Relationship between cocaine and cocaethylene blood concentration with the severity of clinical manifestations.

BACKGROUND: Poisonings resulting from the abuse of drugs currently represent a serious problem for public health. Among the main agents involved, cocaine stands out. It became one of the most abused drugs around the world, and one of the main reasons for visits to the emergency department due to the use of illicit substances. The use of cocaine is primarily in combination with alcoholic beverages. There are few studies that correlate cocaine blood concentration and the severity of clinical manifestations in patients evaluated at Emergency Department. The aim of the present study was to verify the possible relationship between the blood concentration of cocaine and cocaethylene (product of the interaction of cocaine with ethanol) with the severity of the clinical manifestations presented by patients with cocaine intoxication. METHODS: Blood levels were measured by high-performance liquid chromatography (HPLC) and the severity of clinical manifestations was assessed using the Stimulant Intoxication Score (SIS). To establish this relationship, Pearson's chi-square statistical test (x2) was used for categorical variables and Student's t for continuous variables, with statistical significance of 5% (p < 0.05). RESULTS: Of the 81 patients included in the study, 77.8% were men with a mean age of 32.5 years ± 8.5 and mean of SIS 3.4 ± 2.5. Considering the toxicological analysis results, 24.7% of the blood samples were positive. The mean of cocaine and cocaethylene concentrations were 0.34 µg/mL ± 0.45 and 0.38 µg/mL ± 0.34, respectively. The blood concentration of cocaine and cocaethylene has not been shown to be useful information for the treatment and prognosis of patients, but blood levels of these substances at the time of treatment, regardless of their concentration, may be an indicator of severity, showing that any concentrations of these substances should be considered as potentially toxic. CONCLUSION: The application of the SIS score proved to be an important alternative capable of predicting the severity of the patients due to cocaine intoxication in a fast and simplified way.

Development and content validity of the CENEES program - psychoeducation for health staff on neuropsychology of aging.

Worldwide life expectancy has increased dramatically in recent years. Also on the rise are incidents of pathologies related to aging, such as Mild Cognitive Impairment (MCI) or Alzheimer's Disease (AD). An inaccurate diagnosis impairs the well-being and the quality of life of patients and their relatives, as well as being a financial burden on the health system. Continued education pertaining to the neuropsychological field is uncommon for health workers involved in general practice. This article aims to present the process of development and content validity of the "CENEES Program - Psychoeducation for Health Staff on The Neuropsychology of Aging". The CENEES Program was developed in six steps which include: literature review, first draft, focal group, adjustments after focal group, judgment analysis (n = 4), and finally the last version. The inter-rater reliability index after judgment analysis was 0.785. The final version of the CENEES Program contains eight meetings, divided into 4 modules: 1) Fundamentals of Neuroscience; 2) Memory; 3) Executive Functions; and 4) Communication. The final meeting was called "Review". The CENEES Program is a new resource to help professionals who work within the general practice field, especially community health workers. As far as we know, there is no psychoeducation program on aging which contains the four subjects that are covered in the CENEES Program. The CENEES Program could assist the workers' daily activities and make them comfortable to offer and build actions in the community. A pilot and follow-up studies are suggested.

Have countries offered the best data to the Pan American Health Organization? Evidence of potential inconsistencies found in a study on alcohol policies in Brazil.

OBJECTIVE: The objective of this study was to verify the agreement between the alcohol policies score estimated from documental analysis of Brazilian federal regulatory documents (RD), with primary data collection, and the results previously presented by the Pan American Health Organization (PAHO) in its Alcohol Policy Scoring (APS) report. STUDY DESIGN: Document identification and content analysis. METHODS: Documental research was carried out in two phases: a document identification and content analysis. In the first phase, we carried out the search, identification, and systematization of laws, decrees, and federal ordinances in Brazil, with primary data collection. The second phase consisted of three steps: 1) an RD content analysis and classification into the 10 PAHO/World Health Organization (WHO) policy domains; 2) a score estimation of alcohol policies, based on the APS instrument attached to their report; and 3) comparison of the results for Brazil presented at the APS report and the one estimated by the researchers. RESULTS: The study showed divergences between the results for APS published by PAHO about Brazil and the one achieved with primary data collection. 1146 federal promulgated RD were identified, of which 21 were eligible for content analysis. Only the domains "Community and workplace action" (Domain 3) and "Reducing the public health impact of illicit and informally produced alcohol" (Domain 9) had convergent scores. On the other domains, usually the APS score estimated by PAHO differs from the one estimated with the primary data collection. CONCLUSIONS: We conclude that Brazil is not providing the best data for PAHO/WHO estimate its APS report, leading to the dissemination of imprecise results worldwide.

