Bibliography

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Actigraphy-based evaluation of sleep quality and physical activity in individuals with spinal cord injury
Abstract: Sleep disturbances are frequently reported by individuals with spinal cord injury (SCI) and are associated both with poor quality of life and reduced ability to participate in rehabilitation and daily life activities.
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Evaluation of the quality of sleep from the perspective of comfort for the post-graduation student in nursing.
Abstract: Sleepin is considered fundamental for the human being, since it has a restorative function. Ruptures in the circadian rhythm affect cognitive performance and represent a risk factor for several chronic diseases. This problem becomes even more frequent among health workers and university students due to multiple environmental factors that may directly influence their sleep-wake behavior. Thus, this study aims to: Evaluate the quality of sleeping of stricto sensu post-graduation students in nursing.
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Sleep pattern evaluation in medical students at Medical Sciences Multicampi School of Rio Grande do Norte
Abstract: Sleep disturbances are common in medical students and may harm academic formation. Curricular demands tend to desynchronize the sleep-wake cycle and alter sleep quality, sometimes requiring students to choose between maintaining sleep pattern regularity or meeting academic demands. The present study evaluated sleep pattern in medical students at Medical Science Multicampi School of Rio Grande do Norte, located in Caicó-RN, which adopts a Problem Based Learning (PBL) curriculum
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Biomechanical procedure to assess sleep restriction on motor control and learning
Abstract: The analysis of sleep quality during long periods and its impact on motor control and learning performance are crucial aspects for human health. The aim of this study is to analyze effects of chronic sleep restriction on motor performance. It is intended to establish motor control indicators in sleep quality analysis. A wearable actigraphy that records accelerometry, ambient light, and body temperature was used to monitor the sleep habits of 12 healthy subjects for two weeks before performing motor control and learning tests. 
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Baseline Pupil Diameter Is Not a Reliable Biomarker of Subjective Sleepiness

Abstract: Sleepiness is commonly seen as reflecting the basic physiological need to sleep and is associated with physiological and neurobiological changes. Subjective evaluations of sleepiness, however, are neither representative of cognitive and physical performances, nor of physiological sleepiness. Finding a simple, rapid, and objective marker of sleepiness is essential in order to prevent errors and accidents, but this has remained largely unsuccessful. The aim of this study was to determine whether the baseline pupil diameter is a physiological biomarker of sleepiness at all times of day and to isolate the regulatory components involved.
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Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults
Abstract: The lack of sleep, both in quality and quantity, is an increasing problem in modern society, often related to workload and stress. A number of studies have addressed the effects of acute (total) sleep deprivation on postural control. However, up to date, the effects of chronic sleep deficits, either in quantity or quality, have not been analyzed.
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Cycles of activity / rest and food / fast associated with the use of electronic equipment: behavioral aspects and temporal patterns
Abstract: Electric energy used widely in domestic context is a recent phenomenon that incorporates temporal modulations on the expression of biological rhythms and behaviour, like food ingestion and sleep patterns. After popularization of electric energy, electronic technologies have been created and incorporated to our routines. Access to electric light can promote more flexibility on temporal organization of our activities which allow for an extension of the wake phase to later portions of the night. Thus, that situation could promote temporal challenges to the organisms, generated by oscillations of temporal signals, which may cause phase advances or delays in rhythmic events like feeding/fasting, rest/activity and metabolic functions.
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Circadian Light Exposures of Shift Working Nurses
Abstract: Studies have linked adverse health outcomes to work during the body’s subjective night. Certain shift schedules result in light exposure profiles that may cause circadian disruption. Previous studies estimated average artificial illuminance to quantify light at night (LAN) at work which limits their validity and scope. However, daylight, shift length, commuting exposures and light during restricted sleep opportunities compete with LAN as causative agents, as do non-photic factors such as social disruption, activity and food intake during the subjective night. Investigations into the effects of light in shift work should be supported by 24-hour light exposure measurements, e.g. to establish dose-response relationships. The purpose of the study was to collect and suggest interpretations of 24-hour exposure data, and investigate both daytime and night-time workers’ light cycles in more detail.
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Circadian ontogeny through the lens of nonparametric variables of actigraphy
Abstract: Studies focusing on human rhythmicity show that human circadian rhythm suffers constant changes across lifespan. Changes in rest-activity patterns can be studied through nonparametric variables of actigraphy: L5 (an individual’s least active 5 h), M10 (an individual’s most active 10 h) and RA (relative amplitude of the rest-activity rhythm). The variable RA is the normalized difference between L5 and M10 – the higher the RA, the greater the difference between these two variables.
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Circadian rhythm abnormalities and autonomic dysfunction in patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Abstract: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients frequently show autonomic symptoms which may be associated with a hypothalamic dysfunction. This study aimed to explore circadian rhythm patterns in rest and activity and distal skin temperature (DST) and their association with self-reported outcome measures, in CFS/ME patients and healthy controls at two different times of year.
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Comparison between an African town and a neighbouring village shows delayed, but not decreased, sleep during the early stages of urbanisation

