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STUDY OBJECTIVES: In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit are unknown. Here, we investigated whether attention deficits in different subdomains increased as the test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance. METHODS: Twenty-seven untreated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into 3 different interstimulus intervals (1, 2, and 4 seconds). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention) were measured. RESULTS: Alertness was lower in the group with OSA compared with controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task and continued until the end but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval. CONCLUSIONS: The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also suggest significant concerns regarding daily life activities (eg, driving). CITATION: de Souza Bezerra ML, van Duinkerken E, Simões E, Schmidt SL. General low alertness in people with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):689-698.

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The COVID-19 pandemic caused significant disruptions to global operations and supply chains. While the huge impact of the pandemic has nurtured important literature over the last couple of years, little is being said about the role of resource orchestration in supporting resilience in highly disruptive contexts. Thus, this study aims to this knowledge gap by proposing an original model to explore supply chain resilience (SCRE) antecedents, considering supply chain alertness (SCAL) as a central point to support resilience. This study focuses on the resource orchestration theory (ROT) to design a conceptual model. The partial least squares structural equation modeling (PLS-SEM) served to validate the model, exploring data from the UK supply chain decision-makers. The study reveals a number of both expected and unexpected findings. These include the evidence that supply chain disruption orientation (SCDO) has a strong positive effect on the SCAL. In addition, SCAL plays a strong positive effect in resource reconfiguration (RREC), supply chain efficiency (SCEF) and SCRE. We further identified a partial mediation effect of RREC on the relationship between SCAL and SCRE. Surprisingly, it appeared that SCAL strongly influences SCEF, while SCEF itself does not create any significant effect on SCRE. For managers and practitioners, the importance of resource orchestration as a decisive approach to adequately respond to huge disruptions is clearly highlighted by our results. Finally, this paper helps to grasp better how important resource orchestration in operations and supply chains remains for appropriate responses to high disruptions such as the COVID-19 impacts.

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Abstract The aim of this study is to investigate the effect of a continuous stream of pulses of monochromatic blue pulsed (BP) and a combination of blue and green pulsed (BGP) light-emitting diode (LED) light conditions on physiological responses. This study is an approach to clarify the most suitable LED combination and flickering frequency to evoke alertness when a continuous stream of pulsed LED light is delivered and may suggest applications of continuous pulsed light as support for task illumination for shift workers, hospital nurses, school students or office employees. Combinations were delivered by exposures of BPLED and BGPLED pulses at 100, 200, and 400 Hertz over two background light colors (BLC). Participants were exposed to 12 different light conditions in a counterbalanced procedure. By integrating measures of electroencephalogram (EEG) and pupil constriction; results suggested significant changes in responses during the interaction of BLC, LED, and EEG. Beta waves exhibited a statistically significance (p < 0.05) in arousal levels when exposed to BG light, although no active task was involved during exposure. Furthermore, pupil reacted with larger constriction towards BGPLED exposure than towards monochromatic BPLED exposure, thus demonstrating that a continuous stream of pulses can deliver the same irradiance as if delivered in a continuous flow and without affecting perception as no flickering was perceived in any of the conditions by a qualitative evaluation.

Resumen Este estudio tiene por objetivo determinar cuál es la combinación de luz LED más adecuada y la frecuencia de parpadeo que esta deba tener, para evocar un estado de alerta cuando se emite un flujo continuo de la misma al combinarla con una iluminación de ambiente; y poder sugerir aplicaciones como soporte para la iluminación de tareas para trabajadores por turnos, enfermeras, médicos, estudiantes; o en oficinas y hospitales. Es de original importancia resaltar que en el mercado no existe un producto comercial que se pueda ajustar para apoyar en el trabajo al estado de alerta, se tiene la limitante que estas son pruebas a nivel laboratorio y que posteriores pruebas serán necesarias para validar el producto final. El método usado se basó en las combinaciones que se administraron mediante exposiciones de luz azul pulsada (BPLED) y luz azul y verde combinadas (BGPLED) a frecuencias de 100, 200 y 400 Hz adicionadas a la iluminación ambiental (BLC). Los participantes fueron expuestos a 12 condiciones de luz diferentes en un experimento balanceado y contrapesado. Mediante la integración de medidas electroencefalográficas (EEG) y de constricción pupilar; los resultados sugirieron cambios significativos en las respuestas durante la interacción de BLC, LED y EEG. Las ondas beta mostraron una significancia estadística (p <0.05) en los niveles de activación cuando se expusieron a la luz BGPLED, además, la pupila reaccionó con una mayor constricción hacia la exposición a BGPLED que hacia la exposición BPLED monocromática, adicionalmente se demostró que un flujo continuo de pulsos puede proporcionar una irradiación igual a la que se emite en flujo continuo; se concluyó e identificó además la frecuencia (100 Hz) que mejor evoca estado de alerta encefalográfíca y sin afectar la percepción de los usuarios en cuanto a su percepción del ambiente de acuerdo a la evaluación cualitativa.

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OBJECTIVES: The objective of the study was to describe working and sleep conditions and to assess how sleep opportunities are associated with obtained sleep and alertness, in a sample of long-haul bus drivers working with a two-up operations system. METHODS: Measures of subjective sleep and sleepiness, actigraphy, circadian temperature rhythm, and psychomotor vigilance tasks were obtained from a sample of 122 drivers from Argentina. Variables were compared between high and low fatigue risk groups, which were formed using a median split of a fatigue risk score. The score was calculated based on drivers' total working hours, maximum shift duration, minimum short break duration, maximum night work per seven days, and long break frequencies. RESULTS: Considering a standardized one-day period, sleep in the bus accounted for 1.9±0.1 h of total sleep (57±1% efficiency), sleep at destination for 1.6±0.2 h of total sleep (90±1% efficiency), and sleep at home for 3.8±0.2 h of total sleep (89±1% nap efficiency and 90±1% anchor sleep efficiency). In drivers exposed to high-risk working schedules, the circadian temperature rhythm was weaker (lower % of variance explained by the model) (22.0±1.7% vs. 27.6±2.0%, p <0.05) and without a significant acrophase. CONCLUSIONS: Drivers obtained a total amount of weekly sleep similar to the recommended levels for adults, but distributed at different locations and at different times during the day. High-risk working schedules were associated with disruption of circadian temperature rhythms. These results point out to the need of the implementation of shift-work scheduling strategies to minimize sleep misalignment and circadian desynchronization in long-haul bus drivers.

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Introducción. Pese a las estrategias de vigilancia se cree que existe subregistro de dengue, lo que puede ser secundario a la no detección de casos ya sea por no consulta del paciente, por falla en el diagnóstico o diligenciamiento de fichas de notificación. Objetivo. Estimar el subregistro de los casos de dengue en el municipio de Tocaima durante el periodo de enero a septiembre de 2019 y establecer los conocimientos, actitudes y prácticas respecto al dengue de los habitantes del municipio. Metodología. Se realizó un estudio transversal de prevalencia durante el período de enero a septiembre de 2019 en la población urbana de Tocaima, mediante encuestas a dos viviendas de las 262 manzanas seleccionadas por muestreo aleatorio simple en la búsqueda activa comunitaria y en el 100% de los registros individuales de prestación de servicios y del sistema de vigilancia nacional en salud pública SIVIGILA mediante Búsqueda Activa Institucional BAI. Resultados. Se encuestaron 440 personas de las cuales 19 manifestaron haber presentado síntomas y signos de dengue en el periodo de estudio, de estos, seis personas no asistieron a consulta médica. El Subregistro Comunitario por falta de asistencia a consulta médica fue de 31,5%. Se identificaron en SIVIGILA 125 casos de dengue notificados en el periodo y 156 en el Registro Individual de Prestación de Servicios (RIPS), aplicando el método de Chandra-Sekar Deming se estimaron un total de 257 casos, para un Subregistro Institucional de SIVIGILA de 48,5%. Conclusiones. Son diversas las razones por las cuales no se notificaron todos los casos de la enfermedad al sistema de vigilancia, la primera es que solo se notifican los casos de las personas que consultan a los servicios de salud y que además viven en Tocaima, la segunda es que algunos casos detectados no se notificaron al sistema de vigilancia por errores de procedimiento, o por desconocimiento del diagnóstico por el personal de salud.

Introduction. Despite the surveillance strategies, it is believed that there is an underreporting of dengue, which may be secondary to the non-detection of cases, either due to non-consultation of the patient, due to failure in the diagnosis or filling in of notification sheets. Objective. Estimate the under-registration of dengue cases in the municipality of Tocaima during the period from January to September 2019 and to establish the knowledge, attitudes and practices regarding dengue of the inhabitants of the municipality. Methodology and materials. A cross-sectional study of prevalence was carried out during the period from January to September 2019, in the urban population of Tocaima, through surveys of 2 dwellings of the 262 blocks selected by simple random sampling in the active community search, and in 100% of individual records of service provision and Sivigila through institutional active search. Results. 440 people were surveyed, 19 of whom reported having symptoms and signs of dengue in the study period, of these, six people did not attend a medical consultation. The Community Under-registration for lack of attendance at medical consultation was 31.5%. 125 cases of dengue reported in the period were identified in SIVIGILA and 156 in the Individual Service Provision Registry (RIPS), applying the Chandra-Sekar Deming method, a total of 257 cases were estimated, for a SIVIGILA Institutional Sub-registry of 48,5%. Conclusions. There are several reasons why not all cases of the disease were notified to the surveillance system, the first is that only the cases of people who consult the health services and who also live in Tocaima, the second, some cases detected were not notified to the surveillance system due to procedural errors, or due to lack of knowledge of the diagnosis by health personne.

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STUDY OBJECTIVES: Emerging evidence supports a multidimensional perspective of sleep in the context of health. The sleep health model, and composite sleep health score, are increasingly used in research. However, specific cutoff values that differentiate "good" from "poor" sleep, have not been empirically derived and its relationship to cardiometabolic health is less-well understood. We empirically derived cutoff values for sleep health dimensions and examined the relationship between sleep health and cardiometabolic morbidity. METHODS: Participants from two independent Biomarker Studies in the MIDUS II (N = 432, 39.8% male, age = 56.92 ± 11.45) and MIDUS Refresher (N = 268, 43.7% male, age = 51.68 ± 12.70) cohorts completed a 1-week study where sleep was assessed with daily diaries and wrist actigraphy. Self-reported physician diagnoses, medication use, and blood values were used to calculate total cardiometabolic morbidity. Receiver operating characteristic (ROC) curves were generated in the MIDUS II cohort for each sleep health dimension to determine cutoff values. Using derived cutoff values, logistic regression was used to examine the relationship between sleep health scores and cardiometabolic morbidity in the MIDUS Refresher cohort, controlling for traditional risk factors. RESULTS: Empirically derived sleep health cutoff values aligned reasonably well to cutoff values previously published in the sleep health literature and remained robust across physical and mental health outcomes. Better sleep health was significantly associated with a lower odds of cardiometabolic morbidity (OR [95% CI] = 0.901 [0.814-0.997], p = .044). CONCLUSIONS: These results contribute to the ongoing development of the sleep health model and add to the emerging research supporting a multidimensional perspective of sleep and health.

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Attention is a cognitive process crucial for human performance. It has four components: tonic alertness, phasic alertness, selective attention, and sustained attention. All the components of attention show homeostatic (time awake, sleep deprivation) and circadian (time of day) variations. The time course of the circadian rhythms in attention is important to program work and school-related activities. The components of attention reach their lowest levels during nighttime and early hours in the morning, better levels occur around noon, and even higher levels can be observed during afternoon and evening hours. However, this time course can be modulated by chronotype, sleep deprivation, age, or drugs. Homeostatic and circadian variations have also been found in other basic cognitive processes (working memory and executive functions), with a time course similar to that observed for attention. Data reviewed in this paper suggests the need to consider circadian rhythms, age, and chronotype of the person, when programming schedules for work, study, school start time, school testing, psychological testing, and neuropsychological assessment.

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Abstract Purpose: An experiment was conducted to investigate the physiological effects of a continuous blue pulsed light emitting diode (BP-LED) added to a task lamp in an actual indoor lighting environment and its influence in alertness having as a final purpose to develop a commercial product that could be applied in situations similar to those depicted in the present work. Design methodology: Previous research studies have stated that the addition of pulsed light evokes physiological changes that may induce alertness. The participants were exposed to four different lighting conditions. Electroencephalograms (EEG), pupil sizes, heart rates (HR), performance tests, and subjective reactions were measured. Findings: Low colour temperature light and the BP-LED revealed an improved alertness according to the data from the EEG recordings. The intervention of the BP-LED in a high colour temperature ambiance was beneficial in maintaining high levels of alertness compared to the conditions where the BP-LED was not used. It was tested that the use of a BP-LED in a task lamp may be beneficial in improving or maintaining alertness levels in an indoor workplace ambiance. Originality and Value: Designing of an adequate workplace task lamp light that improves alertness for in-house, office, or classroom situations in which it is essential.

Resumen Propósito: Un experimento fue llevado a cabo para investigar los efectos fisiológicos que una luz azul LED pulsada de manera intermitente (BP-LED), adicionada a una lámpara de escritorio, y en un ambiente interior; pueda influir en el estado de alerta de una persona con la finalidad de desarrollar un producto comercial que pueda ser aplicado para los casos desarrollados y otros posibles escenarios. Metodología de Diseño: En estudios anteriores se establece que la adición de luz en pulsaciones evoca cambios fisiológicos que pueden inducir al estado de alerta. Los participantes experimentaron cuatro escenarios de iluminación. Se registraron mediciones con respecto a encefalografía (EEG), tamaño pupilar, ritmo cardiaco, prueba de performance, así como evaluación subjetiva. Hallazgos: Los datos de EEG revelaron un mayor estado de alerta durante la exposición a iluminación cálida aunado a luz BP-LED. La intervención de luz fría y BP-LED denotó ser benéfica en el nivel de estado de alerta en comparación con las condiciones donde el BP-LED no intervino. Se logró evaluar que el uso de BP-LED en una lámpara de escritorio puede ser benéfico para mejorar o mantener el estado de alerta cuando sea usado en un espacio interior. Originalidad y Valor: Propuesta para diseñar una luminaria de escritorio; para uso casero, laboral o de estudio; que mejore el estado de alerta de las personas.

