Felipe Beijamini

Study objectives: the decline of slow-wave activity (SWA) during sleep, a classic marker of dissipation of homeostatic sleep pressure (DHSP), was assessed very differently among studies of nocturnal sleep in adults, not all of which adjusted for age and sex. It is therefore unclear which is the most reliable way of determining the consistency of these SWA changes and how demographics influence them. Methods: SWA (0.5-4 Hz) in N2/N3 sleep stages was assessed over one night’s home polysomnography in a Brazilian community sample (20-59-year-olds; N=427; 237 women). SWA dynamics was analyzed using full mixed-effect models (with random and fixed intercepts and slopes) considering linear and exponential functions of various different SWA metrics [across all available 30 s sleep epochs (whole sample) and mean, peak and total SWA power per NREM sleep cycle in subgroups of participants’ who exhibited four, five and six cycles], before and after adjusting for age, sex and interactions.Results: of the 30 tested MEMs, only linear per cycle models complied with statistical/modelling assumptions, irrespective of SWA metric, and exhibited the same pattern of effects: SWA decayed (fixed slope effects), but not significantly after adjusting for demographics, which altered both average (fixed) and individual difference (random) effects.Conclusion: reliable measures of adult nocturnal sleep SWA dynamics in naturalistic conditions were only obtained when modelled linearly per cycle, but consistent SWA decay was not found when demographics were adjusted for. The usefulness of SWA dynamics alone as a measure of DHSP in adulthood must therefore be reappraised.Keywords: sleep, slow wave sleep, slow wave activity, polysomnography, electroencephalography, age factors, sex factors, statistical models

Wastewater‐based epidemiology (WBE) has been widely applied for SARS‐CoV‐2 surveillance. Yet, operational parameters such as influent flow rate and sewer system characteristics may reflect underlying hydraulic variability relevant to detection performance, raising questions about the representativeness of results from small and medium‐sized plants. We conducted a systematic meta‐analysis of 10 published studies assessing SARS‐CoV‐2 RNA detection across wastewater treatment plants of different sizes and flow ranges. Data were extracted into 2 × 2 tables and analyzed in R using the meta and metafor packages. Odds ratios (ORs) were pooled with Mantel–Haenszel random‐effects models and DerSimonian–Laird τ ² estimation. Subgroup analyses compared studies from developed versus emerging economies, meta‐regression tested population size as a moderator, and publication bias was evaluated with funnel plots and Egger's test. The overall pooled OR was 2.08 (95% CI: 0.99–4.37, p = 0.053; I ² = 82.3%), indicating a non‐significant trend toward higher detection at higher flow rates. Subgroup analyses showed similar pooled effects across developed and emerging economies, though heterogeneity was lower in emerging settings. Meta‐regression revealed no significant association between population size and detection (slope = 0.29, p = 0.52). Funnel plots were relatively symmetric, and Egger's test did not indicate significant publication bias ( p = 0.169). Overall, these findings suggest that influent flow rate is not significantly associated with the probability of SARS‐CoV‐2 detection in WBE studies, supporting the inclusion of small and medium‐sized treatment plants in surveillance networks. At the same time, the concentration of studies in high‐income countries highlights inequities in the global WBE literature and in site deployment, with vulnerable populations often underrepresented. Expanding WBE infrastructure in underserved regions is necessary to ensure equitable and representative surveillance capacity.

With the increasing integration of digital technologies in education, learning platforms are becoming increasingly established tools in pedagogical practices. In this context, this study aims to investigate whether the digital platforms implemented by the Paraná State Department of Education (SEED) have, in fact, contributed significantly to teaching practice. The main objective was to understand teachers' perceptions of the impacts of using these platforms in the classroom. To this end, data were collected through exploratory quantitative and qualitative questionnaires applied to 22 teachers from the state public school system. The results reveal a scenario marked by positive aspects and challenges. Among the positive points, the initial engagement of students stands out. On the other hand, problems such as technical instability, difficulties in integrating into pedagogical practices, and ambivalent responses regarding the effective contribution of the platforms to learning were reported.

