126 research outputs found
Statistical Quantile Learning for Large, Nonlinear, and Additive Latent Variable Models.
The studies of large-scale, high-dimensional data in fields such as genomics and neuroscience have injected new insights into science. Yet, despite advances, they are confronting several chal- lenges, often simultaneously: lack of interpretability, nonlinearity, slow computation, inconsistency and uncertain convergence, and small sample sizes compared to high feature dimensions. Here, we propose a relatively simple, scalable, and consistent nonlinear dimension reduction method that can potentially address these issues in unsupervised settings. We call this method Statistical Quantile Learning (SQL) because, methodologically, it leverages on a quantile approximation of the latent variables together with standard nonparametric techniques (sieve or penalyzed methods). We show that estimating the model simplifies into a convex assignment matching problem; we derive its asymptotic properties; we show that the model is identifiable under few conditions. Compared to its linear competitors, SQL explains more variance, yields better separation and explanation, and delivers more accurate outcome prediction. Compared to its nonlinear competitors, SQL shows considerable advantage in interpretability, ease of use and computations in large-dimensional set- tings. Finally, we apply SQL to high-dimensional gene expression data (consisting of 20, 263 genes from 801 subjects), where the proposed method identified latent factors predictive of five cancer types. The SQL package is available at https://github.com/jbodelet/SQL
The Mediterranean diet is associated with better cardiometabolic health for women in mid-life but not men:A PREVENT dementia cohort cross-sectional analysis
Mediterranean diet and structural neuroimaging biomarkers of Alzheimer's and cerebrovascular disease: A systematic review
Ceres, women and the backlands: representations of the feminine and Brazilian agriculture in the first half of the twentieth century
Our research on the historical trajectory of four Brazilian agricultural schools in the thirties and forties of the twentieth century does not show a significant number of women in the profession. Nevertheless, rethinking these data, inspired by the history of science and gender studies, it is possible to understand the meanings, and the role played of those women within society, and in the scientific milieu. We collected and analyzed speeches, poetry, official documents, images, and photos, which led to a reflection on these representations, as well as the process of institutionalization of agricultural science.Em quatro escolas superiores de agricultura estudadas o percentual de mulheres no corpo discente ou no corpo docente é estatisticamente desprezível nas décadas de 1930 e 1940. Apesar disso, do ponto de vista dos estudos de gênero e da história das ciências, é importante compreender essa presença para entender e reconhecer o papel das mulheres na sociedade e em particular no meio científico. Nosso propósito não foi o de realizar um balanço aprofundado sobre a carreira seguida pelas engenheiras agrônomas. Outrossim, reunimos o que falavam sobre elas as poesias, os ofícios, algumas fotos e figuras, relacionando essas representações ao processo de institucionalização das ciências agrícolas no Brasil no período.36539
NuBrain: UK consortium for optimal nutrition for healthy brain ageing
With an ageing global population, there is an urgent need to identify effective strategies to maintain brain health across the life course and therein minimise the risk of age‐related neurodegenerative disorders reaching a severe stage which may manifest as dementia. An increasing body of evidence indicates that nutrition is a modifiable lifestyle factor that can promote healthy brain ageing and reduce dementia risk. However, at present, little is known about which dietary patterns, foods and food bioactives influence brain function during ageing, and more research is required to identify at‐risk individuals and population subgroups who are most likely to benefit from future nutritional intervention intended to promote healthier brain ageing. This article introduces the newly established Medical Research Council‐funded NuBrain consortium, the vision of which is to provide a step change in research in the area by developing novel approaches and techniques to further understand the complex interactions between diet and brain health and how we can support appropriate behaviour changes in the population. NuBrain will form a new, sustainable and internationally field‐leading research consortium with multidisciplinary and complementary areas of expertise to address the fundamental research challenges in this area
Mediterranean diet score is associated with greater allocentric processing in the EPAD LCS cohort: A comparative analysis by biogeographical region
Background: Adherence to the Mediterranean diet (MedDiet), a primarily plant-based eating pattern, has been associated with lower dementia incidence. Much of the research has focused on Alzheimer’s disease (AD) dementia and mild cognitive impairment (MCI), with less research looking at the preclinical symptomatically silent stages that pre-empt MCI and AD dementia. Although there is evidence from studies conducted globally, no studies have compared the effects of the MedDiet within and outside of the Mediterranean region in one cohort.Methods: Our study explored cross-sectional and longitudinal associations between MedDiet and cognition in the pan-European EPAD LCS, comparing those living within and outside of the Mediterranean region (as classified by European Union biogeographical definitions). After deriving MEDAS scores to quantify adherence to the MedDiet, we used linear regression and linear mixed effects models to test for associations between the MEDAS score and cognitive function measured by the Four Mountains Test (FMT) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). We additionally calculated MEDAS continuous and PYRAMID scores to provide alternative measures of MedDiet adherence.Results: We included 1826 participants, mean age 65.69 (±7.42) years, majority female (56.2%) with family history (65.8%) and minority APOEε4 carriers (38.9%). Higher MEDAS scores were associated with better performance on the FMT both cross-sectionally (n = 1,144, ß: −0.11, SE: 0.04, p = 0.007) and longitudinally (slope: 0.10, 95% CI: 0.04–0.17, p: 0.002). The effect was marginally greater in the Mediterranean region in the cross-sectional analysis, with a stronger effect emerging longitudinally. In exploratory analyses, the association between MEDAS and FMT scores was only seen in female participants. A sensitivity analysis excluding Toulouse and Perugia, as cities near, but not within, the biogeographical region, found significant associations between higher MEDAS and MEDAS continuous scores, and a number of RBANS total and index scores.Conclusion: MedDiet adherence is associated with better FMT scores, with effects seen most strongly in the Mediterranean region from longitudinal data. Our sensitivity analysis suggested a more global cognitive benefit of MedDiet adherence. This study highlights the need to further explore for whom and for what brain health outcomes the MedDiet confers benefit. This evidence would identify a window of opportunity in the life-course to maximise the benefit and better inform public health campaigns and patient-level interventions
