Pricing (almost) any used goods: a first step towards a theoretical framework

From the latest technological gadget to the multi-century collectible item, millions of used goods are exchanged on marketplaces every day. Yet, there have been very few attempts to propose a pricing theory that could help buyers and sellers set a price at any point in time. In this paper, we build a robust framework and introduce a cohort-specific model to explain how the price of used goods evolves over time. Despite its simplicity, we believe that this model could be applied to an extensive range of used goods

Natural aromatic compounds as scaffolds to develop selective G-quadruplex ligands. From previously reported berberine derivatives to new palmatine analogues

In this paper, the selective interactions of synthetic derivatives of two natural compounds, berberine and palmatine,with DNA G-quadruplex structureswere reported. In particular, the previous works on this subject concerning berberine were further presented and discussed, whereas the results concerning palmatine are presented here for the first time. In detail, these palmatine derivatives were developed by inserting seven different small peptide basic chains, giving several new compounds that have never been reported before. The preliminary studies of the interactions of these compounds with various G-quadruplex-forming sequences were carried out by means of various structural and biochemical techniques, which showed that the presence of suitable side chains is very useful for improving the interaction of the ligands with G-quadruplex structures. Thus, these new palmatine derivatives might act as potential anticancer drugs

Classificador inteligente para falhas mecânicas em motores de indução trifásicos

Os motores de indução são um dos equipamentos mais relevantes para a indústria moderna devido a sua alta aplicabilidade e seu elevado rendimento energético. Em condições inadequadas de operação, como temperatura ou pressão elevada, vibrações ininterruptas e variações de carga, os motores tendem a aumentar a suscetibilidade a falhas externas e internas, acarretando em uma contração na sustentabilidade econômica do processo fabril e tornando-se uma fonte de vibrações excessivas, o que para análise estrutural pode ser fontes de risco a segurança de todo o ambiente no qual é instalado e seus arredores. Este trabalho tem como objetivo elaborar um sistema de diagnóstico para falhas mecânicas de motores de indução trifásico, utilizando sinais de vibração do maquinário provenientes base de dados MaFaulDa, para produzir um estudo comparativo de algoritmos inteligentes, como redes neurais artificiais, Florestas aleatórias, Adaboost, regressão logística e XGBoost utilizando características extraídas das séries temporais: índices de entropia, curtose, amplitude média, magnitude espectral média, máxima, sua centróide, em um sistema de segmentação de 10 ms. Avaliando duas técnicas para a otimização de hiperparâmetros - Algoritmos genéticos e a pesquisa randômica. Obtendo um teor de generalização em sua topologia final, indicado pela métrica de accuracy acima de 98%, adequando-se a faixa de valores dos modelos referencias na área.Induction motors are one of the most relevant equipment in modern industry due to their high applicability and energy efficiency. Under inadequate operating conditions, such as high temperature or pressure, uninterrupted vibrations and load variations, motors tend to increase their susceptibility to external and internal failures, resulting in a contraction in the economic sustainability of the manufacturing process and becoming a source of excessive vibrations, which is for structural analysis a risk source to the entire environment safety. This work aims to develop a diagnostic system for mechanical failures of three-phase induction motors, using machinery vibration signals from the MaFaulDa database, to elaborate a comparative study of intelligent algorithms, such as artificial neural networks, Random Forests, Adaboost, logistic regression and XGBoost. Extracting features from the time series such as entropy, kurtosis, mean amplitude, average spectral magnitude, its maximum and its centroid, in a 10 ms segmentation system. Evaluating the best two techniques for hyperparameter optimization - Genetic Algorithms and Random Search. Obtaining a generalization content in its final topology, indicated by the accuracy metric above 98%, fitting in the range of values of the area’s reference models

The use of Wittgenstein\u27s language games to promote argumentation in children at the beginning of scientific literacy: a proposal for analyzing the argumentative process.

