Statistical Power Research Articles

How variable are the classic ERP effects during sentence processing? A systematic resampling analysis of the N400 and P600 effects

Although event-related potential (ERP) research on language processing has capitalized on key, theoretically influential components such as the N400 and P600, their measurement properties—especially the variability in their temporal and spatial parameters—have rarely been examined. The current study examined the measurement properties of the N400 and P600 effects elicited by semantic and syntactic anomalies, respectively, during sentence processing. We used a bootstrap resampling procedure to randomly draw many thousands of resamples varying in sample size and stimulus count from a larger sample of 187 participants and 40 stimulus sentences of each type per condition. Our resampling investigation focused on three issues: (a) statistical power; (b) variability in the magnitudes of the effects; and (c) variability in the temporal and spatial profiles of the effects. At the level of grand averages, the N400 and P600 effects were both robust and substantial. However, across resamples, there was a high degree of variability in effect magnitudes, onset times, and scalp distributions, which may be greater than is currently appreciated in the literature, especially for the P600 effects. These results provide a useful basis for designing future studies using these two well-established ERP components. At the same time, the results also highlight challenges that need to be addressed in future research (e.g., how best to analyze the ERP data without engaging in such questionable research practices as p-hacking).

Doppler-derived pulmonary pulse transit time measurements in chronic obstructive pulmonary disease: Reproducibility and cardiopulmonary function.

Doppler-derived pulmonary pulse transit time (pPTT) is an auspicious hemodynamic marker in chronic pulmonary diseases. The aim is to compare four distinct pPTT measurements and its relation to right cardiac and pulmonary function. Prospectively, 25 chronic obstructive pulmonary disease (COPD) patients (four patients excluded) and 32 healthy subjects underwent repeated distinct pPTT measurements, standard echocardiography, and pulmonary function testing on the same day. pPTT was defined as the interval from the R or Q-wave in the electrocardiogram to the corresponding pulse wave Doppler peak late systolic (S) 2 or diastolic (D) pulmonary vein flow velocity (pPTT R-S, Q-S, R-D, Q-D). Reproducibility was assessed using Bland-Altman analysis, coefficient of variation (COV), intraclass correlation coefficient (ICC), and power calculations. Associations with right ventricular RV tissue and pulse wave Doppler velocities (RV E', RV S', RV A', RV E, RV A, RV E/E', RV E/A), TAPSE, right ventricular fractional area change, left ventricular systolic and diastolic function (LV ejection fraction, E, A, E/A, E/E', septal E', lateral E'), LA diameters, as well as forced expiratory volume in 1 s, forced vital capacity (FVC) predicted (%), and in liters were analyzed. There was no significant difference and no bias between pPTT measures (p range:.1-.9). COV was in COPD 1.2%-2.3%, in healthy subjects 1.0%-3.1%. ICC ranged from.92 (COPD) to.96 (healthy subjects). In COPD significant correlations were found for pPTT R-S, Q-S and R-D with RV E`, (all>ρ:.49,<p=.0364), pPTT R-S, Q-S with RV E/E` (both>ρ:.49,<p=.0291), pPTT Q-S with RV S´ (ρ:.58, p=.0134), RV A (ρ:.59, p=.0339) and heart rate>ρ: -.39,<p=.0297). pPTT R-S, R-D showed significant correlations with FVC predicted (%) (ρ:.48 p=.0224) and FVC (l) (ρ:.47 p=.0347). All pPTT measures exhibited high reproducibility. In COPD patients pPTT measures correlate with diastolic right ventricular function. Defining Q as starting point seems clinically advantageous considering electromechanical desynchrony in patients with conduction disorders.

Current Concepts and Recent Updates of Optical Biometry- A Comprehensive Review.

One of the most recent advancements in the field of cataract surgery is optical biometry. With the advent of optical biometry ocular measurements are now simpler, quicker, and more precise. The devices have made intraocular lens (IOL) power calculations easier in difficult situations too, such as in cases with extremes of axial lengths, silicone filled eyes, cataract surgery in post-keratoplasty eyes, post Laser-Assisted in Situ Keratomileusis (LASIK) eyes, etc. The gold standard for IOL power calculation in the present day is by the use of optical biometry devices. The anatomical measurements by these devices are highly precise and because of these measurements and the incorporation of various IOL power calculation formulas the optical biometry devices give the accurate power and the post-operative visual outcome is highly satisfactory among the patients. The growing use of these devices has made cataract the most commonly performed refractive surgical procedure nowadays. In the current scenario, optical biometry has widespread acceptance in almost all countries and has many advantages over ultrasound or immersion biometry. Cataract surgeons can obtain easy and reliable measurements from these devices. Refractive surprises have also decreased considerably with their use. This article will comprehensively review the principles of the various optical biometry devices, the parameters used in each of the devices, the advantages and disadvantages, and add more like what all this article will add.

Impact of segmented optical axial length on the performance of intraocular lens power calculation formulas.

To investigate the difference between the segmented axial length (AL) and the composite AL on a swept-source optical coherence tomography biometer and to evaluate the subsequent effects on artificial intelligence intraocular lens (IOL) power calculations: the Kane and Hill-RBF 3.0 formulas compared with established vergence formulas. National Hospital Organization, Tokyo Medical Center, Japan. Retrospective case series. Consecutive patients undergoing cataract surgery with a single-piece IOL were reviewed. The prediction accuracy of the Barrett Universal II, Haigis, Hill-RBF 3.0, Hoffer Q, Holladay 1, Kane, and SRK/T formulas based on 2 ALs were compared for each formula. The heteroscedastic test was used with the SD of prediction errors as the endpoint for formula performance. The study included 145 eyes of 145 patients. The segmented AL (24.83 ± 1.89) was significantly shorter than the composite AL (24.88 ± 1.96, P < .001). Bland-Altman analysis revealed a negative proportional bias for the differences between the segmented AL and the composite AL. The SD values obtained by Hoffer Q, Holladay 1, and SRK/T formulas based on the segmented AL (0.52 diopters [D], 0.54 D, and 0.50 D, respectively) were significantly lower than those based on the composite AL (0.57 D, 0.60 D, and 0.52 D, respectively, P < .01). The segmented ALs were longer in short eyes and shorter in long eyes than the composite ALs. The refractive accuracy can be improved in the Hoffer Q, Holladay 1, and SRK/T formulas by changing the composite ALs to the segmented ALs.

Precision in IOL Calculation for Cataract Patients with Prior History of Combined RK and LASIK Histories.

This study aimed to evaluate the accuracy of 12 intraocular lens (IOL) power calculation formulae for eyes that have undergone both radial keratotomy (RK) and laser assisted in situ keratomileusis (LASIK) surgery to determine the efficacy of various IOL calculations for this unique patient group. Currently, research on this surgical topic is limited. In this retrospective study, 11 eyes from 7 individuals with a history of RK and LASIK who underwent cataract surgery at Hoopes Vision were analyzed. Preoperative biometric and corneal topographic measurements were performed. Subjective refraction was obtained postoperatively. Twelve different intraocular lens (IOL) power calculations were used: Barrett True K No History, Barrett True K (prior LASIK, Prior RK history), Barrett Universal 2, Camellin-Calossi-Camellin (3C), Double K-Modified Holladay, Haigis-L, Galilei, OCT, PEARL-DGS, Potvin-Hill, Panacea, and Shammas. The rankings of mean arithmetic error (MAE), from least to greatest, were as follows: 3C (0.088), Haigis-L-L (-0.508), Shammas (-0.516), OCT Average (-0.538), Barrett True K (-0.557), OCT RK (-0.563), Galilei (-0.570), IOL Master (-0.571), OCT LASIK (-0.583), Barrett True K No History (-0.597), Pearl-DGS (-0.606), Potvin-Hill SF (-0.770), Potvin-Hill TNP (-0.778), Panacea (-0.876), and Barrett Universal 2 (-1.522). The 3C formula achieved the greatest percentage of eyes within ±0.25 D of target range (91%), while Haigis-L, Shammas, Galilei, Potvin Hill, Barrett True K, IOL Master, PEARL-DGS, and OCT formulae performed similarly, achieving 45% of eyes within ±0.75D of target refraction. This study demonstrates the accuracy of the lesser known 3C formula in IOL calculation, particularly for patients who have undergone both RK and LASIK. Well-known formulae, such as Haigis-L, Shammas, and Galilei, which are used by the American Society of Cataract and Refractive Surgery (ASCRS), are viable options, although 3C formulae should be considered in this patient population. Furthermore, larger studies can confirm the best IOL power formulas for post-RK and LASIK cataract patients.

Assessment of BRCA1 and BRCA2 Germline Variant Data From Patients With Breast Cancer in a Real-World Data Registry.

The emergence of large real-world clinical databases and tools to mine electronic medical records has allowed for an unprecedented look at large data sets with clinical and epidemiologic correlates. In clinical cancer genetics, real-world databases allow for the investigation of prevalence and effectiveness of prevention strategies and targeted treatments and for the identification of barriers to better outcomes. However, real-world data sets have inherent biases and problems (eg, selection bias, incomplete data, measurement error) that may hamper adequate analysis and affect statistical power. Here, we leverage a real-world clinical data set from a large health network for patients with breast cancer tested for variants in BRCA1 and BRCA2 (N = 12,423). We conducted data cleaning and harmonization, cross-referenced with publicly available databases, performed variant reassessment and functional assays, and used functional data to inform a variant's clinical significance applying American College of Medical Geneticists and the Association of Molecular Pathology guidelines. In the cohort, White and Black patients were over-represented, whereas non-White Hispanic and Asian patients were under-represented. Incorrect or missing variant designations were the most significant contributor to data loss. While manual curation corrected many incorrect designations, a sizable fraction of patient carriers remained with incorrect or missing variant designations. Despite the large number of patients with clinical significance not reported, original reported clinical significance assessments were accurate. Reassessment of variants in which clinical significance was not reported led to a marked improvement in data quality. We identify the most common issues with BRCA1 and BRCA2 testing data entry and suggest approaches to minimize data loss and keep interpretation of clinical significance of variants up to date.

A Retrospective Analysis of Career Outcomes in Neuroscience.

What factors are associated with career outcomes among biomedical PhDs? Research to date has focused on drivers of interest in (and intention to pursue) various careers, especially during graduate school, but fewer studies have investigated participants' ultimate career outcomes. Even less is known about what factors matter for groups historically underrepresented in the US science, technology, engineering, and mathematics (STEM) workforce, such as women, some racial and ethnic groups, and persons with disabilities ( National Center for Science and Engineering Statistics (NCSES), 2021a). This study reports a new analysis of data from 781 PhD neuroscientists that were obtained from a retrospective survey ( Ullrich et al., 2021) to investigate the factors that influence the career sector in which neuroscience PhDs are employed and whether there were group differences according to social identity. We find evidence of academia as a "default path" for incoming PhD students, but interest in different careers increases over time. Those who remained in academia had greater acceptance of the structural aspects of academic careers, such as promotion and tenure processes, and greater faculty support during postdoctoral training. Conversely, prioritizing monetary compensation and/or varied work were associated with not being in academia, while a strong interest in research was positively associated with being in nonacademic research. Somewhat surprisingly, there were few interactions with gender, and no interactions with underrepresentation status, although perhaps this was due to lower statistical power for these analyses. Our findings also underscore the role of advisors, networking, and personal relationships in securing employment in STEM.

21 cm Intensity Mapping with the DSA-2000

Line-intensity mapping is a promising probe of the Universe’s large-scale structure. We explore the sensitivity of the DSA-2000, a forthcoming array consisting of over 2000 dishes, to the statistical power spectrum of neutral hydrogen’s 21 cm emission line. These measurements would reveal the distribution of neutral hydrogen throughout the near-redshift Universe without necessitating resolving individual sources. The success of these measurements relies on the instrument’s sensitivity and resilience to systematics. We show that the DSA-2000 will have the sensitivity needed to detect the 21 cm power spectrum at z ≈ 0.5 and across power spectrum modes of 0.03–35.12 h Mpc−1 with 0.1 h Mpc−1 resolution. We find that supplementing the nominal array design with a dense core of 200 antennas will expand its sensitivity at low power spectrum modes and enable measurement of Baryon Acoustic Oscillations. Finally, we present a qualitative discussion of the DSA-2000's unique resilience to sources of systematic error that can preclude 21 cm intensity mapping.

GWAS advancements to investigate disease associations and biological mechanisms.

Genome-wide association studies (GWAS) have been instrumental in elucidating the genetic architecture of various traits and diseases. Despite the success of GWAS, inherent limitations such as identifying rare and ultra-rare variants, the potential for spurious associations, and in pinpointing causative agents can undermine diagnostic capabilities. This review provides an overview of GWAS and highlights recent advances in genetics that employ a range of methodologies, including Whole Genome Sequencing (WGS), Mendelian Randomization (MR), the Pangenome's high-quality T2T-CHM13 panel, and the Human BioMolecular Atlas Program (HuBMAP), as potential enablers of current and future GWAS research. State of the literature demonstrate the capabilities of these techniques in enhancing the statistical power of GWAS. WGS, with its comprehensive approach, captures the entire genome, surpassing the capabilities of the traditional GWAS technique focused on predefined Single Nucleotide Polymorphism (SNP) sites. The Pangenome's T2T-CHM13 panel, with its holistic approach, aids in the analysis of regions with high sequence identity, such as segmental duplications (SDs). Mendelian Randomization has advanced causative inference, improving clinical diagnostics and facilitating definitive conclusions. Furthermore, spatial biology techniques like HuBMAP, enable 3D molecular mapping of tissues at single-cell resolution, offering insights into pathology of complex traits. This study aims to elucidate and advocate for the increased application of these technologies, highlighting their potential to shape the future of GWAS research.

Prediction of hypoattenuating leaflet thickening in patients undergoing transcatheter aortic valves replacement based on clinical factors and 4D-computed tomography morphological characteristics: A retrospective cross-sectional study

BackgroundThe rapid increase in the number of transcatheter aortic valve replacement (TAVR) procedures in China and worldwide has led to growing attention to hypoattenuating leaflet thickening (HALT) detected during follow-up by 4D-CT. It's reported that HALT may impact the durability of prosthetic valve. Early identification of these patients and timely deployment of anticoagulant therapy are therefore particularly important. MethodsWe retrospectively recruited 234 consecutive patients who underwent TAVR procedure in Fuwai Hospital. We collected clinical information and extracted morphological characteristics parameters of the transcatheter heart valve (THV) post TAVR procedure from 4D-CT. LASSO analysis was conducted to select important features. Three models were constructed, encapsulating clinical factors (Model 1), morphological characteristics parameters (Model 2), and all together (Model 3), to identify patients with HALT. Receiver operating characteristic (ROC) curves and decision curve analysis (DCA) were plotted to evaluate the discriminatory ability of models. A nomogram for HALT was developed and verified by bootstrap resampling. ResultsIn our study patients, Model 3 (AUC = 0.738) showed higher recognition effectiveness compared to Model 1 (AUC = 0.674, p = 0.032) and Model 2 (AUC = 0.675, p = 0.021). Internal bootstrap validation also showed that Model 3 had a statistical power similar to that of the initial stepwise model (AUC = 0.723 95%CI: 0.661–0.786). Overall, Model 3 was rated best for the identification of HALT in TAVR patients. ConclusionA comprehensive predictive model combining patient clinical factors with CT-based morphology parameters has superior efficacy in predicting the occurrence of HALT in TAVR patients.

Improving the Statistical Power of Hospice Research: Lessons from Two Clinical Trials (GP132)

Improving the Statistical Power of Hospice Research: Lessons from Two Clinical Trials (GP132)

Cervical lymphatic vessel dysfunction induced by amyloid-β and in the 5x-FAD mouse model of Alzheimer’s disease

Alzheimer’s dementia is a multifactorial disease characterized by amyloid-β (Aβ) accumulation in the brain. Aβ clearance occurs partially via meningeal lymphatics into cervical lymph nodes through superficial cervical lymphatic vessels (sCLV), which relies on intrinsic contractions of sCLV. Previous studies showed increased Aβ build up in the brain following ablation of meningeal lymphatics; however, whether Aβ alters sCLV function remains unclear. We hypothesize that sCLV contractile function will be reduced by acute Aβ exposure and in the 5x-FAD mouse model of Alzheimer’s disease. Contractile function of freshly isolated sCLV was assessed using pressure myography. Acute Aβ exposure was achieved by intraluminal incubation of pressurized sCLV with Aβ(1-40) (5 μM) or vehicle for 15 minutes prior to the start of the experiment. Repeated end-diastolic (EDD) and end-systolic (ESD) measurements were used to calculate fractional pump flow (FPF), the product of contractile frequency (FREQ) measured as contractions per minute (Hz), and ejection fraction (EF) calculated as (EDD2-ESD2)/EDD2, at incremental intraluminal pressures ranging from 2 to 10 cmH2O. Statistical differences were determined by two-way ANOVA followed by Sidak correction for multiple comparisons. All data are means ± SEM. In sCLV isolated from 5 months-old males and females C57bl/6J mice, acute Aβ exposure significantly decreased FREQ (Vehicle vs Aβ, n=4 / n=7, p&lt;0.01), without changes in EF (Vehicle vs Aβ, n=4 / n=7, p=0.115) or FPF (Vehicle vs Aβ, n=4 / n=7, p= 0.536). In pressurized sCLV isolated from 5x-FAD mice, when compared to wild-type littermates, we observed a significant reduction in FREQ (Wild-type vs 5x-FAD, n=4 / n=5, p&lt;0.01). No differences were observed in EF (Wild-type vs 5x-FAD, n=4 / n=5, p=0.1224) or FPF (Wild-type vs 5x-FAD, n=4 / n=5, p=0.193). Together, these preliminary data suggest that acute exposure to Aβ(1-40) decreases FREQ of isolated sCLV, a similar effect observed in sCLV isolated from 5x-FAD mice, albeit not reaching statistical power for multiple comparison significance. Consequently, a decrease contractile frequency can contribute to impairments in lymphatic pumping, which to some extent, can be compensated by prolonged filling times, thus leading to increased ejection fraction. In conclusion, we predict that in vivo sCLV contractile function is maintained via compensatory increases in ejection fraction in conditions of exacerbated Aβ production and deposition. Funding: National Institutes of Health (R01 AG073230) and the Alzheimer’s Association (AARGD-21-850835). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Genetic variations in immune mediators and prostate cancer risk: A field synopsis with Bayesian calculations

ObjectiveOur study aimed to revaluate the significant data from meta-analyses on genetic variations in immune mediators and the risk of prostate cancer (PCa) by Bayesian approaches. MethodsWe performed a search on the literature before September 5th, 2023, for meta-analytic studies on polymorphisms in immune mediator genes and the risk of PCa. Two Bayesian approaches were used to assess the level of noteworthiness in the meta-analytic data: the False-Positive Rate Probability (FPRP) and the Bayesian False Discovery Probability (BFDP) with a statistical power of 1.2 and 1.5 of Odds Ratio at a prior probability of 10−3 and 10−6. The quality evaluation of studies was performed with the Venice criteria. Gene-gene and protein–protein networks were designed for the genes and products enrolled in the results. ResultsAs results, 18 meta-analyses on 17 polymorphisms in several immune mediator genes were included (IL1B rs16944/rs1143627, IL4 rs2243250/rs2227284/rs2070874, IL6 1800795/rs1800796/rs1800797, IL8 rs4073, IL10 rs1800896/rs1800871/rs1800872, IL18 rs1946518, COX2 rs2745557, TNFA rs361525 and PTGS2 rs20417/689470). The Bayesian calculations showed the rs1143627 and the rs1946518 polymorphisms in IL1B and IL18 genes, respectively, were noteworthy. The Venice criteria showed that only four studies received the highest level of evidence. The gene-gene and protein–protein networks reinforced the findings on IL1B and IL18 genes. ConclusionIn conclusion, this current Bayesian revaluation showed that the rs1143627 and the rs1946518 polymorphisms in the IL1B and IL18 genes, respectively, were noteworthy biomarker candidates for PCa risk.

Comparison of Blue and Infrared Light Transmission Through Dental Tissues and Restorative Materials.

The depth of cure using blue-light photocuring units (BL) is limited by tooth structure and qualities of the restorative material through which the activating wavelength must pass. Recent developments incorporate an infrared (IR) activated upconversion (UC) fluorescence of a lining agent filled with nanocrystals of NaYF4 and doped with YB+3 and Tm+3 that emit both blue and violet light locally at the interface of the liner and restorative resin. The purpose of this study was to evaluate the BL and 975 nm infrared (IR) light power transmission through dental tissues and restorative materials. Power transmissions of the IR laser (975 nm) and a monowave blue-only light-curing unit (Bluephase 16i) through dental tissues (enamel, dentin, and enamel/dentin junction, or DEJ), eight (8) various dental resin composites, and eight (8) dental ceramics, each at four thicknesses (1, 2, 3 and 4 mm) were evaluated (n=5) using a thermopile sensor (PM10, Coherent Inc) connected to a laser power meter (Fieldmate, Coherent Inc). Power transmission values of each light source and restorative material were subjected to analysis of variance and Tukey test at a pre-set alpha of 0.05. A linear correlation (r=0.9884) between the supplied current and emitted IR power of the laser diode was found, showing no statistical power reduction with increased distances (collimated beam). For tooth tissues, the highest power transmissions for both light sources were observed using 1.0 mm enamel while the lowest values were found for 2.0 mm dentin and an association of 2.0 mm DEJ and 1.0 mm dentin. The only group where IR demonstrated significantly higher transmission when compared to BL was 1.0 mm enamel. For all resin composites and dental ceramics, increased thickness resulted in a reduction of IR power transmission (except for EverX Posterior fiber-reinforced composite and e.max HT ceramic). IR resulted in higher transmission through all resin composites, except for Tetric EvoCeram White. The highest BL transmission was observed for SDR Flow, at all thicknesses. Higher IR/BL ratios were observed for EverX Posterior, Herculite Ultra, and Lava Ultimate, while the lowest ratio was observed for Tetric EvoCeram White. Reduced translucency shades within the same material resulted in lower power ratio values, especially for BL transmission. Higher IR/BL ratios were observed for e.Max LT, VitaVM7 Base Dentin, and e.max CAD HT, while the lowest values were found for VitaVM7 Enamel and Paradigm C. IR power transmission through enamel was higher when compared to blue light, while no difference was observed for dentin. The power transmission of IR was higher than BL for resin composites, except for a high value and low chroma shade. Fiber-reinforced resin composite demonstrated the highest IR/BL power transmission ratio. A greater IR/BL ratio was observed for lower translucency ceramics when compared to high translucency.

Does Chronotype Influence Diurnal Changes in Cardiovascular Disease Risk Factors? A Preliminary Analysis

Introduction: Humans experience diurnal fluctuations in the prevalence of cardiovascular events which is likely an output of endogenous circadian influence. Relatedly, vascular endothelial cell function, measured by conduit artery responsiveness to hyperemia during a flow-mediated dilation test, is supposed to follow a diurnal rhythm that is moderated by an individual’s chronotype. We therefore sought to examine the extent to which diurnal changes in other cardiovascular risk factors, such as blood pressure, cardiac chronotropy, and circulating blood leukocytes, were related to chronotype in humans. A moderating influence of chronotype on diurnal changes in the aforementioned parameters was hypothesized given prior research associating a preference for evening wakefulness with an adverse cardiometabolic phenotype. Methods: All data are presented as mean ± standard deviation. This abstract includes secondary data from a preliminary sample of 16 young (19 ± 2 years), healthy males and females. Participants completed a Munich Chronotype Questionnaire (MCQ) to quantify diurnal preference for morning or evening activity. The corrected mid-sleep time on free days (MSFSC) was calculated from the MCQ and interpreted to represent an index for morning or evening chronotype. Participants attended data collection sessions in the morning (09:16 ± 01:27 hh:mm) and again in the evening (16:19 ± 00:31 hh:mm) under resting conditions for the quantification of blood pressure and enumeration of circulating leukocytes from venous blood. Results: The sample included in this analysis had a slight preference for evening wakefulness (MSFSC = 04:58 ± 01:17 hh:mm). A significant and robust diurnal variation was found among circulating venous leukocytes (P &lt; 0.001) which measured higher in the afternoon (2.06×106 ± 3.67×105 cells/mL blood) than morning (1.61×106 ± 4.68×105 cells/mL blood). The diurnal variation in circulating venous leukocytes was independent (β = -9.87×104; R2 = 0.19; P = 0.186) of individual chronotype, as were individual diurnal changes of all other hemodynamic parameters included in this analysis (all P &gt; 0.05). More participants will be recruited to satisfy statistical power for primary outcomes. Discussion: These preliminary results from healthy, young adults indicate that individual disposition towards morning or evening wakefulness may not exert a profound influence over diurnal changes in several cardiovascular disease risk factors under resting conditions. Funding Sources: The study was funded by the Natural Sciences and Engineering Research Council of Canada (DG: 20011033) held by Dr. MJM). JMC and MIB were supported by Ontario Graduate Scholarships. JCS was supported by the Natural Sciences and Engineering Research Council of Canada Graduate Scholarships – Master’s. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Use of Electronic Nicotine Delivery Systems and Age of Asthma Onset Among US Adults and Youths.

The association of use of electronic nicotine delivery systems (ENDS) with the age of asthma onset is unknown. To explore the association of past 30-day ENDS use with the age of asthma onset in adults and youths who did not have asthma or chronic obstructive pulmonary disease and never used cigarettes. This cohort study was a secondary analysis of waves 1 to 6 of the US nationally representative Population of Tobacco and Health Study (2013-2021). Eligible participants included adults (≥18 years) and youths (12-17 years) who did not have asthma or chronic obstructive pulmonary disease at the first wave of participation. Data analysis was conducted from September 2022 to April 2024. Past 30-day ENDS use at the first wave of participation in the study preceding the onset of asthma. Lower and upper age limits were estimated using the age reported at the first wave of participation and the number of weeks between follow-up waves until asthma was first reported or censored. The association of past 30-day ENDS use with the age of asthma onset was estimated using weighted interval-censoring Cox regression. The cumulative hazard function for the age of asthma onset was estimated using interval-censoring survival analysis. A total of 24 789 participants were included, with 7766 adults (4461 female [weighted percentage, 59.11%] and 3305 male [weighted percentage, 40.89%]), representing 80.0 million adults, and 17 023 youths (8514 female [weighted percentage, 50.60%] and 8496 male [weighted percentage 49.32%]), representing 33.9 million youths. By age 27 years, 6.2 per 1000 adults reported asthma incidence (hazard ratio [HR], 0.62%; 95% CI, 0.46%-0.75%). While controlling for covariates, there was a 252% increased risk of the onset of asthma at earlier ages for adults who used ENDS in the past 30 days vs adults who did not (adjusted HR, 3.52; 95% CI, 1.24-10.02). For youths, there was no association of ENDS use in the past 30 days with age of asthma onset (adjusted HR, 1.79; 95% CI, 0.67-4.77), which could be due to a lack of statistical power. In this cohort study, past 30-day ENDS use among adults was associated with earlier ages of asthma onset. These findings suggest that prevention and cessation programs directed to adults who use ENDS are needed to educate the public, protect public health, prevent adverse health outcomes, and motivate users to stop. Furthermore, modifying symptom-screening asthma guidelines, resulting in earlier asthma detection and treatment, may reduce morbidity and mortality due to asthma.

Thermal scanners versus spotlighting: New opportunities for monitoring threatened small endotherms

AbstractThreatened species monitoring is challenging for small, cryptic endotherms that are most effectively detected at night. Low detectability is a challenge for monitoring programmes, resulting in low statistical power and sparse or zero‐inflated datasets. To advance conservation management programmes, efforts to address this are required. In recent years thermal scanners have emerged as an effective tool for detecting small endotherms, but the diversity of available thermal tools, focal habitats and target species mean that their applicability in many key scenarios remain untested. We directly compared vehicle‐mounted thermal surveys with vehicle‐based spotlighting targeting small endotherms in Australian native grasslands. Our targets included both common species that occur at high densities, and species that are notoriously difficult to detect with spotlights, which may occur at very low densities. We completed paired surveys of roosting grassland birds, and nocturnally active small mammals at 22 sites, once using thermal scanners and once using spotlights. Ultimately, distance sampling was conducted across 136 km of transects. Thermal scanners facilitated greater detection distances and higher total detections for small endotherms when compared with spotlighting. Species of greatest conservation concern, the Plains‐wanderer (Pedionomus torquatus—Pedionomidae) and Fat‐tailed Dunnart (Sminthopsis crassicaudata—Dasyuridae) were only detected using thermal scanners. Detection distances generated for thermal scanners were reduced by higher vegetation density; however, thermal scanners continued to outperform spotlights under this scenario. Observers also detected more stationary animals and fewer birds were flushed upon detection using thermal scanners when compared with spotlighting. Thermal scanners have the potential to improve the quality of monitoring datasets by increasing detection probabilities for small endotherms. We recommend the adoption of thermal scanners as a best‐practice tool for monitoring small endotherms in open grassland habitats at night, offering new opportunities to monitor endotherms where monitoring has historically been challenging, inadequate or impossible.

A hierarchical kidney outcome using win statistics in patients with heart failure from the DAPA-HF and DELIVER trials

Win statistics offer a new approach to the analysis of outcomes in clinical trials, allowing the combination of time-to-event and longitudinal measurements and taking into account the clinical importance of the components of composite outcomes, as well as their relative timing. We examined this approach in a post hoc analysis of two trials that compared dapagliflozin to placebo in patients with heart failure and reduced ejection fraction (DAPA-HF) and mildly reduced or preserved ejection fraction (DELIVER). The effect of dapagliflozin on a hierarchical composite kidney outcome was assessed, including the following: (1) all-cause mortality; (2) end-stage kidney disease; (3) a decline in estimated glomerular filtration rate (eGFR) of ≥57%; (4) a decline in eGFR of ≥50%; (5) a decline in eGFR of ≥40%; and (6) participant-level eGFR slope. For this outcome, the win ratio was 1.10 (95% confidence interval (CI) = 1.06–1.15) in the combined dataset, 1.08 (95% CI = 1.01–1.16) in the DAPA-HF trial and 1.12 (95% CI = 1.05–1.18) in the DELIVER trial; that is, dapagliflozin was superior to placebo in both trials. The benefits of treatment were consistent in participants with and without baseline kidney disease, and with and without type 2 diabetes. In heart failure trials, win statistics may provide the statistical power to evaluate the effect of treatments on kidney as well as cardiovascular outcomes.

Sample size and power calculation for testing treatment effect heterogeneity in cluster randomized crossover designs.

The cluster randomized crossover design has been proposed to improve efficiency over the traditional parallel-arm cluster randomized design. While statistical methods have been developed for designing cluster randomized crossover trials, they have exclusively focused on testing the overall average treatment effect, with little attention to differential treatment effects across subpopulations. Recently, interest has grown in understanding whether treatment effects may vary across pre-specified patient subpopulations, such as those defined by demographic or clinical characteristics. In this article, we consider the two-treatment two-period cluster randomized crossover design under either a cross-sectional or closed-cohort sampling scheme, where it is of interest to detect the heterogeneity of treatment effect via an interaction test. Assuming a patterned correlation structure for both the covariate and the outcome, we derive new sample size formulas for testing the heterogeneity of treatment effect with continuous outcomes based on linear mixed models. Our formulas also address unequal cluster sizes and therefore allow us to analytically assess the impact of unequal cluster sizes on the power of the interaction test in cluster randomized crossover designs. We conduct simulations to confirm the accuracy of the proposed methods, and illustrate their application in two real cluster randomized crossover trials.

The study of input power of an underwater free-damping ribbed plate in statistical energy analysis

To study the vibration characteristics of the free-damping ribbed plate with fluid load under point force excitation in statistical energy analysis (SEA), the theoretical model of input power calculation was established in this research. The simulational results from SEA commercial software validated the correctness of the proposed theoretical model. As inferred from the theoretical model, the added damping layer and ribs significantly affect the effective bending stiffness and area density, and the added fluid load only affects the effective area density. These effective parameters will affect the input power of the fluid-loaded free-damping ribbed plate, resulting in increased input power as a function frequency. The research in this paper could provide theoretical guidance on the vibroacoustic analysis of underwater complex ship structures.