Tag: nevin manimala

Phys Rev Lett. 2026 Mar 20;136(11):117101. doi: 10.1103/g468-nbm2.

ABSTRACT

The analysis of local minima in time series data and random landscapes is essential across numerous scientific disciplines, offering critical insights into system dynamics. Recently, Kundu et al. derived the exact distribution of the number of local minima for a broad class of Markovian symmetric walks [Phys. Rev. E 110, 024137 (2024)PRESCM2470-004510.1103/PhysRevE.110.024137]; however, many real-world systems are non-Markovian, typically due to interactions with possibly hidden degrees of freedom. This Letter investigates the statistical properties of local minima in discrete-time samples of fractional Brownian motion, a non-Markovian Gaussian process with stationary increments, widely used to model complex, anomalous diffusion phenomena. We derive a complete asymptotic characterization of the fluctuations of the number of local minima m_{N} in an N-step discrete-time fractional Brownian motion. We show that the fluctuations of m_{N} exhibit a sharp transition at the Hurst exponent H=3/4: for H≤3/4 they satisfy a central limit theorem with Gaussian limiting law, whereas for H>3/4 they converge to a non-Gaussian Rosenblatt process. The convergence at the process level gives us full statistical description at all times. We exemplify it on the covariance of the rescaled minima process, which displays two qualitatively distinct regimes matching Brownian and Rosenblatt covariances on either side of this threshold. Our analysis relies on a Hermite or Wick decomposition of the local-minimum indicator, which isolates a quadratic functional of an effective long-memory mode as the unique driver of the anomalous statistics. These results identify the count of local minima as a simple and robust diagnostic of long-range dependence in non-Markovian Gaussian processes, a conclusion supported by numerical simulations.

PMID:41931793 | DOI:10.1103/g468-nbm2

Phys Rev Lett. 2026 Mar 20;136(11):111401. doi: 10.1103/f74l-3c4y.

ABSTRACT

Because they are likely to accrete substantial amounts of interstellar gas, merging supermassive binary black holes are expected to be strong multimessenger sources, radiating gravitational waves, photons from thermal gas, and photons from relativistic electrons energized by relativistic jets. Here we report on a numerical simulation that covers the late inspiral, merger, and initial postmerger phase of such a system where both black holes have the same mass and spin, and both spin axes are parallel to the orbital angular momentum. The simulation incorporates both 3D general relativistic magnetohydrodynamics and numerical relativity. The thermal photon power during the late inspiral, merger, and immediate postmerger phases is drawn from strong shocks rather than dissipation of turbulence inside a smoothly structured accretion disk as typically found around accreting single black holes. We find that the thermal photon and jet Poynting flux outputs are closely related in time, and we posit a mechanism that enforces this relation. The power radiated in both photons and jets diminishes gradually as merger is approached, but jumps sharply at merger to a noisy plateau. Such a distinct lightcurve should aid efforts to identify supermassive black hole mergers, with or without accompanying gravitational wave detections.

PMID:41931783 | DOI:10.1103/f74l-3c4y

Phys Rev Lett. 2026 Mar 20;136(11):110402. doi: 10.1103/tqrb-4m9p.

ABSTRACT

We explore the joint measurability of incompatible qubit observables on ensembles of parallel and antiparallel spin-1/2 pairs. In parallel configuration, both spins are prepared in the same state, whereas in antiparallel case, each spin is paired with its flipped counterpart. We show that the antiparallel configuration uniquely enables exact simultaneous prediction of three mutually orthogonal spin components-an advantage not achievable with parallel states. Extending beyond three observables, we examine joint measurability for larger sets of spin measurements and further generalize our analysis to state configurations beyond the parallel and antiparallel cases. As we show, our results reveal a deep connection to the “mean King retrodiction task” proposed by Vaidman, Aharonov, and Albert and have implications for a cryptographic protocol introduced by Jeffrey Bub. We further demonstrate how the enhanced compatibility in the antiparallel configuration can facilitate efficient estimation of unknown measurement devices. Finally, we discuss prospects for experimentally realizing the enhanced measurement compatibility in antiparallel configuration by analyzing the effect on finite subensembles of states.

PMID:41931781 | DOI:10.1103/tqrb-4m9p

Neurology. 2026 Apr 28;106(8):e214858. doi: 10.1212/WNL.0000000000214858. Epub 2026 Apr 3.

