bluuebunny/crossref_metadata_2025 huggingface dataset:
Can telemedicine address neurologic health disparities in rural Guatemala: a health promotor educational intervention study
Authors: Adcock Amelia , Frey Jessica E
Published: May 2021

The global burden of neurologic disease is high and its impact manifests in health disparities observed in rural communities of limited resources like those surrounding San Lucas Tolimán, Guatemala. Telehealth may be one method to close these gaps by offering a virtual neurology curriculum. The goal of this project was to determine the pervasiveness of neurologic disease in San Lucas Tolimán and to increase interest and knowledge in neurology topics for local health promotors. A neurologic needs assessment was performed during the initial site visit. This information was subsequently used to create monthly health promotor neurology-based workshops and remote consultations delivered via a telehealth platform over the following year. The 29 health promotors were surveyed before and after the neurology course to measure self-reported knowledge of variable topics as well as their interest in neurology and how effective the remote lectures were. The needs assessment identified at least 68 different patients with neurologic diseases, the most common being headaches and seizures. The health promotors’ knowledge of several neurologic diseases as well as their comfort level diagnosing a condition based on a description of neurologic symptoms significantly increased following the year-long neurology course. The lectures were convenient, easy to see and hear virtually, and increased the health promotors’ interest in neurology. Telehealth is an acceptable and feasible method of delivering educational neurology topics relevant to rural communities. Future, longer-term studies are needed to determine if telehealth interventions such as these impact neurologic patient outcomes.
Intravenous infusion of glucose improved farrowing performance of hyperprolific crossbred sows
Authors: Nielsen Signe E , Feyera Takele , Skovmose Sigrid J W , Krogh Uffe , Eskildsen Maria , Theil Peter K
Published: May 2021

The sow at parturition is challenged with respect to energy status due to increases in energetic expenses associated with 1) nest building 2) uterine contractions, and 3) colostrum production. A previous study indicated that sows were depleted of glucogenic energy around farrowing. The aim was to investigate whether intravenous infusion of glucose from observed nest-building behavior to 24 h postpartum affected the farrowing kinetics and colostrum production in sows. Ten multiparous sows (DanBred landrace × DanBred Yorkshire) were fitted with a jugular vein catheter on each side (one for infusion and the other one for blood sampling). Sows were infused with either 0.9% saline (CON; n = 5) or 10% glucose (GLU; n = 5) solution at a constant rate of 125 mL/h. From day 108 of gestation, sows were fed once daily with 3.33 kg of a standard lactation diet. During farrowing, sows were monitored to register the onset of farrowing, time of birth, birth status (live or dead), sex, stillbirth rate (SR), and weight of newborn piglets. Farrowing assistance (FA) was provided when the birth interval exceeded 60 min. In late gestation, 1 mL of blood was collected every third hour for blood gas analysis and every sixth hour for harvesting plasma. During farrowing, 1 mL (for blood gas) and 9 mL of blood were collected at 0, 3, 6, 9, 12, 15, 18, 21, and 24 h in milk (HIM). Colostrum and milk samples were collected at 0, 6, 12, 18, 24, and 36 HIM and also at 3, 10, 17, and 24 d in milk. Compared with CON sows, GLU infusion decreased the SR (16.1% vs. 7.4%; P = 0.03), FA (21% vs. 9.0%; P = 0.01), and surprisingly also blood glucose at the onset of farrowing (5.53 vs. 5.09 mmol/L; P = 0.03), respectively. A tendency to higher plasma lactate at the onset of farrowing (P = 0.05) but decreased piglet survival from 0 to 24 h (P = 0.06) was also found for GLU sows. No effects of treatment on farrowing duration or mean birth intervals were found. Lactate in whole blood (P = 0.003) and plasma (P = 0.002) was increased for GLU sows as compared with CON sows during the colostrum period. No effect of GLU infusion was seen on colostrum and milk composition and yield. The increase in lactate was most likely due to a shift toward a greater proportion of glucose oxidation and insufficient O2 supply to fuel uterine contractions. In conclusion, infusion of glucose reduced the frequency of SR and FA, and improved energy status of the sow which seems to be crucial to enhance total piglet survival.
Formulation of diets for pigs based on a ratio between digestible calcium and digestible phosphorus results in reduced excretion of calcium in urine without affecting retention of calcium and phosphorus compared with formulation based on values for total calcium
Authors: Lagos L Vanessa , Lee Su A , Bedford Mike R , Stein Hans H
Published: May 2021

