Centre College

Regression discontinuity (RD) designs are a popular approach to estimating a treatment effect of cutoff-based interventions. Two current estimation approaches dominate the literature. One fits separate regressions on either side of the cutoff, and the other performs finite sample inference based on a local randomization assumption. Recent developments of these approaches have often focused on asymptotic properties and large sample sizes. Educational applications often contain relatively small samples or sparsity near the cutoff, making estimation more difficult. As an alternative to the aforementioned approaches, we develop a partial linear estimator for RD designs. We show in simulations that our estimator outperforms certain leading estimators in several realistic, small-sample scenarios. We apply our estimator to school accountability scores in Indiana.

Artificial intelligence (AI) has the potential to aid clinicians in assessing case difficulty in endodontics. The objectives of this study were to develop and validate deep learning models for the detection of clinically negotiable MB2 canals in periapical images of maxillary first and second molars, and to compare the performance of AI models with that of human clinicians. A total of 1504 pre-operative periapical images of maxillary first and second molars that were treated by endodontic specialists were collected with clinical data as to the presence or absence of a clinically negotiable MB2 canal. Six pretrained supervised convolutional neural networks (ResNet-18, ResNet-50, ResNeXt-101, VGG-16, DenseNet-121 and MobileNetV2) and three self-supervised models (DINO, SimCLR and BYOL) were fine-tuned using fivefold cross-validation. Model performance was evaluated on a hold-out test set using accuracy, precision, sensitivity, specificity, and F1-score with 95% confidence intervals. Three independent clinicians (an endodontist, an endodontic resident, and an oral and maxillofacial radiologist) also assessed the test set. In cross-validation, ResNet-50 achieved the highest mean accuracy (67.6%), while DINO was the top-performing self-supervised model (62.8%). ResNet-18, ResNet-50, ResNeXt-101, DenseNet-121 and DINO significantly outperformed BYOL (p < 0.01), while no significant differences were observed among the top-performing models. ResNet-18 achieved the highest accuracy at 66.0% (95% CI, 63.0-68.9) on the test set while human expert accuracy ranged from 53.6% to 61.4%. Stratified analysis showed a general trend for improved AI model performance in maxillary first molars and in teeth without full-crown restorations. There was no significant difference in the accuracy of the top-performing AI model and human experts (p > 0.05). Deep learning models performed similarly to clinician experts in identifying clinically negotiable MB2 canals in periapical images of maxillary first and second molars. These findings support the potential role of AI in endodontic case difficulty assessment.

Abstract High fidelity kinetic equilibria are crucial for tokamak modeling and analysis. Manual workflows for constructing kinetic equilibria are time consuming and subject to user error, motivating development of automated equilibrium reconstruction tools to provide accurate and consistent reconstructions for downstream physics analysis. These automated tools also provide access to kinetic equilibria at large database scales, which enables the quantification of general uncertainties arising from equilibrium reconstruction techniques. In this paper, we compare a large database of DIII-D kinetic equilibria generated manually by physics experts to equilibria from automated kinetic reconstruction tools, assessing the impact of reconstruction method on equilibrium parameters and resulting magnetohydrodynamic stability calculations. We find agreement among scalar parameters, whereas profile quantities, such as the bootstrap current, show larger disagreements. We analyze ideal kink and classical tearing stability with DCON and STRIDE respectively, finding that the kink stability calculation is generally more robust than the tearing index Δ ′ calculation. We find that in 90% of cases, both kink stability classifications are unchanged between the manual expert and automated kinetic equilibria.

Abstract The Shannon entropies in both coordinate and momentum spaces for some low-lying eigenstates of the Hulthén potential (HP) are investigated over a wide range of screening parameters where bound states exist. The system wave functions are expanded in terms of multiple groups of Slater-type orbitals and the Hamiltonian is solved by employing the Rayleigh–Ritz variational method. The accuracy of the obtained bound-state eigenenergies, Shannon entropies, and radial mean values are validated by comparing with the analytical solutions of the HP in s -wave states. The Bialynicki–Birula and Mycielski inequalities for Shannon entropies in both the coordinate and momentum spaces as well as their sum are examined in both weak and strong screening situations. It is shown that the variation of Shannon entropy sum is governed by its upper bound for the system in a well-defined bound state. In the critical bound region where the system undergoes a bound-continuum transition, the Shannon entropies and entropy sum differ in states by their orbital angular momenta and their asymptotic behavior can be properly shaped by the rigorous upper and lower bounds in terms of the radial and momentum expectation values <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>⟨</mml:mo> <mml:mi>r</mml:mi> <mml:mo>⟩</mml:mo> </mml:mrow> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>⟨</mml:mo> <mml:mi>p</mml:mi> <mml:mo>⟩</mml:mo> </mml:mrow> </mml:mrow> </mml:math> . We finally extended the calculation to a modified HP (MHP) that has been widely discussed in the literature and compared our results with previous predictions. Benchmark Shannon entropies are provided for further investigation of the information measures of MHPs.

Abstract This article explores the politics of pageantry in colonial Uganda. As activists looked toward independence, they engineered competing visions of national material culture. Creating political emblems raised complex questions about the moral and theological significance of party colours. Throughout Uganda’s colonial history, debates about flags reflected sectarian struggles between Protestant and Catholic communities that dated to the late nineteenth century. In imperial and Ugandan history writings, flags are often associated with the pageantry of conquest or eventual post-colonial state building. But we know very little about the internal debates that accompanied the invention of the state’s material culture. This article pushes us past a superficial association of flags with either colonial conquest or Cold War liberation and into the conceptual and religious worlds that undergirded the hoisting of flags. Arguments about flags propelled Ugandan politics throughout the twentieth century. By looking at the varied ways that activists imagined the materiality of post-colonial Uganda, we can develop new approaches to intellectual history writing, moving into highly contested visual terrains where patterns, theologies of colour, and struggles to standardize party and national flags animated political mobilization and dissent.