Cancer cases and deaths attributable to lifestyle risk factors in Chile.

BACKGROUND: To identify modifiable risk factors that contribute to cancer holds important public health relevance for setting up prevention strategies. Therefore, the aim of this study was to estimate the proportion of cancer cases and deaths attributable to alcohol consumption, high body mass index (BMI), low fruits and vegetables consumption, lack of physical activity, tobacco smoking, and passive smoking in Chile in 2018. METHODS: We retrieved data from a national representative survey to describe the distribution of six lifestyle risk factors. Relative risks of each risk factor-cancer pair were obtained from published meta-analysis and pooled cohort studies. Cancer cases and deaths were obtained from the GLOBOCAN 2018. RESULTS: Nearly 30% of all cancer cases (15,097 out of 50,320 cases) and 36% of all cancer deaths (10,155 out of 28,010 deaths) in Chile in 2018 were attributable to lifestyle risk factors. Smoking and high BMI accounted for most of the cancer cases (9232 and 4394, respectively) and deaths (6868 and 2572). The cancer burden of other lifestyle risk factors varied by sex. In men, the proportion of all cancer cases attributed to alcohol were 3.7% compare to 2.0% for women. Cancers cases and deaths of the larynx, lung, oral/cavity, esophagus and bladder could be at least halved if lifestyle risk factors were eliminated. CONCLUSION: Smoking and high BMI were the leading causes of preventable cancer cases and deaths within the six lifestyles factors considered. Cancer prevention strategies should consider evidence-based interventions and public policies to encourage the adoption of a healthier lifestyle.

Photoperiodic induction without light-mediated circadian entrainment in a High Arctic resident bird.

Organisms use changes in photoperiod to anticipate and exploit favourable conditions in a seasonal environment. While species living at temperate latitudes receive day length information as a year-round input, species living in the Arctic may spend as much as two-thirds of the year without experiencing dawn or dusk. This suggests that specialised mechanisms may be required to maintain seasonal synchrony in polar regions. Svalbard ptarmigan (Lagopus muta hyperborea) are resident at 74-81°N latitude. They spend winter in constant darkness (DD) and summer in constant light (LL); extreme photoperiodic conditions under which they do not display overt circadian rhythms. Here, we explored how Arctic adaptation in circadian biology affects photoperiodic time measurement in captive Svalbard ptarmigan. For this purpose, DD-adapted birds, showing no circadian behaviour, either remained in prolonged DD, were transferred into a simulated natural photoperiod (SNP) or were transferred directly into LL. Birds transferred from DD to LL exhibited a strong photoperiodic response in terms of activation of the hypothalamic thyrotropin-mediated photoperiodic response pathway. This was assayed through expression of the Eya3, Tshß and deiodinase genes, as well as gonadal development. While transfer to SNP established synchronous diurnal activity patterns, activity in birds transferred from DD to LL showed no evidence of circadian rhythmicity. These data show that the Svalbard ptarmigan does not require circadian entrainment to develop a photoperiodic response involving conserved molecular elements found in temperate species. Further studies are required to define how exactly Arctic adaptation modifies seasonal timer mechanisms.

The World Health Organization Quality of Life instrument for people with intellectual and physical disabilities (WHOQOL-Dis): evidence of validity of the Brazilian version.

