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The American K12 education system has long been seen as centralized and rigid. The 1990s saw the emergence of several changes, which arguably pushed it in a potentially more polycentric, localized direction. Many school choice policies have developed since then, and a large amount of research has been conducted on these trends in American education since 1991. Just prior to these changes, in 1991, Davis and Ostrom published ‘A Public Economy Approach to Education: Choice and Co-Production’. That work sought to examine the extent of co-production in American schools to that time, and the extent to which the system was polycentric. This paper seeks to use Davis & Ostrom’s framing and to update their work in the current context. U.S. education policy has generally become more decentralized during this time, but not consistently. This paper also finds that U.S. education policy and practice has in fact developed along several of the lines Davis & Ostrom predicted.
Food insecurity affects the health of college-aged individuals, but its impact on the gut microbiome (GM) over time is poorly understood. This study explored the association between food insecurity and the GM in eighty-five college students, identifying microbial taxa, metabolites and pathways linked to food security status and examining GM stability and microbe–metabolite interactions. Longitudinal GM and metabolomic data were collected from first-year students over an academic year, encompassing periods of variable food security status. Participants were categorised into three groups: food insecure (FI, n 13), food secure (FS, n 44) and variable (VAR, n 28) status. GM composition varied significantly between FS classifications (Bray–Curtis dissimilarity, P ≤ 0·005). Stability analysis revealed correlations between stability scores and microbial features, pathways and metabolites. Specific microbes (e.g. Bifidobacterium species, Faecalibacterium prausnitizii D and Lachnospiraceae), pathways (energy and microbial turnover) and metabolites (cadaverine, N-acetylcadaverine, putrescine, testosterone sulfate and creatine) associated with FI status were identified. Multi-omic integration revealed metabolic pathways influenced by differentially abundant microbial species and co-occurring fecal metabolites in FI participants related to the microbial production of polyamines, detoxification and energy metabolism. The transition from FS to FI showed no significant differences at specific taxonomic, functional or metabolite levels. This study uncovers complex interactions between food security, GM composition and metabolism. Significant differences were found in microbial community variability and metabolic pathways associated with food security status, but the transition from food security to insecurity disrupted the GM without clear taxonomic or functional distinctions, emphasising the need for further research into these mechanisms.
Testitems using open-ended response formats can increase an instrument’s construct validity. However, traditionally, their application in educational testing requires human coders to score the responses. Manual scoring not only increases operational costs but also prohibits the use of evidence from open-ended items to inform routing decisions in adaptive designs. Using machine learning and natural language processing, automatic scoring provides classifiers that can instantly assign scores to text responses. Although optimized for agreement with manual scores, automatic scoring is not perfectly accurate and introduces an additional source of error into the response process, leading to a misspecification of the measurement model used with the manual score. We propose two joint models for manual and automatic scores of automatically scored open-ended items. Our models extend a given model from Item Response Theory for the manual scores by a component for the automatic scores, accounting for classification errors. The models were evaluated using data from the Programme for International Student Assessment (2012) and simulated data, demonstrating their capacity to mitigate the impact of classification errors on ability estimation compared to a baseline that disregards classification errors.
Precision medicine (PM) encompasses various emerging, data-intensive healthcare and biomedical research initiatives aimed at tailoring care to individual patient characteristics. While “precision” primarily denotes an epistemological shift in how biomedical research is approached and care delivered, the conviction that PM empowers patients in clinical decision-making is central to its vision as it is taken up across policy contexts. In this paper, I critically assess these promises by drawing on recent engagements in agential epistemic injustice (Lackey 2020; Medina 2022). I suggest that the social, cultural, and epistemological conditions in which the epistemic practice of precision care unfolds are conducive to epistemic injustice. Despite PM’s explicit aims to address longstanding criticisms regarding the disease-centric nature of contemporary biomedical care practices by including person-centered, non-biomedical features in clinical consideration, exploring its underlying logic suggests its epistemic economy is stacked against patients’ epistemic interests. As such, despite its laudable aim of patient empowerment, the exacerbated risk of epistemic injustice might truncate patients’ (epistemic) agency, further disempowering them in clinical decision-making. To conclude, I suggest that the reliance on “empowerment”- and “person-centered care”-rhetoric dominating PM discourse is a case of epistemic appropriation (Davis 2018), further discouraging engagement with social, experiential, and phenomenological dimensions of illness, defanging critics of raising those concerns, and impeding the realization of epistemic justice in healthcare.
