Citrate and Polyvinylpyrrolidone Stabilized Silver Nanoparticles as Selective Colorimetric Sensor for Aluminum (III) Ions in Real Water Samples

The use of silver nanoparticles stabilized with citrate and polyvinylpyrrolidone as a sensor for aluminum ions determination is proposed in this paper. These non-functionalized and specific nanoparticles provide a highly selective and sensitive detection system for aluminum in acidic solutions. The synthesized nanoparticles were characterized by transmission electron microscopy. Surface plasmon band deconvolution analysis was applied to study the interaction between silver nanoparticles and aluminum ions in solution. The interaction band in the UV-visible region was used as an analytical signal for quantitation purposes. The proposed detection system offers an effective AND wide linearity range (0.1-103 nM), specificity for Al(III) in THE presence of other metallic ions in solution, as well as high sensitivity (limit of detection = 40.5 nM). The proposed silver-nanoparticles-based sensor WAS successfully used for detecting Al(III) in real water samples.Spanish Ministerio de Economía y Competitividad, MinECo, CTQ2016-78703-P (AEI/FEDER, UE)España, Universidad de Sevilla ,V Plan Propio Grupos Emergentes (PP2016-5937)Junta de Andalucía (2017/FQM-386)CITIUS VI PP USO SSGG (1804031606

Desarrollo de un prototipo de entornos virtuales para fines didácticos en empresas

Debido al avance de las tecnologías, el ser humano es capaz de interactuar con un sistema virtual de muchas maneras distintas, ya sea con nuestras propias manos como es el caso del dispositivo Leap Motion, con nuestra voz (Alexa, Echo Dot de Amazon), étc. Incluso podemos visualizar un entorno como si nos encontráramos en él con el casco de realidad virtual Oculus Rift. Ante esto, muchas empresas han aprovechado la oportunidad para integrar sus productos y crear aplicaciones orientadas a enseñanza, simulaciones o prácticas utilizando las tecnologías de manera simultánea y conjunta. Este trabajo pretende profundizar en este tema ya que nuestra intención es crear un prototipo de entorno que integre a todas estas tecnologías y que pueda ser utilizado en un futuro para tareas didácticas en empresas.Due to the growth of technology, human being is capable of interacting with a virtual system in many differents ways, either with our own hands as in the case of the device Leap Motion, with our voice (Alexa, Amazon's Echo Dot), etc. We can even visualize an environment as if we were there with the virtual reality headset Oculus Rift. Therefore, a lot of companies have taken the opportunity to integrate their products and create applications oriented to education, simulations or practice using the technologies simultaneously and together. This work will deepen in this topic because our intention is to create an environment prototype that will integrate all these technologies and that it can be used in the future for didactic tasks in companies.101 páginas. 20,6M

Homotopy in digital spaces

The main contribution of this paper is a new “extrinsic” digital fundamental group that can be readily generalized to define higher homotopy groups for arbitrary digital spaces. We show that the digital fundamental group of a digital object is naturally isomorphic to the fundamental group of its continuous analogue. In addition, we state a digital version of the Seifert-Van Kampen theorem.Dirección General de Investigación Científica y TécnicaDirección General de Enseñanza Superio

Propriedades psicométricas do DESIT-17 para a medição da satisfação acadêmica em estudantes de Ciências Médicas da Universidad de Iberoamérica (UNIBE)