BACKGROUND: The number of people with disabilities in Brazil and worldwide has grown substantially in recent decades. Cross-cultural quality of life instruments can be helpful in the development of interventions designed to meet the needs of this population and contribute to rational allocation of resources. This study sought to provide evidence of validity and reliability the Brazilian Portuguese version of WHOQOL-Dis-D (a cross-cultural, multicentre instrument developed by the WHOQOL-Group for the assessment of quality of life in persons with physical disability - PD) and WHOQOL-Dis-ID (for persons with intellectual disability - ID). METHODS: Classical psychometric methods were used to conduct independent analyses of the PD and ID samples. Criterion groups were established for analysis of construct validity. Concurrent validity was assessed in relation to SWLS and BDI-II scores; discriminant validity, in relation to WHODAS-II. Cronbach alpha was used to test the instrument scales and subscales for reliability. The ID subgroup was retested, and test-retest reliability assessed by means of intraclass correlation coefficients and paired Student's t-test. RESULTS: A total of 162 (98 females) people with PD and 156 (55 females) people with ID participated in the study. Cronbach alpha was satisfactory across practically all domains and factors in the PD subsample. In IDs, most factors or domains had coefficients higher than 0.70, but four subscales exhibited less satisfactory performance. Evidence of construct and concurrent validity and reliability were obtained. CONCLUSIONS: The analyses presented herein provide satisfactory evidence of the validity and reliability of the instrument and corroborated the factor structure revealed during cross-cultural research. Further studies with larger sample sizes are required to obtain additional evidence of validity and reliability.

Substance use and adolescent mental health during the COVID-19 pandemic in Brazil: a longitudinal approach.

OBJECTIVE: To describe the changes in alcohol and drug use by Brazilian adolescents during the COVID-19 pandemic (April-August 2021), and to analyze the relationship between alcohol use changes and psychiatric symptomatology. METHODS: A secondary analysis with a longitudinal approach was performed with data from a cluster-randomized controlled trial, conducted in 73 public middle schools in three Brazilian cities, to evaluate the effectiveness of a drug use prevention program. The sample included 535 students (61% girls; Mage = 15.2 years). Data were collected pre-intervention (February-March 2019), after 9 months (November-December 2019), and after 26 months (April-August 2021), when the students were in their first year of high school. The authors analyzed drug use prevalence (alcohol, binge drinking, tobacco, inhalants, marijuana, cocaine, and crack) in a lifetime, past year, and past month periods, and the association between alcohol use change subsamples with psychiatric symptoms. Logistic regressions were adjusted by sex, age, socioeconomic status, city, and group (control and intervention). RESULTS: The present findings suggest that the COVID-19 pandemic led to a decrease in past-year substance use and in past-month substance use frequency, despite the gradually increased (but decelerating) prevalence of lifetime use. However, some adolescents initiated, maintained, or increased the frequency of their alcohol use. Mainly, they were more likely to present behavioral problems, as well as symptoms of inattentive hyperactivity, and peer and emotional problems. CONCLUSIONS: Despite the extensive decline in substance use during the pandemic period, these results suggest an association between previous mental health conditions and behavioral risk factors, leading to increased alcohol consumption and behavioral disorders manifestations.

Performance of primary health care in São Paulo state, Brazil, during the period 2010-2019. / Desempenho da atenção primária à saúde no estado de São Paulo, Brasil, no período de 2010-2019.

This article presents the results of an analysis of the performance of primary health care in São Paulo state over the last decade against a backdrop of financial crisis and health funding cuts. We conducted a time series analysis (2010-2019) of performance indicators across the following dimensions based on an adapted conceptual framework: health service performance, health system, and determinants of health. Annual percentage change was calculated for each indicator using a log-linear model. Performance across the indicators was generally positive; however, there was a decline in performance across indicators of quality of care (congenital syphilis, cesarean section rate and cervical cancer screening). The findings also show a potential rise in demand for public services (due to population aging and a reduction in the percentage of the population with private health insurance) and increase in health expenditure against a backdrop of falling GDP per capita.

O artigo apresenta uma análise do desempenho da APS no estado de São Paulo na última década, em contexto de crise econômica e retração dos investimentos em saúde. Utilizaram-se indicadores de desempenho, determinantes em saúde e sistema de saúde, em série temporal (2010 a 2019), a partir de matriz conceitual adaptada. Foram calculadas variações percentuais anuais (VPA) de cada indicador em modelo log-linear. Os indicadores de desempenho apresentaram, no geral, evolução favorável; no entanto, ocorreu piora em indicadores relacionados à qualidade do cuidado (sífilis congênita, partos cesáreos e rastreamento de câncer de colo uterino). Verificou-se, ainda, um potencial aumento das demandas ao SUS (envelhecimento da população e redução da cobertura da saúde suplementar) e aumento das despesas em saúde em contexto de redução do PIB per capita.