An experiment was conducted to test the hypothesis that formulating diets for pigs based on a ratio between standardized total tract digestible (STTD) Ca and STTD P instead of total Ca and STTD P does not decrease Ca retention, but increases P utilization. Forty barrows (59.4 ± 3.8 kg) were individually housed in metabolism crates and allotted to four corn-soybean meal-based diets in a randomized complete block design with two blocks and five pigs per diet in each block. Diets were formulated using a 2 × 2 factorial design with two diet formulation principles (total Ca or STTD Ca) and two inclusion levels of microbial phytase (0 or 500 units per kg of feed). Phytase was assumed to release 0.11% STTD P and 0.16% total Ca. Diets were formulated based on requirements for total Ca and STTD P or a ratio between STTD Ca and STTD P of 1.25:1. Diets were fed for 11 d and fecal and urine samples were collected from feed provided from day 6 to day 10. Interactions (P < 0.05) between diet formulation principle and phytase level were observed for Ca intake, Ca in feces, Ca absorbed, Ca retained, P digestibility, P absorbed, and P in urine. Phytase increased (P < 0.05) the digestibility of Ca in both total Ca and STTD Ca diets. Without phytase, Ca intake, Ca in feces, and Ca absorbed was greater (P < 0.05) from pigs fed total Ca diets than from pigs fed STTD Ca diets, but P absorbed, P digestibility, and P in urine was greater (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. However, in the presence of phytase, no differences between diet formulation principles were observed in these variables. Regardless of phytase, Ca in urine was lower (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. There were no differences in Ca retention between pigs fed STTD Ca diets and total Ca diets, but pigs fed total Ca diets retained less (P < 0.05) Ca if diets contained phytase. No differences in P retention were observed between diet formulation principles, but pigs fed non-phytase diets retained more (P < 0.05) P than pigs fed diets with phytase. In conclusion, because diets formulated based on STTD Ca contain less Ca than total Ca diets, pigs fed STTD Ca diets excreted less Ca in urine, but retention of Ca was not affected. Formulating non-phytase diets based on STTD Ca instead of total Ca increased P absorption, which confirms the detrimental effect of excess Ca on P digestibility. However, P retention was not improved if pigs were fed STTD Ca diets.
Multitasking as Consumer Compensatory Control
Authors: Han Jerry J , Broniarczyk Susan M
Published: May 2021

Consumer multitasking (i.e., working on multiple tasks simultaneously) is a widespread modern phenomenon, yet the literature lacks an understanding of when and why consumers multitask. We experimentally show that consumers engage in multitasking behavior as a way to compensate for feelings of low control. Specifically, across five main studies and seven web appendix studies using two different multitasking paradigms, we find that consumers feeling low (vs. high) control volitionally choose to multitask more on subsequent tasks, rather than do the tasks sequentially (i.e., one task at a time). Mediation and moderation evidence demonstrate that this effect is driven by increased motivations to use time resources efficiently for those feeling low (vs. high) control. We also find that multitasking generally results in suboptimal consumer decision-making and decreased task performance. An intervention that altered consumer lay beliefs regarding multitasking and time efficiency was effective in lowering multitasking behavior for consumers experiencing low control during the COVID-19 pandemic. By investigating a cause of consumer multitasking and the underlying mechanism, our studies contribute to research on consumer multitasking, perceptions of control, and resource allocation with important implications for advertisers and marketing managers.
Making Endemic Goiter an American Disease, 1800-1820
Authors: Naramore Sarah E
Published: May 2021

In 1800, American physician and naturalist Benjamin Smith Barton (1766-1815) published A Memoir Concerning the Disease of Goitre as it Prevails in Different Parts of North-America. The text documented the nature of the disease in the United States and highlighted how it differed from the ailment’s presentation in European patients. While medical topographies were common during this period, Barton’s goiter research and the steady stream of American goiter research that followed are worth special attention. This body of literature demonstrates how American physicians understood their relationship to transnational medical discussions and the unique perspective they brought to them. Goiter literature was common in European medical and travel writing during this period and intensely focused on the appearance of the disease in the mountains of Switzerland and Northern Italy. American goiter by its very appearance in non-mountainous regions of the United States contradicted nearly all of the received wisdom about the ailment’s cause and potential cure. For two decades, American writers leveraged their own observations and local knowledge to challenge larger narratives in their field.
Chloroplast dismantling in leaf senescence
Authors: Domínguez Fernando , Cejudo Francisco Javier
Published: May 2021

In photosynthetic plant cells, chloroplasts act as factories of metabolic intermediates that support plant growth. Chloroplast performance is highly influenced by environmental cues. Thus, these organelles have the additional function of sensing ever changing environmental conditions, thereby playing a key role in harmonizing the growth and development of different organs and in plant acclimation to the environment. Moreover, chloroplasts constitute an excellent source of metabolic intermediates that are remobilized to sink tissues during senescence so that chloroplast dismantling is a tightly regulated process that plays a key role in plant development. Stressful environmental conditions enhance the generation of reactive oxygen species (ROS) by chloroplasts, which may lead to oxidative stress causing damage to the organelle. These environmental conditions trigger mechanisms that allow the rapid dismantling of damaged chloroplasts, which is crucial to avoid deleterious effects of toxic by-products of the degradative process. In this review, we discuss the effect of redox homeostasis and ROS generation in the process of chloroplast dismantling. Furthermore, we summarize the structural and biochemical events, both intra- and extraplastid, that characterize the process of chloroplast dismantling in senescence and in response to environmental stresses.
A Focus on Non-Amputation Combat Extremity Injury: 2001-2018
Authors: Perez Katheryne G , Eskridge Susan L , Clouser Mary C , McCabe Cameron T , Galarneau Michael R
Published: May 2021

Introduction

Extremity injuries have comprised the majority of battlefield injuries in modern U.S. conflicts since World War II. Most reports have focused on serious injuries only and, to date, no reports have described the full extent of combat extremity injuries, from mild to severe, resulting from post-9/11 conflicts. This study aims to identify and characterize the full spectrum of non-amputation combat-related extremity injury and extend the findings of previous reports.

