude de la temperature, l'activite et la vigilance au cours d'une privation de sommeil de 36 heures et du sommeil de recuperation, c) bed rest de 24 heures et le sommeil apres celui-ci. Nous avons analyse le sommeil, la temperature corporelle et l'activite motrice, la vigilance et l'humeur. L'absence de differences significatives concernant le sommeil lent profond (sommeil de base et de recuperation) s'oppose a l'hypothese d'un mauvais fonctionnement de la regulation homeostasique chez les mauvais dormeurs. Chez les mauvais dormeurs, la correlation entre les horaires de sommeil et la dimension matin/soir est plus faible, les rythmes circadiens de la vigilance et de la performance sont de moindre amplitude et le minimum de temperature pendant le sommeil est ...
Eight healthy subjects were studied during 39-h spans (from 07:00 on one day until 22:00 the seco... more Eight healthy subjects were studied during 39-h spans (from 07:00 on one day until 22:00 the second) in which they remained awake. During one experiment, subjects were exposed to 100 lux of light between 18:00 and 8:00, and during a second experiment, they were exposed to 1000 lux during the same time span. Throughout the daytime period, they were exposed to normal daylight (1500 lux or more). The nighttime 1000-lux light treatment suppressed the melatonin metabolite aMT6s, while the 100 lux treatment did not. On the treatment day, the 1000 lux, in comparison to the 100 lux, light treatment resulted in both an elevated temperature minimum and a delay in its clock-time occurrence overnight. No real circadian phase shift in the temperature, urinary melatonin, or cortisol rhythms was detected after light treatment. This study confirmed that nocturnal exposure to lower light intensities is capable of modifying circadian variables more than previously estimated. The immediate effects of all-night light treatment are essentially not different from those of evening light. This may be important if bright light is used to improve alertness of night workers. Whether subsequent daytime alertness and sleep recovery are affected by the protocol used in our study remains to be determined.
Neuroreport, Dec 1, 1993
Sleep and body temperature characteristics were studied in man in baseline (B), 24 h-constant rou... more Sleep and body temperature characteristics were studied in man in baseline (B), 24 h-constant routine (CR) and recovery (R) after the CR. The sleep advanced and deepened the trough of the minimum temperature when compared with CR. No relevant difference in minimum body temperature, or in the slope of temperature decrease was found, however, between B and R sleeping nights. No correlation was found between the amount of slow wave sleep and body cooling. The results do not support a homeostatic role of slow wave sleep in brain and/or body cooling.
Int Arch Occup Envir Health, 1994
Seventy-three permanent morning workers, 33 three-shift workers and 43 workers with irregular wor... more Seventy-three permanent morning workers, 33 three-shift workers and 43 workers with irregular working schedules (roster) filled out a questionnaire on sleep, well-being and health complaints. The frequency of sick leave tended to be smaller in workers in the roster group. However, in this group health was rated "poor" more often; digestive, respiratory, osteoarticular and nervous symptoms as well as sleep difficulties were more frequently reported. In the day work and shift group, ratings of sleep quality were higher on days of rest than on working days but not in the roster group. This suggests that a worker does not at present get enough non-work days for a complete short-term recovery. In contrast, the length of sleep reported did not differ among groups. The gap between the subjective assessment of health and the actual frequency of sick leave corresponded with the irregularity of the working schedule.
Journal of Tropical Pediatrics, Sep 1, 1969
In a recent discussion of the social implications of nutrition and disease, Dr. JOHN GORDON discu... more In a recent discussion of the social implications of nutrition and disease, Dr. JOHN GORDON discussed the effects of family size on mortality as revealed in his own studies in the Punjab, India (WYON and GORDON, 1962). He went on to note that, "The practical question of the ...