Universities have a crucial responsibility in their role of social and professional training, as well as being vehicles of social mobility in the current difficult global socioeconomic context. For this reason, it is especially relevant not only to have psychometrically adequate instruments, but also easy to apply with respect to the quality of education. The aim of this article is to explore the psychometric properties of an academic satisfaction (AS) instrument developed from the self-evaluation questionnaire of the National Higher Education Accreditation System (SINAES), used by universities seeking accreditation in Costa Rica, together with the relevant information found in this particular case. The instrument was applied to 226 students of Medical Sciences at UNIBE in person during the first four-month period of the year 2021 in San José. As a result, after an exploratory factor analysis, the DESIT-17 was obtained, an instrument to measure SA based on four factors of satisfaction: with the teaching attention (SAD), with the equipment (SAE), with the services (SAS), and with the scientific and technological aspects of the training (SACT). In addition, it was found that the more time elapsed since entering the career, the lower the level of both general SA and its factors, while age shows no relationship with SA, except for SAS, which is lower in older students. Finally, a lower SAE was found in 16.9% of students who report working.Las universidades tienen una crucial responsabilidad en su papel de formación social y profesional, además de ser vehículos de movilidad social en el actual y difícil contexto socioeconómico global. Por esta razón, es especialmente relevante no solo el contar con instrumentos psicométricamente adecuados, sino también de fácil aplicación respecto a la calidad de la educación. El objetivo del artículo es explorar las propiedades psicométricas de un instrumento de satisfacción académica (SA) desarrollado a partir del cuestionario de autoevaluación del Sistema Nacional de Acreditación de la Educación Superior (SINAES), empleado por las universidades que procuran estar acreditadas en Costa Rica, junto con el aporte de información relevante encontrada en este caso particular. El instrumento fue aplicado a 226 estudiantes de Ciencias Médicas de la UNIBE de forma presencial durante el primer cuatrimestre del año 2021 en San José. Como resultado, tras un análisis factorial exploratorio se obtuvo el DESIT-17, un instrumento para medir SA a partir de cuatro factores de satisfacción: con la atención docente (SAD), con el equipo (SAE), con los servicios (SAS), y con los aspectos científicos y tecnológicos de la formación (SACT). Adicionalmente, se encontró que a mayor tiempo transcurrido de haber ingresado a la carrera, menor el nivel tanto de SA general, como de sus factores, a la vez que la edad no muestra relación con la SA, excepto en lo que atañe a la SAS que resulta menor en estudiantes de mayor edad. Por último, se encontró una SAE menor en el 16.9% de estudiantes que reportan trabajar.As universidades têm uma responsabilidade crucial em seu papel de formação social e profissional, além de serem veículos de mobilidade social no difícil contexto socioeconômico global atual. Por esse motivo, é especialmente importante ter instrumentos não apenas psicometricamente adequados, mas também de fácil aplicação em relação à qualidade da educação. O objetivo do artigo é explorar as propriedades psicométricas de um instrumento de satisfação acadêmica (SA) desenvolvido a partir do questionário de autoavaliação do Sistema Nacional de Acreditação do Ensino Superior (SINAES), usado por universidades que buscam acreditação na Costa Rica, juntamente com as informações relevantes encontradas nesse caso específico. O instrumento foi aplicado a 226 alunos de Ciências Médicas da UNIBE durante o primeiro quadrimestre do ano de 2021 em San José. Como resultado, após uma análise fatorial exploratória, obteve-se o DESIT-17, um instrumento para medir a SA com base em quatro fatores de satisfação: com a atenção docente (SAD), com o equipamento (SAE), com os serviços (SAS) e com os aspectos científicos e tecnológicos da formação (SACT). Além disso, verificou-se que quanto maior o tempo decorrido desde o ingresso no curso de graduação, menor o nível de SA geral e de seus fatores, enquanto a idade não mostra relação com a SA, exceto para SAS, que é menor nos alunos mais velhos. Por fim, foi encontrada uma SAE mais baixa em 16,9% dos alunos que relataram trabalhar

Propiedades psicométricas del DESIT-17 para la medición de la satisfacción académica en estudiantes de Ciencias Médicas de la Universidad de Iberoamérica (UNIBE)

Las universidades tienen una crucial responsabilidad en su papel de formación social y profesional, además de ser vehículos de movilidad social en el actual y difícil contexto socioeconómico global. Por esta razón, es especialmente relevante no solo el contar con instrumentos psicométricamente adecuados, sino también de fácil aplicación respecto a la calidad de la educación. El objetivo del artículo es explorar las propiedades psicométricas de un instrumento de satisfacción académica (SA) desarrollado a partir del cuestionario de autoevaluación del Sistema Nacional de Acreditación de la Educación Superior (SINAES), empleado por las universidades que procuran estar acreditadas en Costa Rica, junto con el aporte de información relevante encontrada en este caso particular. El instrumento fue aplicado a 226 estudiantes de Ciencias Médicas de la UNIBE de forma presencial durante el primer cuatrimestre del año 2021 en San José. Como resultado, tras un análisis factorial exploratorio se obtuvo el DESIT-17, un instrumento para medir SA a partir de cuatro factores de satisfacción: con la atención docente (SAD), con el equipo (SAE), con los servicios (SAS), y con los aspectos científicos y tecnológicos de la formación (SACT). Adicionalmente, se encontró que a mayor tiempo transcurrido de haber ingresado a la carrera, menor el nivel tanto de SA general, como de sus factores, a la vez que la edad no muestra relación con la SA, excepto en lo que atañe a la SAS que resulta menor en estudiantes de mayor edad. Por último, se encontró una SAE menor en el 16.9% de estudiantes que reportan trabajar

A digital index theorem

Proc. of the 7th Int. Workshop on Combinatorial Image Analysis. IWCIA00. Caen. France. July 2000.This paper is devoted to prove a Digital Index Theorem for digital (n − 1)-manifolds in a digital space (Rn, f), where f belongs to a large family of lighting functions on the standard cubical decomposition Rn of the n-dimensional Euclidean space. As an immediate consequence we obtain the corresponding theorems for all (α, β)-surfaces of Kong-Roscoe, with α, β ∈ {6, 18, 26} and (α, β) 6≠(6, 6),(18, 26),(26, 26), as well as for the strong 26-surfaces of Bertrand-Malgouyres.Dirección General de Investigación Científica y TécnicaDirección General de Enseñanza Superio

