The Stackage Repository: An Exploratory Study of its Evolution

Context. Package repositories for a programming language are increasingly common. A repository can keep a register of the evolution of its packages. In the programming language Haskell, with its defining characteristic monads, we can find the Stackage repository, which is a curated repository for stable Haskell packages in the Hackage repository. Despite the widespread use of Stackage in its industrial target, we are not aware of much empirical research about how this repository has evolved, including the use of monads. Objective. This paper conducts empirical research about the evolution of Stackage considering monad packages through 22 Long-Term Support releases during the period 2014-2023. Focusing on five research questions, this evolution is analyzed in terms of packages with their dependencies and imports; including the most used monad packages. To the best of our knowledge, this is the first large-scale analysis of the evolution of the Stackage repository regarding packages used and monads. Method. We define six research questions regarding the repository's evolution, and analyze them on 51,716 packages (17.05 GB) spread over 22 releases. For each package, we parse its cabal file and source code to extract the data, which is analyzed in terms of dependencies and imports using Pandas scripts. Results. From the methodology we get different findings. For example, there are packages that depend on other packages whose versions are not available in a particular release of Stackage; opening a potential stability issue. The mtl and transformers are on the top 10 packages most used/imported across releases of the Stackage evolution. We discussed these findings with Stackage maintainers, which allowed us to refine the research questions.Comment: 22 pages, 12 figure

Prevalence of Code Smells in Reinforcement Learning Projects

Reinforcement Learning (RL) is being increasingly used to learn and adapt application behavior in many domains, including large-scale and safety critical systems, as for example, autonomous driving. With the advent of plug-n-play RL libraries, its applicability has further increased, enabling integration of RL algorithms by users. We note, however, that the majority of such code is not developed by RL engineers, which as a consequence, may lead to poor program quality yielding bugs, suboptimal performance, maintainability, and evolution problems for RL-based projects. In this paper we begin the exploration of this hypothesis, specific to code utilizing RL, analyzing different projects found in the wild, to assess their quality from a software engineering perspective. Our study includes 24 popular RL-based Python projects, analyzed with standard software engineering metrics. Our results, aligned with similar analyses for ML code in general, show that popular and widely reused RL repositories contain many code smells (3.95% of the code base on average), significantly affecting the projects' maintainability. The most common code smells detected are long method and long method chain, highlighting problems in the definition and interaction of agents. Detected code smells suggest problems in responsibility separation, and the appropriateness of current abstractions for the definition of RL algorithms.Comment: Paper preprint for the 2nd International Conference on AI Engineering Software Engineering for AI CAIN202

A Dynamic Instance Binding Mechanism Supporting Run-Time Variability of Role-Based Software Systems

Role-based approaches gain more and more interest for modeling and implementing variable software systems. Role models clearly separate static behavior represented by players and dynamic behavior modeled as roles which can be dynamically bound and unbound to players at run time. To support the execution of role-based systems, a dynamic binding mechanism is required. Especially, since instances of the same player type can play different roles in a single context, the binding mechanism is required to operate at instance level. In this paper, we introduce a mechanism called dynamic instance binding for implementing a runtime for role-based systems. It maintains a look-up table that allows the run-time system to determine and invoke the currently active role binding at instance level. We explain dynamic instance binding mechanism in detail and demonstrate that it is flexible enough to support both adaptation and evolution of software systems at run time

A Rollback Mechanism to Recover from Software Failures in Role-based Adaptive Software Systems

Context-dependent applications are relatively complex due to their multiple variations caused by context activation, especially in the presence of unanticipated adaptation. Testing these systems is challenging, as it is hard to reproduce the same execution environments. Therefore, a software failure caused by bugs is no exception. This paper presents a rollback mechanism to recover from software failures as part of a role-based runtime with support for unanticipated adaptation. The mechanism performs checkpoints before each adaptation and employs specialized sensors to detect bugs resulting from recent configuration changes. When the runtime detects a bug, it assumes that the bug belongs to the latest configuration. The runtime rolls back to the recent checkpoint to recover and subsequently notifes the developer to fix the bug and re-applying the adaptation through unanticipated adaptation. We prototype the concept as part of our role-based runtime engine LyRT and demonstrate the applicability of the rollback recovery mechanism for unanticipated adaptation in erroneous situations

Las rebeliones lideradas por Calchaquí y Viltipoco (Gobernación del Tucumán, virreinato del Perú, siglo XVI): Una revisión bibliográfica centrada en la visibilización de los vínculos regionales