Predicting long-term outcome trajectories in psychosis remains a crucial and challenging goal in clinical practice. The identification of reliable neuroimaging markers has often been hindered by the clinical and biological heterogeneity of psychotic disorders and the limitations of traditional case-control methodologies, which often mask individual variability. Recently, normative brain charts derived from extensive magnetic resonance imaging (MRI) data-sets covering the human lifespan have emerged as a promising biologically driven solution, offering a more individualised approach.
Aims
To examine how deviations from normative cortical and subcortical grey matter volume (GMV) at first-episode psychosis (FEP) onset relate to symptom and functional trajectories.
Method
We leveraged the largest available brain normative model (N > 100 000) to explore normative deviations in a sample of over 240 patients with schizophrenia spectrum disorders who underwent MRI scans at the onset of FEP and received clinical follow-up at 1, 3 and 10 years.
Results
Our findings reveal that deviations in regional normative GMV at FEP onset are significantly linked to overall long-term clinical trajectories, modulating the effect of time on both symptom and functional outcome. Specifically, negative deviations in the left superior temporal gyrus and Broca’s area at FEP onset were notably associated with a more severe progression of positive and negative symptoms, as well as with functioning trajectories over time.
Conclusions
These results underscore the potential of brain developmental normative approaches for the early prediction of disorder progression, and provide valuable insights for the development of preventive and personalised therapeutic strategies.
Do social media offer more opportunities for parliamentary opposition and independent candidates to reach voters in electoral autocracies? Social media have been seen as a great liberation tool, facilitating the mobilisation of disenfranchised citizens. However, scholarship on electoral autocracies highlights how they are well-versed in subverting democratic innovations. Taking the 2021 legislative campaign in Uganda as a case, we show that social media offer a range of opportunities for the opposition to campaign, while also providing new ways for the regime to try to maintain its dominance. Our findings rely on insights from 35 interviews with legislative candidates combined with data collected from their Facebook pages and Twitter profiles as well as from those of their opponents. We contribute to the literature on electoral autocracy and on candidates' use of social media in electoral campaigns by identifying the opportunities social media offer for both the regime and its opposition.
Climbing aroids, despite their abundance in tropical forests, remain underexplored. This study is focused on species richness, abundance, density, and distribution patterns of climbing aroid community in a lowland rainforest in Los Tuxtlas, Veracruz, Mexico. Over two years, two censuses were conducted across 14 plots, recording 12 aroid species from five genera and their potential hosts. Ontogenetic classes were defined and validated, showing a positive correlation between total plant length/apex height and ontogenetic stage, indicating distinct growth phases. Host size (DBH) was significant predictor of the establishment probability across ontogenetic classes. Vertical distribution varied significantly among species, ranging from Philodendron hederaceum (7 m) to Anthurium flexile (0.88 m), with some species predominantly distributed on specific host sizes. Tree falls impacted specific species. Although limitations, including a short study period, restrict broader generalizations, this research establishes a foundational understanding of climbing aroid ecology and underscores the need for standardized methods and long-term monitoring to elucidate their population dynamics and ecological strategies.