Methods

The Expeditionary Medical Encounter Database was queried for all extremity injured service members (SMs) deployed in support of post-9/11 conflicts through July 2018. Only injuries incurred during combat operations were included in this report. Major amputations were excluded as well as SMs killed in action or who died of wounds. Extremity injuries were categorized by body region, nature of injury, and severity. Demographics and injury event characteristics are also presented.

Results

A total of 17,629 SMs sustained 42,740 extremity injuries during 18,004 separate injury events. The highest number of SMs were injured in 2004 (n = 3,553), 2007 (n = 2,244), and 2011 (n = 2,023). Injured SMs were mostly young (78% under 30 years), male (97%), junior- to mid-level enlisted (89%), in the Army (69%) or Marine Corps (28%), active duty (84%), serving as infantry and gun crew (59%), and injured in support of Operation Iraqi Freedom (60%). Blast weaponry was responsible for 75% of extremity injuries. Injuries were similarly distributed between the lower (52%) and upper (48%) extremities. The most common sites of lower extremity injury were the lower leg/ankle complex (40%) and thigh (26%). The most common upper extremities sites were the shoulder and upper arms (37%), and the hand, wrist, and fingers (33%). Nearly half (48%) of all extremity injuries were open wounds (48%), followed by fractures (20%) and contusions/superficial injuries (16%). SMs sustained an average of 2.4 extremity injuries per event and 56% of injuries were considered mild, with a median Injury Severity Score (ISS) of 3.

Conclusion

This study is the first publication to capture, review, and characterize the full range, from mild to severe, of non-amputation combat-related extremity injuries resulting from post-9/11 conflicts. The high prevalence of extremity injury, particularly in such a young population, and associated short- and long-term health outcomes, will impact military health care systems for decades to come.
Population-based identification of H α-excess sources in the Gaia DR2 and IPHAS catalogues
Authors: Fratta M , Scaringi S , Drew J E , Monguió M , Knigge C , Maccarone T J , Court J M C , Iłkiewicz K A , Pala A F , Gandhi P , Gänsicke B
Published: May 2021

We present a catalogue of point-like H α-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photomeric information from Gaia to select H α-bright outliers in the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS), across the colour–absolute magnitude diagram. To mitigate the selection biases due to stellar population mixing and to extinction, the investigated objects are first partitioned with respect to their positions in the Gaia colour–absolute magnitude space, and Galactic coordinates space, respectively. The selection is then performed on both partition types independently. Two significance parameters are assigned to each target, one for each partition type. These represent a quantitative degree of confidence that the given source is a reliable H α-excess candidate, with reference to the other objects in the corresponding partition. Our catalogue provides two flags for each source, both indicating the significance level of the H α-excess. By analysing their intensity in the H α narrow band, 28 496 objects out of 7474 835 are identified as H α-excess candidates with a significance higher than 3. The completeness fraction of the H α outliers selection is between 3 and 5 per cent. The suggested 5σ conservative cut yields a purity fraction of 81.9 per cent.
A Disciplined Dissident—Aung San Suu Kyi as Opposition Backbencher (2012–2016)
Authors: Egreteau Renaud
Published: May 2021

This article investigates the legislative activity of Aung San Suu Kyi, Myanmar's iconic dissident, during her inaugural tenure as opposition MP in the country’s first post-junta parliament (2012–2016). How did such a totemic figure behave in a legislature dominated by an army-backed party and military-appointed MPs? What legislative tools did she use? The study draws evidence from Burmese-language proceedings of Myanmar’s Union legislature and field interviews. The findings point to a largely marginal, yet disciplined, involvement of Aung San Suu Kyi in legislative business. She neither acted as party whip nor openly criticised government record or took disruptive action in the context of Myanmar’s ‘discipline-flourishing democracy’. Yet, she joined policy debates through the occasional motion, used her position as a catalyst for engaging the government and the world, and successfully marshalled her party to win the next two general elections in 2015 and 2020. The findings have implications for understanding how the strategies of such near-mythical figure can explain subsequent electoral or political (mis)fortunes.
Specific Electroencephalographic Signatures for Pain and Descending Pain Inhibitory System in Spinal Cord Injury
Authors: Simis Marcel , Pacheco-Barrios Kevin , Uygur-Kucukseymen Elif , Castelo-Branco Luis , Battistella Linamara R , Fregni Felipe
Published: May 2021

Objectives

The pain related to spinal cord injury (SCI) is difficult to treat, and it is associated with significant morbidity. One aspect to improve therapeutics is to explore markers of pain and its correlates in SCI.

