Single Night Research Articles

Abstract P540: Sleep Duration, Rapid Eye Movement Sleep, and Subclinical Myocardial Damage

Introduction: Sleep is strongly linked to clinical cardiovascular disease and was added in 2022 to the AHA’s Life’s Essential 8. Optimizing sleep duration and quality may reduce the risk of cardiovascular disease. Few studies have examined self-reported sleep duration and percent time in rapid eye movement (REM) sleep measured by single night in-home polysomnography with high sensitivity cardiac troponin T (hs-troponin T), a biomarker of subclinical cardiovascular disease. Methods: We conducted a cross-sectional study of adults without a history of cardiovascular disease who participated in both the Atherosclerosis Risk in Communities (ARIC) Study and the Sleep Heart Health Study (SHHS) in 1995-1998. We used linear regression with sleep duration and percentage time of REM sleep modeled as predictors with restricted cubic splines and examined associations with the outcome, hs-troponin T. We adjusted for age, sex, body mass index, waist-to-hip ratio, alcohol intake, smoking status, systolic blood pressure, hypertension medication use, diabetes, HDL- and LDL-cholesterol, and cholesterol-lowering medication use. Results: Among 1,587 participants (mean age 63, 54% female), the mean sleep duration was 7.3 hours, and mean % REM time was 20.7. Sleep duration was not associated with hs-troponin T ( Figure, Panel A ). However, percentage REM sleep was negatively associated with hs-troponin T, but with a threshold effect; there was a negative linear association of hs-troponin T with % REM sleep but only at values <15% ( Figure, Panel B ). Conclusion: While self-reported sleep duration was not associated with TnT levels, there was evidence that low % REM sleep, a specific neurophysiological sleep state, was associated with subclinical cardiovascular disease. These findings suggest that multiple sleep dimensions should be considered in efforts to optimize cardiovascular health.

Role of Religion and Partition in Khuswant Singh’s Novel Train to Pakistan

Train to Pakistan is a novel written by famous Indian Writer Khushwant Singh speaks about the partition during the Independence of India in 1947. Dividing sub-continent along the sectarian line. The northern part of India predominantly Muslim people become republic of Pakistan because of the partition. Brotherhood between Indians and Muslims were stated to destroy. Many Muslims people went side of Pakistan only few people of Muslims are stay holed India. Many people were killed during the Partition both a side due to the religious problem. Hindus are became more strongest religion in India during the Independence. India is a county became county of Hindu. Economically, land scope, and population in these Hindus are became more powerful then Muslim. 15 million people were displaced their home, government rules and government sector were changed. Hindus and Muslims were living together since long but they filed in inculcate the feelings emotions and love with in a single night neighbor are changed into neighbor county peoples this makes the black day to both a religions people. In India many writes were speaks about this incident eg. Midnight’s Children by Salman Rushdie, Tamas by Bhisham Sahani, Shadow Lines by Amitav Ghosh, Ice Candy Man by Bapsi Sidhwaect...

Two Left Shoes

In retrospect, it’s not surprising that I experienced homelessness during one winter as a college student. The winter of 1983 in Seattle was typical: cold, cloudy, and wet. Peanut butter was my primary food. I had a small camping stove for coffee but lacked any other means of heat. Gasworks Park was my main source of drinking water. But my story is not unusual; it is regrettably far too common. After all, on any single night in the U.S., about 1 in 500 individuals, representing a diverse cross-section of the population, find themselves without housing (1). Among college students, estimates indicate that about 5% to 10% will experience homelessness at some point during their academic journey (2,3). Although many temporary couch surf with friends, a significant proportion, like myself, end up sleeping outdoors or urban camping (4). Globally, hundreds of millions of people have inadequate shelter every night. The hard reality is that individuals of all ages and backgrounds, including children, students, adults, and seniors, have either already confronted or will confront housing insecurity and homelessness.

A case-control study to investigate the prevalence of obstructive sleep apnea and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in children and young people with epilepsy.