Circadian rhythm regulates several physiological functions, and influences endocrine and metabolic responses in mammals, with cortisol acting as important modulator of this mechanism. Cortisol secretion is affected by both internal and external factors and is intensified under stress conditions. The response to surgical stress is consistently observed after surgical procedures, such as ovariohysterectomy (OVH). Therefore, this study aimed to evaluate the influence of the circadian rhythm on the surgical stress response following elective OVH in healthy bitches. Twenty patients weighing between 10 and 20 kg were hospitalized 48 h before surgery and remained hospitalized for 48 h postoperative. The animals were randomly allocated into two groups and underwent OVH either in the morning (6–8 h—a.m., GAM) or at night (18–20 h—p.m., GPM). Surgical procedures were standardized with respect to the surgical team, technique applied and duration; this was carried out in order to induce a comparable level of surgical stress. Physical parameters (systolic blood pressure, heart rate, respiratory rate and rectal temperature) and laboratorial analyses (cortisol, leukogram, protein thiols, no protein thiols, vitamin C, ferric reducing ability of plasma and thiobarbituric acid reactive substances) were assessed immediately before surgery and at 2, 4, 6, 12, 24 and 48 h, as well as 14 days postoperatively. No significant changes in cortisol profile were detected. However, significant alteration in the respiratory rate, rectal temperature, time to first urine, and lipid peroxidation were observed in the GPM group, suggesting that surgeries performed at night induce greater disturbances in homeostasis than those performed in the morning.

Professor Malcolm passed away unexpectedly on October 24, 2025, during the XVIII Latin American Symposium on Chronobiology, in Maceió, Brazil. Born in Sweden in May 1966, Malcolm lived in Sweden, the United States, Brazil, and the United Kingdom for many years. He earned his PhD in Zoology in 1994 and began his academic journey at the University of Surrey. After a postdoctoral fellowship in Russell Foster's laboratory at Imperial College, he joined the faculty at Surrey, where he built a remarkable career and became Professor of Chronobiology. Later, he was invited to Northumbria University, where he served as Deputy Faculty Pro Vice-Chancellor for Research and Knowledge Exchange. He was also an Honorary Visiting Professor at the University of the Witwatersrand in South Africa. In Brazil, the country that held a special place in his heart, Malcolm had been a Visiting Professor at the University of São Paulo in 2016. He was internationally recognized for his research on circadian rhythms and sleep, and for exploring how they relate to our physical and mental health. Fluent in Portuguese, Malcolm gave a few lectures entirely in the language, even at one edition of the Brazilian Sleep Congress. He felt truly at home in Brazil, the country where he spent his final moments surrounded by colleagues and friends. Malcolm will be remembered not only for his scientific contributions but also for the joy he brought to those around him. His legacy lives on in the students, collaborators, and friends whose lives he touched with his genuine warmth and good sense of humour. Claudia Moreno, Felipe Beijamini, Mário Pedrazzoli, and Mário Miguel, on behalf of his Brazilian colleagues and friends. Article published online: 31 December 2025 © 2025. Brazilian Sleep Academy. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Thieme Revinter Publicações Ltda. Rua Rego Freitas, 175, loja 1, República, São Paulo, SP, CEP 01220-010, Brazil

Considerable evidence supports the importance of sleep for memory consolidation, learning, academic performance, and mental health. College students in health-related fields are often deprived of adequate sleep due to the high volume of clinical assignments and academic workload. Studies on the relationship between sleep quality, chronotypes and academic performance in Brazilian university students are scarce. Therefore, we investigated how study and sleep habits, chronotype and sleep quality influence college performance. We conducted a questionnaire-based study with 573 health-related fields students from several Brazilian institutions. The participants filled out an individual form with personal data, answered the Morningness-Eveningness Questionnaire and Pittsburgh Sleep Quality Index. The sleep-wake cycle pattern and sleep behavioural habits in the day before a test/assessment were obtained with 4 answer options of the question "On the day before the assessment in question, what was your behaviour? "I stay up late studying and don't sleep (Deprived), I stay up late studying and sleep before the test (Study-Sleep), I sleep early and wake up early and study until the exam is close (Sleep-Study), I don't change my sleep routine (No Deprived). The comparison of academic performance between the groups showed that those students who did not change their routine performed better compared to the others. Our results reveal that most Brazilian undergraduate students in the health-related fields have poor sleep quality. Sleep quality scores and chronotype´s scores were significantly associated with academic performance only in the female population. It is essential in the academic space to take care of the sleep/wake cycle and consequently the learning process, in order to develop interventions to promote the quality of sleep and quality of life for students in the health area.

Summary: Gender and age are well‐established determinants of health and sleep health that influence overall health, which also often varies by gender and age. Sleep architecture is an important component of sleep health. The goal of this analysis was to examine whether associations between age and sleep stages differ by gender in the absence of moderate–severe obstructive sleep apnea (OSA) in a rural setting in Brazil. This study conducted polysomnography recordings in the Baependi Heart Study, a cohort of Brazilian adults. Our sample included 584 women and 309 men whose apnea–hypopnea index was ≤15 events/h. We used splines to distinguish non‐linear associations between age, total sleep time, wake after sleep onset (WASO), N2, N3, and rapid‐eye‐movement sleep. The mean (standard deviation; range) age was 47 (14; 18–89) years. All sleep outcomes were associated with age. Compared to men, women had more N3 sleep and less WASO after adjusting for age. Model‐based comparisons between genders at specific ages showed statistically higher mean WASO for men at ages 60 (+13.6 min) and 70 years (+19.5 min) and less N3 for men at ages 50 (−13.2 min), 60 (−19.0 min), and 70 years (−19.5 min) but no differences at 20, 30, 40 or 80 years. The other sleep measures did not differ by gender at any age. Thus, even in the absence of moderate–severe OSA, sleep architecture was associated with age across adulthood, and there were gender differences in WASO and N3 at older ages in this rural community.