Abstract: The well-established negative health outcomes of sleep deprivation, and the suggestion that availability of electricity may enable later bed times without compensating sleep extension in the morning, have stimulated interest in studying communities whose sleep pattern may resemble a pre-industrial state. Here, we describe sleep and activity in two neighbouring communities, one urban (Milange) and one rural (Tengua), in a region of Mozambique where urbanisation is an ongoing process. The two communities differ in the amount and timing of daily activity and of light exposure, with later bedtimes (≈1 h) associated with more evening and less daytime light exposure seen in the town of Milange.
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Comparison of sleep parameters assessed by actigraphy of healthy young adults from a small town and a megalopolis in an emerging country
Abstract: The analysis of sleep quality and its impact on diurnal sleepiness is a crucial aspect of human health. Modern life in large cities compels people to spend less hours sleeping than they need. A wearable actigraphy that records accelerometry, light and body temperature was used to register the sleep habits of 54 healthy subjects for 14 days. From them, 28 participants resided in a town that could be regarded as a rural environment while the other subjects lived in the largest metropole of South America. The subjects filled three questionnaires to assess sleep quality (Pittsburgh Sleep Quality Index - PSQI), sleepiness (Epworth Sleepiness Scale - ESS) and chronotype (Morningness-Eveningness Questionnaire - MEQ-HO). 
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Comparison of sleep quality assessed by actigraphy and questionnaires to healthy subjects
Abstract: Sleep quality analysis is crucial for human health and it is related to duration, rhythm and quality. The goal of this study is to analyze objective assessment of the sleep-wake cycles with actigraphy, subjective questionnaires and their relationship with sleep quality indices. A wearable actigraph registered the sleep habits of 41 healthy subjects for 9 days. Afterwards, the subjects filled two questionnaires about sleep quality (Pittsburgh Sleep Quality Index) and sleepiness (Epworth Sleepiness Scale). The subjects were divided into two groups based on cut-off scores and the actigraphy parameters were compared between groups. Group 1 in ESS and PSQI categorization had less diurnal sleepiness and better sleep quality, respectively, than Group 2. Measurements of regularity (IS), fragmentation (IV), active phase amplitude (M10), rest amplitude (L5), and relative amplitude (RA) were compared between groups. Group 2 had higher L5 values. Parameter L5 (lowest of 5 consecutive hours of activity) was concluded to be relevant to identify the sleep conditions of the subjects.
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Behavior, verbal fluency and circadian rhythm in individuals with autism spectrum disorder (asd) before and after the use of melatonin