Epilepsy and obstructive sleep apnea syndrome (OSAS) are each relatively common in children. OSAS may affect cognition, such that recognition of OSAS is important for children and young people with epilepsy (CYPWE). Published pilot data reported 55% of CYPWE had symptoms suggestive of OSAS, compared with 7% of typically developing controls. The primary aim of this study was to ascertain OSAS prevalence by polysomnography in CYPWE, with secondary aims being to evaluate the utility of sleep questionnaires in CYPWE. CYPWE and age- and sex-matched typically developing controls were studied. A single night of level I attended polysomnography was undertaken, along with questionnaires (Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire, Pittsburgh Sleep Quality Index, and the childhood and adolescent Epworth Sleepiness Scale). OSAS was defined as obstructive apnea-hypopnea index of ≥ 1 event/h. Polysomnography was performed in 72 children including 48 CYPWE (60% male) and 24 controls (54% male). Mean age (11 years) was similar for CYPWE and controls (P = .42), with slightly higher body mass index z scores (0.7 vs 0.1, P = .03) noted in CYPWE. Mean obstructive apnea-hypopnea index was 0.61 in CYPWE vs 0.42 in controls (P = .62). Despite higher Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire scores in CYPWE (0.38 vs 0.12, P < .001), no difference in OSAS prevalence (10% vs 4%, P = .78) was found. CYPWE had higher childhood and adolescent Epworth Sleepiness Scale (6 vs 3.5, P = .01) and Pittsburgh Sleep Quality Index (5 vs 3.3, P = .02) scores, indicating greater levels of daytime sleepiness and poorer sleep quality. The study found no evidence for increased OSAS prevalence in CYPWE, and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in predicting OSAS appears limited for CYPWE. CYPWE are, however, demonstrably sleepier and have poorer sleep quality. The cause for these findings remains unclear. Registry: ClinicalTrials.gov; Name: Investigation of Sleep Quality and Prevalence of Sleep-disordered Breathing in Children and Young People With Epilepsy; URL: https://www.clinicaltrials.gov/study/NCT03103841; Identifier: NCT03103841. Urquhart DS, McLellan AE, Hill LE, etal. A case-control study to investigate the prevalence of obstructive sleep apnea and the utility of the Sleep-Related Breathing Disorder scale of the Pediatric Sleep Questionnaire in children and young people with epilepsy. J Clin Sleep Med. 2024;20(7):1039-1047.

Detection of an intranight optical hard lag with colour variability in blazar PKS 0735+178

ABSTRACT Blazars are a highly variable subclass of active galactic nuclei that have been observed to vary significantly during a single night. This intranight variability remains a debated phenomenon, with various mechanisms proposed to explain the behaviour including jet energy density evolution or system geometric changes. We present the results of an intranight optical monitoring campaign of four blazars: TXS 0506+056, OJ287, PKS 0735+178, and OJ248 using the Carlos Sánchez Telescope. We detect significant but colourless behaviour in OJ287 and both bluer- and redder-when-brighter colour trends in PKS 0735+178. Additionally, the g band shows a lag of $\sim 10\, \mathrm{min}$ with respect to the r, i, zs bands for PKS 0735+178 on 2023 January 17. This unexpected hard lag in PKS 0735+178 is not in accordance with the standard synchrotron shock cooling model (which would predict a soft lag) and instead suggests the variability may be a result of changes in the jet’s electron energy density distribution, with energy injection from Fermi acceleration processes into a post-shocked medium.

Homelessness And Health: Factors, Evidence, Innovations That Work, And Policy Recommendations.

On a single night in 2023, more than 653,000 people experienced homelessness in the United States. In this overview, we highlight structural and individual risk factors that can lead to homelessness, explore evidence on the relationship between homelessness and health, discuss programmatic and policy innovations, and provide policy recommendations. Health system efforts to address homelessness and improve the health of homeless populations have included interventions such as screening for social needs and medical respite programs. Initiatives using the Housing First approach to permanent supportive housing have a strong track record of success. Health care financing innovations using Medicaid Section 1115 waivers offer promising new approaches to improving health and housing for people experiencing homelessness. To substantially reduce homelessness and its many adverse health impacts, changes are needed to increase the supply of affordable housing for households with very low incomes. Health care providers and systems should leverage their political power to advocate for policies that scale durable, evidence-based solutions to reduce homelessness, including increased funding to expand housing choice vouchers and greater investment in the creation and preservation of affordable housing.

Design and rationale of the Post-Intensive Care Syndrome – paediatrics (PICS-p) Longitudinal Cohort Study

IntroductionAs paediatric intensive care unit (PICU) mortality declines, there is growing recognition of the morbidity experienced by children surviving critical illness and their families. A comprehensive understanding of the adverse...

Acoustic stimulation during slow wave sleep shows delayed effects on memory performance in older adults

IntroductionIn young healthy adults, phase-locked acoustic stimulation (PLAS) during slow wave sleep (SWS) can boost over-night episodic memory consolidation. In older adults, evidence is scarce and available results are inconsistent, pointing toward reduced PLAS-effectiveness. We argue that multiple stimulation nights are required for effects to unfold in older individuals to compensate for age-related reductions in both SWS and memory performance. We test this assumption in a longitudinal within-subject design.MethodsIn a larger previous project, older adults participated in a three-night intervention receiving either real-PLAS (STIM group) or sham-PLAS (SHAM group). Encoding and immediate recall of face-occupation pairs was administered on the evening of the first intervention night (session one), with feedback-based retrievals ensuing on all following mornings and evenings across the intervention. To test for the benefit of the real-PLAS over sham-PLAS intervention within participants, 16 older adults [agemean: 68.9 (SD: 3.7)] were re-invited receiving the real-PLAS intervention exclusively. This resulted in a SHAMSTIM group (n = 9; T1: sham-PLAS intervention, T2: real-PLAS intervention) and a STIMSTIM group (n = 7; T1 and T2: real-PLAS intervention).ResultsWhile the STIMSTIM group exhibited highly similar responses during T1 and T2, the SHAMSTIM group exhibited a significantly higher increase in memory performance at T2 (real-PLAS) compared to T1 (sham-PLAS). These gains can be attributed to the late stages of the experiment, after three nights of real-PLAS, and remained stable when correcting for changes in baseline sleep quality (PSQI) and baseline cognitive ability (Montreal Cognitive Assessment) between T1 and T2.ConclusionsWe show that in older adults, PLAS-induced memory effects are delayed and manifest over the course of a three-night-PLAS intervention. Our results might explain the lack of effects in previous PLAS studies, where memory performance was solely assessed after a single night of PLAS.

Accessibility of the ILMT Survey Data

The 4m International Liquid Mirror Telescope (ILMT) continuously scans a 22′ wide strip of the zenithal sky and records the images in three broadband filters (g’, r’ and i’) using a 4K×4K CCD camera. In about 10–12 hours of observations during a single night, ∼15 GB of data volume is generated. The raw images resulting from the observations in October–November 2022 have been pre-processed and astrometrically calibrated. In order to exploit the scientific capabilities of the ILMT survey data by the larger scientific community, we are disseminating the raw data (along with dark and flat fields) and the astrometrically calibrated data. These data sets can be downloaded by the users to conduct the scientific projects of their interest. In future, the data will be processed in near real-time and will be available via the ARIES data archive portal.

First upper limits on the 21 cm signal power spectrum from cosmic dawn from one night of observations with NenuFAR

The redshifted 21 cm signal from neutral hydrogen is a direct probe of the physics of the early universe and has been an important science driver of many present and upcoming radio interferometers. In this study we use a single night of observations with the New Extension in Nançay Upgrading LOFAR (NenuFAR) to place upper limits on the 21 cm power spectrum from cosmic dawn at a redshift of z = 20.3. NenuFAR is a new low-frequency radio interferometer, operating in the 10–85 MHz frequency range, currently under construction at the Nançay Radio Observatory in France. It is a phased array instrument with a very dense uv coverage at short baselines, making it one of the most sensitive instruments for 21 cm cosmology analyses at these frequencies. Our analysis adopts the foreground subtraction approach, in which sky sources are modeled and subtracted through calibration and residual foregrounds are subsequently removed using Gaussian process regression. The final power spectra are constructed from the gridded residual data cubes in the uv plane. Signal injection tests are performed at each step of the analysis pipeline, the relevant pipeline settings are optimized to ensure minimal signal loss, and any signal suppression is accounted for through a bias correction on our final upper limits. We obtain a best 2σ upper limit of 2.4 × 107 mK2 at z = 20.3 and k = 0.041 h cMpc−1. We see a strong excess power in the data, making our upper limits two orders of magnitude higher than the thermal noise limit. We investigate the origin and nature of this excess power and discuss further improvements to the analysis pipeline that can potentially mitigate it and consequently allow us to reach thermal noise sensitivity when multiple nights of observations are processed in the future.

Artificial intelligence augmented home sleep apnea testing device study (AISAP study).

This study aimed to prospectively validate the performance of an artificially augmented home sleep apnea testing device (WVU-device) and its patented technology. The WVU-device, utilizing patent pending (US 20210001122A) technology and an algorithm derived from cardio-pulmonary physiological parameters, comorbidities, and anthropological information was prospectively compared with a commercially available and Center for Medicare and Medicaid Services (CMS) approved home sleep apnea testing (HSAT) device. The WVU-device and the HSAT device were applied on separate hands of the patient during a single night study. The oxygen desaturation index (ODI) obtained from the WVU-device was compared to the respiratory event index (REI) derived from the HSAT device. A total of 78 consecutive patients were included in the prospective study. Of the 78 patients, 38 (48%) were women and 9 (12%) had a Fitzpatrick score of 3 or higher. The ODI obtained from the WVU-device corelated well with the HSAT device, and no significant bias was observed in the Bland-Altman curve. The accuracy for ODI > = 5 and REI > = 5 was 87%, for ODI> = 15 and REI > = 15 was 89% and for ODI> = 30 and REI of > = 30 was 95%. The sensitivity and specificity for these ODI /REI cut-offs were 0.92 and 0.78, 0.91 and 0.86, and 0.94 and 0.95, respectively. The WVU-device demonstrated good accuracy in predicting REI when compared to an approved HSAT device, even in patients with darker skin tones.

Validation of Trøndelag Apnoea Score Proxy for Obstructive Sleep Apnoea in the General Population of Norway: The HUNT Study.

The aim was to validate a new seven-item "TASC" (Trøndelag Apnoea Score) proxy for obstructive sleep apnoea (OSA) against polysomnography in the general population. Objectives included validation against different polysomnographic criteria, stratification by age and gender, and estimation of OSA prevalence. From the fourth wave of the Trøndelag Health Study (HUNT4), 1,201 participants were randomly invited to a substudy focusing on sleep and headaches, of whom 232 accepted and 84 (64% women, mean age 55.0 years, and standard deviation 11.5 years) underwent polysomnography. The TASC proxy sums seven binary items for snoring, observed breathing pauses, restricted daytime activities, hypertension, body mass index (≥30 kg/m2), age (≥50 years), and gender (male). A single night of ambulatory (home) polysomnography was analysed using both the recommended and optional hypopnoea criteria of the American Academy of Sleep Medicine (AASM). We found 65% sensitivity and 87% specificity (Cohen's κ = 0.53, 95% confidence interval 0.34-0.72) for TASC ≥ 3 against AHI ≥ 15 (recommended AASM criteria). Validity was similar against AHI ≥ 30 but lower against AHI ≥ 5 and against the optional AASM criteria. Sensitivity and overall validity were higher among men and those above 50 years of age. The prevalence of an apnoea-hypopnoea index (AHI) of at least 5, 15, or 30 using the recommended (and optional) AASM criteria was 73% (46%), 37% (18%), or 15% (5%). A seven-item TASC proxy for OSA showed good validity and may be useful in screening and epidemiological settings. Sensitivity, specificity, and validity vary considerably by cut-off, by polysomnographic scoring criteria, and by gender and age strata.