Uncoupling of behavioral and metabolic 24-h rhythms in reindeer.

Reindeer in the Arctic seasonally suppress daily circadian patterns of behavior present in most animals.1 In humans and mice, even when all daily behavioral and environmental influences are artificially suppressed, robust endogenous rhythms of metabolism governed by the circadian clock persist and are essential to health.2,3 Disrupted rhythms foster metabolic disorders and weight gain.4 To understand circadian metabolic organization in reindeer, we performed behavioral measurements and untargeted metabolomics from blood plasma samples taken from Eurasian tundra reindeer (Rangifer tarandus tarandus) across 24 h at 2-h intervals in four seasons. Our study confirmed the absence of circadian rhythms of behavior under constant darkness in the Arctic winter and constant daylight in the Arctic summer, as reported by others.1 We detected and measured the intensity of 893 metabolic features in all plasma samples using untargeted ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS). A core group of metabolites (66/893 metabolic features) consistently displayed 24-h rhythmicity. Most metabolites displayed a robust 24-h rhythm in winter and spring but were arrhythmic in summer and fall. Half of all measured metabolites displayed ultradian sleep-wake dependence in summer. Irrespective of the arrhythmic behavior, metabolism is rhythmic (24 h) in seasons of low food availability, potentially favoring energy efficiency. In seasons of food abundance, 24-h rhythmicity in metabolism is drastically reduced, again irrespective of behavioral rhythms, potentially fostering weight gain.

Reindeer in the Arctic reduce sleep need during rumination.

Timing and quantity of sleep depend on a circadian (∼24-h) rhythm and a specific sleep requirement.1 Sleep curtailment results in a homeostatic rebound of more and deeper sleep, the latter reflected in increased electroencephalographic (EEG) slow-wave activity (SWA) during non-rapid eye movement (NREM) sleep.2 Circadian rhythms are synchronized by the light-dark cycle but persist under constant conditions.3,4,5 Strikingly, arctic reindeer behavior is arrhythmic during the solstices.6 Moreover, the Arctic's extreme seasonal environmental changes cause large variations in overall activity and food intake.7 We hypothesized that the maintenance of optimal functioning under these extremely fluctuating conditions would require adaptations not only in daily activity patterns but also in the homeostatic regulation of sleep. We studied sleep using non-invasive EEG in four Eurasian tundra reindeer (Rangifer tarandus tarandus) in Tromsø, Norway (69°N) during the fall equinox and both solstices. As expected, sleep-wake rhythms paralleled daily activity distribution, and sleep deprivation resulted in a homeostatic rebound in all seasons. Yet, these sleep rebounds were smaller in summer and fall than in winter. Surprisingly, SWA decreased not only during NREM sleep but also during rumination. Quantitative modeling revealed that sleep pressure decayed at similar rates during the two behavioral states. Finally, reindeer spent less time in NREM sleep the more they ruminated. These results suggest that they can sleep during rumination. The ability to reduce sleep need during rumination-undisturbed phases for both sleep recovery and digestion-might allow for near-constant feeding in the arctic summer.

Factors associated with attending "open bar" parties amongst early adolescents.

BACKGROUND: "Open bar" parties are events where a flat fee is paid for unlimited alcohol consumption. At these events, alcohol intoxication is frequent amongst attendees. This study explored the prevalence of "open bar" attendance amongst Brazilian youth and the factors associated with this practice. METHODS: Data was collected at the baseline of randomized controlled trial amongst 5,213 8th grade students in three Brazilian cities. Weighted logistic regression was performed. RESULTS: Mean age was of 13.23 years (SE 0.01) and 17.1% of the students have reported attending "open bar" events in the past year. Attendees were wealthier, had higher odds to engage in binge drinking, to use marijuana, to be exposed to alcohol advertising, and to report more alcohol problems and clinical psychiatric symptoms when compared with non-attendees. CONCLUSIONS: The ban on selling alcohol to minors has not been properly enforced. Legislation to restrict alcohol promotions and advertising in Brazil needs to be implemented and effectively monitored.

Subjective perception of health in elderly inpatients.

