Modelización molecular de complejos de inclusión de ciclodextrinas con acetazolamida

Las ciclodextrinas (CDs) son oligomeros cíclicos constituidos por seis, siete, ocho o mas unidades de α-D-glucopiranosa unidos por enlaces 1-4. Se obtienen por una reacción de degradación de la enzima ciclodextrin-glucotransferasa sobre el almidón. Tanto las CDs naturales como sus diferentes derivados poseen la capacidad de formar compuestos de inclusión con una amplia variedad de especies químicas, modificando las propiedades fisicoquímicas de las mismas de forma ventajosa. Este fenómeno constituye la base de múltiples aplicaciones en el campo de la Medicina, Farmacia, Química, Agricultura, Alimentación y Medio ambiente, entre otras. En la actualidad, en nuestro departamento se están estudiando diferentes aspectos de la complejacion de ACZ con CDs, con objeto de aumentar su solubilidad y permitir la incorporación de una mayor concentración de fármaco en el desarrollo de un medicamento solución oftalmica para tratamiento del glaucoma. En este trabajo, intentaremos profundizar el conocimiento de las interacciones entre ACZ y una serie de CDs, en concreto β-CD e hidroxipropil β-CD (HP-b-CD) al formar complejos de inclusión a través de modelización molecular (in silico), mediante el uso de software de modelización molecular. Para ello, se acudió al empleo de mecánica molecular (campo de fuerza MM+ en el vacio), complementándose con la aplicación de métodos semiempiricos de mecánica cuántica (Parametric Model 3). Para la correcta realización de esta técnica y así poder hallar el mínimo global de energía, fue necesario partir de estructuras de mínima energía de los monómeros (fármacos y CDs). Los resultados obtenidos sugieren la formación de complejos estables y por tanto viables, para los cuales se observó que los puentes de hidrogeno jugaban un papel muy importante. En general, los valores de diferencial de energía HOMO-LUMO se hallaron en buena correlación con los valores de energía de complejacion e interacción confirmando también la estabilidad de los complejosUniversidad de Sevilla. Grado en Farmaci

Autoeficácia nos papéis de carreira e exploração vocacional de jovens que vivem em lares de infância e juventude

Dissertação de mestrado integrado em Psicologia (área de especialização em Psicologia Escolar e da Educação)Analisou-se o desenvolvimento de carreira de jovens institucionalizados em Lares de Infância e Juventude relativamente às dimensões da Exploração vocacional e da Autoeficácia nos papéis de carreira. Os participantes foram 136 jovens (Midade = 16.20, DP = 2.19) que foram comparados com uma amostra de 184 jovens que vivem com as famílias (Midade = 16.72, DP = 2.13). A Exploração vocacional foi avaliada através do Inventário de Exploração Vocacional (CES; Stumpf, Colarelli & Hartman, 1983, versão adaptada por Taveira, 1997) e a Autoeficácia de carreira através do Inventário de Crenças de Autoeficácia Relativamente aos Papéis de Carreira (ICARPC; Vale, 1997). Foram realizadas análises de comparação de médias, análise de relações e uma Manova. Verificou-se que o grupo institucionalizado revela menores valores de Autoeficácia nos papéis de Trabalhador e Tempos livres e nas crenças de Exploração que remetem para a Importância da posição preferida e Instrumentalidade externa. Paralelamente, maiores níveis de Autoeficácia são preditores de maior stresse relacionado com a Exploração vocacional. Com base nos resultados, são retiradas implicações para a intervenção no âmbito da psicologia da carreira com esta população.The career development of foster care youth on the dimensions of Vocational Exploration and Self-efficacy in career roles was analyzed. Participants were 136 foster care young (Mage = 16.20, SD = 2.19) compared with a sample of 184 young people living with their families (Mage = 16.72, SD = 2.13). The Vocational exploration was assessed using Inventário de Exploração de Carreira (CES; Stumpf, Colarelli & Hartman, 1983, version adapted by Taveira, 1997) and Self-efficacy through the Inventário de Crenças de Autoeficácia Relativamente aos Papéis de Carreira (ICARPC; Vale, 1997). The analyzes included comparison of means, analysis of relations and a Manova. It was found that the institutionalized group revealed lower levels of Self-Efficacy in Worker and Leisure role's, and also in beliefs of Exploration, that refers to the importance of the preferred position and external Instrumentality. Further, Career exploration was lower for young living out-of-home in exploration beliefs preferred position Importance and external Instrumentality which are related. In parallel, higher levels of Self-efficacy are predictors of stress related to career exploration. Based on the results, implications are drawn for intervention in the psychological career with this population