Intensive longitudinal data (ILD) collected in mobile health (mHealth) studies contain rich information on the dynamics of multiple outcomes measured frequently over time. Motivated by an mHealth study in which participants self-report the intensity of many emotions multiple times per day, we describe a dynamic factor model that summarizes ILD as a low-dimensional, interpretable latent process. This model consists of (i) a measurement submodel—a factor model—that summarizes the multivariate longitudinal outcome as lower-dimensional latent variables and (ii) a structural submodel—an Ornstein–Uhlenbeck (OU) stochastic process—that captures the dynamics of the multivariate latent process in continuous time. We derive a closed-form likelihood for the marginal distribution of the outcome and the computationally-simpler sparse precision matrix for the OU process. We propose a block coordinate descent algorithm for estimation and use simulation studies to show that it has good statistical properties with ILD. Then, we use our method to analyze data from the mHealth study. We summarize the dynamics of 18 emotions using models with one, two, and three time-varying latent factors, which correspond to different behavioral science theories of emotions. We demonstrate how results can be interpreted to help improve behavioral science theories of momentary emotions, latent psychological states, and their dynamics.
Latin American countries have pioneered innovations in social protection, but their welfare institutions suffer from large and persistent gaps and inequalities in access and provision. This article reviews the substantive body of research addressing this anomaly. A focus on social protection offers a window on what is distinctive about social policy in the region. The social protection matrix in Latin America combines three core institutions: occupational insurance funds, personal pensions and social assistance. The article highlights the role of political realignments shaping current institutions. The critical review yields several pointers for a ‘general’ theory of welfare institutions.
The purpose of the South African Competition Act is to resolve the present problems of inequality by emphasizing its multiple goals, which differ from those of other countries. Its objectives broadly contain efficiency, state economic development and consumer welfare. In addition, the ideas of providing opportunities for small businesses and promoting a greater spread of ownership among different groups indicate its goal of favouring or protecting weak trading parties or certain groups of people. To achieve the aim of equity and fairness, South African competition law should be vigorously applied, but the existing substantive provisions may not fulfil the task of moving towards an equal and fair society. A comparative study of competition law may help to discover a proper model and a better solution for the problems of unequal economic power in South Africa.
Neuroimaging studies, such as the Human Connectome Project (HCP), often collect multifaceted data to study the human brain. However, these data are often analyzed in a pairwise fashion, which can hinder our understanding of how different brain-related measures interact. In this study, we analyze the multi-block HCP data using data integration via analysis of subspaces (DIVAS). We integrate structural and functional brain connectivity, substance use, cognition, and genetics in an exhaustive five-block analysis. This gives rise to the important finding that genetics is the single data modality most predictive of brain connectivity, outside of brain connectivity itself. Nearly 14% of the variation in functional connectivity (FC) and roughly 12% of the variation in structural connectivity (SC) is attributed to shared spaces with genetics. Moreover, investigations of shared space loadings provide interpretable associations between particular brain regions and drivers of variability. Novel Jackstraw hypothesis tests are developed for the DIVAS framework to establish statistically significant loadings. For example, in the (FC, SC, and substance use) subspace, these novel hypothesis tests highlight largely negative functional and structural connections suggesting the brain’s role in physiological responses to increased substance use. Our findings are validated on genetically relevant subjects not studied in the main analysis.
Factor score indeterminacy is a characteristic property of factor analysis (FA) models. This research introduces a novel procedure, regression-based factor score exploration (RFE), which uniquely determines factor scores and simultaneously estimates other parameters of the FA model. RFE uniquely determines factor scores by minimizing a loss function that balances FA and multivariate regression, regulated by a tuning parameter. Theoretical aspects of RFE, including the uniqueness of factor scores, the relationship between observed and latent variables, and rotational indeterminacy, are examined. Additionally, clustering-based factor exploration (CFE) is presented as a variant of RFE, derived by generalizing the penalty term to enable the clustering of factor scores. It is demonstrated that CFE creates cluster structures more accurately than the existing method. A simulation study shows that the proposed procedures accurately recover true parameter matrices even in the presence of error-contaminated data, with lower computational demand compared to existing methods. Real data examples illustrate that the proposed procedures provide interpretable results, demonstrating high relevance to the factor scores obtained by existing methods.