Journal of Sleep Research
Journal of Sleep Research
Aviation Space and Environmental Medicine
The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk ... more The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk of diminished alertness at work. Applications of CAS include assessment of operational fatigue risk, work schedule optimization, and fatigue-related accident investigation. Based on the documented work schedules of employees, sleep and alertness patterns are estimated and a cumulative fatigue score is calculated. The risk assessment algorithms are based on physiological sleep/wake principles including homeostatic and circadian processes. The free parameters of the algorithms were optimized using over 10,000 d of sleep and alertness data sets collected from transportation workers performing their regular jobs. The validity and applicability of the CAS fatigue score was then tested using work/rest and accident data from three trucking operations. Heavy truck drivers involved in DOT-recordable or high-cost accidents were found to have significantly higher CAS fatigue risk scores than accide...
Aviation, space, and environmental medicine, 2004
The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk ... more The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk of diminished alertness at work. Applications of CAS include assessment of operational fatigue risk, work schedule optimization, and fatigue-related accident investigation. Based on the documented work schedules of employees, sleep and alertness patterns are estimated and a cumulative fatigue score is calculated. The risk assessment algorithms are based on physiological sleep/wake principles including homeostatic and circadian processes. The free parameters of the algorithms were optimized using over 10,000 d of sleep and alertness data sets collected from transportation workers performing their regular jobs. The validity and applicability of the CAS fatigue score was then tested using work/rest and accident data from three trucking operations. Heavy truck drivers involved in DOT-recordable or high-cost accidents were found to have significantly higher CAS fatigue risk scores than accide...
Proceedings of the 2003 International Conference on Machine Learning and Cybernetics (IEEE Cat. No.03EX693), 2003
A Circadian Alertness Simulator (CAS) is presented as an interactive tool for assessing sleep beh... more A Circadian Alertness Simulator (CAS) is presented as an interactive tool for assessing sleep behavior and fatigue risk in 24/7 operations. The simulation model uses as input sleep-wake data and information about individual sleep characteristics (short vs. long sleeper, morning type vs. evening type, napper vs. non-napper). The validation of the CAS model was based on a figure of merit function reflecting the model's ability to minimize the difference between reported and predicted sleep data. The purpose of the alertness model is the assessment of work schedules in terms of fatigue risk.
Lecture Notes in Computer Science, 2003
The Expert System "Circadian Alertness Simulator" predicts employee sleep and alertness patterns ... more The Expert System "Circadian Alertness Simulator" predicts employee sleep and alertness patterns in 24/7-work environments using rules of complex interactions between human physiology, operational demands and environmental conditions. The system can be tailored to the specific biological characteristics of individuals as well as to specific characteristics of groups of individuals (e.g., transportation employees). This adaptation capability of the system is achieved through a built-in learning module, which allows transferring information from actual data on sleep-wake-work patterns and individual sleep characteristics into an internal knowledge database. The expert system can be used as a fatigue management tool for minimizing the detrimental biological effects of 24-hour operations by providing feedback and advice for work scheduling and/or individualspecific lifestyle training. Consequently, it can help reduce accident risk and human-related costs of the 24/7 economy.
Lecture Notes in Computer Science, 2006
To track the alertness changes of 14 subjects during a night driving simulation study traditional... more To track the alertness changes of 14 subjects during a night driving simulation study traditional alertness measures such Visual Analog Sleepiness Scale, Alpha Attenuation Test (AAT), and number of Microsleep events per driving session were used. The aim of the paper is to assess these traditional alertness measures regarding their mutual correlations, revise one of them (AAT) and introduce new more general methods to capture changes in human alertness without too many constraints attached. The applied methods are utilizing data fusion methods and data discrimination capabilities via Learning Vector Quantification networks. The advantage of using more general data analysis methods which allows one to assess the validity of proposed alertness measures and opens possibilities to get a more comprehensive knowledge of obtained results.