Objective: People with diabetes are more likely to have obstructive sleep apnea, but there are few studies examining sleep architecture in people with diabetes, especially in the absence of moderate-severe sleep apnea. Therefore, we compared sleep architecture among people with diabetes, prediabetes or neither condition, whilst excluding people with moderate-severe sleep apnea. Research design and methods: This sample is from the Baependi Heart Study, a prospective, family-based cohort of adults in Brazil. 1,074 participants underwent at-home polysomnography (PSG). Diabetes was defined as 1) FBG>125 OR 2) HbA1c>6.4 OR 3) taking diabetic medication, and prediabetes was defined as 1) [(5.7≤HbA1c≤6.4) OR (100≤FBG≤125)] AND 2) not taking diabetic medication. We excluded participants that had an apnea-hypopnea index (AHI)>30 from these analyses to reduce confounding due to severe sleep apnea. We compared sleep stages among the 3 groups. Results: Compared to those without diabetes, we found shorter REM duration for participants with diabetes (−6.7min, 95%CI -13.2, -0.1) or prediabetes (−5.9min, 95%CI -10.5, -1.3), even after adjusting for age, gender, BMI, and AHI. Diabetes was also associated with lower total sleep time (−13.7min, 95%CI -26.8, -0.6), longer slow-wave sleep (N3) duration (+7.6min, 95%CI 0.6, 14.6) and higher N3 percentage (+2.4%, 95%CI 0.6, 4.2), compared to those without diabetes. Conclusions: People with diabetes and prediabetes had less REM sleep after taking into account potential confounders, including AHI. People with diabetes also had more N3 sleep. These results suggest that diabetes is associated with different sleep architecture, even in the absence of moderate-severe sleep apnea.

Publicado em 17 de outubro de 2022. No último século, as condições de vida e saúde têm melhorado de forma contínua e sustentada devido aos progressos políticos, econômicos, sociais e ambientais, além de grandes avanços na saúde pública. Na primeira conferência internacional sobre promoção da saúde em 1986 foi elaborada a carta de Ottawa que descrevia a promoção da saúde como processo de capacitação da comunidade para atuar na melhoria da sua qualidade de vida e saúde, incluindo uma maior participação no controle deste processo. A promoção da saúde representa uma estratégia promissora para enfrentar os múltiplos problemas de saúde que afetam a população. Neste contexto, propõe uma concepção ampla do processo saúde-doença e de seus determinantes, a articulação dos saberes técnicos e populares, além da mobilização de recursos institucionais e comunitários, públicos ou privados com o intuito de enfrentar e promover a resolução destas dificuldades no âmbito da saúde. A obra “Promoção da saúde e qualidade de vida” da Atena Editora está dividida em dois volumes. O volume 3 está constituído em 20 artigos técnicos e científicos que destacam pesquisas principalmente na esfera pública do Sistema Único de Saúde em todos os ciclos da vida da gestação ao envelhecimento, contemplando a saúde e as mais diversas patologias. Pesquisas envolvendo a comunidade geral e universitária, abordagens e técnicas diferenciadas, além de percepções da promoção da saúde e qualidade de vida internacional. Já, o volume 4 contempla 21 artigos técnicos e científicos com pesquisas focadas principalmente na esfera ambulatorial e hospitalar juntamente com técnicas laboratoriais e profissionais, englobando interpretação de exame, suplementação, atuações profissionais, pesquisas voltadas para urgência, emergência e unidade de terapia intensiva, além de opções de tratamento para diversas patologias. Sendo assim, o e-book possibilita uma infinidade de experiências nos diferentes cenários de atuação, permitindo extrapolar fronteiras e limites do conhecimento dos profissionais da área da saúde e demais interessados. Além disso, desejamos que a leitura seja fonte de inspiração e sirva de instrumento didático-pedagógico para acadêmicos e professores nos diversos níveis de ensino, e estimule o leitor a realizar novos estudos focados na promoção da saúde e qualidade de vida. Agradecemos aos autores por suas contribuições científicas nesta temática e desejamos a todos uma excelente leitura! Taísa Ceratti Treptow