120 research outputs found

    Método de diferenciación de Caolinitas y Cloritas

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    En el presente trabajo se hace una revision bibliografica de los distintos métodos de identificación de Caolinita y Clorita en mezclas naturales y artificiales, valorando la distinta problematica que presentan cada uno de ellos, y aplicandolos a muestras patrones y mezclas naturales que presentan esta problematica a fin de obtener una mejor valoraci6n de los distintos métodos expuesto

    3D Face Recognition with Sparse Spherical Representations

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    This paper addresses the problem of 3D face recognition using simultaneous sparse approximations on the sphere. The 3D face point clouds are first aligned with a novel and fully automated registration process. They are then represented as signals on the 2D sphere in order to preserve depth and geometry information. Next, we implement a dimensionality reduction process with simultaneous sparse approximations and subspace projection. It permits to represent each 3D face by only a few spherical functions that are able to capture the salient facial characteristics, and hence to preserve the discriminant facial information. We eventually perform recognition by effective matching in the reduced space, where Linear Discriminant Analysis can be further activated for improved recognition performance. The 3D face recognition algorithm is evaluated on the FRGC v.1.0 data set, where it is shown to outperform classical state-of-the-art solutions that work with depth images

    Búsqueda de indicadores de interdisciplinariedad/integración en las ciencias naturales en la EGB3

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    La implementación del Tercer Ciclo de la Educación General Básica constituyó un desafío en Argentina. Construyó su identidad a partir de la vieja escuela secundaria y primaria, integrando saberes académicos y prácticas educativas heterogéneas. Santa Fe organizó las Cs. Naturales (CN) aglutinando disciplinas diversas (Física, Química, Biología, Geología, Astronomía). Se presentan resultados emergentes de entrevistas a informantes claves, que permitieron conformar categorías de análisis para elaborar un cuestionario a fin de caracterizar las condiciones en que se gestionaron las CN. Se registró una postura crítica de los profesores ante la falta de alternativas orientadas a un enfoque integrador, si bien abordaron situaciones cotidianas en el aula. Tales situaciones se tomaron, en general, de la Biología, y en pocos casos la Física y la Química las explican

    The atypical CDK activator RingoA/Spy1 regulates exit from quiescence in neural stem cells

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    In the adult mammalian brain, most neural stem cells (NSCs) are held in a reversible state of quiescence, which is essential to avoid NSC exhaustion and determine the appropriate neurogenesis rate. NSCs of the mouse adult subependymal niche provide neurons for olfactory circuits and can be found at different depths of quiescence, but very little is known on how their quiescence-to-activation transition is controlled. Here, we identify the atypical cyclin-dependent kinase (CDK) activator RingoA as a regulator of this process. We show that the expression of RingoA increases the levels of CDK activity and facilitates cell cycle entry of a subset of NSCs that divide slowly. Accordingly, RingoA-deficient mice exhibit reduced olfactory neurogenesis with an accumulation of quiescent NSCs. Our results indicate that RingoA plays an important role in setting the threshold of CDK activity required for adult NSCs to exit quiescence and may represent a dormancy regulator in adult mammalian tissues.© 2023 The Author(s)

    Búsqueda de indicadores de interdisciplinariedad/integración en las ciencias naturales en la EGB3

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    La implementación del Tercer Ciclo de la Educación General Básica constituyó un desafío en Argentina. Construyó su identidad a partir de la vieja escuela secundaria y primaria, integrando saberes académicos y prácticas educativas heterogéneas. Santa Fe organizó las Cs. Naturales (CN) aglutinando disciplinas diversas (Física, Química, Biología, Geología, Astronomía). Se presentan resultados emergentes de entrevistas a informantes claves, que permitieron conformar categorías de análisis para elaborar un cuestionario a fin de caracterizar las condiciones en que se gestionaron las CN. Se registró una postura crítica de los profesores ante la falta de alternativas orientadas a un enfoque integrador, si bien abordaron situaciones cotidianas en el aula. Tales situaciones se tomaron, en general, de la Biología, y en pocos casos la Física y la Química las explican

    Measuring dairy cow welfare with real-time sensor-based data and farm records: a concept study

