Applying feature reduction analysis to a PPRLM-multiple Gaussian language identification system

This paper presents the application of a feature selection technique such as LDA to a language identification (LID) system. The baseline system consists of a PPRLM module followed by a multiple-Gaussian classifier. This classifier makes use of acoustic scores and duration features of each input utterance. We applied a dimension reduction of the feature space in order to achieve a faster and easier-trainable system. We imputed missing values of our vectors before projecting them on the new space. Our experiments show a very low performance reduction due to the dimension reduction approach. Using a single dimension projection the error rates we have obtained are about 8.73% taking into account the 22 most significant features

On the synchronization of coupled random walks and applications to social systems

Some political strategies to win elections over the last years were based heavily on fomenting general distrust in information institutions and favoring distrustful sources. The misinformation pandemic has the straightforward consequence that people do not believe any information unless it is compatible with their own beliefs. We present a simple model to study the emergence of consensus in opinion pools of uncertain agents that trust (couple to) their neighbors (information sources) with strength K. We focus the studies on regular lattices and linear coupling. Depending on the coupling constant, K, and the propensity to choose an opinion (the probability to manifest a given opinion in solitude), p_0, we get regions where consensus is surely reached even in infinity systems (K greater than or equal to K_c), regions where not-consensus is the only steady state (K lesser than K_c), and a region where consensus on any opinion is transitory with each agent presenting periods of strong oscillation of opinions before changing polarization (p_0 equal to p_c and K greater than or equal K_c. The first model in this last region presents transition probabilities identical to the voter model (p_0 equal to p_c and K equal to K_c). Different upbringings, exposition to education biased to a single political view, and previous coexistence with opinion polarized people can change the opinion of agents in isolation. We model such characteristics with heterogeneous populations (p^i_0 not equal to p^j_0 for some pairs of nodes i,j). Such systems present regions where the coexistence of local consensus (bulk-stable clusters of like-minded opinions), weak consensus (bulk-unstable temporary clusters where contrary opinions emerge inside the cluster), and distrust (random orientations that do not form clusters) are possible.Comment: 14 pages, 7 figures, 4 section appendi

Narrativas de Si: Tessituras das aprendizagens da docência em Matemática

The present study addresses the reflections of a mathematics teacher engaged in experiential learning built over their teaching career. Grounded in a qualitative approach, the text unfolds through narrative research, utilizing personal narrative as a tool for systematizing and developing knowledge and practices in mathematics education. The narrative emerges as essential in building awareness that everyday experiences and professional trajectories shape mathematics education. The conclusion emphasizes that in the field of teaching, a constructive and collaborative attitude is fundamental to sharing knowledge that develops through interaction with students and strategies used in mathematics education, resulting in the production of knowledge acquired through professional experience.El presente trabajo versa sobre las autorreflexiones que teje un docente de Matemáticas al emprender el aprendizaje experiencial que ha construido al habitar la profesión docente. Anclado en una perspectiva cualitativo, el texto se desarrolla a partir de la textura de la investigación narrativa, teniendo como dispositivo la narrativa del yo como elemento de sistematización y constitución de saberes y prácticas de enseñanza en matemáticas. La narrativa surgió como un elemento de producción de conciencia de que la enseñanza de las matemáticas se teje bajo una base formativa de experiencias y trayectorias del cotidiano de la profesión Concluye explicando que en la docencia se incurre en una actitud constructiva y colaborativa para producir un compartir de saberes que se construye en la relación con sus alumnos, y con lo que ha hecho para enseñar matemáticas, y así producir conocimientos experienciales de la profesión.O presente estudo aborda as reflexões de um professor de matemática que se envolve em aprendizagens experienciais, construídas ao longo de sua carreira docente. Embasado em uma abordagem qualitativa, o texto se desenvolve a partir da pesquisa narrativa, utilizando a narrativa pessoal como um dispositivo para a sistematização e a formação dos conhecimentos e práticas no ensino de matemática. A narrativa emergiu como um componente essencial na construção da consciência de que o ensino de matemática é moldado a partir das experiências e trajetórias cotidianas da profissão. A conclusão destaca que no campo da docência, uma atitude construtiva e colaborativa é fundamental para compartilhar conhecimentos que se desenvolvem por meio da interação com os estudantes e das estratégias utilizadas no ensino da matemática, resultando na produção de saberes adquiridos por meio da experiência profissional

Validation of smart nanoparticles as controlled drug delivery systems: loading and pH-dependent release of pilocarpine

Micelles are good devices for use as controlled drug delivery systems because they exhibit the ability to protect the encapsulated substance from the routes of degradation until they reach the site of action. The present work assesses loading kinetics of a hydrophobic drug, pilocarpine, in polymeric micellar nanoparticles (NPs) and its pH-dependent release in hydrophilic environments. The trigger pH stimulus, pH 5.5, was the value encountered in damaged tissues in solid tumors. The new nanoparticles were prepared from an amphiphilic block copolymer, [(HEMA19%-DMA31%)-(FMA5%-DEA45%)]. For the present research, three systems were validated, two of them with cross-linked cores and the other without chemical stabilization. A comparison of their loading kinetics and release profiles is discussed, with the support of additional data obtained by scanning electron microscopy and dynamic light scattering. The drug was loaded into the NPs within the first minutes; the load was dependent on the degree of cross-linking. All of the systems experienced a boost in drug release at acidic pH, ranging from 50 to 80% within the first 48 h. NPs with the highest degree (20%) of core cross-linking delivered the highest percentage of drug at fixed times. The studied systems exhibited fine-tuned sustained release features, which may provide a continuous delivery of the drug at specific acidic locations, thereby diminishing side effects and increasing therapeutic rates. Hence, the studied NPs proved to behave as smart controlled drug delivery systems capable of responding to changes in pH.Peer ReviewedPostprint (published version

Antioxidant activity of alkyl gallates and glycosyl alkyl gallates in fish oil in water emulsions: Relevance of their surface active properties and of the type of emulsifier

The antioxidant activity of gallic acid and a series of alkyl gallates (C4-C18) and glycosylated alkyl gallates (C4-C18) on fish oil-in-water emulsions was studied. Three types of emulsifiers, lecithin, Tween-20 and sodium dodecyl sulphate (SDS) were tested. A nonlinear behavior of the antioxidant activity of alkyl gallates when increasing alkyl chain length was observed for emulsions prepared with lecithin. Medium-size alkyl gallates (C6-C12) were the best antioxidants. In contrast, for emulsions prepared with Tween-20, the antioxidants seem to follow the polar paradox. Glucosyl alkyl gallates were shown previously to be better surfactants than alkyl gallates. Nevertheless, they exhibited a worse antioxidant capacity than their corresponding alkyl gallates, in emulsions prepared with lecithin or Tween-20, indicating the greater relevance of having three OH groups at the polar head in comparison with having improved surfactant properties but just a di-ortho phenolic structure in the antioxidant