246 research outputs found
Predicting the Deterrence Effect of Tax Audits. A Machine Learning Approach
No full textWe apply machine learning methods to the prediction of deterrence effects of tax audits. Based on tax declarations data, we predict the increase in future income declarations after being targeted by an audit. We find that flexible models, such as classification trees and ensemble methods based on them, outperform penalized linear models such as Lasso and ridge regression in predicting taxpayers more likely to increase their declarations after an audit. We show that despite the non-randomness of audits, their specific time structure and the distribution of changes in declared amounts suggest a causal interpretation of our results; that is, our approach detects a heterogeneity in the reaction to a tax audit, rather than just forecasting an unconditional future increase. We find that taxpayers identified by our model will on average increase their declared income by €14,461—the average among all audited taxpayers being €−205. Our approach allows the tax agency to yield significantly larger revenues by appropriately targeting tax audit
Predicting the deterrence effect of tax audits. A machine learning approach
No full textWe apply machine learning methods to the prediction of deterrence effects of tax audits. Based on tax declarations data, we predict the increase in future income declarations after being targeted by an audit. We find that flexible models, such as classification trees and ensemble methods based on them, outperform penalized linear models such as Lasso and ridge regression in predicting taxpayers more likely to increase their declarations after an audit. We show that despite the non-randomness of audits, their specific time structure and the distribution of changes in declared amounts suggest a causal interpretation of our results; that is, our approach detects a heterogeneity in the reaction to a tax audit, rather than just forecasting an unconditional future increase. We find that taxpayers identified by our model will on average increase their declared income by 14,461 euro the average among all audited taxpayers being 205 euro. Our approach allows the tax agency to yield significantly larger revenues by appropriately targeting tax audit
La pertinencia de la capacitación en el sector productivo. Análisis y resultados de la implementación del curso “Tecnología de los materiales Plásticos” (convenio UTN-FRAy la UOyEP)
No full textEl trabajo tiene por objeto describir la incumbencia de la vinculación entre la UTN-FRA y la UOyEP, en el marco de las relaciones entre universidad y empresa. Esta vinculación nació en el año 2002 y representa un ejemplo contundente sobre cómo desde los diferentes ámbitos –académicos, sindicales, industriales y empresariales– se pueden ejecutar políticas tendientes a la capacitación y a la especialización de los recursos necesarios para cumplimentar los requerimientos productivos de los distintos sectores. A estos fines, se hará un recorrido cronológico que dé cuenta de dichas relaciones, tomando como punto de referencia tanto a los indicadores internos como a los externos. En el primer caso se considerarán la cantidad de alumnos matriculados y egresados por año, desde el inicio de la institución. Los altibajos en la matrícula, las deserciones y los egresos servirán para interpretar las inflexiones del contexto en este ámbito. En el segundo caso se tomarán en consideración los siguientes factores: las fluctuaciones de la industria y las nuevas condiciones generadas por la crisis económica mundial del año 2008; las trabas a la capacitación de los obreros y por último, las políticas educativas que apuntan a fortalecer los vínculos generados por este tipo de instituciones
Réplica de Concha Díez-Pastor a Martín Domínguez Ruz y Pablo Rabasco
No full textEl novembre de 2017 vam publicar l’article “Carlos Arniches. Arquitectura i documents “(On the w @ terfront vol. 58, nº 1, de 10 de novembre de 2017) signat per la Dra. Concha Deu-Pastor.Després de la seva publicació vam rebre una petició de dret de rèplica per part de Martín Domínguez Ruz i del Dr. Pablo Rabasco, que va originar la publicació d’un nou article, “Els arquitectes Arniches i Domínguez” (On the w @ terfront vol. 60, núm 10, de 30 de juny de 2018). Aquest article posava en dubte algunes de les afirmacions i conclusions de l’article anterior.A la fi de 2019 vam rebre una petició de dret de rèplica de l’autora abans esmentada. En pro de la clarificació de posicions passem a publicar l’esmentada rèplica.In November 2017 we published the article “Carlos Arniches. Architecture and documents ”(On the w @ terfront vol. 58, nº 1, of November 10, 2017) signed by Dra. Concha Diez-Pastor.After its publication, we received a request for a right of reply from Martín Domínguez Ruz and Dr. Pablo Rabasco, which led to the publication of a new article, “The architects Arniches y Domínguez” (On the w @ terfront vol. 60, nº 10, of June 30, 2018). This article called into question some of the statements and conclusions of the previous article.At the end of 2019 we received a request for a right of reply from the aforementioned author. In order to clarify positions, we will publish the aforementioned reply.En Noviembre de 2017 publicamos el artículo “Carlos Arniches. Arquitectura y documentos” (On the w@terfront vol. 58, nº 1, de 10 de noviembre de 2017) firmado por la Dra. Concha Diez-Pastor. Tras su publicación recibimos una petición de derecho de réplica por parte de Martín Domínguez Ruz y del Dr. Pablo Rabasco que originó la publicación de un nuevo artículo, “Los arquitectos Arniches y Domínguez” (On the w@terfront vol. 60, nº 10, de 30 de junio de 2018). Este artículo ponía en entredicho algunas de las afirmaciones y conclusiones del artículo anterior.A finales de 2019 recibimos una petición de réplica de la autora antes mencionada. En pro de la clarificación de posiciones pasamos a publicar la citada réplica
Comparison Between Gleason Score and Apparent Diffusion Coefficient Obtained from Diffusion-Weighted Imaging of Prostate Cancer Patients
No full textObjectives: To correlate the apparent diffusion coefficient (ADC) of prostate cancer patients with pathological Gleason scores (GS). Methods: 40 patients with GS 2 + 3, 3 + 3, 3 + 4, or 4 + 4 were selected. The magnetic resonance imaging (MRI) study was performed adding axial diffusion-weighted imaging (DWI) sequences to the standard MRI protocol. ADC values obtained were correlated with the GS data. Results: Statistically significant differences of ADC (p < .05) were found among GS groups with a trend of decreasing ADC values with increasing GS. Conclusions: The ADC values may help clinicians to delineate prostate carcinoma, recognizing its high- or low-grade compartments
SURGICAL AND NON-SURGICAL THERAPY OF OBSTRUCTIVE SLEEP APNEA SYNDROME IN CHILDREN.
No full textInterventions of paediatric obstructive sleep apnea syndrome are complex, varied and multidisciplinary. The goal of the treatment is to restore optimal breathing during the night and to relieve associated symptoms. Evidence suggests that the surgical intervention with removal of the tonsils and adenoids will lead to significant improvements in the most incomplicated cases, as recently reported from a meta-analysis. However, post-operative persistence of this syndrome in paediatric population is more frequent than expected, which supports the idea of the complexity of this syndrome. Adenotomy alone may not be sufficient in children with OSAS, because it does not address oropharyngeal obstruction secondary to tonsillar hyperplasia. Continuous positive airway pressure can effectively treat this syndrome in selected groups of children, improving both nocturnal and daytime symptoms, but poor adherence is a limiting factor. For this reason, CPAP is not recommended as first-line therapy for OSAS when adenotonsillectomy is an option. It is now being investigated the incorporation of nonsurgical approaches for milder forms and for residual OSAS after surgical intervention. Althought adeno-tonsillar hypertrophy is the most common for OSAS in children; obesity is emerging as an equally important etiological factor. Therefore an intensive weight reduction program and adequate sleep hygiene are also important lifestyle changes that may be very effective in mitigating the symptoms of this syndrome. Pharmacological therapy (leukotriene antagonists, topical nasal steroids) is usually use for mild forms of OSAS and in children with associated allergic diseases. Special orthodontic treatment and oropharyngeal exercises are a relatively new and promising alternative therapeutic modality used in selected groups of children with OSAS
DISCRETE PHOSPHORYLATION GENERATES THE ELECTROPHORETIC HETEROGENEITY OF OVINE BETA-CASEIN
No full textThe heterogeneity of ovine beta-casein, apparent after discontinuous gel electrophoresis at alkaline pH and gel isoelectric focusing either by staining with Coomassie blue or immunoblotting, was investigated in detail. Electrospray mass spectrometry was used to characterize ovine casein by direct examination of whole casein samples. beta-Casein in individual milks consisted of several components which were characterized through the accurate determination of their molecular masses. It was demonstrated that protein species occurring simultaneously in individual ovine milks differed mainly in the number of phosphate groups
Modified doxorubicin for improved encapsulation in PVA polymeric micelles
No full textPolyvinylalcohol, partially substituted with lipophilic acyl chains, generates polymeric micelles in aqueous phase, containing a hydrophobic core able to encapsulate lipophilic drugs. Two types of polymers were obtained by conjugation of polyvinylakohol with oleoyl or linoleoyl chains as pendant groups. The polymers, at a substitution degree of ∼1%, are soluble in water and form polymeric micelles whose size increases with polymer concentration. Doxorubicin was hydrophobized, by linking an oleoyl chain via amide bond, to make the drug more similar to the substituted polymers and promote its encapsulation into the inner core of the micelles. The properties of the drug-polymer systems were evaluated in solution by dynamic light scattering technique and correlated to the physicochemical characteristics of the drug and the substituted polymers. Solubilization tests revealed that the similarity of the chain, in both the polymer and the drug, promotes better drug encapsulation in the oleoyl than linoleoyl derivative. The drug-polymer systems are stable in phosphate buffer saline (pH 7.4) at 37°C, and the release of the drug is activated by the presence of the proteolytic enzyme pronase-E. The enzyme activated drug release and the size of the polymeric micelles, compatible with the pore dimensions of the tumor vessels, make these systems interesting for targeting lipophilic drugs to solid tumors, where the proteolytic enzyme concentration strongly raises with respect to the other body compartments
El sistema Ctesiphonte. Evolución de la estructura catenaria
No full textThe difficult situation in Spain during the autarchy years (1940-55) led some architects to propose extremely economic and rapid solutions in order to solve the serious problem generated by the lack of housing. One of these proposals, and of particular interest, is the Ctesiphon system, based on a catenary structure as the only element that defines the space. This solution was to be used later for agricultural, social and religious purposes.La complicada situación de la España de los años de autarquía (1940-55), llevó a que algunos arquitectos propusieran soluciones sumamente económicas y de rápida construcción para tratar de solucionar el grave problema de la falta de vivienda. Entre esas propuestas llama especialmente la atención el sistema Ctesiphonte, basado en una catenaria estructural como único elemento que define el espacio. La solución se extenderá para otras funciones como la agropecuaria, pero igualmente llegará a utilizarse para edificios de uso social o religiososos
Correlative Chemical Imaging of Nanoscale Subcellular Structures
No full textChemical imaging can elucidate complex mechanisms, relationships, and components of biological samples. For example, it can reveal properties such as chemical composition, chemical structure, reactivity, and topography. Several imaging techniques exist, each providing different types of information. Yet, no single technique can comprehensively characterize a sample. Having a holistic profile often requires correlating complementary methods; for example, scanning electron microscopy (SEM) can be combined with secondary ion mass spectrometry (SIMS) imaging to obtain insights on both the physical topography (via SEM) and the chemical composition (via SIMS) of a sample surface. This approach is referred to as correlative imaging.
Correlative chemical imaging is applicable in many scientific fields, such as biology, chemistry, geology, and material science. Among the wide variety of modern imaging techniques that exist, nanoscale SIMS (NanoSIMS) emerges as a powerful tool, having seen growing applications, especially in biochemistry and cell biology. To this end, it can be used for the detection of isotopically labeled material in a sample and provides the chemical composition of the sample surface with high lateral resolution (down to 50 nm), sensitivity (ppm-ppb range), and mass resolution (up to 10000). By using an isotopic label, target molecules in the sample can be studied, although unlabeled samples can be used in some cases. NanoSIMS presents some limitations; for example, it usually cannot discern the ultrastructure of very small, intricate sample details (e.g., subcellular ultrastructure). Therefore, NanoSIMS is often correlated with additional imaging techniques, such as microscopy, to push its capabilities and overcome its shortcomings.
In the papers which are part of this thesis, NanoSIMS imaging was correlated with either electron or light microscopy to address different biological questions. To discern nanoscale subcellular ultrastructures, transmission electron microscopy (TEM) was employed, and to localize an organelle labeled with an antibody and a fluorescent tag, STED microscopy was used. In paper I, NanoSIMS was employed to detect 13C-dopamine in PC12 cells, and the images correlated with TEM to localize the dopamine within large dense core vesicles (LDCVs). In paper II, NanoSIMS was correlated with stimulated emission-depletion (STED) microscopy to localize endoplasmic reticulum stress-induced stress granules (SGs) in neuronal progenitor cells (NPCs) incubated with an isotopically labeled amino acid, and to characterize their protein turnover by changes in isotopic enrichment. In paper III, I investigated the role of vesicle size in the dynamics of partial release exocytosis events of PC12 cells by correlating TEM and NanoSIMS imaging data. In paper IV, NanoSIMS and TEM were correlated to look at the subcellular protein turnover in NPCs using different isotopically labeled amino acids and time-points. Overall, these studies demonstrate the importance of adequate correlative imaging strategies, and the variety of biological aims that can be achieved through different correlative chemical imaging approaches
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