ABSTRACT

BACKGROUND AND OBJECTIVES: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a complex etiology. Although a range of genetic and lifestyle factors have been implicated, the potential role of environmental airborne pollution exposure is uncertain. This study examined the association between long-term ambient exposure to air pollutants and the incidence of ALS in UK Biobank participants.

METHODS: This prospective cohort study was based on the UK Biobank participants aged 40-69 years. The analytical sample comprised participants free of ALS at baseline and had complete data on air pollution exposure. Long-term exposure (2006-2021) to nitrogen dioxide (NO₂), nitrogen oxides (NO_X), fine particulate matter (PM_2.5; <2.5 µm), and coarse particulate matter (PM₁₀; <10 µm) was assessed using data from the UK Department for Environment, Food and Rural Affairs at a spatial resolution of 1 × 1 km. To evaluate the association between these pollutants and ALS risk, we used multivariable time-varying Cox proportional hazards models. Several sensitivity analyses were conducted to assess the robustness of the results. We also examined for gene-environment interaction stratified by C9orf72 status and UNC13A genotype.

RESULTS: Among the 501,308 participants with a mean age of 56.5 (SD 8.1) years at baseline, 272,764 (54.4%) were female. Over a median follow-up of 8.4 years, 687 individuals developed ALS. We did not observe any associations for any of the examined pollutants and ALS risk. Specifically, the hazard ratios per SD increment for PM₁₀, PM_2.5, NO_X, and NO₂ were 1.03 (95% CI 0.92-1.15), 1.00 (95% CI 0.88-1.14), 1.01 (95% CI 0.90-1.13), and 1.00 (95% CI 0.89-1.12), respectively. Individuals living in areas with the highest tertile of air pollutant exposure, compared with those in the lowest tertile, did not show a higher risk of ALS across any of the pollutants examined (p for trend >0.05). Restricted cubic spline analyses revealed no nonlinear associations between air pollution and ALS risk (all p for nonlinearity >0.05). These results remained robust in various subgroup and sensitivity analyses. No evidence of gene-environment interaction was found.

DISCUSSION: In this large population-based study with high statistical power, ambient air pollution was not a risk factor for the development of ALS.

PMID:41931746 | DOI:10.1212/WNL.0000000000214858

J Drugs Dermatol. 2026 Apr 1;25(4):316-323. doi: 10.36849/jdd.9441.

ABSTRACT

BACKGROUND: Janus kinase (JAK) inhibitors represent promising therapies for dermatologic conditions, including psoriasis, hidradenitis suppurativa (HS), atopic dermatitis (AD), systemic lupus erythematosus (SLE), and vitiligo. There are little data available evaluating the composition of research cohorts for this emerging treatment modality. Adequate racial representation in clinical trials is essential.

OBJECTIVE: To characterize the study populations of clinical trials for Janus kinase inhibitors for dermatologic indications.

METHODS: Clinical trials were identified from January 2000 to March 2025 through PubMed using the following keywords: “Janus kinase inhibitor,” “JAK inhibitor,” “alopecia areata,” “atopic dermatitis,” “hidradenitis suppurativa,” “systemic lupus erythematosus,” “systemic sclerosis,” “psoriasis,” and “vitiligo.” Additional trials were retrieved from ClinicalTrials.gov using the search term “JAK inhibitor.” Each trial was reviewed for demographic data, including race and ethnicity. Additional variables collected included Fitzpatrick skin type and quality-of-life measures. The distribution of race among trial participants was compared to the current US population and the condition-specific prevalence data where available.

RESULTS: Of 399 identified studies, 207 clinical trials were included in our analysis, including 57,112 study participants were analyzed. Among studies reporting race (57.5%), representation was predominantly White (75.1%), followed by Asian (13.2%), Black (6.6%), American Indian/Alaska Native (0.48%), Native Hawaiian (0.11%), and multiple races (0.43%). Underrepresentation was pronounced among Black participants in psoriasis (1.3%), SLE (1.0%), and vitiligo trials (5.1%), although higher in HS (27.9%). Representation in these trials significantly differed from the racial distribution of US patients with vitiligo (P=0.012) and AD (P=0.00088). White patients were overrepresented in vitiligo and AD trials (Pearson residual=1.06, 2.71), while Black patients were underrepresented in these trials (Pearson residual=-2.66, -2.14). Additionally, a minority of studies (28.98%) reported on QoL metrics, which are essential tools for measuring disease burden and impact on patients.

CONCLUSION AND RELEVANCE: Reporting on racial data, Fitzpatrick skin type, and quality of life measures is lacking in clinical trials for Janus kinase inhibitors. These factors play a key role in addressing comorbidities and mitigating disease burden. These findings highlight a need for improved recruitment strategies targeting underrepresented populations in dermatologic clinical research. &nbsp.

PMID:41931696 | DOI:10.36849/jdd.9441

J Drugs Dermatol. 2026 Apr 1;25(4):357-362. doi: 10.36849/jdd.9505.

ABSTRACT

BACKGROUND: Dermatologists remain unevenly distributed throughout the United States (US), leading to disparities in access to dermatologic care.

OBJECTIVE: To evaluate geographic variation in patient interest in dermatology services and compare it to dermatologist supply to identify areas of potential unmet need.

METHODS: An ecological, cross-sectional study was conducted using Google Trends data from 2004 to 2023 to assess relative search volume (RSV) for “dermatologist” across US states. RSV was normalized and combined with dermatologist density data from the AAMC to generate a Relative Demand Index (RDI) for each state. Spearman’s rank correlation assessed associations between RDI, dermatologist supply, urbanization, and population size.

RESULTS: States with high RDI, such as Alabama and Mississippi, had high patient interest but low dermatologist density, suggesting workforce shortages. Conversely, states like Massachusetts and the District of Columbia had low RDI and high provider density. RDI showed a strong inverse correlation with dermatologist density (rs = -0.76, P&lt;0.0001).

LIMITATIONS: This study relied on a keyword, Google-only search data, and assumed internet access. County-level nuances were not captured.

CONCLUSION: Significant geographic disparities in dermatologist availability and demand exist, highlighting the need for targeted workforce distribution strategies to ensure equitable access to dermatologic care. &nbsp.

PMID:41931691 | DOI:10.36849/jdd.9505

J Drugs Dermatol. 2026 Apr 1;25(4):345-348. doi: 10.36849/jdd.9373.

ABSTRACT

BACKGROUND: Since January 2022, the United States Medical Licensing Examination (USMLE) Step 1 discontinued reporting a 3-digit score. The objective of this study is to share survey results and to communicate the changes Dermatology residency program directors (PDs) will make to evaluate candidates.

METHODS: The research team conducted an online survey of PDs and analyzed the responses using R programming and MATLAB scripts. Chi-squared tests were used to identify significant differences in responses to multiple-choice questions, while paired t tests were utilized to compare pre- and post-values for criteria ranking questions.

RESULTS: Following the implementation of a pass/fail grading system for Step 1, many PDs will place greater emphasis on Step 2 CK (Clinical Knowledge) scores to differentiate among candidates. Some believe that medical schools should also disclose National Board of Medical Examiners (NBME) shelf exam scores and factor in a student’s medical school ranking.

CONCLUSION: The added emphasis on Step 2 CK scores, NBME shelf exam scores, a student’s medical institution, and class rank may cloud the positive impacts of this change, providing an opportunity for programs to evaluate students more holistically. &nbsp.

PMID:41931687 | DOI:10.36849/jdd.9373

J Bras Nefrol. 2026 Jul-Sep;48(3):e20250318. doi: 10.1590/2175-8239-JBN-2025-0318en.

ABSTRACT

BACKGROUND: Sacubitril/valsartan is a recommended medication for managing heart failure (HF). However, its role in peritoneal dialysis (PD) patients remains uncertain. We conducted this systematic review and singlearm meta-analysis to assess the efficacy and safety of sacubitril/valsartan in this population.

METHODS: We systematically searched PubMed, EMBASE, and Cochrane Central until December 2024 for randomized controlled trials (RCTs) and observational studies assessing changes in left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, systolic blood pressure (SBP), left atrial diameter (LAD), and left ventricular end-diastolic dimension (LVDd) with sacubitril/valsartan use in PD patients. Safety endpoints included hyperkalemia, hypotension, and angioedema. Statistical analyses were performed in R, using proportions for binary and mean differences (MDs) for continuous outcomes.