Methods

In this cross-sectional neurophysiological analysis of a randomized, double-blind controlled trial, 39 patients with SCI were included. We analyzed conditioned pain modulation (CPM) efficiency as the index of the descending pain inhibitory system, EEG variables, and clinical pain levels as measured by the Visual Analogue Scale. Regression analyses were performed to assess the relationship among EEG variables, pain levels, and CPM.

Results

We included 39 SCI patients, 74% reported SCI-related pain. We found that (1) less alpha and beta power are related to pain presence, (2) less alpha and beta power are associated with higher pain levels among patients with pain, (3) patients with pain have decreased peak alpha-theta frequency compared to no-pain group, (4) more relative theta power are related to the presence of low CPM efficiency, (5) higher relative theta power is associated with lower CPM efficiency.

Conclusions

Our results confirm and provide additional data on the relationship between decreased alpha and beta frequencies and higher pain levels. One important finding, though, was a specific and different EEG signature for the descending inhibitory pain system, as we showed that increased theta EEG power is related to decreased CPM efficiency; suggesting that, although low CPM efficiency plays a major role in pain in these participants, it does seem to be associated with a specific oscillatory brain rhythm different from clinical pain. These findings have significant implications for future research on EEG-based biomarkers of pain in post-SCI and new interventions as neurofeedback to manage pain in this population.
Measuring the Equilibrium Impacts of Credit: Evidence from the Indian Microfinance Crisis
Authors: Breza Emily , Kinnan Cynthia
Published: May 2021

In October 2010, the state government of Andhra Pradesh, India, issued an emergency ordinance, bringing microfinance activities in the state to a complete halt and causing a nationwide shock to the liquidity of lenders, especially those with loans in the affected state. We use this massive dislocation in the microfinance market to identify the causal impacts of a reduction in credit supply on consumption, earnings, and employment in general equilibrium in rural labor markets. Using a proprietary district-level data set from 25 separate, for-profit microlenders matched with household data from the National Sample Survey, we find that district-level reductions in credit supply are associated with significant decreases in casual daily wages, household wage earnings, and consumption. We find a substantial consumption multiplier from credit that is likely driven by two channels—aggregate demand and business investment. We calibrate a simple two-period, two-sector model of the rural economy that incorporates both channels and show that the magnitude of our wage results is consistent with the model’s predictions.
Financial Constraints and Corporate Environmental Policies
Authors: Xu Qiping , Kim Taehyun
Published: May 2021

This paper documents evidence that financial constraints increase firms’ toxic emissions given that firms actively trade off abatement costs against potential legal liabilities. Exploring three quasi-natural experiments in which firms’ financial resources are likely exogenously affected, we find that relaxing financial constraints reduces U.S. public firms’ toxic releases. The effects of financial constraints on toxic releases are amplified when regulatory enforcement and external monitoring weaken. Overall, our evidence highlights the real effects of financial constraints in the form of environmental pollution, which is a costly negative externality imposed on society and public health.
028 Sleep loss disrupts hippocampal memory consolidation via an acetylcholine- and somatostatin interneuron-mediated inhibitory gate
Authors: Delorme James , Wang Lijing , Kuhn Femke , Kodoth Varna , Ma Jingqun , Jiang Sha , Aton Sara
Published: May 2021

Introduction

Sleep loss profoundly disrupts consolidation of hippocampus-dependent memory. To better characterize effects of learning and sleep loss on the hippocampal circuit, we quantified activity-dependent phosphorylation of ribosomal subunit S6 (pS6) across the dorsal hippocampus of mice.

Methods

We first measured pS6 throughout the hippocampus after learning (single trial contextual fear conditioning; CFC), and after subsequent sleep or sleep deprivation (SD). To characterize cell populations with activity affected by SD, we used translating ribosome affinity purification (TRAP)-seq to identify cell type-specific transcripts on pS6 ribosomes after SD vs. sleep. We next used pharmacogenetics to mimic the effects of SD, selectively activating hippocampal Sst+ interneurons or cholinergic inputs to hippocampus from the medial septum (MS) while mice slept in the hours following CFC. We also inhibited these neuronal populations to assess effects on memory consolidation.

Results

We find that pS6 in enhanced in the dentate gyrus (DG) following single-trial CFC, but is reduced throughout the hippocampus after brief SD – a manipulation which disrupts contextual fear memory (CFM) consolidation. Cell type-specific enrichment analysis (CSEA) of these transcripts revealed that hippocampal somatostatin-expressing (Sst+) interneurons, and cholinergic and orexinergic inputs to hippocampus, are selectively activated after SD. We used TRAP targeted to hippocampal Sst+ interneurons to identify cellular mechanisms mediating SD-driven Sst+ interneuron activation. . We find that activation of Sst+ interneurons is sufficient to disrupt CFM consolidation, by gating activity in surrounding pyramidal neurons, while inhibition of Sst+ interneurons enhances memory consolidation. Similarly, pharmacogenetic activation of cholinergic input to hippocampus from the MS disrupted CFM. Inhibition of MS cholinergic neurons promoted CFM consolidation and disinhibited neurons in the DG, increasing pS6 expression among DG granule cells.