Viltipoco and Calchaquí are the names of two indigenous leaders who remain alive in the collective memory of the Argentine provinces of Jujuy and Salta. Their names are claimed by indigenous organizations, they are mentioned in folklore, and there are neighborhoods, streets and monuments that remember them. They are an unavoidable reference for the historiography of colonial Tucumán, but, paradoxically, we know very little about them. In this work I propose to recover what little we know about these two indigenous leaders based on what historiography has written about them, proposing a regional perspective that transcends the localism that relates Viltipoco to Jujuy and Calchaquí to Salta. From there I propose to raise or recover hypotheses to be taken into account in subsequent studies that contemplate the regional links that these rebellions make visible, creating a dialogue between the historiography of the Calchaquíes valleys, the puna and ravine of Jujuy and Atacama.Viltipoco y Calchaquí son los nombres de dos líderes indígenas que permanecen vivos en la memoria colectiva de las provincias argentinas de Jujuy y Salta. Sus nombres son reivindicados por organizaciones indígenas, son mencionados en el folklore, hay barrios, calles y monumentos que los recuerdan. Son una referencia ineludible para la historiografía del Tucumán colonial, pero, paradójicamente, es muy poco lo que sabemos de ellos. En este trabajo propongo recuperar lo poco que sabemos acerca de estos dos líderes indígenas partiendo de lo que la historiografía ha escrito sobre ellos, proponiendo una perspectiva regional, que trascienda el localismo que relaciona a Viltipoco con Jujuy y a Calchaquí con Salta. A partir de allí propongo plantear o recuperar hipótesis para tener en cuenta en estudios posteriores que contemplen los vínculos regionales que estas rebeliones visibilizan, creando un diálogo entre la historiografía de los valles Calchaquíes, la puna y quebrada jujeñas y Atacama.  

Aproximações teóricas a uma pedagogia crítica para o ensino das ciências

Some reflections, mainly theoretical, are presented regarding the considerations of a critical pedagogy for the teaching of science - biology. In the first place, some important elements of science education are collected that place it as a democratic project with an emphasis on social justice to prove the need for a critical pedagogy within the science classroom. Following this, two didactic approaches are proposed to integrate characteristic elements of the critical (reflection and action). Once these approaches have been described, dimensions of feminist epistemologies are suggested as anchor points with the critical possibility of reconstructing the knowledge of school science; additionally, the categories for a critical pedagogy in the teaching of science-biology are established and it is briefly exemplified how these elements are integrated in practice. Finally, the importance of the production of knowledge located in school settings is pointed out and action research is suggested as a privileged methodology for this purpose.El texto presenta algunas reflexiones, principalmente teóricas, frente a las consideraciones de una pedagogía crítica para la enseñanza de las Ciencias- Biología. En primer lugar, se recogen algunos elementos importantes de la educación en ciencias que la sitúan como un proyecto democrático y con énfasis en la justicia social para justificar la necesidad de una pedagogía crítica dentro del aula de ciencias. Seguido de esto, se proponen dos enfoques didácticos para integrar dimensiones propias de lo crítico (reflexión y acción). Una vez descritos estos enfoques, se privilegian las epistemologías feministas como puntos de anclaje con la posibilidad crítica de reconstruir el conocimiento de la ciencia escolar; adicionalmente, se establecen las categorías para una pedagogía crítica en la enseñanza de las ciencias-biología y se ejemplifica brevemente cómo se pueden integrar estos elementos en la práctica. Por último, se señala la importancia de la producción de conocimiento situado en los escenarios escolares y se sugiere a la investigación acción como una metodología privilegiada para este fin.O artigo apresenta algumas reflexões, principalmente teóricas, frente às considerações de uma pedagogia crítica para o ensino da ciência-biologia. Em primeiro lugar, são coletados alguns elementos importantes do ensino de ciências que o colocam como um projeto democrático com ênfase na justiça social para justificar a necessidade de uma pedagogia crítica dentro da sala de aula de ciências. Em seguida, são propostas duas abordagens didáticas para integrar elementos característicos da crítica (reflexão e ação). Uma vez descritas essas abordagens, são sugeridas dimensões das epistemologias feministas como pontos de ancoragem com a possibilidade crítica de reconstruir o conhecimento da ciência escolar; além disso, são estabelecidas as categorias para uma pedagogia crítica no ensino da ciência-biologia e exemplifica-se brevemente como esses elementos são integrados na prática. Por fim, aponta-se a importância da produção de conhecimento localizada nos ambientes escolares e sugere-se a pesquisa-ação como metodologia privilegiada para esse fim