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Study Objectives: The Psychomotor Vigilance Test (PVT) is reported to be free of practice effects that can otherwise confound the effects of sleep loss and circadian misalignment on performance. This differentiates the PVT from more complex cognitive tests. To the best of our knowledge, no study has systematically investigated practice effects on the PVT across multiple outcome domains, depending on administration interval, and in ecologically more valid settings. Methods: We administered a validated 3-minute PVT (PVT-B) 16 times in 45 participants (23 male, mean ± SD age 32.6 ± 7.3 years, range 25-54 years) with administration intervals of ≥10 days, ≤5 days, or 4 times per day. We investigated linear and logarithmic trends across repeated administrations in 10 PVT-B outcome variables. Results: The fastest 10% of response times (RT; plin = .0002), minimum RT (plog = .0010), and the slowest 10% of reciprocal RT (plog = .0124) increased while false starts (plog = 0.0050) decreased with repeated administration, collectively decreasing RT variability (plog = .0010) across administrations. However, the observed absolute changes were small (e.g., -0.03 false starts per administration, linear fit) and are probably irrelevant in practice. Test administration interval did not modify the effects of repeated administration on PVT-B performance (all p > .13 for interaction). Importantly, mean and median RT, response speed, and lapses, which are among the most frequently used PVT outcomes, did not change systematically with repeated administration. Conclusions: PVT-B showed stable performance across repeated administrations. Combined with its high sensitivity, this corroborates the status of the PVT as the de facto gold standard measure of the neurobehavioral effects of sleep loss and circadian misalignment.

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Resumo Objetivo: verificar o efeito do esforço físico sobre as funções cognitivas de trabalhadores eletricistas utilizando equipamento de proteção individual (EPI). Métodos: participaram 28 eletricistas que trabalhavam na construção, manutenção e operação de redes de distribuição de energia. Todos do sexo masculino, sadios e aptos para a prática de exercícios físicos. As funções cognitivas foram representadas pelo teste de reação simples (TRS) e pelo nível de vigilância mental (NVM). O TRS e o NVM foram mensurados pré e pós-teste máximo progressivo, em esteira rolante, a 27 °C de temperatura seca e umidade relativa do ar de 64%. O teste consistiu em aumentos progressivos na velocidade e na inclinação da esteira até a fadiga, com utilização de EPI. Resultados: a média (desvio padrão) do TRS não foi significativamente diferente antes, 227,8 (35,1) ms, e após o exercício, 220,6 (24,6) ms. O NVM foi significativamente maior após o exercício em todas as situações: frequência crescente - 36,5 (5,1) Hz vs 39,5 (2,7) Hz, frequência decrescente - 36,0 (5,2) vs 39,0 (3,88) Hz, e frequência geral - 36,2 (4,9) vs 39,2 (3,1) Hz. Conclusão: o exercício progressivo máximo realizado com EPI não modificou o tempo de reação simples e aumentou o nível de vigilância mental de eletricistas.

Abstract Objective: to verify the effects of physical effort on the cognitive functions of electricians wearing personal protective equipment (PPE). Methods: 28 electricians participated. They worked on the construction, maintenance and operation of electrical power distribution networks. All were male, healthy and able to practice physical exercises. The cognitive functions were checked by measuring simple reaction time (SRT) and mental alertness level (MAL). SRT and MAL were measured before and after progressive maximal exercise, on a treadmill, at 27 °C dry temperature and 64% relative humidity, wearing PPE. The test consisted of progressive increases in treadmill speed and incline, until fatigue. Results: SRT mean difference was not significantly different before - 227.8 (35.1) ms - and after exercising -220.6 (24.6) ms. MAL was significantly higher after exercise in all situations: increasing frequency - 36.5 (5.1) Hz vs. 39.5 (2.7) Hz; decreasing frequency-36.0 (5.2) Hz vs. 39.0 (3.88) Hz; and general frequency 36.2 (4.9) Hz vs. 39.2 (3.1) Hz. Conclusion: progressive maximal exercise performed while wearing PPE caused no change in simple reaction time, and increased electricians' mental alertness level.