Digital homotopy with obstacles

As a sequel of [4] Ayala, R., E. Dom´ıguez, A. R. Franc´es and A. Quintero, Homotopy in Digital Spaces, Discrete and Applied Mathematics, To Appear, this paper is devoted to the computation of the digital fundamental group π d 1 (O/S; σ) defined by loops in the digital object O for which the digital object S acts as an “obstacle”. We prove that for arbitrary digital spaces the group π d 1 (O/S; σ) maps onto the usual fundamental group of the difference of continuous analogues |AO∪S | − |AS |. Moreover, we show that this epimorphism turns to be an isomorphism for a large class of digital spaces including most of the examples in digital topology.Dirección General de Enseñanza Superio

Assessing the Evidential Value of Mental Fatigue and Exercise Research

Open access funding provided by University of Lausanne. Cristian Mesquida is funded by Technological University Dublin (project ID PTUD2002), Darías Holgado is supported by a grant from “Ministerio de Universidades” of Spain and Next Generation Fonds from the European Union, and Rafael Román-Caballero is funded by a predoctoral fellowship from the Spanish Ministry of Education, Culture, and Sport (FPU17/02864).It has often been reported that mental exertion, presumably leading to mental fatigue, can negatively affect exercise performance; however, recent findings have questioned the strength of the effect. To further complicate this issue, an overlooked problem might be the presence of publication bias in studies using underpowered designs, which is known to inflate false positive report probability and effect size estimates. Altogether, the presence of bias is likely to reduce the evidential value of the published literature on this topic, although it is unknown to what extent. The purpose of the current work was to assess the evidential value of studies published to date on the effect of mental exertion on exercise performance by assessing the presence of publication bias and the observed statistical power achieved by these studies. A traditional meta-analysis revealed a Cohen's d(z) effect size of - 0.54, 95% CI [- 0.68, - 0.40], p 1000, and inconclusive evidence in favor of the effect, adjusted d(z) = 0.01, 95% CrI [- 0.46, 0.37], BF10 = 0.90. Furthermore, the median observed statistical power assuming the unadjusted meta-analytic effect size (i.e., - 0.54) as the true effect size was 39% (min = 19%, max = 96%), indicating that, on average, these studies only had a 39% chance of observing a significant result if the true effect was Cohen's d(z) = - 0.54. If the more optimistic adjusted effect size (- 0.36) was assumed as the true effect, the median statistical power was just 20%. We conclude that the current literature is a useful case study for illustrating the dangers of conducting underpowered studies to detect the effect size of interest.University of LausanneTechnological University Dublin ID PTUD2002“Ministerio de Universidades” of SpainNext Generation Fonds European UnionSpanish Ministry of Education, Culture, and Sport FPU17/0286

A New wavelet tool to quantify non-periodicity of non-stationary economic time series

We introduce a new wavelet tool, the windowed scale index, to study the degree of non-periodicity of time series. The windowed scale index is based on some recently defined tools, such as the windowed scalogram and the scale index. This novel measure is appropriate for non-stationary time series whose characteristics change over time and, therefore, it can be applied to a wide variety of disciplines. Furthermore, we revise the concept of the scale index and pose a theoretical problem: it is known that if the scale index of a function is not zero then it is non-periodic, but if the scale index of a function is zero, then it is not proved that it has to be periodic. This problem is solved for the particular case of the Haar wavelet, reinforcing the interpretation of the windowed scale index as a useful tool to quantify non-periodicity. In addition, the applicability of this wavelet-based measure is illustrated through several examples, including an economic application which compares the non-periodicity of two major commodities in the world economy, such as crude oil and gold. Finally, we discuss the relationship between non-periodicity and unpredictability, comparing the windowed scale index with the sample entropy

A new species of Stethelmis Hinton (Coleoptera: Elmidae) from Argentina and description of its larva

A new species of Stethelmis, S. shepardi sp. nov., is described for Patagonia, Argentina from adults of both sexes. A full description and illustrations of both the adult and the larva of the new species are provided with comments on its habitat and distribution. Adults of the new species are compared with those of S. kaszabi (Hinton 1970) and S. chilensis (Hinton 1945). The larva of S. shepardi is compared with that of S. kaszabi, the other Stethelmis larva described. We also describe and illustrate for the first time the male genitalia of S. kaszabi. A key to the known species of Stethelmis is also included.Fil: Martínez Román, Nicolás Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaFil: Manzo, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; ArgentinaFil: Archangelsky, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentin