Lingering Impacts on Sleep Following the Daylight Savings Time Transition

Background: The “spring forward” change to Daylight Savings Time (DST) has been epidemiologically linked with numerous health and safety risks in the days following the transition, but direct measures of sleep are infrequently collected in community dwelling individuals. Methods: The Project Baseline Health Study (PBHS), a prospective, multicenter, longitudinal representative U.S. cohort study begin in 2017 launched a Sleep Mission in March 2021 to characterize sleep using patient-reported and wearable device measures, in free-living circumstances during the DST switch. Estimated sleep period duration, subjective restedness and quality, and watch metrics were compared before and after the DST transition during specified timeframes. Results: Of the total PBHS population of 2502 participants, 606 participants received an invitation and 419 participants opted in to the Sleep Mission (69.1%). The transition to DST resulted in both acute and lingering impacts on sleep. Acute effects included a 29.6 minute reduction in sleep period (p=0.01) and lower ratings of how well participants slept, as well as reduced next-day restedness. In the week following the time change, a persistent reduction in restedness scores, and a trend towards a decrease in sleeping heart rate variability were observed. Conclusion: The Daylight Savings Time transition is associated with an acute reduction in sleep period, and lingering impacts on self-reported restedness, as well as a trend towards reduced heart rate variability into the week following the transition. This work adds to a growing understanding of the persistence of impacts on sleep health metrics due to the DST transition.

Latin America in the fight against the Coronavirus crisis: The impact on economic and political stability in the region

The world has entered the third decade of the century, gripped by the global crisis and the COVID-19. These specific conditions have undermined the development and sustainability of the less prepared countries of Latin America and the Caribbean (LCA). The authors show that the COVID-19 pandemic was the largest shock for the LCA countries in the social and economic spheres. Before the pandemic, the LCA states had rather modest indicators of economic development. They were strongly influenced by external factors of protectionism opposition to the free trade and the looming global economic crisis. They have accumulated deep internal contradictions of social inequality and low domestic demand. The economic situation in the LCA countries has become even more complicated due to the development of a pandemic in 2020-2021: it was characterized by a halt or decline in economic activity, growing budget deficit and public debt, decline in domestic demand for goods and services, decreasing export revenues, declining investments, businesses closure, rising unemployment and poverty. To contain the spread of coronavirus, prevent overstrain of health systems and reduce human losses, the LCA governments took a number of measures to overcome the COVID-19 crisis, which came down to general measures of population social support and direct measures against the spread of the pandemic, including vaccination which has become an issue of utmost importance in the absence of local vaccines and a shortage of purchased vaccines or delivered under the COVAX program. However, as it is shown in the article, the measures taken by the LCA states to protect the population and the economy from the strikes of the pandemic are insufficient; vaccination programs are almost completely dependent on external vaccine manufacturers and international assistance.

Correspondence between gene expression and neurotransmitter receptor and transporter density in the human brain

Neurotransmitter receptors modulate the signaling between neurons. Thus, neurotransmitter receptors and transporters play a key role in shaping brain function. Due to the lack of comprehensive neurotransmitter receptor/transporter density datasets, microarray gene expression is often used as a proxy for receptor densities. In the present report, we comprehensively test the expression-density association for a total of 27 neurotransmitter receptors, receptor binding-sites, and transporters across 9 different neurotransmitter systems, using both PET and autoradiography imaging modalities. We find poor spatial correspondences between gene expression and density for all neurotransmitter receptors and transporters except four single-protein metabotropic receptors (5-HT1A, D2, CB1, and MOR). These expression-density associations are related to population variance and change across different classes of laminar differentiation. Altogether, we recommend using direct measures of receptor and transporter density when relating neurotransmitter systems to brain structure and function.

Beyond Counting Clients and Surveying Satisfaction: Directly Measuring the Impacts of CTL Consultations

Evidence-based practice in educational development includes leveraging data to iteratively refine CTL services. However, CTL data collection is often limited to counts and satisfaction surveys, rather than direct measures of outcomes. To directly assess impacts of CTL consultations on course and syllabus design practices, we analyzed 94 clients’ syllabi (n=32 faculty, n=62 graduate students and postdocs), before and after CTL consultations. Faculty and non-faculty clients demonstrated significant change following consultations (6% and 10% gains in syllabus rubric scores, representing 50% and 31% of possible gains, respectively). We compared faculty clients to quasi-experimental control groups who did not receive consultations. Syllabi from non-clients scored lower and did not demonstrate similar changes across semesters. Attendance at a CTL seminar on course and syllabus design did not explain variation in clients’ syllabi. We discuss implications for assessment of CTL services. Additionally, we compare and contrast the affordances of syllabi and other teaching artifacts as data sources in direct assessments of CTL impacts.      

Problems with comparative analyses of avian brain size

There are multiple hypotheses for the evolution of cognition. The most prominent hypotheses are the Social Intelligence Hypothesis (SIH) and the Ecological Intelligence Hypothesis (EIH), which are often pitted against one another. These hypotheses tend to be tested using broad-scale comparative studies of brain size, where brain size is used as a proxy of cognitive ability, and various social and/or ecological variables are included as predictors. Here, we test how methodologically robust such analyses are. First, we investigate variation in brain and body size measurements across >1000 species of bird. We demonstrate that there is substantial variation in brain and body size estimates across datasets, indicating that conclusions drawn from comparative brain size models are likely to differ depending on the source of the data. Following this, we subset our data to the Corvides infraorder and interrogate how modelling decisions impact results. We show that model results change substantially depending on variable inclusion, source and classification. Indeed, we could have drawn multiple contradictory conclusions about the principal drivers of brain size evolution. These results reflect recent concerns that current methods in comparative brain size studies are not robust. We add our voices to a growing community of researchers suggesting that we move on from using such methods to investigate cognitive evolution. We suggest that a more fruitful way forward is to instead use direct measures of cognitive performance to interrogate why variation in cognition arises within species and between closely related taxa.

Williams syndrome: on the role of intellectual abilities in anxiety

Background Individuals with Williams syndrome (WS) have an elevated risk for anxiety disorders throughout the life span, making it a research priority to identify the individual factors associated with anxiety. Most of the existing literature is based on questionnaire data and suggests that impaired executive functions (EF) increase the risk for anxiety in WS. The aim of this study was to use direct measures by trained clinicians to investigate the effects of general intelligence, inhibition, sustained attention, and working memory on anxiety in WS, to further elucidate potential underlying mechanisms. Method Twenty-four individuals with WS participated in the study (mean age: 29 years, range: 9–53 years), together with at least one of their parents. The MINI international neuropsychiatric interview for DSM-5 was completed to establish clinical diagnosis of anxiety, and the Clinical Global Impression Scale – Severity was used for an expert rating of symptom severity. Intellectual abilities were measured using the Wechsler scales, and attention and inhibition using the Conner’s Continuous Performance Test. In addition, a parent-report questionnaire measuring EF, learning and memory was collected. Results In contrast to the apriori hypothesis, there was no significant association between anxiety and core elements of EF such as working memory, sustained attention, and inhibition (i.e. the process of restraining one’s impulses or behaviour). Using ordinal logistic regression analyses, we showed that decreasing intelligence quotient (IQ) and age are associated with elevated anxiety. We confirmed these results in between-groups analyses (anxiety disorder vs no current anxiety disorder), and low IQ was associated with higher risk of having an anxiety diagnosis. In addition, Bayesian statistics gave substantial evidence for no significant association between anxiety and inhibition. Conclusion By using direct measures of psychological pathology and functioning, the current results provide a deeper characterisation of the WS phenotype and provide novel insights into the potential mechanisms underpinning anxiety.

A new, fluorescence-based method for visualizing the pseudopupil and assessing optical acuity in the dark compound eyes of honeybees and other insects

Recent interest in applying novel imaging techniques to infer optical resolution in compound eyes underscores the difficulty of obtaining direct measures of acuity. A widely used technique exploits the principal pseudopupil, a dark spot on the eye surface representing the ommatidial gaze direction and the number of detector units (ommatidia) viewing that gaze direction. However, dark-pigmented eyes, like those of honeybees, lack a visible pseudopupil. Attempts over almost a century to estimate optical acuity in this species are still debated. Here, we developed a method to visualize a stable, reliable pseudopupil by staining the photoreceptors with fluorescent dyes. We validated this method in several species and found it to outperform the dark pseudopupil for this purpose, even in pale eyes, allowing more precise location of the gaze centre. We then applied this method to estimate the sampling resolution in the frontal part of the eye of the honeybee forager. We found a broad frontal acute zone with interommatidial angles below 2° and a minimum interommatidial angle of 1.3°, a broader, sharper frontal acute zone than previously reported. Our study provides a new method to directly measure the sampling resolution in most compound eyes of living animals.

The photobiology of the human circadian clock

In modern society, the widespread use of artificial light at night disrupts the suprachiasmatic nucleus (SCN), which serves as our central circadian clock. Existing models describe excitatory responses of the SCN to primarily blue light, but direct measures in humans are absent. The combination of state-of-the-art neuroimaging techniques and custom-made MRI compatible LED devices allowed to directly measure the light response of the SCN. In contrast to the general expectation, we found that SCN activity was suppressed by light. The suppressions were observed not only in response to narrowband blue light (λmax: 470nm) but remarkably, also in response to green (λmax: 515nm) and orange (λmax: 590nm), but not to violet light (λmax: 405nm). The broadband sensitivity of the SCN implies that strategies on light exposure should be revised: enhancement of light levels during daytime is possible with wavelengths other than blue, while during nighttime, all colors are potentially disruptive.