HACIA LA CREACIÓN Y ORGANIZACIÓN DE UN ESPACIO INSTITUCIONAL PARA EL AREA MATEMÁTICA
La importancia y multiplicidad de situaciones que plantea la enseñanza de la Matemática en los ciclos básicos, de las diferentes carreras que se imparten en la Universidad Nacional de Tucumán, requiere de un tratamiento exhaustivo y permanente. Es por ello que el H.C.S de la U.N.T. aprobó la propuesta de creación de un Centro Superior de Matemática, independiente de las unidades académicas, con el propósito de promover, coordinar y difundir acciones tendientes a superar algunas dificultades detectadas en el área. El Centro tiene como principal finalidad que los docentes del área Matemática de las diferentes carreras dispongan de un ámbito donde puedan compartir experiencias, problemáticas comunes y capacitación. Este trabajo tiene como propósito, por un lado, presentar parte de la tarea, realizada por los integrantes del Grupo de Trabajo, que condujo a la creación del Centro y por otra, iniciar la etapa de concretización y consolidación de dicho Centro en cuanto a su organización, funcionamiento y búsqueda de financiamiento
Contratación colectiva de protección en México. Informe a la Organización Regional Interamericana de Trabajadores (ORIT)
Los contratos colectivos de protección patronal en México, constituyen una práctica que afecta a la mayor parte de los trabajadores mexicanos, impide la democratización y la negociación colectiva y genera una simulación en el conjunto de instituciones del mundo laboral. Debido a esta realidad que preocupa a diferentes sectores -académicos, sociales y laborales-, la Organización Regional Interamericana de Trabajadores (ORIT) interesada en el fenómeno de la contratación colectiva simulada en nuestro país, solicitó a un grupo de especialistas en materia laboral un diagnóstico sobre la problemática, que es el contenido que se presenta en este documento en calidad de Informe.
La finalidad es plantear todas las aristas posibles de la problemática que encierra la contratación colectiva de protección. Partir de un diagnóstico que ayude a entretejer los hilos que sostienen y persisten en un fenómeno de tan graves dimensiones para la calidad de trabajo, los trabajadores y sus condiciones de vida derivadas de éste, allana el camino para identificar las causas y efectos del problema, los actores involucrados, las características de su modus operando y las relaciones deformadas que se han ido derivando de todo ello.
Este Informe contiene un análisis multifactorial del problema de estudio: 1) institucional, histórico, político-conceptual, y 2) el que corresponde a algunos casos concretos de los que se puede inferir la existencia de contratos colectivos de protección.
Finalmente no sobra decir que, esta investigación se realiza dentro de los trabajos del proyecto "Perspectivas de las relaciones laborales en México" del Instituto de Investigaciones Económicas de la UNAM, a solicitud de la Organización Regional Interamericana de Trabajadores (ORIT), lo cual muestra el reconocimiento que a nivel latinoamericano tiene nuestra institución
The Mediterranean diet is not associated with neuroimaging or cognition in middle‐aged adults: : a cross‐sectional analysis of the PREVENT dementia programme
Funding: The PREVENT dementia programme is funded by the Alzheimer's Society (grant numbers 178, 264 and 329), Alzheimer's Association (grant number TriBEKa-17-519,007) and philanthropic donations. The analytical work was funded by the MRC UK Nutrition Research Partnership (NRP) Collaboration Award (MR/T001852/1). Professor Muniz-Terrera acknowledges the support of the Osteopathic Heritage Foundation through funding for the Osteopathic Heritage Foundation Ralph S. Licklider, D.O., Research Endowment in the Heritage College of Osteopathic Medicine.Background and purpose The Mediterranean diet (MedDiet) has been associated with reduced dementia incidence in several studies. It is important to understand if diet is associated with brain health in midlife, when Alzheimer's disease and related dementias are known to begin. Methods This study used data from the PREVENT dementia programme. Three MedDiet scores were created (the Pyramid, Mediterranean Diet Adherence Screener [MEDAS] and MEDAS continuous) from a self‐reported food frequency questionnaire. Primary outcomes were hippocampal volume and cube‐transformed white matter hyperintensity volume. Secondary outcomes included cornu ammonis 1 and subiculum hippocampal subfield volumes, cortical thickness and measures of cognition. Sex‐stratified analyses were run to explore differential associations between diet and brain health by sex. An exploratory path analysis was conducted to study if any associations between diet and brain health were mediated by cardiovascular risk factors for dementia. Results In all, 504 participants were included in this analysis, with a mean Pyramid score of 8.10 (SD 1.56). There were no significant associations between any MedDiet scoring method and any of the primary or secondary outcomes. There were no differences by sex in any analyses and no significant mediation between the Pyramid score and global cognition by cardiovascular risk factors. Conclusions Overall, this study did not find evidence for an association between the MedDiet and either neuroimaging or cognition in a midlife population study. Future work should investigate associations between the MedDiet and Alzheimer's disease and related dementias biomarkers as well as functional neuroimaging in a midlife population.Peer reviewe
The Mediterranean diet is not associated with neuroimaging or cognition in middle‐aged adults: a cross‐sectional analysis of the PREVENT dementia programme
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