The insertion of the individual in the scientific culture goes through scientific literacy and this, through teaching that privileges research and argumentation in the school scenario, mainly in Science classes. Based on indicators found in the literature that point to scientific literacy and models proposed by Lawson to define the structure of the argument, a table was elaborated to relate the argumentation of children in the second year of elementary school, leveling it in five levels that point to the logical reasoning and the dominion of content, taking into account Wittgenstein\u27s linguistic games. To analyze what level the children were at, a didactic sequence was elaborated that allowed the observation and study of the arguments used by them. Considering such activities and the children\u27s age group, it was observed that they tend not to complete the argumentative sequence, but they already have strong traces of scientific literacy

Rotatividade de colaboradores: um estudo de caso em uma escola particular de educação infantil em Brasília/DF

O presente estudo objetiva analisar a efetividade das ações que são tomadas para minimizar a rotatividade dos colaboradores em uma escola particular do segmento educação infantil em Brasília/DF. Este assunto é relevante pelo fato de preocupar diversas empresas, devido às elevadas taxas de rotatividade de colaboradores existentes no Brasil. Além disso, os gestores estão cada vez mais preocupados em reter seus colaboradores, por entenderem a importância das pessoas no sucesso das organizações. Assim, serão descritas as ações de uma determinada escola para combater a rotatividade e será mensurado o índice de rotatividade dos colaboradores em um determinado período. O referencial apresentado obteve os conceitos de rotatividade, os fatores geradores, as consequências, as ferramentas e as ações para controle. Dentre essas ferramentas será aprofundada a fórmula do índice de rotatividade, visto que é o principal instrumento para mensurar a rotatividade de colaboradores de forma estatística e confiável. Com isso, a metodologia usada no presente estudo se deu de forma qualitativa e quantitativa, com caráter descritivo, em forma de estudo de caso quanto aos meios de investigação. A unidade de caso é uma escola tradicional de Brasília e bem conceituada no segmento educação infantil. Para este trabalho, utilizou-se uma entrevista semi-estruturada com o responsável pelo Departamento de Pessoal / Recursos Humanos para levantar as ações tomadas pela escola para minimizar a rotatividade e a análise de documentos da instituição para mensurar o índice de rotatividade. Ao final do estudo, são descritas as ações levantadas na entrevista, comparadas com a evolução dos índices de rotatividade no período proposto. Dessa forma, identifica-se a efetividade das ações tomadas para controlar a rotatividade na escola analisada, quando relacionadas à redução do índice de rotatividade, propiciando a reflexão de que as organizações devem prestar atenção à rotatividade de colaboradores e encontrar formas para combater esse fenômeno

A simple cultural method for the presumptive detection of the yeasts Brettanomyces/Dekkera in wines

The development of a simple and reliable procedure, compatible with routine use in wineries, for the presumptive detection of Brettanomyces/Dekkera from wine and wine-environment samples. Methods and Results: The method of detection of these yeasts employs a selective enrichment medium. The medium contains glucose (10 g l⁻¹1) as carbon and energy source, cycloheximide (20 mg l⁻¹1) to prevent growth of Saccharomyces, chloramphenicol (200 mg l⁻¹1) to prevent growth of bacteria and p-coumaric acid (20 mg l⁻¹1) as the precursor for the production of 4-ethyl-phenol. After the inoculation with wine, the medium is monitored by visual inspection of turbidity and by periodic olfactive analysis. Contaminated wines will develop visible turbidity in the medium and will produce the 4-ethyl-phenol off-odour, which can be easily detected by smelling. Conclusions: A selective enrichment liquid medium was developed to differentially promote the growth and activity of Brettanomyces/Dekkera. The method is simple to execute, employing a simple-to-prepare medium and a periodic olfactive detection. Significance and Impact of the Study: The characteristics of the procedure make it particularly applicable in a wine-making environment thus presenting important advantages to the wine industry

An overlook on the current registries for rare and complex connective tissue diseases and the future scenario of TogethERN ReCONNET

European Reference Networks; Rare and complex connective tissue diseases; RegistriesRedes Europeas de Referencia; Enfermedades raras y complejas del tejido conjuntivo; RegistrosXarxes de referència europees; Malalties rares i complexes del teixit conjuntiu; RegistresBackground: Patient registries play a crucial role in supporting clinical practice, healthcare planning and medical research, offering a real-world picture on rare and complex connective tissue diseases (rCTDs). ERN ReCONNET launched the first European Registry Infrastructure with the aim to plan, upgrade and link registries for rCTDs, with the final goal to promote a harmonized data collection approach all over Europe for rCTDs. Methods: An online survey addressed to healthcare professionals and patients' representatives active in the field of rCTDs was integrated by an extensive database search in order to build a mapping of existing registries for rCTDs. Findings: A total of 140 registries were found, 38 of which include multiple diseases. No disease-specific registry was identified for relapsing polychondritis, mixed connective tissue disease and undifferentiated connective tissue disease. Discussion: This overview on the existing registries for rCTDs provides a useful starting point to identify the gaps and the strengths of registries on the coverage of rCTDs, and to develop a common data set and data collection approach for the establishment of the TogethERN ReCONNET Infrastructure.This work was funded by the European Union's Health Program (2014–2020). ERN ReCONNET is one of the 24 European Reference Networks (ERNs) approved by the ERN Board of Member States. The ERNs are co-funded by the EC (European Commission) (grant no. 947700)

A novel similarity-measure for the analysis of genetic data in complex phenotypes

BACKGROUND: Recent technological advances in DNA sequencing and genotyping have led to the accumulation of a remarkable quantity of data on genetic polymorphisms. However, the development of new statistical and computational tools for effective processing of these data has not been equally as fast. In particular, Machine Learning literature is limited to relatively few papers which are focused on the development and application of data mining methods for the analysis of genetic variability. On the other hand, these papers apply to genetic data procedures which had been developed for a different kind of analysis and do not take into account the peculiarities of population genetics. The aim of our study was to define a new similarity measure, specifically conceived for measuring the similarity between the genetic profiles of two groups of subjects (i.e., cases and controls) taking into account that genetic profiles are usually distributed in a population group according to the Hardy Weinberg equilibrium. RESULTS: We set up a new kernel function consisting of a similarity measure between groups of subjects genotyped for numerous genetic loci. This measure weighs different genetic profiles according to the estimates of gene frequencies at Hardy-Weinberg equilibrium in the population. We named this function the "Hardy-Weinberg kernel". The effectiveness of the Hardy-Weinberg kernel was compared to the performance of the well established linear kernel. We found that the Hardy-Weinberg kernel significantly outperformed the linear kernel in a number of experiments where we used either simulated data or real data. CONCLUSION: The "Hardy-Weinberg kernel" reported here represents one of the first attempts at incorporating genetic knowledge into the definition of a kernel function designed for the analysis of genetic data. We show that the best performance of the "Hardy-Weinberg kernel" is observed when rare genotypes have different frequencies in cases and controls. The ability to capture the effect of rare genotypes on phenotypic traits might be a very important and useful feature, as most of the current statistical tools loose most of their statistical power when rare genotypes are involved in the susceptibility to the trait under study

Radionauta: comunicación y horizontes colectivos

El propósito de esta tesis de investigación es sistematizar y describir procesos de conformación de medios y de redes de medios populares-alternativos-comunitarios (sociales) que exceden los límites geográficos y buscan el trabajo colectivo en pos de un objetivo de transformación social amplio, sustentados en proyectos sociales y políticos. Mediante la participación observante, siempre cerca de los colectivos, incluso impulsando y protagonizando actividades conjuntas, buscamos contar la experiencia desde las sensaciones y construcciones propias. Así como dar cuenta de los espacios de formación inherente a las prácticas de comunicación surgidas de la voluntad y el deseo compartido, en una búsqueda por crear y producir modos de comunicación para las necesidades propias. A partir de entrevistas en profundidad, y reportajes realizados por mail buscamos analizar las perspectivas de los sujetos involucrados en esos colectivos para analizar su visión de las prácticas, las búsquedas individuales y colectivas en los procesos de construcción de radios, programas de radio y portales de comunicación en Internet. Con esta tesis creemos contribuir al vasto estudio la comunicación alternativa, proponiendo nuevas conceptualizaciones para pensar estas prácticas, en relación al escenario actual planteado por la inserción de internet al campo de las comunicaciones y la información. Asimismo reflexionar sobre el mapa planteado luego de la sanción de la LSCA.Facultad de Periodismo y Comunicación Socia