Physiology & Behavior, 1993
Les mauvais dormeurs constituent un modele d'etude de la regulation veille/sommeil chez l'... more Les mauvais dormeurs constituent un modele d'etude de la regulation veille/sommeil chez l'insomniaque. Notre travail comprend 3 protocoles : a) etude du sommeil et la vigilance de base, b) etude de la temperature, l'activite et la vigilance au cours d'une privation de sommeil de 36 heures et du sommeil de recuperation, c) bed rest de 24 heures et le sommeil apres celui-ci. Nous avons analyse le sommeil, la temperature corporelle et l'activite motrice, la vigilance et l'humeur. L'absence de differences significatives concernant le sommeil lent profond (sommeil de base et de recuperation) s'oppose a l'hypothese d'un mauvais fonctionnement de la regulation homeostasique chez les mauvais dormeurs. Chez les mauvais dormeurs, la correlation entre les horaires de sommeil et la dimension matin/soir est plus faible, les rythmes circadiens de la vigilance et de la performance sont de moindre amplitude et le minimum de temperature pendant le sommeil est ...
Eight healthy subjects were studied during 39-h spans (from 07:00 on one day until 22:00 the seco... more Eight healthy subjects were studied during 39-h spans (from 07:00 on one day until 22:00 the second) in which they remained awake. During one experiment, subjects were exposed to 100 lux of light between 18:00 and 8:00, and during a second experiment, they were exposed to 1000 lux during the same time span. Throughout the daytime period, they were exposed to normal daylight (1500 lux or more). The nighttime 1000-lux light treatment suppressed the melatonin metabolite aMT6s, while the 100 lux treatment did not. On the treatment day, the 1000 lux, in comparison to the 100 lux, light treatment resulted in both an elevated temperature minimum and a delay in its clock-time occurrence overnight. No real circadian phase shift in the temperature, urinary melatonin, or cortisol rhythms was detected after light treatment. This study confirmed that nocturnal exposure to lower light intensities is capable of modifying circadian variables more than previously estimated. The immediate effects of all-night light treatment are essentially not different from those of evening light. This may be important if bright light is used to improve alertness of night workers. Whether subsequent daytime alertness and sleep recovery are affected by the protocol used in our study remains to be determined.
Neuroreport, Dec 1, 1993
Sleep and body temperature characteristics were studied in man in baseline (B), 24 h-constant rou... more Sleep and body temperature characteristics were studied in man in baseline (B), 24 h-constant routine (CR) and recovery (R) after the CR. The sleep advanced and deepened the trough of the minimum temperature when compared with CR. No relevant difference in minimum body temperature, or in the slope of temperature decrease was found, however, between B and R sleeping nights. No correlation was found between the amount of slow wave sleep and body cooling. The results do not support a homeostatic role of slow wave sleep in brain and/or body cooling.
Int Arch Occup Envir Health, 1994
Seventy-three permanent morning workers, 33 three-shift workers and 43 workers with irregular wor... more Seventy-three permanent morning workers, 33 three-shift workers and 43 workers with irregular working schedules (roster) filled out a questionnaire on sleep, well-being and health complaints. The frequency of sick leave tended to be smaller in workers in the roster group. However, in this group health was rated "poor" more often; digestive, respiratory, osteoarticular and nervous symptoms as well as sleep difficulties were more frequently reported. In the day work and shift group, ratings of sleep quality were higher on days of rest than on working days but not in the roster group. This suggests that a worker does not at present get enough non-work days for a complete short-term recovery. In contrast, the length of sleep reported did not differ among groups. The gap between the subjective assessment of health and the actual frequency of sick leave corresponded with the irregularity of the working schedule.
Journal of Tropical Pediatrics, Sep 1, 1969
In a recent discussion of the social implications of nutrition and disease, Dr. JOHN GORDON discu... more In a recent discussion of the social implications of nutrition and disease, Dr. JOHN GORDON discussed the effects of family size on mortality as revealed in his own studies in the Punjab, India (WYON and GORDON, 1962). He went on to note that, "The practical question of the ...