Conclusion

Our data suggest that state-dependent gating of DG activity during SD is mediated by cholinergic input. Together these data provide evidence for an inhibitory gate on hippocampal information processing, which is activated by sleep loss.

Support (if any)

R01-NS118440 to SJA from NINDS, DP2-MH104119 to SJA from the NIH Director’s Office, and a Human Frontiers Science Program Young Investigator Award
034 Dreaming as Constructive Episodic Future Simulation
Authors: Wamsley Erin
Published: May 2021

Introduction

Memories of the past help us respond to similar situations in the future. The “episodic future simulation” hypothesis proposes that waking thought combines fragments of various past episodes into imagined simulations of events that may occur in the future. We asked whether this framework from waking cognitive neuroscience may be useful for understanding the function of sleep and dreaming. We hypothesized that participants would commonly identify future events as the source of a dream. Further, we expected future-oriented dreams to draw on multiple different waking memories, with fragments of past experience combined into novel scenarios relevant to anticipated events in participants’ personal futures.

Methods

N=48 students spent the night in the laboratory with polysomnographic recording. During the night, participants were awakened up to 13 times to report on their experiences during sleep onset, REM and NREM sleep. The following morning, participants identified and described waking life sources for each dream reported the previous evening. A total of N=481 reports were analyzed.

Results

While dreams were most commonly traced to past memory (53.5% of reports), more than a quarter (25.7%) were related to specific impending future events. Nearly half of reports with a waking source were traced to multiple different sources (49.7%). Over a third of dreams with a future event source were additionally related to one or more specific past episodic memories (37.4% of all reports with a future episodic source). Future-oriented dreams became proportionally more common later in the night.

Conclusion

First, we confirm prior reports that dreams not only reflect past memory, but also anticipate probable future events. Furthermore, these data provide a novel description of how future-oriented dreams draw simultaneously from multiple waking-life sources, utilizing fragments of past experience to construct novel scenarios anticipating future events. The proportional increase of future-oriented dreams later in the night may be driven by temporal proximity to the events of the following day. While these dreams rarely depict future events realistically, the activation and recombination of future-relevant memory fragments may nonetheless serve an adaptive function.

Support (if any)

This work was supported by Bursaries award 83/12 from the BIAL Foundation.
049 The Effect of Obstructive Sleep Apnea on Emotional Memory Consolidation
Authors: Cunningham Tony , Kishore Divya , Guo Mengshuang , Igue Moroke , Malhotra Atul , Stickgold Robert , Djonlagic Ina
Published: May 2021

Introduction

A growing body of evidence suggests that sleep is critical for the processing and consolidation of emotional information into long-term memory. Previous research has indicated that emotional components of scenes particularly benefit from sleep in healthy groups, yet sleep dependent emotional memory processes remain unexplored in many clinical cohorts, including those with obstructive sleep apnea (OSA).

Methods

In this study, a group of newly diagnosed OSA patients (n=26) and a matched group of healthy controls (n=24) encoded scenes with negative or neutral foreground objects placed on neutral backgrounds prior to a night of polysomnographically recorded sleep. In the morning, they completed a recognition test in which objects and backgrounds were presented separately and one at a time.

Results

OSA patients have a deficit in both overall gist memory and the specific recognition memory for the scenes. Impairment of gist recognition was across all elements of the scenes, both negative and neutral objects and backgrounds [main effect of group: F(1,48) = 13.5, p=0.001], while specific recognition impairment was exclusively found for negative objects [t(48)=2.0, p=0.05]. Across all participants, successful gist recognition correlated positively with sleep efficiency (p=0.001) and REM sleep (p=0.009), while successful specific memory recognition correlated only with REM sleep (p=0.004).

Conclusion

Our findings indicate that fragmented sleep and reduced REM sleep, both hallmarks of OSA, significantly disrupt distinct memory processes for emotional content. Gist memory is universally impacted, while memory for specific details appears to have a greater deterioration for negative aspects of memories. These memory affects may have impacts on complex emotional processes, such as emotion regulation, and could contribute to the high comorbid depressive symptoms in OSA.

Support (if any)

The authors would like to thank the funding sources awarded to author ID for supporting this research: NIH grant # K23HL103850 and American Sleep Medicine Foundation grant #54-JF-10. Author TJC is currently funded by the Research Training Program in Sleep, Circadian and Respiratory Neurobiology (NIH T32 HL007901) through the Division of Sleep Medicine at Harvard Medical School and Brigham & Women’s Hospital.
050 Evening Alcohol Consumption and Slow Wave Sleep: Impact on Morning Hippocampus-Dependent Learning across Three Nights
Authors: Elkhadem Alexandria , Saletin Jared , Gredvig-Ardito Caroline , McGeary John , Carskadon Mary
Published: May 2021

Introduction

Numerous studies interrogated the relationship between alcohol and a single night of sleep. Yet, many adults engage in cumulative days of drinking. Previous studies show alcohol on a single night increases slow wave sleep in the first third of night. Similarly, sleep has been associated with the success of daytime learning. Our goal was to investigate across three consecutive nights how evening alcohol use and nighttime sleep are associated with morning learning.

