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STUDY OBJECTIVES: We aimed to determine whether patients diagnosed with obstructive sleep apnea (OSA) who fail to respond to upper airway surgery may be successfully treated with supplemental oxygen and whether we could identify baseline physiologic endotypes (ie, collapsibility, loop gain, arousal threshold, and muscle compensation) that predict response to oxygen therapy. METHODS: We conducted a single night, randomized double-blinded cross over trial in which patients with OSA who failed to respond to upper airway surgery were treated on separate nights with oxygen therapy (4 L/min) or placebo (medical air). Effect of oxygen/air on OSA on key polysomnography outcomes were assessed: apnea-hypopnea index (AHI), AHI without desaturation (ie, flow-based AHI), arousal index, and morning blood pressure. OSA endotypes were estimated from the polysomnography signals to determine whether baseline OSA physiology could be used to predict response to oxygen therapy. RESULTS: There was a statistically significant reduction in AHI and flow-based AHI on oxygen vs placebo (flow-based AHI: 42.4 ± 21.5 vs 30.5 ± 17.1 events/h, P = .008). Arousal index was also reduced on oxygen vs placebo (41.1 ± 19.5 vs 33.0 ± 15.3 events/h, P = .006). There was no significant difference in morning blood pressure between oxygen and placebo. Although 7 of 20 individuals experienced a 50% reduction or greater in flow-based AHI on oxygen (responders), there was no difference in the baseline OSA endotypes (or clinical characteristics) between responders and nonresponders. CONCLUSIONS: Our findings demonstrate that a proportion of patients who fail to respond to upper airway surgery for OSA respond acutely to treatment with supplemental oxygen. CLINICAL TRIAL REGISTRATION: Registry: Australian New Zealand Clinical Trials Registry; Name: Oxygen therapy for treating patients with residual obstructive sleep apnea following upper airway surgery; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373566; Identifier: ACTRN12617001361392. CITATION: Joosten SA, Tan M, Wong A-M, et al. A randomized controlled trial of oxygen therapy for patients who do not respond to upper airway surgery for obstructive sleep apnea. J Clin Sleep Med. 2021;17(3):445–452.

Recovery after acute pulmonary embolism occurs on a continuum from complete restoration of flow to persistent perfusion defects causing pulmonary hypertension. An under-recognized complication of p...

Performance variability is an important measure for a reliable high performance computing (HPC) system. Performance variability is affected by complicated interactions between numerous factors, suc...

Increases in the quantity of available data have allowed all fields of science to generate more accurate models of multivariate phenomena. Regression and interpolation become challenging when the dimension of data is large, especially while maintaining tractable computational complexity. Regression is a popular approach to solving approximation problems with high dimension; however, there are often advantages to interpolation. This paper presents a novel and insightful error bound for (piecewise) linear interpolation in arbitrary dimension and contrasts the performance of some interpolation techniques with popular regression techniques. Empirical results demonstrate the viability of interpolation for moderately high-dimensional approximation problems, and encourage broader application of interpolants to multivariate approximation in science.

DELAUNAYSPARSE contains both serial and parallel codes written in Fortran 2003 (with OpenMP) for performing medium- to high-dimensional interpolation via the Delaunay triangulation. To accommodate the exponential growth in the size of the Delaunay triangulation in high dimensions, DELAUNAYSPARSE computes only a sparse subset of the complete Delaunay triangulation, as necessary for performing interpolation at the user specified points. This article includes algorithm and implementation details, complexity and sensitivity analyses, usage information, and a brief performance study.

Funding Acknowledgements Type of funding sources: None. Introduction Obstructive sleep apnoea (OSA) is associated with increased plaque burden in coronary artery disease (CAD), but the role of vascular inflammation in this relationship is unclear. Coronary computed tomography angiography (CTA) enables surrogate assessment of systemic inflammation via subcutaneous adipose tissue attenuation (ScAT-a), and of coronary inflammation via epicardial adipose tissue volume and attenuation (EAT-v and EAT-a) and pericoronary adipose tissue attenuation (PCAT-a). Purpose To investigate whether vascular inflammation is increased in patients with severe OSA and high plaque burden. Methods Patients with clinically indicated polysomnography and coronary CTA were included. Severe OSA was classified as apnoea/hypopnoea index (AHI) >30. High plaque burden was defined as a CT-Leaman score (CT-LeSc) >8.3. Patients with both severe OSA and high plaque burden were defined as ‘Group 1’, all other patients were classified as ‘Group 2’. ScAT-a, EAT-a, EAT-v and PCAT-a were assessed on semi-automated software. Results A total of 91 patients were studied (59.3 ± 11.1 years). Severe OSA was associated with high plaque burden (p = 0.02). AHI correlated with CT-LeSc (r = 0.24, p = 0.023). Group 1 had lower EAT-a and PCAT-a compared to Group 2 (EAT-a: -87.6 vs. -84.0 HU, p = 0.01; PCAT-a: -90.4 vs. -83.4 HU, p Conclusions EAT attenuation is decreased in patients with severe OSA and high plaque burden but increased in patients with severe OSA and low plaque burden. These divergent results suggest coronary inflammation may be increased in OSA independent of CAD, but larger studies are required to validate these findings.

Although proning is beneficial to acute respiratory distress syndrome, impressions vary about its efficacy. Some providers believe that paralysis is required to facilitate proning. We studied impact of paralysis on prone-induced gas exchange improvements and provider attitudes regarding paralytics.DesignObservational.SettingUniversity of California San Diego.PatientsIntubated COVID acute respiratory distress syndrome patients.InterventionsNone.Measurements and main results1) Changes in Pao2:Fio2 and Spo2:Fio2 ratios before and after proning with and without paralytics, 2) adverse events during proning with and without paralytics, and 3) nurse and physician attitudes about efficacy/safety of proning with and without paralytics. Gas-exchange improvement with proning was similar with and without paralytics (with no serious adverse events). Survey results showed similar attitudes between nurses and physicians about proning efficacy but differing attitudes about the need for paralytics with proning.ConclusionsFindings support use of proning and may help in design of randomized trials to assess paralytics in acute respiratory distress syndrome management.

Honey bee queens undergo dramatic behavioral (e.g., reduced sexual receptivity), physiological (e.g., ovary activation, ovulation, and modulation of pheromone production) and transcriptional changes after they complete mating. To elucidate how queen post-mating changes are influenced by seminal fluid, the non-spermatozoa-containing component of semen, we injected queens with semen or seminal fluid alone. We assessed queen sexual receptivity (as measured by likelihood to take mating flights), ovary activation, worker retinue response (which is influenced by queen pheromone production), and transcriptional changes in queen abdominal fat body and brain tissues. Injection with either seminal fluid or semen resulted in decreased sexual receptivity, increased attractiveness of queens to workers, and altered expression of several genes that are also regulated by natural mating in queens. The post-mating and transcriptional changes of queens receiving seminal fluid were not significantly different from queens injected with semen, suggesting that components in seminal fluid, such as seminal fluid proteins, are largely responsible for stimulating post-mating changes in queens.

Performance variability is an important factor of high-performance computing (HPC) systems. HPC performance variability is often complex because its sources interact and are distributed throughout the system stack. For example, the performance variability of I/O throughput can be affected by factors such as CPU frequency, the number of I/O threads, file size, and record size. In this paper, we focus on the I/O throughput variability across multiple executions of a benchmark program. For a given system configuration, the distribution of throughputs from run to run is of interest. We conduct large-scale experiments and collect a massive amount of data to study the distribution of I/O throughput under tens of thousands of system configurations. Despite normality often being assumed in the literature, our statistical analysis reveals that the performance variability is not normally distributed under most system configurations. Instead, multimodal distributions are common for many system configurations. We propose the use of mixture distributions to describe the multimodal behavior. Various underlying parametric distributions such as normal, gamma, and the Weibull are considered. We apply an expectation–maximization (EM) algorithm for parameter estimation and use the Bayesian information criterion (BIC) for parametric model selections. We also illustrate how to use the estimated mixture distribution to calculate the number of runs needed for future experiments on variability analysis. The paper provides a useful tool set in studying the behavior of performance variability.

Background and Aims As grapegrowers move to adapt to climate change, they need more detailed information on what cultivars to plant and where to plant them. The aims of this study were to understand how different cultivars in different regions are responding to changes in climate, in order to inform future cultivar selections. Methods and Results Trends in the day of year maturity (DOYM) between 1999 and 2018 were analysed for 23 grape cultivars (covering at least 7 years) and four Victorian vineyard regions against vintage year, seasonal growing degree day (GDDSep–Mar) and Spring Index. In most cases there were significant trends in DOYM advancement as a function of GDDSep–Mar and spring index. Temporal advancement of DOYM was more variable. One cultivar showed a significant advancement at two of three sites and another showed a significant delay. Different cultivars advanced DOYM at significantly different rates at a given site, later ripening cultivars advanced DOYM faster than earlier ripening cultivars and for a cultivar grown across several sites, the DOYM advancement was faster at cooler sites. Conclusions Grapevine cultivars respond to warming temperature differently and the advancement of grape maturity is predicted to slow as temperature further increases. Significance of the Study The study showed diversity in the phenological response of cultivars to temperature, which may be utilised to better adapt to climate change.

BACKGROUND: Patient care ownership improves accountability, clinical skills, and quality of patient care among resident physicians, but appears to be gradually eroding. Research is limited by the lack of a reliable, objective measure of ownership. OBJECTIVE: To validate the Patient Care Ownership Scale, an instrument that measures decision ownership among internal medicine residents. DESIGN: Multi-institutional, cross-sectional study using a 66-item, online survey that queried residents on ownership’s key constructs (advocacy, responsibility, accountability, follow-through, knowledge, communication, initiative, continuity of care, autonomy, self-efficacy, and perceived ownership) as well as mood and burnout. PARTICIPANTS: Internal medicine residents in five geographically diverse residency programs completing an inpatient rotation. MAIN MEASURES: We performed exploratory and confirmatory factor analysis in two randomly split groups to evaluate for subscales and inform item reduction. We conducted reliability testing with Cronbach’s α. We performed bivariate analyses to examine construct validity and identify correlates of ownership. KEY RESULTS: Of the 785 eligible residents, 625 completed the survey (80% response rate); we included responses from 563 in the analysis. We identified three factors corresponding to assertiveness, conscientiousness, and confidence or perceived competence. After iterative item reduction, the 13-item ownership scale demonstrated good reliability (Cronbach’s α = 0.82). Convergent validity was supported by a significant association with perceived ownership (eliminated from the final scale) (r = 0.67, p < 0.001). There was a positive association between ownership and training level (p < 0.01) and prior experience in the intensive care unit (p < 0.001). There were significant, inverse relationships between ownership and self-defined burnout (r = − 0.24, p < 0.001), depression (r = − 0.22, p < 0.001), detachment (r = − 0.26, p < 0.001), and frustration (r = − 0.15, p = 0.02), and significant positive associations between ownership and feeling energetic (r = 0.29, p < 0.001), happy (r = 0.33, p < 0.001), and fulfilled (r = 0.34, p < 0.001). CONCLUSIONS: The Patient Care Ownership Scale is valid in diverse residency program settings. Medical educators and investigators can use our scale to assess interventions aimed at fostering ownership. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11606-021-06703-x.

Objective The objective of this study is to document pain scores during withdrawal of abortive medication in patients diagnosed with medication overuse headache. Design Cross-sectional study. Setting Children’s National Hospital’s Headache Program. Subjects Patients 6–18 years of age who presented to the Headache Clinic at Children’s National Hospital with presumed medication overuse headache between March 2017 and March 2019 were invited to participate. Methods Patients were instructed to abruptly discontinue overused medications and record their headache characteristics daily in a diary for 8 weeks. Results Fourteen diaries were returned and analyzed at a 4-week follow-up visit. Ninety-three percent of the patients were females, with a median age of 14.9 years (standard deviation [SD] = 2.0). The average headache intensity upon study entry was 4.7 out of 10 (SD = 2.5), and the average headache intensity upon study completion was 3.1 (SD = 2.5). Of the patients, 57% had daily headaches upon study entry, 71% had improved pain intensity from the first diary entry to the last diary entry, and 57% had complete headache resolution at an average of 7.6 days from medication discontinuation (SD = 5.1). Ibuprofen was the most overused medication (71%). Conclusions Our findings suggest that medication overuse headache will improve in the majority of pediatric patients who abruptly stop the offending medication(s) in an average of 8 days from withdrawal. Average pain intensity was reduced by more than one point among all patients who stopped taking abortive medications. Further larger-scale studies on medication withdrawal in pediatric patients with medication overuse headache could help us better understand whether this management strategy is effective.