Journal of Sleep Research
Journal of Sleep Research
Aviation Space and Environmental Medicine
The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk ... more The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk of diminished alertness at work. Applications of CAS include assessment of operational fatigue risk, work schedule optimization, and fatigue-related accident investigation. Based on the documented work schedules of employees, sleep and alertness patterns are estimated and a cumulative fatigue score is calculated. The risk assessment algorithms are based on physiological sleep/wake principles including homeostatic and circadian processes. The free parameters of the algorithms were optimized using over 10,000 d of sleep and alertness data sets collected from transportation workers performing their regular jobs. The validity and applicability of the CAS fatigue score was then tested using work/rest and accident data from three trucking operations. Heavy truck drivers involved in DOT-recordable or high-cost accidents were found to have significantly higher CAS fatigue risk scores than accide...
Aviation, space, and environmental medicine, 2004
The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk ... more The Circadian Alertness Simulator (CAS) was developed as a practical tool for assessing the risk of diminished alertness at work. Applications of CAS include assessment of operational fatigue risk, work schedule optimization, and fatigue-related accident investigation. Based on the documented work schedules of employees, sleep and alertness patterns are estimated and a cumulative fatigue score is calculated. The risk assessment algorithms are based on physiological sleep/wake principles including homeostatic and circadian processes. The free parameters of the algorithms were optimized using over 10,000 d of sleep and alertness data sets collected from transportation workers performing their regular jobs. The validity and applicability of the CAS fatigue score was then tested using work/rest and accident data from three trucking operations. Heavy truck drivers involved in DOT-recordable or high-cost accidents were found to have significantly higher CAS fatigue risk scores than accide...
Proceedings of the 2003 International Conference on Machine Learning and Cybernetics (IEEE Cat. No.03EX693), 2003
A Circadian Alertness Simulator (CAS) is presented as an interactive tool for assessing sleep beh... more A Circadian Alertness Simulator (CAS) is presented as an interactive tool for assessing sleep behavior and fatigue risk in 24/7 operations. The simulation model uses as input sleep-wake data and information about individual sleep characteristics (short vs. long sleeper, morning type vs. evening type, napper vs. non-napper). The validation of the CAS model was based on a figure of merit function reflecting the model's ability to minimize the difference between reported and predicted sleep data. The purpose of the alertness model is the assessment of work schedules in terms of fatigue risk.
Lecture Notes in Computer Science, 2003
The Expert System "Circadian Alertness Simulator" predicts employee sleep and alertness patterns ... more The Expert System "Circadian Alertness Simulator" predicts employee sleep and alertness patterns in 24/7-work environments using rules of complex interactions between human physiology, operational demands and environmental conditions. The system can be tailored to the specific biological characteristics of individuals as well as to specific characteristics of groups of individuals (e.g., transportation employees). This adaptation capability of the system is achieved through a built-in learning module, which allows transferring information from actual data on sleep-wake-work patterns and individual sleep characteristics into an internal knowledge database. The expert system can be used as a fatigue management tool for minimizing the detrimental biological effects of 24-hour operations by providing feedback and advice for work scheduling and/or individualspecific lifestyle training. Consequently, it can help reduce accident risk and human-related costs of the 24/7 economy.
Lecture Notes in Computer Science, 2006
To track the alertness changes of 14 subjects during a night driving simulation study traditional... more To track the alertness changes of 14 subjects during a night driving simulation study traditional alertness measures such Visual Analog Sleepiness Scale, Alpha Attenuation Test (AAT), and number of Microsleep events per driving session were used. The aim of the paper is to assess these traditional alertness measures regarding their mutual correlations, revise one of them (AAT) and introduce new more general methods to capture changes in human alertness without too many constraints attached. The applied methods are utilizing data fusion methods and data discrimination capabilities via Learning Vector Quantification networks. The advantage of using more general data analysis methods which allows one to assess the validity of proposed alertness measures and opens possibilities to get a more comprehensive knowledge of obtained results.
Physiology & Behavior, 1993