Methods

23 adults (11F, mean age 33.5±12 years) completed six nights of PSG monitored sleep. Participants consumed alcohol with a target 0.08 breath alcohol concentration (BrAC) and no alcohol on three consecutive nights in counterbalanced order. Percent of slow wave sleep (SWS%) in the first third of the night was derived. Learning was assessed each morning with distinct stimuli on the Mnemonic Similarity Task (MST). The MST score derived was the Lure Discrimination Index (LDI), defined as the proportion of similar images correctly identified minus the proportion of old images incorrectly identified.

Results

SWS% during the first third of the night was greater for alcohol nights compared to non-alcohol nights (F(1, 110)=10.891, p=0.01). However, there was no evidence that either night number or the interaction of drink content and night number affected %SWS in the first third of night (all p’s > 0.05). There was a modest decrease in LDI on mornings following alcohol consumption; however, this effect was not significant. In a separate linear mixed-effect model we found no evidence for an effect of night number, drink content, or their interaction on MST LDI scores (all p’s > 0.05).

Conclusion

Our results indicate that slow wave sleep in the first third of the night is sensitive to evening alcohol consumption. Despite prior literature associating slow wave sleep with next-day learning, we observed no effect of alcohol or night number on morning learning. It is possible that the small sample size contributed to our results. There is little prior research on the cumulative effects of alcohol on sleep and learning; our study adds to this area of research despite the negative findings.

Support (if any)

R01AA025593
055 Novel sleep-dependent spatial memory and navigation task using Minecraft
Authors: Simon Katharine , Clemenson Gregory , Clayton Brandon , Zhang Jing , Alzueta Elisabet , Dulai Teji , Baker Fiona , Mednick Sara
Published: May 2021

Introduction

Spatial navigation and memory are hippocampally-dependent and decrease with age, yet, ecologically-valid methods remain elusive. We developed an engaging and inherently flexible spatial navigation/memory task using the Minecraft platform to test sleep-dependent memory. We validated baseline performance and learning rates across two separate Minecraft environments.

Methods

Using a within-subjects design, twenty-two subjects experienced two conditions (wake/sleep) and two Minecraft environments, counterbalanced across subjects. At encoding, subjects learned the locations of 12 objects. Memory for object location accuracy and navigation route (distance between start and target; vector: angle of direction towards target location from start) was tested immediately and following 12-hours of wake or sleep. Post-hoc analyses were conducted using a median split on subjects’ Immediate test performance.

Results

There were no significant differences across conditions for the Immediate test performance (t(22) = .567, p = .576) across the two environments. Delayed test showed greater improvement in accuracy after sleep compared to wake (t(18) = 2.795, p=.012), no differences in distance or vector. Median split by Immediate test performance revealed that initially lower performance showed the greatest improvement after delay in the sleep group (t(18) = 2.818, p =.011), but not the wake group (t(18) = -1.051, p =.308). Additionally, these same subjects’ vector direction was initially worse at Immediate Test (t(18) = -2.9, p = .01), and improved with sleep, becoming equivalent to the better performers at Delay test (t(18) = -.336, p = .74).

Conclusion

We demonstrate a novel spatial navigation/memory tasks using Minecraft that shows sleep-dependent learning across two distinct environments. We showed enhancement of spatial location accuracy after a night of sleep compared to wake. We further demonstrate that with sleep, those with worse initial performance show the greatest memory and navigation improvement, consistent with other findings that sleep supports enhancement of weaker memories and extended to the spatial-domain. This novel platform can be used to evaluate spatial memory across the lifespan and within special clinical populations.

Support (if any)

NIH R01 AG061355
073 Whole-brain network analysis of neural oscillations during light sleep
Authors: Fan Joline , Kudo Kiwamu , Ranasinghe Kamalini , Morise Hirofumi , Findlay Anne , Kirsch Heidi , Krystal Andrew , Nagarajan Srikantan
Published: May 2021

Introduction

Sleep is a highly stereotyped phenomenon that is ubiquitous across species. Although behaviorally appearing as a homogeneous process, sleep has been recognized as cortically heterogenous and locally dynamic. PET/fMRI studies have provided key insights into regional activation and deactivation with sleep onset, but they lack the high temporal resolution and electrophysiology for understanding neural interactions. Using simultaneous electrocorticography (EEG) and magnetoencephalography (MEG) imaging, we systematically characterize whole-brain neural oscillations and identify frequency specific, cortically-based patterns associated with sleep onset.