Abstract: The features common to the ASD highlighted by the DSM-5 are: communication deficit, difficulty making friends or relating, routine dependence, resistance to change, inappropriate items obsession. Such behavior can be verified since childhood, but with individual variations, which led the ASD to be considered as a "continuum" ranging from less committed (mild) to very committed (serious). Among the complex symptoms of ASD there is the high prevalence of sleep disorders, with a negative influence on behavioral changes, mood instability, deficits in neurocognitive functions including memory, attention, verbal creativity, cognitive flexibility and abstract reasoning.
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Daytime sleepiness affects gait auditory synchronization ability
Abstract: Sleep disturbances in modern life lead to cognitive and motor performance impairments in everyday tasks such as gait. The most common symptom of these disturbances is daytime sleepiness, which can be assessed by questionnaires such as the Epworth Sleep Scale (ESS). The ESS evaluates sleep health and daytime dysfunction. The goal of this study is to assess the influence of sleepiness on a motorauditory synchrony task, rhythmed gait. High and low sleepiness clusters were formed based on the participants ESS scores. 
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Effect of the alternating shift work on the food consumption of rotating shift workers
Abstract: Background: Studies highlighted unhealthy eating patterns and irregular meal times among shift workers. However, the impact of the rotation between day, afternoon and night work and free days within a short period of time on the food consumption pattern is poorly addressed in the literature. Objective: To evaluate the effect of shift rotation on eating duration (ED) and also to assess the effect of ED on energy and macronutrients intake.
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Effect of intake of a high-protein meal during the night shift on the postprandial metabolic response the following day: a crossover study, randomized and controlled
Abstract: Shift work has been associated with nutritional and metabolic diseases, and the quality, quantity and time of eating are considered important factors associated with the development of chronic diseases and weight gain in shift workers. However, the impact of nocturnal eating on the metabolic response of shift workers is poorly explored in the literature. Objective: To evaluate the acute effect of a high-protein meal compared to a normal protein meal served at night on the postprandial metabolic response of night workers the following day.
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El temps biològic. Els ritmes circadiaris i les seves implicacions en la salut
Abstract: In the course of evolution living beings have adapted to the changes caused by the Earth’s movement. As a result, they show daily variations in their physiology and behaviour. The circadian rhythms of all the organs and cells of the organism are in perfect synchrony, generating a well-defined organic structure over time. The science that studies biological rhythms is chronobiology.
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Evaluating the efficacy of Internet-Based Exercise programme Aimed at Treating knee Osteoarthritis (iBEAT-OA) in the community: a study protocol for a randomised controlled trial
Abstract: Knee osteoarthritis (OA) is the most common joint disease worldwide. As of today, there are no disease-modifying drugs, but there is evidence that muscle strengthening exercises can substantially reduce pain and improve function in this disorder, and one very well tested physiotherapy protocol is the ‘Better Management of Patients with Osteoarthritis’ developed in Sweden. Given the high prevalence of knee OA, a potentially cost-effective, digitally delivered approach to treat knee OA should be trialled. This study aims to explore the benefits of iBEAT-OA (Internet-Based Exercise programme Aimed at Treating knee Osteoarthritis) in modulating pain, function and other health-related outcomes in individuals with knee OA.
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Melatonin and circadian rhythms in autism: Case report
Abstract: Among the most co-occurring conditions in autism spectrum disorders (ASD), there are sleep disorders which may exacerbate associated behavioral disorders and lead to intensification of existing autistic symptoms. Several studies investigating the use of melatonin in the treatment of sleep disorders in ASD have shown comparative efficiency in sleep with little or no side effects. Here we report a case of ASD with non-24-hour rhythm and the effect of melatonin in circadian parameters by actigraphy. Visual analysis of the first 10 days recorded and the periodogram suggest that this patient showed a non-24-hour rhythm. This ASD subject showed before melatonin administration an activity/rest rhythm lower than 24 hours.
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Modification of a personal dosimetry device for logging melanopic irradiance
Abstract: Performance characterisations were carried out before and after a modification to the optics of the Condor Instruments’ ActTrust light and activity data loggers to improve the spectral performance for measuring melanopic-weighted irradiance in non-visual studies. The results confirm the intended improvement, so that the device provides the best-known single-sensor match to the melanopic response. In addition, the device includes a separate sensor which remained well-matched for illuminance logging.
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Nocturnal motor activity and light exposure: Objective actigraphy-based marks of melancholic and non-melancholic depressive disorder. Brief report
Abstract: Differentiation of melancholic (MEL) and non-melancholic (N-MEL) depression results from subjective assessment of psychomotor disturbance, which obscures their accurate diagnosis. CORE instrument assigned participants with severe or refractory depression to MEL or N-MEL group. Participants underwent 7 days of actigraphy. Data was fitted to a cosinusoidal curve corresponding to a 24-h rhythm. Nocturnal activity was significantly higher in N-MEL. ROC curve shows that average night activity discriminate participants with 71% sensitivity and 100% specificity (area under the curve = 0.84). Actigraphy contribute to the objective differentiation of depression subtypes, and have implications for research on their neurobiology and clinical management.
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Non-visual effects of light: How to use light to promote circadian entrainment and elicit alertness