ABSTRACTThe dipole polarizability and hyperpolarizability of the hydrogen atom confined in spherical Gaussian potential under the influence of an external electric field are calculated within the sum‐over‐states framework, where all system eigenenergies and wave functions are obtained using the generalized pseudospectral method. It is interestingly found that the Gaussian potential produces a stronger suppression effect on the hyperpolarizability than on the polarizability, especially at moderate values of confinement radius. By analyzing the second‐ and fourth‐order energy corrections for the ground state of the hydrogen atom under an external electric field, we define the maximal electric field strength where the perturbation approximation of the field–atom interaction is applicable. Based on the accurate ground state energies, polarizabilities, and hyperpolarizabilities, as well as the corresponding ‐scaling laws, the Stark shifts of hydrogenic ions confined in Gaussian potentials are estimated over a wide range of confinement radius and potential depth.

Background:Pharmacists are essential to team-based care, contributing knowledge and expertise that positively impact patient care. However, it is less clear how interprofessional collaboration is enacted by pharmacists in single-disciplinary outpatient practice environments.Methods:We recruited pharmacists from 3 university-affiliated, pharmacist-led primary care clinics in Canada. Employing a social network analysis approach, the data collection encounter explored the nature and composition of collaboration in patient care. We conducted semistructured interviews, including participant drawings (sociograms), to illustrate their network experiences caring for specific patients. Transcripts from the data collection encounters were systematically coded and analyzed in an iterative process. Initial codes were generated inductively and broader categories refined through constant comparison and finalized by author discussion.Results:Eleven (78%) pharmacists were interviewed and drew 28 sociograms. Pharmacist networks encompassed a wide array of health professionals and patient family members. Despite the physical distribution of interprofessional members, pharmacists formed and maintained relationships to support patient care through conscientious communication and medication management decision-making. Network relationships and system factors influenced collaboration and patient care, often resulting in practice paralysis and/or the need to re-emphasize patient self-advocacy.Interpretation and conclusion:Our findings underscore the dynamic nature of pharmacist networks and how they are navigated to support pharmacist-led medication management. Primary care pharmacists attempt to overcome encountered barriers to implementing patient care plans through various strategies, including leveraging new and existing network relationships. System obstacles impeding effective and efficient patient care could in part be overcome through pharmacist scope of practice expansion.

Microviruses are single-stranded DNA bacteriophages and members of the highly diverse viral family Microviridae. Microviruses have a seemingly ubiquitous presence across animal gut microbiomes and other global environmental ecosystems. Most of the studies on microvirus diversity so far have been associated with vertebrate gut viromes. In this study, we investigate the less explored invertebrate microviruses in a freshwater ecosystem. We analysed microviruses from invertebrates in the Chironomidae, Gastropoda, Odonata, Sphaeriidae, Unionidae clades, as well as from water and benthic sediment sampled from a lake ecosystem in New Zealand. Using gene-sharing networks and an expanded framework of informal and proposed microvirus subfamilies, the 463 distinct microvirus genomes identified in this study were grouped as follows: 382 genomes in the Gokushovirinae subfamily and 47 in the Pichovirinae subfamily clade, 18 belonging to Group D, 3 belonging to the proposed Alpavirinae subfamily clade, 1 belonging to the proposed Occultatumvirinae/Tainavirinae subfamilies clade and 12 belonging to an undefined viral cluster VC 1. Inverse associations of microviruses were noted between environmental benthic sediment samples and the Odonata group, while 'defended' invertebrates in the Gastropoda, Sphaeriidae and Unionidae groups showed correlative associations in the principal coordinate analysis of unique microvirus genomes (each genome sharing <98% genome-wide pairwise identity with each other) across sample types. This study expands the known diversity of microviruses and highlights the diversity of these relatively poorly classified bacteriophages.

Stress echocardiography is widely used to assess patients with chest pain. The clinical value of a positive or negative test result to inform on likely longer-term outcomes when applied in real-world practice across a healthcare system has not been previously reported. Five thousand five hundred and three patients recruited across 32 UK NHS hospitals between 2018 and 2022, participating in the EVAREST/BSE-NSTEP prospective cohort study, with data on medical outcomes up to 2023 available from NHS England were included in the analysis. Stress echocardiography results were related to outcomes, including death, procedures, hospital admissions, and relevant cardiovascular diagnoses, based on Kaplan-Meier analysis and Cox proportional hazard ratios (HRs). Median follow-up was 829 days (interquartile range 224-1434). A positive stress echocardiogram was associated with a greater risk of myocardial infarction [HR 2.71, 95% confidence interval (CI) 1.73-4.24, P < 0.001] and a composite endpoint of cardiac-related mortality and myocardial infarction (HR 2.03, 95% CI 1.41-2.93, P < 0.001). Hazard ratios increased with ischaemic burden. A negative stress echocardiogram identified an event-free 'warranty period' of at least 5 years in patients with no prior history of coronary artery disease and 4 years for those with disease. In real-world practice, the degree of myocardial ischaemia recorded by clinicians at stress echocardiography correctly categorizes risk of future events over the next 5 years. Reporting a stress echocardiogram as negative correctly identifies patients with no greater than a background risk of cardiovascular events over a similar time period.