Consistent Unanticipated Adaptation for Context-Dependent Applications

Unanticipated adaptation allows context-dependent applications to overcome the limitation of foreseen adaptation by incorporating previously unknown behavior. Introducing this concept in language-based approaches leads to inconsistencies as an object can have different views in different contexts. Existing language-based approaches do not address unanticipated adaptation and its associated run-time inconsistencies. We propose an architecture for unanticipated adaptation at run time based on dynamic instance binding crafted in a loosely manner to asynchronously replace adaptable entities that allow for behavioral changes of objects. To solve inconsistencies, we introduce the notion of transactions at the object level. Transactions guard the changing objects during their execution, ensuring consistent views. This allows for disruption-free, safe updates of adaptable entities by means of consistent unanticipated adaptation

Nivel de actividad física de los estudiantes de la LEFRYD en IUACJ de Montevideo en el año 2020

Es bien sabida la importancia de la actividad física (AF) en la salud de las personas y en la prevención de enfermedades crónicas no trasmisibles. A partir de esto, se considera importante que los futuros egresados de la Licenciatura en Educación Física, Recreación y Deporte (LEFRYD) como promotores de salud, cumplan con las recomendaciones mínimas propuestas por la Organización Mundial de la Salud (OMS). Se analizó la relación entre los niveles de AF con las actividades de la vida diaria (AVD) de los estudiantes de la LEFRYD del IUACJ para el año 2020. Los objetivos específicos se orientaron a describir las variables de sexo y grado de la LEFRYD; de las AVD se seleccionó el descanso y trabajo, y se compararon los niveles de AF con los perfiles de conducta sedentaria (CS), estos últimos determinados a partir del tiempo diario sentado. Se aplicó el Cuestionario Internacional de Actividad Física (IPAQ) adaptado, obteniendo también estas variables anteriormente nombradas. Se recopilaron datos de 137 estudiantes (un 41,51% del universo) y se encontró que un 75,9% presentaron un nivel de AF “alto”, un 22,6% un nivel “moderado” y un 1,46% un nivel “bajo”. No se encontraron diferencias estadísticamente significativas entre sexos ni grado de la carrera. No se encontró relación entre el nivel de AF y las variables de descanso y trabajo. Al comparar los niveles de AF con los perfiles de CS, sólo un 1,61% del total femenino presenta un nivel de AF “bajo” y un perfil de CS “alto”. Se encontró que a mayor nivel de AF menor es el perfil de CS sin diferencias entre sexos ni grado de la carrera.UY-MoUC

Biological Control of the Chagas Disease Vector Triatoma infestans with the Entomopathogenic Fungus Beauveria bassiana Combined with an Aggregation Cue: Field, Laboratory and Mathematical Modeling Assessment

Background: Current Chagas disease vector control strategies, based on chemical insecticide spraying, are growingly threatened by the emergence of pyrethroid-resistant Triatoma infestans populations in the Gran Chaco region of South America. Methodology and findings: We have already shown that the entomopathogenic fungus Beauveria bassiana has the ability to breach the insect cuticle and is effective both against pyrethroid-susceptible and pyrethroid-resistant T. infestans, in laboratory as well as field assays. It is also known that T. infestans cuticle lipids play a major role as contact aggregation pheromones. We estimated the effectiveness of pheromonebased infection boxes containing B. bassiana spores to kill indoor bugs, and its effect on the vector population dynamics. Laboratory assays were performed to estimate the effect of fungal infection on female reproductive parameters. The effect of insect exuviae as an aggregation signal in the performance of the infection boxes was estimated both in the laboratory and in the field. We developed a stage-specific matrix model of T. infestans to describe the fungal infection effects on insect population dynamics, and to analyze the performance of the biopesticide device in vector biological control. Conclusions: The pheromone-containing infective box is a promising new tool against indoor populations of this Chagas disease vector, with the number of boxes per house being the main driver of the reduction of the total domestic bug population. This ecologically safe approach is the first proven alternative to chemical insecticides in the control of T. infestans. The advantageous reduction in vector population by delayedaction fungal biopesticides in a contained environment is here shown supported by mathematical modeling.Fil: Forlani, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Pedrini, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Girotti, Juan Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Mijailovsky, Sergio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Cardozo, Rubén Marino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentina. Provincia de Salta. Ministerio de Salud Pública. Coordinación de Gestión Epidemiológica; ArgentinaFil: Gentile, Alberto G.. Provincia de Salta. Ministerio de Salud Pública. Coordinación de Gestión Epidemiológica; ArgentinaFil: Hernández Suárez, Carlos. Universidad de Colima. Facultad de Ciencias; MéxicoFil: Rabinovich, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Juarez, Marta Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin