Category: Statistics

Phys Rev Lett. 2025 Apr 11;134(14):140601. doi: 10.1103/PhysRevLett.134.140601.

ABSTRACT

Gaussian boson sampling is a promising method for experimental demonstrations of quantum advantage because it is easier to implement than other comparable schemes. While most of the properties of Gaussian boson sampling are understood to the same degree as for these other schemes, we understand relatively little about the statistical properties of its output distribution. The most relevant statistical property, from the perspective of demonstrating quantum advantage, is the “anticoncentration” of the output distribution as measured by its second moment. The degree of anticoncentration features in arguments for the complexity-theoretic hardness of Gaussian boson sampling. In this Letter, we develop a graph-theoretic framework for analyzing the moments of the Gaussian boson sampling distribution. Using this framework, we show that Gaussian boson sampling undergoes a transition in anticoncentration as a function of the number of modes that are initially squeezed compared to the number of photons measured at the end of the circuit. When the number of initially squeezed modes scales sufficiently slowly with the number of photons, there is a lack of anticoncentration. However, if the number of initially squeezed modes scales quickly enough, the output probabilities anticoncentrate weakly.

PMID:40279623 | DOI:10.1103/PhysRevLett.134.140601

Phys Rev Lett. 2025 Apr 11;134(14):147401. doi: 10.1103/PhysRevLett.134.147401.

ABSTRACT

Geometrically frustrated assemblies where building blocks misfit have been shown to generate intriguing phenomena from self-limited growth, fiber formation, to structural complexity. We introduce a graph theory formulation of geometrically frustrated assemblies, capturing frustrated interactions through the concept of incompatible flows, providing a direct link between structural connectivity and frustration. This theory offers a minimal yet comprehensive framework for the fundamental statistical mechanics of frustrated assemblies, and connects it to tensor gauge theory formulations of amorphous solids. Through numerical simulations, the theory reveals new characteristics of frustrated assemblies, including two distinct percolation transitions for structure and incompatible flows, a crossover between cumulative and noncumulative frustration controlled by disorder, and a divergent length scale in their response.

PMID:40279594 | DOI:10.1103/PhysRevLett.134.147401

Phys Rev Lett. 2025 Apr 11;134(14):148001. doi: 10.1103/PhysRevLett.134.148001.

ABSTRACT

Accurate and efficient theoretical techniques for describing ionic fluids are highly desirable for many applications across the physical, biological, and materials sciences. With a rigorous statistical mechanical foundation, classical density functional theory (cDFT) is an appealing approach, but the competition between strong Coulombic interactions and steric repulsion limits the accuracy of current approximate functionals. Here, we extend a recently presented machine learning (ML) approach [Sammüller et al., Proc. Natl. Acad. Sci. U.S.A., 120, e2312484120 (2023)PNASA60027-842410.1073/pnas.2312484120] designed for systems with short-ranged interactions to ionic fluids. By adopting ideas from local molecular field theory, the framework we present amounts to using neural networks to learn the local relationship between the one-body direct correlation functions and inhomogeneous density profiles for a “mimic” short-ranged system, with effects of long-ranged interactions accounted for in a mean-field, yet well-controlled, manner. By comparing to results from molecular simulations, we show that our approach accurately describes the structure and thermodynamics of prototypical models for electrolyte solutions and ionic liquids, including size-asymmetric and multivalent systems. The framework we present acts as an important step toward extending ML approaches for cDFT to systems with accurate interatomic potentials.

PMID:40279585 | DOI:10.1103/PhysRevLett.134.148001

Phys Rev Lett. 2025 Apr 11;134(14):140404. doi: 10.1103/PhysRevLett.134.140404.

