Tag: statistics

Phys Rev E. 2026 Mar;113(3-1):034219. doi: 10.1103/3jtj-sxrw.

ABSTRACT

In this work, we quantify the timescales and information flow associated with multiscale energy transfer in a weakly turbulent system. This is done through a greedy optimization algorithm which finds the maximum conditional-mutual information across lagged embeddings of time series localized by wave number. For our chosen weakly turbulent system, the algorithm finds asymmetries in the information flow across wave numbers, reflecting what are typically described as forward and inverse cascades. However, our approach goes beyond typical heuristic arguments and provides quantitative insight into the intricate multiwave mixing dynamics necessary to maintain the steady statistical state characterizing weak turbulence. Our work then provides a detailed and fully nonlinear statistical analysis of a weakly turbulent system. The flexibility of our approach points to broader applicability in real-world data coming from chaotic or turbulent dynamical systems.

PMID:41998961 | DOI:10.1103/3jtj-sxrw

Phys Rev E. 2026 Mar;113(3-1):034110. doi: 10.1103/kjdp-1g12.

ABSTRACT

We describe in detail a mathematical framework in which statistical ensembles of hybrid classical-quantum systems can be properly described. We show how a maximum entropy principle can be applied to derive the microcanonical ensemble of hybrid systems. We investigate its properties, and in particular how the microcanonical ensemble and its marginal classical and quantum ensembles can be defined for arbitrarily small range of energies for the whole system. We show how, in this situation, the ensembles are well defined for a continuum of energy values, unlike the purely quantum microcanonical ensemble, thus proving that hybrid systems translate properties of classical systems to the quantum realm. We also analyze the relation with the hybrid canonical ensemble by considering the microcanonical ensemble of a compound system composed of a hybrid subsystem weakly coupled to a reservoir and computing the marginal ensemble of the hybrid subsystem. Lastly, we apply the theory to the statistics of a toy model, which gives some insight on the different properties presented along the article.

PMID:41998951 | DOI:10.1103/kjdp-1g12

Phys Rev E. 2026 Mar;113(3-1):034117. doi: 10.1103/sj6t-pctp.

ABSTRACT

For statistics of rare events in systems obeying a large-deviation principle, the rate function is a key quantity. When numerically estimating the rate function, one is always restricted to finite system sizes. Thus, if the interest is in the limiting rate function for infinite system sizes, first, several system sizes have to be studied numerically. Here, rare-event algorithms using biased ensembles give access to the low-probability region. Second, some kind of system-size extrapolation has to be performed. Here, we demonstrate how rare-event importance sampling schemes can be combined with multihistogram reweighting. We study two ways of performing the system-size extrapolation, either directly acting on the empirical rate functions or on the scaled cumulant generating functions, to obtain the infinite-size limit. The presented method is demonstrated for a binomial distributed variable, a Markov process of random bits, and the largest connected component of Erdős-Rényi random graphs. Analytical solutions are available in all cases for direct comparison. It is observed in particular that phase transitions appearing in the biased ensembles can lead to systematic deviations from the true result.

PMID:41998940 | DOI:10.1103/sj6t-pctp

Phys Rev E. 2026 Mar;113(3-2):035302. doi: 10.1103/2g6m-whm2.

ABSTRACT

Energy-based generative models, such as restricted Boltzmann machines (RBMs), require unbiased Boltzmann samples for effective training. Classical Markov chain Monte Carlo methods, however, converge slowly and yield correlated samples, making large-scale training difficult. We address this bottleneck by applying the analytic relation between annealing schedules and effective inverse temperature in diabatic quantum annealing. By implementing this prescription on a quantum annealer, we obtain temperature-controlled Boltzmann samples that enable RBM training with faster convergence and lower validation error than classical sampling. We further identify a systematic temperature misalignment intrinsic to analog quantum computers and propose an analytical rescaling method that mitigates this hardware noise, thereby enhancing the practicality of quantum annealers as Boltzmann samplers. In our method, the model’s connectivity is set directly by the qubit connectivity, transforming the computational complexity inherent in classical sampling into a requirement on quantum hardware. This shift allows the approach to extend naturally from RBMs to fully connected Boltzmann machines, opening opportunities inaccessible to classical training methods.

PMID:41998876 | DOI:10.1103/2g6m-whm2

Cancer Med. 2026 Apr;15(4):e71810. doi: 10.1002/cam4.71810.

ABSTRACT

BACKGROUND: Lymphoma risk varies by demographics, environmental/occupational exposures, and medical care between active-duty service members (ADSM) and the general US population (GUSP). This study compared age-adjusted incidence rates and trends of Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) between these groups.

METHODS: Data were obtained from the Department of War’s Central Cancer Registry and the National Cancer Institute’s Surveillance, Epidemiology, and End Results database, including individuals aged 18-59 diagnosed with lymphoma between 1998 and 2014. Incidence rate ratio (IRR) and 95% CIs were calculated to compare the incidence of HL and NHL between ADSM and GUSP, with analyses stratified by sex, race, age, stage, and histology.

RESULTS: Lymphoma incidence was lower in ADSM than GUSP (HL: 0.93 [0.86, 1.00]; NHL: 0.82 [0.77, 0.88]); specifically, for men (HL: 0.89 [0.82, 0.97]; NHL: 0.69 [0.64, 0.74]), White (HL: 0.87 [0.80, 0.95]; NHL: 0.80 [0.73, 0.86]), and Black individuals (HL: 0.82 [0.68, 0.99]; NHL: 0.61 [0.51, 0.73]). Incidence was lower among ADSM aged 18-39 (HL: 0.91 [0.84, 0.99]; NHL: 0.74 [0.68, 0.81]), but similar at ages 40-59. ADSM had lower HL (early-stage: 0.86 [0.77, 0.96]; nodular lymphocyte predominant: 0.88 [0.80, 0.97]) and NHL (early stage: 0.86 [0.77, 0.96]; advanced stage: 0.87 [0.78, 0.97]; diffuse large B-cell: 0.65 [0.58, 0.74]; other histologies: 0.83 [0.74, 0.93]) incidence.

CONCLUSION: Lymphoma incidence was lower in ADSM than GUSP, particularly among men and younger individuals. Based on prior literature, this may be related to the healthier status of ADSM and earlier detection and treatment of medical conditions that can predispose to lymphoma. Diminished differences between the two populations for older individuals may reflect cumulated military-related exposures within a generally healthier population.

PMID:41998820 | DOI:10.1002/cam4.71810

Int J Epidemiol. 2026 Apr 17;55(3):dyag045. doi: 10.1093/ije/dyag045.

ABSTRACT

BACKGROUND: Foreign-born residents in high-income countries often outlive the native-born population, but it remains unclear how this advantage varies across countries and socioeconomic groups. We aimed to assess socioeconomic inequalities in the life expectancy advantage of foreign-born populations across 10 European countries.

METHODS: Using national population registers and census, we collected data on mortality by country of birth and educational attainment in 10 European countries from 2010 to 2019. Based on these data, we estimated partial life expectancy between ages 35 and 80 years for native-born and foreign-born populations in each country, both overall and by education. We then decomposed the overall gap between native- and foreign-born populations into differences in education-specific mortality and the educational composition of the population.

RESULTS: Foreign-born populations had higher partial life expectancies than native-born populations in all countries except Sweden and Estonia, especially among individuals with low-level education. Decomposition analyses revealed that the overall longevity advantage of foreign-born populations was largely attributable to their lower mortality in less-educated groups. However, in most countries-except Estonia, Lithuania, and Spain-the overrepresentation of less-educated individuals among the foreign-born partially cancelled out these advantages.

CONCLUSIONS: The longevity advantages among foreign-born populations in European countries may reflect socioeconomic barriers that concentrate relatively healthy, resource-rich immigrants into lower socioeconomic groups. Improving how societies recognize and use the skills and resources of foreign-born populations can help reduce these barriers, benefiting their longevity outcomes and contributing to more inclusive societies.

PMID:41995424 | DOI:10.1093/ije/dyag045

BMC Pregnancy Childbirth. 2026 Apr 17;26(1):427. doi: 10.1186/s12884-025-08325-1.

ABSTRACT

BACKGROUND: Childbirth is a unique and significant experience in every woman’s life. A negative childbirth experience, often due to difficult labor, can adversely affect a mother’s feelings toward her baby and their subsequent relationship. Massage, a non-pharmacological pain relief method involving coordinated manipulation of soft tissues by hand, aims to alleviate pain and enhance comfort. This ancient technique is widely used during labor and has demonstrated effectiveness in reducing both the intensity and duration of labor pain. This study aimed to compare the effects of two massage methods-rotational effleurage massage and connective tissue massage (CTM)-on pain intensity and labor outcomes. The study subjects in the two intervention groups received effleurage massage and connective tissue massage, but the control group did not receive any intervention and only routine labor care was provided to them.

METHODS: This quasi-experimental, multicenter study was conducted on 90 pregnant women (gestational age 38-40 weeks) admitted in labor at three hospitals. Participants were selected through convenience sampling and randomly allocated into three groups of 30 using permuted block randomization within each center. Although random allocation was performed, due to the multicenter design and non-probability sampling, the study is more accurately classified as quasi-experimental. Written informed consent was obtained from all participants. Data collection tools included a demographic and obstetric questionnaire, the McGill Childbirth Satisfaction Questionnaire, a visual analogue scale for pain, and a labor evaluation checklist.

DATA: Statistical analyses were performed using SPSS software version 22 (IBM Corp., Armonk, NY, USA). In this randomized clinical trial, 90 primiparous women were randomly assigned to three groups: effleurage massage, Connective tissue massage, and control. The interventions were performed during the active phase of labor (4-10 cm cervical dilation). Pain intensity was measured using the Visual Analogue Scale at different dilation stages: 3-4 cm, 5-6 cm, 7-8 cm, and 9-10 cm).

RESULTS: Pain intensity significantly decreased in both intervention groups compared to the control group at all stages of the active phase of labor (p < 0.001). At 7-8 cm dilation, the mean pain scores were 6.13 ± 0.94 in the effleurage group, 6.23 ± 0.77 in the connective tissue massage group, and 7.87 ± 0.86 in the control group (p < 0.001). Effleurage massage demonstrated greater efficacy than connective tissue massage in reducing pain during the later stages of active labor (p < 0.05).

CONCLUSION: Effleurage massage was more effective than connective tissue massage in reducing pain intensity during active labor. Integrating effleurage into maternity care as a non-pharmacological method may improve maternal comfort and support positive birth experiences.

PMID:41998514 | DOI:10.1186/s12884-025-08325-1

CVIR Endovasc. 2026 Apr 18;9(1):43. doi: 10.1186/s42155-026-00691-x.

ABSTRACT

OBJECTIVE: To compare continuous vs pulsed transarterial embolization techniques with microCT and determine their impact on distal vascular penetration.

MATERIAL AND METHODS: Transarterial embolization was performed in 7 swine using 75-100-micron microspheres. In each subject, 1 kidney was embolized using continuous injection and contralateral with a pulsed injection technique. Histological analysis validated MicroCT findings (50-100 pixels, postprocedural quantification) in 2 subjects (4 kidneys), after which MicroCT alone was used for outcome assessments.

RESULTS: MicroCT imaging demonstrated similar outcomes to histology. Larger number of particles delivered with continuous vs pulsed technique (6806 vs 6174 particles into 223 ml vs 168 ml renal volume respectively). Percentage of the embolized renal cortex at 50 pixels was 1.1% for the continuous technique (0.1 – 2.3%) vs 0.7% pulsed (0.5 – 1.1%) (p = 0.3). Embolized renal cortex at 100 pixels was 2.9% continuous (1.3 – 4.2%) vs 2.3% pulsed (1.3 – 3.2%) (p = 0.3). Average kidney volume in both groups was 78.1 ml (r, 49-138) and 81 ml (r, 46-111), respectively. A slightly larger amount of embolic was delivered using the continuous vs pulsed: 14 ml (r, 12-20) vs 13.1 ml (r, 8-22). Mean embolic/kidney volume ratio was 0.20 for continuous vs 0.16 for pulsed (25% difference, p = 0.2).

CONCLUSION: Continuous embolization technique resulted in a larger absolute concentration of embolic particles within the distal renal cortex and overall volume compared to the pulsed technique, though the difference was not statistically significant. Our findings suggest embolic delivery technique for particle embolics may influence amount and efficacy of distal embolization.

PMID:41998479 | DOI:10.1186/s42155-026-00691-x

J Racial Ethn Health Disparities. 2026 Apr 17. doi: 10.1007/s40615-026-02976-2. Online ahead of print.

NO ABSTRACT

PMID:41998471 | DOI:10.1007/s40615-026-02976-2

High Blood Press Cardiovasc Prev. 2026 Mar 17. doi: 10.1007/s40292-026-00793-6. Online ahead of print.

ABSTRACT

INTRODUCTION: Effective cardiovascular (CV) prevention requires accurate risk estimation and patient engagement, which depends on perceived risk. The Perception of Risk of Heart Disease Scale (PRHDS) is a validated tool, yet clinical thresholds for its brief Italian version are lacking.

AIM: To provide further validation of the Brief Italian version of the PRHDS (PRHDS-BI) in a new cohort, examining convergent and divergent validity, and to establish clinical thresholds and a discrepancy index comparing perceived risk with objective estimates.

METHODS: 285 adults (40-69 years) were involved in this multicentre cross-sectional study (NCT06190743). Participants were without a history of CV disease and completed the PRHDS-BI and the Patient Health Questionnaire-4 (PHQ-4). CV real risk was estimated using the Systematic Coronary Risk Evaluation 2 (SCORE2). Confirmatory Factor Analysis (CFA), correlation analyses, and cut-off definitions were used to validate the scale and analyze risk discrepancies.

RESULTS: The PRHDS-BI showed good internal consistency and strong convergent validity. Clinical thresholds were defined by percentiles: scores 6-12 (low/moderate), 13-17 (high), and 18-24 (very high). A significant mismatch emerged: 63.5% of participants at low/moderate actual risk overestimated their risk, while 80% at very high actual risk underestimated it. This perception-reality gap was statistically confirmed.

CONCLUSIONS: The PRHDS-BI is a valid tool for assessing CV risk perception. Establishing thresholds allows for tailored risk communication and patient-centered interventions, particularly by nursing professionals in primary prevention settings.

PMID:41998465 | DOI:10.1007/s40292-026-00793-6