We analyse seismic time series collected during experimental campaigns in the area of the David Glacier, Victoria Land, Antarctica, between 2003 and 2016. We observe hundreds of repeating seismic events, characterized by highly correlated waveforms (cross-correlation > 0.95), which mainly occur in the grounding zone, i.e. the region where the ice transitions from grounded ice sheet to freely floating ice shelf. The joint analysis of seismic events and observed local tidal measurements suggests that seismicity is not only triggered by a regular, periodic driver such as the ocean tides but also more likely by transient pulses. We consider potential environmental processes and their impact on the coupling between the glacier flow and the bedrock brittle failure. Among the environmental variables examined, our findings suggest that clustered and repeated seismic events may be related to transient episodes of ice-mass discharge correlated to a change in the subglacial hydrographic system that originates upstream of the glacier, lubricating the interface with the bedrock. This hypothesis is supported by the gravity variation observations provided by the GRACE satellite mission, which observed mass variations during periods characterized by seismic clustering.
We present a new corpus of child and child-directed speech (CDS) in Palestinian Arabic. It includes transcriptions following the CHILDES guidelines and features recordings of 16 monolingual Palestinian Arabic-speaking children with an age range of 19–58 months and their adult interlocutors. We analyse the children’s morphosyntactic development and identify a variety of target word orders (45 in child speech, 50 in CDS), with prevalent SV(O) structures; we also found high rates of null subjects in both populations, marginal errors in children’s verbal agreement morphology, and early emergence of serial verb constructions, observed from 23 months of age.
This paper presents a method to stabilise oscillations occurring in a mixed convective flow in a nearly hemispherical cavity, using actuation based on the receptivity map of the unstable mode. This configuration models the continuous casting of metallic alloys, where hot liquid metal is poured at the top of a hot sump with cold walls pulled in a solid phase at the bottom. The model focuses on the underlying fundamental thermohydrodynamic processes without dealing with the complexity inherent to the real configuration. This flow exhibits three branches of instability. The solution of the adjoint eigenvalue problem for the convective flow equations reveals that the regions of highest receptivity for unstable modes of each branch concentrate near the inflow upper surface. Simulations of the linearised governing equations show that a thermomechanical actuation modelled on the adjoint eigenmode asymptotically suppresses the unstable mode. If the actuation’s amplitude is kept constant in time, which is easier to implement in an industrial environment, the suppression is still effective but only over a finite time, after which it becomes destabilising. Based on this phenomenology, we apply the same actuation during the stabilising phase only in the nonlinear evolution of the unstable mode. It turns out stabilisation persists, even when the unstable mode is left to evolve freely after the actuation period. These results not only demonstrate the effectiveness of receptivity-informed actuation in stabilising convective oscillations but also suggest a simple strategy for their long-term control.
We construct moduli spaces of framed logarithmic connections and also moduli spaces of framed parabolic connections. It is shown that these moduli spaces possess a natural algebraic symplectic structure. We also give an upper bound of the transcendence degree of the algebra of regular functions on the moduli space of parabolic connections.
The study objective was to identify the specific challenges experienced by nurses, assess the mental health impacts, and evaluate their role adaptation in response to the ongoing conflict.
Methods
A quantitative, descriptive study was conducted involving 202 nurses from 3 hospitals in the South West Bank. Data were collected through a structured questionnaire addressing socio-demographic information, psychological challenges, and role adaptation during the conflict.
Results
The study surveyed 300 nurses, revealing critical findings regarding their psychological well-being and professional challenges. Approximately 65% of respondents reported experiencing symptoms consistent with PTSD, indicating a significant psychological toll due to their work conditions. In terms of workload, 78% of nurses reported an increased patient influx, leading to higher stress levels and burnout. The analysis indicated that nurses faced severe resource shortages, with 60% reporting inadequate medical supplies and 55% citing insufficient staffing.
Conclusions
The findings underscore the urgent need for enhanced training programs, mental health support, and improved disaster management protocols. Educational background and marital status significantly influence nurses’ resilience and adaptability in conflict zones. Addressing these challenges is essential to improving the well-being of nurses and enhancing the quality of care in conflict-affected areas.