ABSTRACT

The eigenstate thermalization hypothesis (ETH) has been established as the general framework to understand quantum statistical mechanics. Only recently has the attention been paid to so-called full ETH, which accounts for higher-order correlations among matrix elements, and that can be rationalized theoretically using the language of free probability. In this work, we perform the first numerical investigation of the full ETH in physical many-body systems with local interactions by testing the decomposition of higher-order correlators into thermal free cumulants for local operators. We perform exact diagonalization on two classes of local nonintegrable (chaotic) quantum many-body systems: spin chain Hamiltonians and Floquet brickwork unitary circuits. We show that the dynamics of four-time correlation functions are encoded in fourth-order free cumulants, as predicted by ETH. Their dependence on frequency encodes the physical properties of local many-body systems and distinguishes them from structureless, rotationally invariant ensembles of random matrices.

PMID:40279584 | DOI:10.1103/PhysRevLett.134.140404

Phys Rev Lett. 2025 Apr 11;134(14):147203. doi: 10.1103/PhysRevLett.134.147203.

ABSTRACT

The Wigner-Smith time delay of flux conserving systems is a real quantity that measures how long an excitation resides in an interaction region. The complex generalization of time delay to non-Hermitian systems is still under development, in particular, its statistical properties in the short-wavelength limit of complex chaotic scattering systems has not been investigated. From the experimentally measured multiport scattering (S) matrices of one-dimensional graphs, a two-dimensional billiard, and a three-dimensional cavity, we calculate the complex Wigner-Smith (τ_{WS}), as well as each individual reflection (τ_{xx}) and transmission (τ_{xy}) time delay. The complex reflection time-delay differences (τ_{δR}) between each port are calculated, and the transmission time-delay differences (τ_{δT}) are introduced for systems exhibiting nonreciprocal scattering. Large time delays are associated with scattering singularities such as coherent perfect absorption, reflectionless scattering, slow light, and unidirectional invisibility. We demonstrate that the large-delay tails of the distributions of the real and imaginary parts of each time-delay quantity are superuniversal, independent of experimental parameters: wave propagation dimension D, number of scattering channels M, Dyson symmetry class β, and uniform attenuation η. The tails determine the abundance of the singularities in generic scattering systems, and the superuniversality is in direct contrast with the well-established time-delay statistics of unitary scattering systems, where the tail of the τ_{WS} distribution depends explicitly on the values of M and β. We relate the distribution statistics to the topological properties of the corresponding singularities. Although the results presented here are based on classical microwave experiments, they are applicable to any non-Hermitian wave-chaotic scattering system in the short-wavelength limit, such as optical or acoustic resonators.

PMID:40279582 | DOI:10.1103/PhysRevLett.134.147203

J Med Internet Res. 2025 Apr 25;27:e67114. doi: 10.2196/67114.

ABSTRACT

BACKGROUND: Recent years have seen an immense surge in the creation and use of chatbots as social and mental health companions. Aiming to provide empathic responses in support of the delivery of personalized support, these tools are often presented as offering immense potential. However, it is also essential that we understand the risks of their deployment, including their potential adverse impacts on the mental health of users, including those most at risk.

OBJECTIVE: The study aims to assess the ethical and pragmatic clinical implications of using chatbots that claim to aid mental health. While several studies within human-computer interaction and related fields have examined users’ perceptions of such systems, few studies have engaged mental health professionals in critical analysis of their conduct as mental health support tools. This paper comprises, in turn, an effort to assess the ethical and pragmatic clinical implications of using chatbots that claim to aid mental health.

METHODS: This study included 8 interdisciplinary mental health professional participants (from psychology and psychotherapy to social care and crisis volunteer workers) in a mixed methods and hands-on analysis of 2 popular mental health-related chatbots’ data handling, interface design, and responses. This analysis was carried out through profession-specific tasks with each chatbot, eliciting participants’ perceptions through both the Trust in Automation scale and semistructured interviews. Through thematic analysis and a 2-tailed, paired t test, these chatbots’ implications for mental health support were thus evaluated.

RESULTS: Qualitative analysis revealed emphatic initial impressions among mental health professionals of chatbot responses likely to produce harm, exhibiting a generic mode of care, and risking user dependence and manipulation given the central role of trust in the therapeutic relationship. Trust scores from the Trust in Automation scale, while exhibiting no statistically significant differences between the chatbots (t₆=-0.76; P=.48), indicated medium to low trust scores for each chatbot. The findings of this work highlight that the design and development of artificial intelligence (AI)-driven mental health-related solutions must be undertaken with utmost caution. The mental health professionals in this study collectively resist these chatbots and make clear that AI-driven chatbots used for mental health by at-risk users invite several potential and specific harms.