There is evidence that subjective health is an important variable in general health outcomes. It can be an indicator of the individual's overall health status, creating a reliable and valid estimate about health. Quality of life (QoL) assessment can be associated with the individuals' subjective assessment of their own health status. The aim of the present study was to investigate variables associated with subjective perception of health in older inpatients. Ninety elderly inpatients over 60 years old were interviewed. The perception of health assessment (healthy/unhealthy) allocated elders in either of two groups. All the elders answered sociodemographic questions, the WHOQOL-100 and the Beck Depression Inventory (BDI). Comparing the group that considered themselves unhealthy to the other group, the former showed a tendency of worse QoL assessments in five out of six domains investigated. Significant differences were found for the physical and level of independence domains, as well as overall QoL. There was a significant association between health perception and lower intensity of depressive symptoms, as well as better QoL perception in the level of independence domain. This study shows the existence of an association between depressive symptoms and health assessment. It also suggests that the independence dimension is important in the elders' perception of their health status. These findings can help identify cause-effect relations between variables in aging studies involving health indicators and bring new intervention proposals for the elderly.

National Institute of Mental Health Life Chart Method - Self/Prospective (NIMH-LCM-S/P™): translation and adaptation to Brazilian Portuguese.

OBJECTIVE: The objective of this study was to translate and adapt the National Institute of Mental Health Life Chart Method - Self/Prospective (NIMH-LCM-S/P™) instrument for self-monitoring of mood into Brazilian Portuguese and provide evidence of content validity. Additionally, a user guide was prepared for the instrument and evaluated by mental health professionals. METHODS: The study was divided into two stages - Stage 1: Translation and cross-cultural adaptation and Stage 2: Determination of content validity index (CVI) scores. The translation and cross-cultural adaptation process involved 37 participants between translators, experts, target population, and evaluators. RESULTS: The CVI was evaluated by 15 mental health professionals. 11 (78.57%) of the items evaluated attained the maximum CVI score of 1.00, which constitutes the highest level of content validity, and no changes were suggested by participants. Only one of the items evaluated had a CVI score lower than 0.80. CONCLUSION: The final translated and adapted version of the NIMH-LCM-S/P™ and its user guide were evaluated by the target population and the mental health professionals. Both groups displayed satisfactory comprehension levels, suggesting there is potential for using this instrument in clinical practice to assess therapeutic interventions in Brazilian settings.

Time series analysis of the suicide attempts assisted by firefighters from 2017 to 2021 in São Paulo, Brazil.

OBJECTIVE: This study aimed to analyze the time trends of suicide attempts assisted by the Fire Department of the Military Police of the State of São Paulo (Corpo de Bombeiros da Polícia Militar do Estado de São Paulo - CBPMESP) from 2017 to 2021, between sexes. METHODS: This is an ecological study of 11,435 suicide attempts assisted by CBPMESP calls from January 2017 to December 2021. Three seasonal auto-regressive integrated moving average with exogenous (SARIMAX) models were adjusted considering total population, only men, and only women. RESULTS: The total occurrences of suicide attempts were stationary in the prepandemic period but had an increased growth pattern after the pandemic began. This trend was higher among men, due to (1) lower assistance of suicide attempts during early pandemic than in the prepandemic period and (2) significant increased assistance after the beginning of vaccination against COVID-19, followed by a decrease, but with a tendency to increase, in the long-term pandemic. CONCLUSION: Our results indicate a growth in the long-term suicide attempts during COVID-19. The beginning of vaccination was not considered significant in the reduction of CBPMESP attendances. These results corroborate the need for a multisectoral national suicide prevention strategy to mitigate the effects of the pandemic on mental health in the State of São Paulo.

Suicide Attempts Assisted By Firefighters According to Traumatic Brain Injury.