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    Welfare assessment of dairy cows by in-person farm visits provides only a snapshot of welfare and is time-consuming and costly. Possible solutions to reduce the need for in-person assessments would be to exploit sensor data and other routinely collected on-farm records. The aim of this study was to develop an algorithm to classify dairy cow welfare based on sensors (accelerometer and/or milk meter) and farm records (e.g. days in milk, lactation number). In total, 318 cows from six commercial farms located in Finland, Italy and Spain (two farms each) were enrolled for a pilot study lasting 135 days. During this time, cows were routinely scored using 14 animal-based measures of good feeding, health and housing based on the Welfare Quality® (WQ®) protocol. WQ® measures were evaluated daily or approximately every 45 days, using disease treatments from farm records and on-farm visits, respectively. WQ® measures were supplemented with daily temperature-humidity index to account for heat stress. The severity and duration of each welfare measure were evaluated, and the final welfare index was obtained by summing up the values for each cow on each pilot study day, and stratifying the result into three classes: good, moderate and poor welfare. For model building, a machine-learning (ML) algorithm based on gradient-boosted trees (XGBoost) was applied. Two model versions were tested: (1) a global model tested on unseen herd, and (2) a herd-specific model tested on unseen part of the data from the same herd. The version (1) served as an example on the model performance on a herd not previsited by the evaluator, while version (2) resembled a custom-made solution requiring in-person welfare evaluation for model training. Our results indicated that the global model had a low performance with average sensitivity and specificity of 0.44 and 0.68, respectively. For the herd-specific version, the model performance was higher reaching an average of 0.64 sensitivity and 0.80 specificity. The highest classification performance was obtained for cows in poor welfare, followed by cows in good and moderate welfare (balanced accuracy of 0.77, 0.71 and 0.68, respectively). Since the global model had low classification accuracy, the use of the developed model as a stand-alone system based solely on sensor data is infeasible, and a combination of in-person and sensor-based welfare evaluation would be preferable for a reliable welfare assessment. ML-based solutions, even with fair discriminative abilities, have the potential to enhance dairy welfare monitoring

    Cost-effectiveness of pregabalin versus venlafaxine in the treatment of generalized anxiety disorder: findings from a Spanish perspective

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    The objective of the present study was to describe a new model of the cost-effectiveness of treatment of generalized anxiety disorder (GAD) and its application to a comparison of pregabalin versus venlafaxine extended-release (XR) from a Spanish healthcare perspective. Microsimulation techniques, including Hamilton Anxiety Scale (HAM-A) score, number of weeks with minimal or no anxiety (HAM-A ≤ 9), and quality-adjusted life-years (QALYs), were used to predict treatment outcomes for patients with moderate-to-severe GAD who would be treated with pregabalin vs venlafaxine XR. Expected levels of healthcare utilization and unit cost of care are derived from Spanish published sources. We express cost-effectiveness alternatively in terms of incremental cost per additional week with minimal or no anxiety, and incremental cost per QALY gained [in 2007 Euros (€)]. Considering costs of drug treatment only, the incremental cost [mean (95% confidence interval)] of pregabalin (vs venlafaxine XR) would be €96 (€86, €107) per additional week with minimal or no anxiety, and €32,832 (€29,656, €36,308) per QALY gained. When other medical care costs are considered, cost-effectiveness ratios decline to €70 (€61, €80) per additional week with no or minimal anxiety, and €23,909 (€20,820, €27,006) per QALY gained. We conclude that, using a new microsimulation model of the treatment of GAD, pregabalin appears to be cost-effective vs venlafaxine XR in a Spanish healthcare setting

    The bounds of education in the human brain connectome

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    Inter-individual heterogeneity is evident in aging; education level is known to contribute for this heterogeneity. Using a cross-sectional study design and network inference applied to resting-state fMRI data, we show that aging was associated with decreased functional connectivity in a large cortical network. On the other hand, education level, as measured by years of formal education, produced an opposite effect on the long-term. These results demonstrate the increased brain efficiency in individuals with higher education level that may mitigate the impact of age on brain functional connectivity.This work was funded by the European Commission (FP7): “SwitchBox” (Contract HEALTH-F2-2010-259772) and co-financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER). José M. Soares, Paulo Marques, and Nadine C. Santos are supported by fellowships of the project “SwitchBox”; Ricardo Magalhães is supported by a fellowship from the project FCT ANR/NEU-OSD/0258/2012 funded by FCT/MEC (www.fct.pt) and by ON.2 – ONOVONORTE – North Portugal Regional Operational Programme 2007/2013, of the National Strategic Reference Framework (NSRF) 2007/2013, through FEDER
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