The Context Of Ḥadīth Narration On Prophet Sulaymān Visiting Multiple Wives In A Single Night

The paper aims to shed light on the contextual background of prophetic tradition on “Prophet Sulaymān Visiting Multiple Wives in A Single Night” which has been given as an example of a contradiction between ḥadīth and logic. It tells the story of Prophet Sulaymān sleeping with an enormous number of wives in a single night. Being portrayed as carrying erotic message, the ḥadīth has also been deduced as an example of forgery committed by the ḥadīth scholars themselves. This study aims to clarify the problematic allegations, deduce a number of responses and compare the ideas from significant finding in Jewish and Christian sources. It suggests that such problematic ḥadīth implicitly implying a form of muʿjizāt and karāmah in such tradition. The study is conducted in qualitative manner based on library research technique. Relevant data material were collected from the nine canonical ḥadīth books, traditional commentaries (sharh), Biblical sources and related article and were analysed in a descriptive and analytical, and comparative manner. The finding shows that the ḥadīth fulfils the criteria of a rigorously authenticated ḥadīth given its inclusion in the canonical works of hadith and corroborated in other tradition and highly established in ḥadīth narrations. Hence, the claim of fabrication was categorically dismissed; the number of wives should be understood in general as indicating numerous wives while, ignoring the particular numbers. The study implicitly shows that the paragraph “single night” alluded to the narrative of muʿjizāt.

Performance of the Dreem 2 EEG headband, relative to polysomnography, for assessing sleep in Parkinson’s disease

Goal and aimsTo pilot the feasibility and evaluate the performance of an EEG wearable for measuring sleep in individuals with Parkinson’s disease. Focus technologyDreem Headband, Version 2. Reference technologyPolysomnography. SampleTen individuals with Parkinson’s disease. DesignIndividuals wore Dreem Headband during a single night of polysomnography. Core analyticsComparison of summary metrics, bias, and epoch-by-epoch analysis. Additional analytics and exploratory analysesCorrelation of summary metrics with demographic and Parkinson’s disease characteristics. Core outcomesSummary statistics showed Dreem Headband overestimated several sleep metrics, including total sleep, efficiency, deep sleep, and rapid eye movement sleep, with an exception in light sleep. Epoch-by-epoch analysis showed greater specificity than sensitivity, with adequate accuracy across sleep stages (0.55-0.82). Important supplemental outcomesGreater Parkinson’s disease duration and rapid eye movement behavior were associated with more wakefulness, and worse Parkinson’s disease motor symptoms were associated with less deep sleep. Core conclusionThe Dreem Headband performs similarly in Parkinson’s disease as it did in non-Parkinson’s disease samples and shows promise for improving access to sleep assessment in people with Parkinson’s disease.

Sleep breathing patterns and neurocognitive function in a diverse Hispanic/Latino cohort

AbstractBackgroundSleep disorders are common in patients with Alzheimer’s Disease (AD). Obstructive sleep apnea (OSA), characterized by intermittent cessation of breathing and hypoxemia, has been associated with increased risk of AD and worse cognitive function. However, the interacting effects of neurocognitive function with sleep breathing patterns, independent of the apnea‐hypopnea index, (a measure of OSA severity) have not been carefully studied. We use a novel approach to analyzing home sleep apnea data to examine breathing patterns and their relationships with neurocognitive function.MethodThe Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a prospective multicenter study of diverse Latinos. Around 16,000 diverse Hispanic/Latinos were recruited from four major metropolitan cities. Participants used an ARES unirecorder device for a single night of unsupervised at home recording. We used python package “bycycle” to cannula data (sampled at 10Hz). Bycycle uses a time domain approach to parameterizing rhythmic time‐series data. We extracted breathing rate (breaths per minute), breathing variability (interquartile range of breathing rate) and time spent in inhalation phase (percent time). Participants ages ≥45 (unweighted n = 5,957) were tested in their preferred language using a brief battery including: B‐SEVLT (3‐trials sum) and Delayed Recall (memory), World Fluency (verbal fluency), and Digit Symbol Substitution (executive function). Covariates used in our models are described in Table 1. All presented estimates were weighted for appropriate generalization to the HCHS/SOL target population.ResultIn unadjusted models, all breathing measures were negatively associated with cognitive function, but only breathing rate remained significant after full covariate adjustment (Figure 1). We found significant interactions between breathing rate and sex, as well as age for verbal fluency models. Being female and older age were associated with steeper slopes of cognitive under‐performance for both breathing rate and breathing variability (Figure 2).ConclusionThese results suggest that breathing patterns outside apneas‐hypopneas may be as critical in understanding sleep related changes and cognitive function in an aging population. Given cessation of breathing during an apnea‐hypopnea event, breathing variability may add more precision to account for varying oxygen demands. Further studies should examine whether breathing instability is also associated with cognitive decline, impairment, and dementia.