Studies worldwide have reported increasing trends in suicides and attempts during the pandemic. The literature shows that improving surveillance and monitoring of suicide and attempts requires broad multisectoral prevention strategies. In Brazil, the São Paulo State Fire Department (CBPMESP) makes up the emergency response team for suicide and suicide attempted calls and public emergencies. Given this context, this paper sought to describe the characteristics of suicide attempts assisted by the CBPMESP according to traumatic brain injury (TBI), between 2018 and 2020, measured by the Glasgow Coma Scale (GCS). For this purpose, a descriptive study of 6,582 suicide attempts attended by CBPMESP was carried out. The factors associated with trauma brain injury according to the Glasgow Coma Scale (dependent variable) were analyzed by a multinomial regression model. Results show a significant increase of 8.0% (p = 0.039) in the number of calls responded by CBPMESP between 2018 and 2020. Men presented a higher prevalence of more violent methods for suicide attempts, namely firearms and hanging, followed by severe TBI; in women, severe TBI occurred mostly by hanging. Despite the increase in fatal suicide attempts during the pandemic, time to attend to victim acted as a protective factor for preventing severe TBI in men and women.

Primary health care performance according to clusters of convergent municipalities in the state of São Paulo.

OBJECTIVE: To describe the performance of Primary Health Care, according to conglomerates of São Paulo cities that present homogeneous indicators. METHODS: This is a descriptive study, based on secondary data extracted from official sources of the Unified Health System, for the year 2018. An analysis matrix was created, with the proposition of performance (access, effectiveness and adequacy) and context indicators (population, health determinants and financing) selected and organized in dimensions and sub-dimensions. Cluster Analysis was used to identify the groups of homogeneous municipalities. RESULTS: 645 municipalities were divided in 6 conglomerates. Clusters 2 and 3 were formed predominantly by small municipalities with greater access to health; cluster 3 has less social vulnerability and greater investment in health. Clusters 1, 4 and 5 were formed by the largest municipalities with less access to health; cluster 4 presents greater social vulnerability, less coverage of private health plans and a greater percentage of health resources; cluster 5 was characterized by greater Gross Domestic Product per capita and greater coverage of private health plans. Cluster 6, formed by the city of São Paulo, was a particular case. Cluster 2 drew attention, as it was shown to have increased coverage, but signaled lower efficacy and adequacy levels. Cluster 3 had the best performance among all clusters. CONCLUSION: These findings can support regional and municipal management, given the complexity of the territory of São Paulo, pointing to scenarios that demand broader public management initiatives.

Cognitive estimation abilities in healthy and clinical populations: the use of the Cognitive Estimation Test.

Estimation abilities are a group of processes that involve functions such as planning, attention, abstract reasoning, and also mnemonic processes, like semantic and working memory. They are allocated in order to solve problems for which the answers are not readily available. Estimation abilities can be measured using the Cognitive Estimation Test (CET). The aim of this article was to review the use of the CET and other tests of cognitive estimation in healthy and pathological populations. We discussed studies examining correlations between the CET and other measures of executive functions and the importance of the standardization of measures that assess estimation abilities.

Body Temperature and Activity Rhythms Under Different Photoperiods in High Arctic Svalbard ptarmigan (Lagopus muta hyperborea).

Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (T b) alongside locomotor activity in captive birds under different photoperiods. We show that T b and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in T b attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in T b preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.

Evidence for circadian-based photoperiodic timekeeping in Svalbard ptarmigan, the northernmost resident bird.

The high Arctic archipelago of Svalbard (74°-81° north) experiences extended periods of uninterrupted daylight in summer and uninterrupted night in winter, apparently relaxing the major driver for the evolution of circadian rhythmicity. Svalbard ptarmigan (Lagopus muta hyperborea) is the only year-round resident terrestrial bird species endemic to the high Arctic and is remarkably adapted to the extreme annual variation in environmental conditions.1 Here, we demonstrate that, although circadian control of behavior disappears rapidly upon transfer to constant light conditions, consistent with the loss of daily activity patterns observed during the polar summer and polar night, Svalbard ptarmigans nonetheless employ a circadian-based mechanism for photoperiodic timekeeping. First, we show the persistence of rhythmic clock gene expression under constant light within the mediobasal hypothalamus and pars tuberalis, the key tissues in the seasonal neuroendocrine cascade. We then employ a "sliding skeleton photoperiod" protocol, revealing that the driving force behind seasonal biology of the Svalbard ptarmigan is rhythmic sensitivity to light, a feature that depends on a functioning circadian rhythm. Hence, the unusual selective pressures of life in the high Arctic have favored decoupling of the circadian clock from organization of daily activity patterns, while preserving its importance for seasonal synchronization.