Mechanical characterization of composites based on a novel vacuum-infused thermoplastic matrix

Este estudo está focado na avaliação do desempenho mecânico e dos mecanismos de falha de compósitos à base de uma resina termoplástica líquida sob várias condições de carregamento em comparação com compósitos à base de epóxi. Os laminados compostos reforçados por fibras de carbono foram fabricados pela VARTM (Moldagem por transferência de resina assistida a vácuo). Os compósitos foram submetidos às condições de carregamento do modo II, a fim de verificar sua tolerância a danos. Nesse caso, os compósitos termoplásticos apresentaram 40% mais resistência à fratura interlaminar em comparação aos compósitos epóxi. Esses materiais obtiveram desempenho superior na resistência à propagação de trincas, pois tendem a absorver a energia associada à propagação de trincas na forma de deformação plástica em comparação aos compósitos epóxi. Também foram realizados testes de resistência à tração e cisalhamento no plano para avaliar a resposta de ambos os materiais em amostras não condicionadas e condicionadas. Os compósitos termoplásticos apresentaram 30% mais resistência à tração em comparação aos compósitos epóxi. Para amostras condicionadas, essa diferença foi de 14%. Esses resultados foram relacionados à plastificação, que tende a favorecer o amolecimento do polímero, proporcionando maior deformação plástica da matriz, promovendo uma fratura dúctil do compósito. Por outro lado, as propriedades de cisalhamento no plano foram 30% maiores para os laminados termoendurecíveis em ambas as condições. Nesse caso, a umidade pode ter favorecido a formação de rachaduras na superfície e enfraquecido a adesão interfacial fibra / matriz. Análises adicionais baseadas no projeto de experimentos mostraram que a resina Elium® 150 afeta significativamente todas as respostas e apresentou, de fato, um melhor comportamento em comparação à resina epóxi. Embora os efeitos do condicionamento tenham apresentado uma contribuição estatisticamente perceptível à resistência à tração, a presença da umidade não proporcionou um aprimoramento significativo da resistência ao cisalhamento no plano. A análise baseada na metodologia de teste acelerado de compósitos Carbon Fiber / Elium® 150 mostra que as altas frequências aumentam a transição vítrea (Tg) para valores mais altos, provavelmente favorecidos pelo movimento das cadeias poliméricas. A rede neural artificial evidenciou uma excelente concordância entre os valores treinados e experimentais. A previsão de vida útil em longo prazo usando curvas mestres confirma que este novo material pode ser considerado para fins de amortecimento acústico ou vibracional, considerando seu uso em temperaturas abaixo de Tg

Older portuguese celebrities on Instagram: a snapshot of their strategies and communication practices

Older social media influencers and in particular celebrities have recently found a new arena where they can gather an entourage of fans: social networking sites (SNS). As their digital born and raised counterparts – social media influencers – they have the power to attract millions of followers by carefully and strategically sharing curated content from their lives, or their opinions and points of view on digital platforms such as Instagram, Facebook and TikTok (e.g., Chappie & Cownie, 2017; Schouten et al., 2019). Scholars and practitioners have long been acknowledging that celebrities are important influencers of human behavior in several life domains, including in social media. And in today’s digital zeitgeist, companies still recognize their potential effect on consumers, resorting to celebrities’ endorsements in the form of positive electronic word-of-mouth about the company’s products or services. Yet, research on older celebrities and their strategies and communication practices in SNS, as well as their influence on their digital followers is still scant. Building on theories related to self-disclosure and celebrity endorsement, this exploratory study examines the top 5 Instagram accounts of older Portuguese celebrities, analyzing their presence and branded personae on Instagram as well as their communicative practices and engagement. Instagram, one of the most popular SNS for individuals of all age cohorts, was chosen not only for its popularity but also because it has been changing the social media ecosystem and because it lends itself particularly well to influencer marketing (Duffy, 2020). A quali-quanti study was conducted involving the analysis of all the Instagram publications of these five celebrities during a three-month period, from April to June 2022. The dimensions examined were: the number of posts, the number of followers, the number of sponsored posts, hashtags, themes/subjects of interest, audiovisual and multimedia resources, as well as their interaction and engagement with followers. The results suggest that diversity is their common feature, with clear and marked differences in what concerns their communicative styles and strategies, as well as in interactions and engagement rate with their followers. These older celebrities appear to be unique digital content creators, with an unrepeatable charisma that attracts an increasing number of followers. Their distinctive digital branded personae, their strong investment in their work or other interests, their digital empowerment and their active and interventive posture on what goes on in their life, around them or in the world defy old-age stereotypes. Although exploratory in nature, this study highlights the bright, successful aging of these older celebrities and reveals that they still have the power to mobilize and engage a considerable number of fans, despite they do not take advantage of this to promote brands or products.N/

Stereoscopy in Nineteenth Century Brazil: the case of Rio de Janeiro

This study presents a preliminary systematisation of the stereographs that are part of the public collections of Rio de Janeiro. We start with an investigation of the presence of optical devices in nineteenth century Brazil, especially in the city of Rio de Janeiro, examining both users and diffusers, as well as the forms of observation and social contexts of their use. Our original research was based on the studies of the first cinema, especially the work of Tom Gunning and Charles Musser, and on art history by Jonathan Crary, authors who helped us analyse, respectively, the re-contextualization process regarding the use of optical devices and the resizing of the observer of modernity. Our empirical work was based on the systematic study of advertisements published in the newspapers of the period in question, especially in the Jornal do Commercio, between the 1850s and the 1870s. We conducted a survey of the establishments that imported and marketed these devices during the period, using advertisements published in Almanak Laemmert, between the years 1844 and 1889. We place a special emphasis on the arrival of photography in Brazil and to the precocity with which stereoscopy was developed here by the photographer Revert Henrique Klumb. We mapped themes as a reference for Brazilian visuality, and made an inventory of the Brazilian photographers who developed this technique in their works. From the information gathered, we answered research questions about the presence of optical devices in the city of Rio de Janeiro in the nineteenth century, especially stereoscopy considering its particularities in the historical, economic and social context of the time

A robust version of the FGLS estimator for panel data

Panel or longitudinal data sets are frequent in financial and economic studies. This type of data combines cross-sectional with time series data, providing extra information and allowing to evaluate and measure statistical effects that would otherwise keep unknown. Different degree of restrictions upon the structure of the data leads to different ap proaches with least squares methodology. This results in estimators that can be highly affected by a violation of those assumptions. The Feasible Generalized Least Squares estimator (FGLS) is an estimator that pre serves good properties without requiring strong distribution requisites. In spite of this, it is highly affected with the presence of observations too much different from all the rest. These are known as atypical ob servations or outliers. Economical and financial real data often present this type of data and the FGLS estimator may be seriously affected by those observations. This might be avoided if a robust option is chosen. Although robustness is a main concern in recent econometric modelling, there is still much to do in this field. Recent studies in those fields point to the advantage of using robust estimators. With this work we want to contribute to the use of robust methodologies in the estimation of panel data models and present a robust version of FGLS, the RFGLS (Robust Feasible Generalized Least Squares). In this paper, the performance of the proposed estimator is compared with the FGLS using a real data previously analysed by some authors.publishe