CONCLUSIONS: Through this work, we contributed insights into the mental health professional perspective on the design of chatbots used for mental health and underscore the necessity of ongoing critical assessment and iterative refinement to maximize the benefits and minimize the risks associated with integrating AI into mental health support.

PMID:40279575 | DOI:10.2196/67114

J Med Internet Res. 2025 Apr 25;27:e66037. doi: 10.2196/66037.

ABSTRACT

BACKGROUND: Osteoarthritis (OA) is a chronic degenerative bone and joint disease that significantly impacts patients’ quality of life and mental health, while also imposing a substantial economic burden on society. However, access to rehabilitation for patients with OA is challenging upon hospital discharge. Digital exercise therapy represents a promising telemedicine strategy for enhancing the management of OA, but its effect on OA is not yet clear.

OBJECTIVE: This study aimed to systematically evaluate the therapeutic effects of digital exercise therapy on pain and physical function in patients with OA.

METHODS: Databases including PubMed, Embase, Cochrane Library, Web of Science, and SPORTDiscus were searched for randomized controlled trials on using digital exercise therapy for OA until October 25, 2023. The primary outcomes included the measures of pain scores or physical function scores immediately after the intervention and at full follow-up. The risk of bias was evaluated using the Physiotherapy Evidence Database scale. Relevant data were extracted, and a meta-analysis was performed using RevMan5.3 software (Cochrane Collaboration).

RESULTS: A total of 9 studies with 1604 patients were included in the final meta-analysis. Compared with the conventional treatment group, digital exercise therapy significantly reduced numerical rating scale pain scores (mean difference [MD]=-1.07, 95% CI -1.35 to -0.78; P<.001) and Western Ontario and McMaster Universities Osteoarthritis Index physical function scores (MD=-2.39, 95% CI -3.68 to -1.10; P<.001) in patients with OA immediately after the intervention. However, follow-up results revealed no statistically significant difference in numerical rating scale pain scores (MD=-0.20, 95% CI -0.59 to 0.20; P=.34), while Western Ontario and McMaster Universities Osteoarthritis Index physical function scores showed a significant improvement in the digital exercise therapy group compared with the control group (MD=-1.89, 95% CI -3.52 to -0.26; P=.02). These findings suggest that digital exercise therapy provides immediate benefits for both pain and physical function in patients with OA, with sustained improvements in physical function observed during follow-up, though pain relief may not persist long term.

CONCLUSIONS: Digital exercise therapy can alleviate the pain and improve the physical function in patients with OA and can be used as an auxiliary means in the rehabilitation treatment of OA. It provides great convenience for patients with OA who need long-term treatment, allowing them to exercise at home for rehabilitation training.

TRIAL REGISTRATION: PROSPERO CRD42023484819; https://www.crd.york.ac.uk/PROSPERO/view/CRD42023484819.

PMID:40279572 | DOI:10.2196/66037

Retina. 2025 Apr 24. doi: 10.1097/IAE.0000000000004496. Online ahead of print.

ABSTRACT

PURPOSE: Outcomes of sutureless scleral-fixated intraocular lens (SSFIOL) have primarily focused upon short-term results. This retrospective, observational clinical study focuses upon the long-term visual acuity and anatomic outcomes of SSFIOLs.

METHODS: A comprehensive medical record review of patients that underwent SSFIOL placement by a single surgeon from 2015 through 2024 was performed. Pre- and postoperative BCVA, anatomic outcomes, and complications were documented. Statistical analysis was performed.

RESULTS: Forty-three patients (ages 18 to 91 years, mean = 63) with follow-up ranging from 1 to 100.5 months (mean = 27.5, median = 14.67) met inclusion criteria. Mean preoperative BCVA was 1.11 logMAR units (Snellen ratio: 20/250) ± 0.59 SD. Mean postoperative BCVA improvement was statistically significant at 1, 3, 6, 9 months, and 1, 2, 3 years. Postoperative complications included hyphema (n=3), vitreous hemorrhage (n=14), transient ocular hypertension (n=8) and hypotony (n=5), haptic erosion (n=3), IOL dislocation or damage (n=4), cystoid macular edema (CME, n=8). All complications were identified within 1.25 years of follow-up excluding 2 cases of CME.

CONCLUSION: SSFIOL patients demonstrated statistically significant and gradual BCVA improvement up to 3 years postoperatively. Cases of CME were identified up to 3 years postoperatively.

PMID:40279564 | DOI:10.1097/IAE.0000000000004496

J Healthc Qual. 2025 Apr 25. doi: 10.1097/JHQ.0000000000000477. Online ahead of print.

ABSTRACT

INTRODUCTION: Catheter-associated urinary tract infections (CAUTIs) are common complications in patients with traumatic brain injury (TBI) who require indwelling bladder catheters (IBCs). This study examined the impact of an Acute Urinary Retention Algorithm (AURA) nursing protocol that incorporates intermittent catheterization (IC) on CAUTI incidence.

METHODS: A retrospective analysis was conducted on TBI patients with IBCs placed between 2018 and 2022 at a Level I trauma center in Southern California. Catheter-associated urinary tract infection incidence and catheter-associated complications were compared between patients treated with and without the AURA protocol.

RESULTS: Among 73,005 patients with IBC, 255 had TBI and were admitted to the intensive care unit. Only 27 (10.6%) patients had catheters removed through the AURA protocol and had longer dwell times than the nonprotocol patients (2.59 vs. 2.44 days, p < .001). Catheter-associated urinary tract infection incidence was statistically similar between the protocol (7.4%) and nonprotocol groups (3.5%) (p = .327). However, patients who developed CAUTI were more likely to have undergone more than one IC.

CONCLUSIONS: Timely removal of IBCs is crucial to minimizing the risk of CAUTI. This study highlights the underutilization of nurse-driven protocols such as AURA and suggests a careful application of IC in such protocols because of its potential association with increased CAUTI risk.

PMID:40279521 | DOI:10.1097/JHQ.0000000000000477

Eur J Dent Educ. 2025 Apr 25. doi: 10.1111/eje.13104. Online ahead of print.

ABSTRACT

INTRODUCTION: The literature has established burnout syndrome as a modern epidemic with adverse consequences. Burnout data for dental students training in the United States is lacking. This study aimed to examine differences in the dimensions of burnout between traditional standing (TS) and advanced standing (AS) dental students.

MATERIALS AND METHODS: TS and AS predoctoral dental students transitioning from didactic course work to preclinical and clinical education completed an informed consent, a demographic survey, and the Maslach Burnout Inventory-General Survey for Students. Statistical analyses included descriptive statistics, assumptions testing, independent samples t-test analysis, and Cronbach’s alpha analysis.

RESULTS: Significant differences in the burnout dimension of exhaustion, M = 0.82, 95% CI (0.41, 1.22), t (108) = 3.97, p < 0.001, and the burnout dimension of cynicism, M = 0.96, 95% CI (0.50, 1.42), t (182) = 4.11, p < 0.001, existed between TS and AS dental students. TS dental students demonstrated significantly higher exhaustion (M = 4.61) and cynicism (M = 3.43) compared to AS dental students (M = 3.79 exhaustion and M = 2.47 cynicism). No significant difference in professional efficacy, M = -0.096, 95% CI [-0.38, 0.18], t (182) = 0.68, p = 0.50, was observed between the TS dental students (M = 4.38) and AS dental students (M = 4.47).

CONCLUSION: While both groups of dental students experienced burnout, TS dental students experienced significantly more burnout along the dimensions of exhaustion and cynicism. The presence of burnout in both groups of students suggests the need to develop programme-based strategies that aim to alleviate academic burnout and promote the wellbeing of the future dental workforce.

PMID:40279476 | DOI:10.1111/eje.13104