Methods

In this study, 14 healthy subjects underwent simultaneous EEG and MEG imaging. Sleep states were determined by scalp EEG. Eight 15s artifact-free epochs, e.g. 120s sensor time series, were selected to represent each behavioral state: N1, N2 and wake. Atlas-based source reconstruction was performed using adaptive beamforming methods. Functional connectivity measures were computed using imaginary coherence and across regions of interests (ROIs, segmentation of 210 cortical regions with Brainnetome Atlas) in multiple frequency bands, including delta (1-4Hz), theta (4-8Hz), alpha (8-12Hz), sigma (12-15Hz), beta (15-30Hz), and gamma (30-50Hz). Directional phase transfer entropy (PTE) was also evaluated to determine the direction of information flow with transition to sleep.

Results

We show that the transition to sleep is encoded in a spatially and temporally specific dynamic pattern of whole-brain functional connectivity. With sleep onset, there is increased functional connectivity diffusely within the delta frequency, while spatially specific profiles in other frequency bands, e.g. increased fronto-temporal connectivity in the alpha frequency band and fronto-occipital connectivity in the theta band. In addition, rather than a decoupling of anterior-posterior regions with transition to sleep, there is a spectral shift to delta frequencies observed in the synchrony and information flow of neural activity.

Conclusion

Sleep onset is cortically heterogeneous, composed of spatially and temporally specific patterns of whole-brain functional connectivity, which may play an essential role in the transition to sleep.

Support (if any)

Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the NIH under Award Number (5TL1TR001871-05 to JMF). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.
075 Systematic Individual Differences in Vulnerability to Sleep Inertia
Authors: Lundholm Kirsie , Van Dongen Hans , Honn Kimberly
Published: May 2021

Introduction

Sleep inertia (SI), the transient grogginess and disorientation that occurs upon awakening, may be particularly problematic in on-call operations that require safety-sensitive and time-critical action, such as healthcare and emergency response. The magnitude of SI is determined by multiple factors, including sleep history, and anecdotal evidence suggests individuals may differ considerably in susceptibility to impairment from SI.

Methods

As part of a larger study investigating individual differences in neurobehavioral impairment, N=21 healthy adults (aged 21–38y; 9 females) completed three laboratory-based neurobehavioral testing sessions, each preceded by baseline sleep. Baseline sleep and nightly at-home sleep opportunities during the week prior were either 12h (extended) or 6h (restricted); two sessions involved extension and one involved restriction in randomized, counterbalanced order. Baseline sleep opportunities ended at 10:00, whereupon subjects completed a 60min neurobehavioral test battery, which began with the Karolinska Sleepiness Scale (KSS). The test battery was repeated every 2h throughout the testing sessions.

Results

A nonlinear mixed-effects regression, controlling for prior sleep restriction/extension and session number, was used to estimate the subjective magnitude of SI immediately upon awakening from baseline sleep, as measured by KSS scores, and the exponential dissipation rate of the effect relative to KSS scores later in the day (12:00-20:00). Following prior sleep extension, SI was associated with a 1.82±0.59 KSS score increase (p=0.006), which subsequently dissipated from a level of 4.80±0.65 to 2.98±0.29 (p=<0.001) later in the day. Following prior sleep restriction, SI was associated with a 1.58±0.58 KSS score increase (p=0.014), which subsequently dissipated from a level of 5.39±0.63 to 3.80±0.30 later in the day. SI took ~45min to dissipate to a negligible level based on a time constant estimate of 23.6±15.8min. Importantly, there were substantial, systematic individual differences in the magnitude of SI, with a between-subjects standard deviation of 1.15±0.42 points on the KSS (ICC=0.51, F=19.5, p<0.001).

Conclusion

We observed sizeable, systematic individual differences in subjective sleepiness due to sleep inertia. To what degree these individual differences predict objective performance deficits remains to be investigated.

Support (if any)

NASA grant NAG9-1161 and CDMRP grant W81XWH-20-1-0442
080 Is Napping Only Beneficial to Evening Chronotypes? A Pilot Study
Authors: Zamore Zachary , Goldschmied Jennifer , Deldin Patricia
Published: May 2021

Introduction

Research shows associations between chronotype and behavior. While eveningness is associated with lower levels of self-control, morningness is associated with increased conscientiousness. Additionally, throughout the day, the increase in homeostatic sleep pressure due to wakefulness can affect executive functioning, including emotional regulation. Napping is an effective countermeasure to sleepiness and associated emotional dysregulation, but the impact of chronotype on this benefit is unknown. Therefore, this study aimed to examine the impact of chronotype and a midday nap on an aspect of emotional regulation: frustration tolerance.

Methods

40 participants between the ages of 18–50 were randomized into a 60-minute, midday nap or no-nap condition. Chronotype was measured using the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ). Frustration tolerance (FT) was measured pre and post nap using an adaption of Feather’s frustration tolerance task where FT was measured as the time spent on an impossible task. To examine the association of chronotype and FT, correlational analysis was used. Chronotype was also determined using a median split of the MEQ due to few true morning and evening types in the sample. This data was then subjected to a repeated measures ANOVA with condition (pre or post-nap) as a within-subjects factor and group (nap or no-nap; high or low MEQ score) as between-subject factors.