Moodle tests: not so much of a fuss when you have R

One of the least motivating parts of the teaching-learning process is evaluation. It is a task done with some periodicity and one of the aspects that teachers seek to improve. In higher education institutions, evaluation consolidates the learning process and it is an important tool that permits the accountability and certification of the results. During that process teachers aim to achieve equity, suitability, reliability, and efficiency. The preparation of different components of evaluation is one of the most time-consuming activities and so it is highly desirable to reduce the time used in that process, namely, in the preparation of written exams. All over the world, educational institutions of all degrees have adopted some mixed models of communications between the agents of the process of learning-teaching. The digital way is largely spread using suitable platforms. One of the top preferences among a great part of those institutions is Moodle. Moodle provides some tools to perform formative as well as summative evaluation. We've seen how Pandemic disease increased the need for the use of such tools. Recent studies show new problems raised with home evaluation tests, one of which is the easier possibility of fraud. As a response to this problem, one can increase the number of different questions presented to different students. With particularly advantages to statistics teachers (familiarized with R), the R package exams is a powerful tool that provides some answers to those problems: it produces questions that can be exported directly to Moodle quiz format (as well as in paper format) and it allows for random generation of parametrized questions. This way, one rapidly obtain a number of multiple questions, all of them with the same level of difficulty and related to the same topics, ready to include in the Moodle bank of questions. This paper aims to show how these tools combined with latex and markdown environments may contribute to help Statistics teacher's activity.publishe

Knowledge intensive business services (KIBS) in Portugal: location and innovative capacity

Within the service industry, the swift growth of the KIBS (Knowledge Intensive Business Service(s)) sector has played a crucial role in innovation processes. Above all, this role is confirmed by the fact that such entities do not turn in a simple performance in innovation activities as would be the case in simply meeting the needs of prevailing levels of demand or, more specifically, their clients. Instead, they establish bridges of knowledge and points of innovation between companies and science. The literature goes so far as to identify the origins of the third industrial revolution with the importance attributable to KIBS. While the debate on the growth of KIBS unfolds around these new specialist fields and the growth in the tertiary sector in general, there is ever growing recognition that both new manufacturing processes and new services and innovations in more general terms increasingly derive from KIBS. Our interest in KIBS derives from a position broadly defended by a wide range of authors (Muller, 2001; Howells and Tether, 2004; Toivonen, 2004; Koch and Stahlecker, 2006): the irrefutable role played by KIBS in the development of their surrounding regions. In the Thesis below, we have sought to study these companies across four fundamental research facets: (i) location; (ii) cooperation with universities; (iii) factors of innovation and (iv) innovative and competitive capacities. To approach factors of location, we deployed exploratory factorial analysis and Logit regression modelling and found that in this aspect, there was statistical significance for rural and urban KIBS. The results revealed that rural KIBS are essentially influenced by personal motivations and their owners tend to be younger and with fewer years of experience. In the case of urban KIBS, the main factor is the prevailing business conditions in the location with entrepreneurs tending to be older and with more years of experience. Our analysis of cooperation between KIBS and universities involved the application of exploratory factorial analysis and a logit regression model. Our findings show that the probability of KIBS establishing partnerships with universities rises in accordance with the levels of proximity and trust, the types of cost associated with such partnerships and the age of the entrepreneur. Furthermore, we encounter no difference in terms of either location or typology. The results also enable us to conclude that there is a statistically significant effect between the employment of staff with higher education, the age and academic background of the company owner, and the logistical probability of the company locating in rural areas. This means that, while there is little or no direct cooperation between universities and KIBS companies, there is a transfer of knowledge courtesy of the university graduates employed in these professions. The level of graduate employment is high at both rural and urban KIBS. To study the factors of innovation, we made recourse to confirmatory factorial analysis with the objective of verifying whether the strategy, the organisation, the learning, the networks and the process, influence the innovation activities ongoing at KIBS. We found that the network factor is of high importance to both KIBS types (professional and technological). However, professional KIBS also returned the strategy factor as the driver of innovation while technological KIBS attributed greatest priority to learning as a factor for innovation. Furthermore, no statistically significant differences were identified between rural and urban located KIBS. Finally, we applied structural equations for analysis of the innovative and competitive capacities of KIBS and evaluating up to just what point innovation depends on the nature of the service (technological or professional) and location (rural and urban). Firstly, the results of certain analytical processes found that the innovative capacities of the different types of rurally located KIBS displayed no statistical significance while at KIBS in urban locations, professional KIBS companies innovated less than their technological peers and the latter thereby proved able to simultaneously turn in better financial performance and hence may be deemed more competitive