Abstract: In addition to stimulating the visual system, light incident on the retina stimulates other biological functions, also referred to as non-visual responses. Among the most notable biological functions are human circadian rhythms, which are bodily rhythms that, in constant darkness, oscillate with a period close to, but typically slightly longer than 24 hours. Twenty-four-hour light–dark patterns incident on the retina are the major synchroniser of circadian rhythms to the local time on Earth. Entrainment of circadian rhythms has been implicated in health and well-being. Light can also elicit an acute alerting effect on people, similar to a ‘cup of coffee.’ This review summarises the literature on how light affects entrainment and alertness and how it can be used to achieve these aims.

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Optical performance characterization of light-logging actigraphy dosimeters

Abstract: There are several wearable products specially developed or marketed for studying sleep, circadian rhythms, and light levels. However, new recommendations relating to human physiological responses to light have changed what measurements researchers may demand. The performances of 11 light-logging dosimeters from eight manufacturers were compared. The directional and spectral sensitivities, linearity, dynamic range, and resolution were tested for seven models, and compared along with other published data. The sample mainly comprised light-logging actigraphy dosimeters wearable as badges, in accordance with measurement protocols for larger-scale field studies. A proposed standard for optical performance assessments is set out.

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Project and Construction of a Device to Measure Illuminance Levels and Temperature for the Study of Human Biological Rhythms

Abstract: This paper presents the conception, project and construction of a device capable of measuring different parameters for a study regarding changes in human biological rhythms for people in prolonged exposure to artificial illumination. The collected date includes luminosity and temperature of hospital rooms, following the criteria established by the research project of the Hospital de Clínicas de Porto Alegre. These parameters’ sensors are connected to two types of microcontrollers, both capable of storing and transmitting the collected data for further analysis.
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Relationship between the level of knowledge about sleep and the habits and quality of sleep, and the components of attention in university students
Abstract: The delayed sleep phase, characterized by later sleeping and waking hours, seen in adolescence, may persist after the youths' entry into university. This delay is associated to a reduction on sleep duration in students of morning shift, since they must wake-up earlier on school days. This behavior can modify the habits and quality of sleep and thus, cause damage in the attention of those of the morning shift. Knowing that attention is a basic process capable of interfering in other cognitive processes and that knowledge acts in decision making, we investigate the relationship between the level of knowledge about sleep and habits and the quality of sleep, and the components of attention in young people from an RN public university. 
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Relação entre exposição à luz em sala de aula, ciclo sono-vigília e atenção em adolescentes de diferentes cidades do RN
Abstract: In adolescents, sleep phase delay is associated with reduced sleep duration, causing increased daytime sleepiness and poor academic performance. Low performance may be related to reduced attention, cognitive process, whose components present circadian variation, and as well as the sleep-wake cycle (SCA) may be modulated by dark light cycles. Therefore, this study aims to verify the existence of relationships between the luminous intensity in the classroom and the CSV, quality of sleep, daytime sleepiness and attention in adolescents in the morning shift of private schools in the capital (C) (Natal: Latitude: 05º 47' 42" South, Longitude: 35º 12' 34" West) and the interior (I) (Santa Cruz: Latitude: 6° 13' 46'' South, Longitude: 36° 1' 24'' West) of the State of RN. A total of 115 adolescents (C: 56 and I: 59), of both sexes (41 boys), enrolled in the 1st and 2nd years of high school participated in the study.
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Rhythmic changes in Fabry disease: Inversion and non-oscillatory pattern in 6-sulfatoxymelatonin daily profile
Abstract: Fabry disease is a progressive disease characterized by an enzymatic deficiency of acid alpha-galactosidase and glycosphingolipids storage within the lysosomes. The disease has two phenotypes: classic and nonclassic. Excessive daytime sleepiness is a common sign reported by patients and can be caused by a circadian rhythm sleep disorder. Activity and rest cycle, variation of body temperature and melatonin biosynthesis are known rhythmicity markers. In the face of these evidences, our goal was to evaluate the rhythmic profile in Fabry’s disease patients using rhythmicity markers. 
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Sleep and light exposure across different levels of urbanisation in Brazilian communities
Abstract: Quilombos are settlements originally founded by Africans and African descendants (Quilombolas) in remote parts of Brazil to escape slavery. Due to individual histories, Quilombos nowadays exhibit different states of industrialisation, making them ideal for studying the influence of electrification on daily behaviour. In a comparative approach, we aimed to understand whether and how human sleep changes with the introduction of artificial light. We investigated daily rest-activity-rhythms and sleep-patterns in the Quilombolas’ by both wrist actimetry and the Munich ChronoType Questionnaire (MCTQ; the results of these two instruments correlated highly). 

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SleepData - Sleep Disorders Clinical Platform
Abstract: This dissertation presents the design and development of SleepData, a new information platform for managing clinical information on sleep disorders. The platform can integrate data from multiple sources produced by a diversity of monitoring devices and lab tests. SleepData provides tools for statistical analysis and diagnostic support tools specially designed to study patients with delayed sleep phase disorder (DSPD) and insomnia.
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Social jetlag impairs balance control

Abstract: We assessed the impact of a common sleep disturbance, the social jetlag, on postural control during a period involving workdays and free days. The sleep habits of 30 healthy subjects were registered with a wrist actimeter for nine days (starting on Friday) and they participated in a set of four postural control tests carried out on Friday and on Monday. In addition, the subjects filled questionnaires about their sleep conditions and preferences. Actimetry measurements were used to calculate the Mid Sleep Phase (MSP). The difference between the MSP values on the workdays and free days measures the social jetlag. There were significant differences in sleep variables between workdays and free days. Postural control performance improved on Monday, after free sleep over the weekend, when compared with the tests performed on Friday. It seems that social jetlag affects brain areas involved in the control of posture, such as thalamus and the prefrontal cortex as well as the cerebellum, resulting in a worse performance in postural control. The performance improvement in the posture tests after the free days could be attributed to a lower sleep debt.

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The Psychological and Physiological Part of Emotions: Multimodal Approximation for Valence Classification
Abstract: In order to develop more precise and functional affective applications, it is necessary to achieve a balance between the psychology and the engineering applied to emotions. Signals from the central and peripheral nervous systems have been used for emotion recognition purposes, however, their operation and the relationship between them remains unknown. In this context, in the present work we have tried to approach the study of the psychobiology of both systems in order to generate a computational model for the recognition of emotions in the dimension of valence. To this end, the electroencephalography (EEG) signal, electrocardiography (ECG) signal and skin temperature of 24 subjects have been studied.
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The Use of Actigraphy for Risk Stratification in Pediatric Obstructive Sleep Apnea
Abstract: Sleep disordered breathing (SDB) in children is a spectrum of abnormal breathing patterns, characterized by a limitation of airflow during sleep. Upper airway resistance and collapse of the pharynx can cause varying degrees of obstruction, which can be exacerbated by the presence of adenotonsillar hypertrophy, obesity, and craniofacial or neuromuscular disorders. The spectrum of SDB ranges from primary snoring (PS), to upper airway resistance syndrome (UARS), to the most severe diagnosis of obstructive sleep apnea (OSA).1 Obstructive sleep apnea can be further stratified into mild, moderate, and severe categories. This spectrum is based on the frequency and severity of airflow obstructions, arousals, and gas exchange abnormalities during sleep.
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Validation of a national actigraphy
Abstract: The actor consists of a pulse device equipped with an accelerometer, a microprocessor and an internal memory, which are capable of detecting and storing motion recording. Actigraphy is used in the evaluation of sleep disorders such as circadian rhythm disorders, insomnia and excessive daytime sleepiness. This method has some advantages over polysomnography, such as a longer evaluation period, simplicity of use and interpretation, and low cost. This study aims to validate the ActTrust actigrapher in the evaluation of sleep and wakefulness, comparing him with polysomnography. 
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