Results

Results revealed a significant correlation between MEQ score and change in time spent on the impossible task, with those with lower MEQ scores (more evening) showing an increase in time spent on the impossible task, r(20) = -.51, p = .016. Similarly, results of the ANOVA revealed a significant condition (pre or post-nap) by group (nap, no nap; high, low MEQ) interaction, F(1,1) = 4.694, p = .039, such that, those in the nap group with lower MEQ (more evening) spent more time on the impossible task following the nap.

Conclusion

Our results indicate that chronotype may impact a nap’s positive effect on emotional regulation, with greater benefit for those with the eveningness chronotype. Because napping is currently practiced by 1/3 of American adults, from a personalized medicine perspective, it’s imperative that its chronotype-dependent benefits be investigated further to effectively guide evidence-based recommendations.

Support (if any):
086 Sleep midpoint after job loss predicts breakfast skipping patterns
Authors: Callovini Leah , Gubka Gaby , Mayer Candace , Rojo-Wissar Darlynn , Glickenstein David , Thomson Cynthia , Quan Stuart , Silva Graciela , Haynes Patricia
Published: May 2021

Introduction

Few studies have examined circadian phase after job loss, an event that upends daily routine. It is common that a daily routine begins with the consumption of breakfast, and breakfast behavior may contribute to health status in adults. Therefore, we sought to examine whether a later midpoint of sleep was associated with breakfast skipping among adults whose schedules were no longer dictated by employment.

Methods

Data were obtained from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study. The sample of 155 participants had involuntarily lost their jobs in the last 90 days. Both cross-sectional and 18-month longitudinal analyses assessed the relationship between sleep midpoint after job loss and current and later breakfast skipping. Assessment periods were 14 days. Sleep was measured via actigraphy, and breakfast skipping was measured via daily diary (1 = had breakfast; 0 = did not have breakfast). The midpoint of sleep was calculated as the circular center based on actigraphy sleep onset and offset times.

Results

The midpoint of sleep at baseline was negatively associated with breakfast consumption at baseline (B = -.09, SE = .02, p = .000). Also, a later midpoint was associated with breakfast skipping over the next 18 months (estimate = -.08; SE = .02; p = .000). Prospective findings remained significant when adjusting for gender, ethnicity, age, perceived stress, body mass index (BMI), education, and reemployment over time. Education (estimate = 14.26, SE = 6.23, p < .05) and BMI (estimate = -.51, SE = .25, p < .05) were the only significant covariates. No other sleep indices predicted breakfast behavior cross-sectionally or prospectively.

Conclusion

Consistent with research in adolescents, unemployed adults with a later circadian phase are more likely to skip breakfast more often. Breakfast skipping was also associated with higher BMI. Taken together, these findings provide support for the future testing of sleep/wake scheduling interventions to modify breakfast skipping and potentially mitigate weight gain after job loss.

Support (if any)

#1R01HL117995-01A1
103 Young Adult’s Sleep Efficiency is Positively Related to Risky Decision- Making in Novel BART
Authors: Duby Nicole , Mizell Jack Morgan , Huskey Alisa , Wardle Sophie Pinkston , Taylor Daniel , Wilson Robert
Published: May 2021

Introduction

Numerous studies have indicated that poor sleep quality is relatively common among young adults and is related to less than optimal decision-making behavior. In order to assess decision-making behavior, we utilize a new variant of a Balloon Analogue Risk Task (BART) to assess sleep efficiency and other self-report measures’ relation to risky decision-making in young adults. We hypothesize that individuals who have poorer sleep will make more risky decisions than those who have better sleep in a novel measure called the One-Shot BART.

Methods

200 undergraduate participants were recruited from the University of Arizona Psychology subject pool. Participants completed sleep quality questionnaires including the Sleep Condition Indicator and Split-Week Self-Assessment of Sleep-Y. Participants also completed a battery of self-report measures to assess exposure to traumatic events and trauma-related symptoms through the PTSD Checklist and Adverse Childhood Experiences Questionnaire. Lastly, participants were also tasked with completing a novel risk-taking task measure (the One-Shot BART) to assess risk-taking propensity and elucidate the cognitive processes underlying the risk-taking behavior. This task showed a significant correlation with (r=.24, p<.05) real-world risk measures from the RISQ assessment.

Results

We found that better sleep efficiency showed a positive relationship with risk-taking(r=21, p<.05) in the BART, in conflict with our initial hypothesis that better sleep would lead to less risk-taking. However, in the BART some level of risk-taking is necessary to do well in the task, so risk-taking is beneficial. We found that those people with lower levels of sleep efficiency also performed more randomly in the BART (p<.05), showing that a lack of sleep affects noise in the decision process, which is also supported by our finding showing that people with lower sleep efficiency also show a higher level of response time variability (p<.05).

Conclusion

Behavioral results from the One-Shot BART are affected by Sleep Efficiency in a college student population. Interestingly, Sleep Efficiency was positively correlated with risky decision making in the One-Shot BART, indicating more optimal risk-taking in the game that may be mirrored in real-world decisions.

Support (if any):