Foraging fidelity and individual specialisation in a temperate bat Myotis nattereri

This study explores whether Natterer’s bats exhibit fidelity to their foraging sites and individual specialisation in their use of habitat types. The research tracked 34 individual bats in two different landscapes, with some bats tracked twice over varying time intervals. The study found that Natterer’s bats show consistency in their fidelity to foraging sites across different landscapes and intervals between observations. The bats repeatedly exploited specific foraging areas, and some showed individual specialisation in their habitat use. The study also found considerable variation in individual behaviour. The research suggests that a single full night of radio-tracking data can serve as a useful proxy for longer periods and contribute to more robust descriptions of resource requirements by Natterer’s bats in their breeding seasons. This study emphasises the importance of maximising the number of individuals from which movement data is obtained to inform conservation and management of temperate bats, whilst ensuring that the data represent a meaningful measure of behaviour. The results also suggest that protecting a mosaic of habitats rather than a single habitat may be important for Natterer’s bats, given their individual specialisation in habitat use.

Evaluation of the Continuous Positive Airway Pressure Effect on Neurotrophins’ Gene Expression and Protein Levels

Neurotrophins (NT) might be associated with the pathophysiology of obstructive sleep apnea (OSA) due to concurrent intermittent hypoxia and sleep fragmentation. Such a relationship could have implications for the health and overall well-being of patients; however, the literature on this subject is sparse. This study investigated the alterations in the serum protein concentration and the mRNA expression of the brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), neurotrophin-3 (NTF3), and neurotrophin-4 (NTF4) proteins following a single night of continuous positive airway pressure (CPAP) therapy. This study group consisted of 30 patients with OSA. Venous blood was collected twice after a diagnostic polysomnography (PSG) and PSG with CPAP treatment. Gene expression was assessed with a quantitative real-time polymerase chain reaction. An enzyme-linked immunosorbent assay was used to determine the protein concentrations. After CPAP treatment, BDNF, proBDNF, GDNF, and NTF4 protein levels decreased (p = 0.002, p = 0.003, p = 0.047, and p = 0.009, respectively), while NTF3 increased (p = 0.001). Sleep latency was correlated with ΔPSG + CPAP/PSG gene expression for BDNF (R = 0.387, p = 0.038), NTF3 (R = 0.440, p = 0.019), and NTF4 (R = 0.424, p = 0.025). OSA severity parameters were not associated with protein levels or gene expressions. CPAP therapy could have an impact on the posttranscriptional stages of NT synthesis. The expression of different NTs appears to be connected with sleep architecture but not with OSA severity.

The effects of sleep deprivation, acute hypoxia, and exercise on cognitive performance: A multi-experiment combined stressors study

IntroductionBoth sleep deprivation and hypoxia have been shown to impair executive function. Conversely, moderate intensity exercise is known to improve executive function. In a multi-experiment study, we tested the hypotheses that moderate intensity exercise would ameliorate any decline in executive function after i) three consecutive nights of partial sleep deprivation (PSD) (Experiment 1) and ii) the isolated and combined effects of a single night of total sleep deprivation (TSD) and acute hypoxia (Experiment 2). MethodsUsing a rigorous randomised controlled crossover design, 12 healthy participants volunteered in each experiment (24 total, 5 females). In both experiments seven executive function tasks (2-choice reaction time, logical relations, manikin, mathematical processing, 1-back, 2-back, 3-back) were completed at rest and during 20 min semi-recumbent, moderate intensity cycling. Tasks were completed in the following conditions: before and after three consecutive nights of PSD and habitual sleep (Experiment 1) and in normoxia and acute hypoxia (FIO2 = 0.12) following one night of habitual sleep and one night of TSD (Experiment 2). ResultsAlthough the effects of three nights of PSD on executive functions were inconsistent, one night of TSD (regardless of hypoxic status) reduced executive functions. Significantly, regardless of sleep or hypoxic status, executive functions are improved during an acute bout of moderate intensity exercise. ConclusionThese novel data indicate that moderate intensity exercise improves executive function performance after both PSD and TSD, regardless of hypoxic status. The key determinants and/or mechanism(s) responsible for this improvement still need to be elucidated. Future work should seek to identify these mechanisms and translate these significant findings into occupational and skilled performance settings.

Messung des Atemzugvolumens bei Patienten mit Obesitas-Hypoventilations-Syndrom und Opiumabhängigkeit

Abstract Background Both obesity hypoventilation syndrome (OHS) and opium dependence can negatively affect nocturnal respiratory functionality. However, the effects of a combination of the two are relatively unknown. In this study, the tidal volume (VT) of OHS patients with and without opium dependence was estimated by measuring changes in the circumference of the thorax and the abdomen during sleep. Materials and methods This case–control study was performed in Iran, Isfahan. Initially, 20 healthy subjects calibrated the Pneumobelts (Löwenstein Medical Technology GmbH, Hamburg, Germany) by wearing the device and also breathing in and out of a Spirobag. From this, it was possible to estimate the coefficient factors for determining VT based on thoracic and abdominal measures. Subsequently, the study included 55 patients with OHS, who were divided into two groups: opium dependent and non-users. They were then admitted to the sleep lab for a single night of polysomnography (PSG). VT was estimated and then compared between groups. Results In total, there were 24 patients in the opium group and 31 in the non-user control group. All PSG variables were analyzed with independent-sample t-tests and an analysis of covariance was used to adjust for potential confounding variables. The following confounding variables were adjusted: sex, smoking, body mass index, and hypertension. VT values were not significantly different between groups (opium: 772 ± 125.4; non-user: 774 ± 95). Average oxygen saturation values were significantly lower in opium-dependent patients (opium: 86.1 ± 5.5; non-user: 89.1 ± 4.1). All other variables from PSG including chest and abdominal circumference were not significantly different between groups. Conclusion OHS patients with opium dependency showed similar VT levels when compared to non-users with OHS. Due to the rarity of the sample, it was difficult to gather exactly matched pairs. Therefore, it is possible that with a more closely related sample, we might be able to see a difference in VT between groups.

Long-term exposure to experimental light affects the ground-dwelling invertebrate community, independent of light spectra.

Our planet endures a progressive increase in artificial light at night (ALAN), which affects virtually all species, and thereby biodiversity. Mitigation strategies include reducing its intensity and duration, and the adjustment of light spectrum using modern light emitting diode (LED) light sources. Here, we studied ground-dwelling invertebrate (predominantly insects, arachnids, molluscs, millipedes, woodlice and worms) diversity and community composition after 3 or 4 years of continued nightly exposure (every night from sunset to sunrise) to experimental ALAN with three different spectra (white-, and green- and red-dominated light), as well as for a dark control, in natural forest-edge habitat. Diversity of pitfall-trapped ground-dwelling invertebrates, and the local contribution to beta diversity, did not differ between the dark control and illuminated sites, or between the different spectra. The invertebrate community composition, however, was significantly affected by the presence of light. Keeping lights off during single nights did show an immediate effect on the composition of trapped invertebrates compared to illuminated nights. These effects of light on species composition may impact ecosystems by cascading effects across the food web. This article is part of the theme issue 'Light pollution in complex ecological systems'.