RESULTS: Nine studies were included, comprising 8 observational studies and 1 RCT, involving 343 PD patients. LVEF improved significantly (MD 5.22; 95% CI, 3.86 to 6.58; p < 0.0001; I2 = 38.9%). Sacubitril/valsartan reduced NT-proBNP levels (MD -5630.40; 95% CI, -9177.57 to -2083.23; p = 0.0019; I2 = 86%) and SBP (MD -14.59; 95% CI, -20.59 to -8.59; p < 0.0001; I2 = 93.5%). No statistically significant changes were noted in LAD (p = 0.0561) or LVDd (p = 0.1037). Hypotension and angioedema were rare events, whereas hyperkalemia showed a slight increase (11.94%).

CONCLUSION: Sacubitril/valsartan was associated with improvements in cardiac function surrogates and blood pressure in PD patients with HF, with an overall acceptable safety profile despite a modest increase in hyperkalemia. These findings suggest potential benefit in this understudied population, though confirmation in adequately powered RCTs remains necessary.

PMID:41931676 | DOI:10.1590/2175-8239-JBN-2025-0318en

Neurologist. 2026 Apr 3. doi: 10.1097/NRL.0000000000000662. Online ahead of print.

ABSTRACT

OBJECTIVE: Optimal timing of initiation of pharmacologic venous thromboembolism (VTE) prophylaxis following intracerebral hemorrhage is controversial. This study aims to assess the association between the timing of pharmacologic VTE prophylaxis initiation and the risk of VTE and hemorrhagic complications.

METHODS: This was a multicenter, retrospective cohort study completed at 7 community hospitals. This study included patients with nontraumatic intracerebral hemorrhage admitted from August 1, 2023, to July 31, 2024. A total of 111 patients were assessed and categorized based on the administration of early (≤48 h) versus delayed (>48 h) initiation of VTE prophylaxis.

RESULTS: Findings showed no statistically significant difference in the primary outcome of the incidence of VTE with early versus delayed initiation of VTE prophylaxis (5% vs. 8%, P=0.713). Secondary outcomes included incidence of deep vein thrombosis (5% vs. 8%, P=0.713), pulmonary embolism (0% vs. 0%), hematoma enlargement (16% vs. 15%, P=0.623), median intensive care unit (ICU) length of stay (3 vs. 3.5 d, P=0.670), hospital length of stay (7 vs. 8 d, P=0.724), inpatient all-cause mortality (8% vs. 7%, P=1.000), and discharge disposition.

CONCLUSION: Early pharmacologic VTE prophylaxis (≤48 h from ICH onset) was not found to be statistically significant in lowering the incidence of VTE. This occurred with no statistically significant differences in hematoma enlargement, increased inpatient mortality, or increased length of ICU/hospital stay. Additional adequately powered studies are needed to determine if early pharmacologic VTE prophylaxis is associated with a lower incidence of VTE.

PMID:41931660 | DOI:10.1097/NRL.0000000000000662

Oncology (Williston Park). 2026 Mar 16;40(2):106-114. doi: 10.46883/2026.25921066.

ABSTRACT

BACKGROUND: Soft tissue sarcomas (STS) are rare but aggressive tumors. Although surgery and radiotherapy are standard treatments for localized STS, the role of adjuvant chemotherapy, particularly doxorubicin, in high-grade STS is debated.

METHODS: This retrospective study evaluated the effectiveness of single-agent doxorubicin in resectable grade 2 and 3 STS, with a focus on oncologic outcomes. Adults with biopsy-confirmed STS of the extremities or trunk, treated at a tertiary center in Taiwan between January 2004 and March 2020, were included. Primary outcomes were distant metastasis-free survival (DMFS) and overall survival (OS).

RESULTS: The study enrolled 62 patients in either the single-agent doxorubicin adjuvant chemotherapy group (n = 8) or the observation-only group (n = 54). The mean age was 45.4 years in the adjuvant chemotherapy group and 58.2 years in the observation-only group. The 3-year OS was 100% in the chemotherapy group and 60% in the observation group (log-rank P = .064). The 3-year DMFS rate was 75% in the chemotherapy group and 45% in the observation group (log-rank P = .078).

CONCLUSION: In resectable, high-grade STS of 8 cm or more, single-agent doxorubicin as adjuvant chemotherapy showed a trend toward improved OS and DMFS compared with observation alone; however, statistical significance was not reached.

PMID:41931644 | DOI:10.46883/2026.25921066