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No full textTocopilla, in the north of Chile, is a typical case of towns shaped by extractivism. For more than a hundred years, thermoelectric plants there supplied the mines in the hinterland. However, Tocopilla never benefitted from this vital role. With the closure of the thermoelectric plants that began in 2019, the town’s future looks even more sombre. This article analyses whether there are prospects for endogenous development in Tocopilla. The authors present a corresponding conceptual framework and argue that Tocopilla’s decline and stagnation result from the absence of the conditions whose presence normally serves to explain endogenous development. Drawing pessimistic conclusions, the article makes a contribution not only to the endogenous development approach, but also to the literature on peripheral regions rich in raw materials.Tocopilla, en el norte de Chile, es un caso típico de las ciudades medianas y pequeñas marcadas por el extractivismo. Durante más de cien años, plantas termoeléctricas allí abastecieron las minas en el interior, pero Tocopilla nunca se benefició de este rol clave. Con el cierre de las termoeléctricas que comenzó en 2019, el futuro de la ciudad se ve aún más oscuro. El presente artículo investiga si hay perspectivas para el desarrollo endógeno en Tocopilla. Los autores presentan un marco conceptual correspondiente y argumentan que el estancamiento y retroceso de Tocopilla resulta de la ausencia de las condiciones cuya presencia normalmente sirve para explicar el desarrollo endógeno. Con conclusiones pesimistas, el artículo hace una contribución no solo al enfoque del desarrollo endógeno, sino también a la literatura sobre las regiones periféricas ricas en materia prima.
Efecto de las fibras de acero en la resistencia y los modos de fallo de vigas de hormigón armado con aberturas circulares en la zona de cortante
No full textTransverse openings in the shear zone of reinforced concrete beams, without taking prior precautions, generate stress concentrations around these openings, reducing the capacity of the beams and thus favoring brittle failure modes. This study investigates the use of steel fibers to address this issue.
A series of three-point bending tests was conducted on nine beams with dimensions of 100x200x1000 mm, incorporating Ø63 mm transverse openings in the high-shear zone. In addition to the flexural and shear reinforcements, these beams, both with and without openings, were strengthened with hooked steel fibers type FIBERTEK A at rates of 0.2%, 0.4%, 0.6%, and 0.8%.
The test results indicated that the steel fibers significantly enhance the performance of beams with openings. It allows the beams to maintain their ultimate bending capacity despite the presence of openings, achieving significant improvements compared to the reference beam: a 34.69% increase in first crack load, a 39% increase in ultimate capacity, and a 56% increase in absorbed energy. Additionally, increasing the fiber content makes it possible to shift the shear failure mode from frame-type to beam-type.Las aberturas transversales en la zona de cortante de vigas de hormigón armado, sin tomar precauciones previas, generan concentraciones de tensiones alrededor de dichas aberturas, lo que reduce la capacidad resistente de las vigas y favorece modos de fallo frágiles. Este estudio investiga el uso de fibras de acero para abordar este problema.
Se realizaron ensayos de flexión en tres puntos sobre nueve vigas con dimensiones de 100x200x1000 mm, incorporando aberturas transversales de Ø63 mm en la zona de alto esfuerzo cortante. Además de las armaduras de flexión y cortante, estas vigas —tanto con cómo sin aberturas— fueron reforzadas con fibras de acero con gancho tipo FIBERTEK A en tasas de 0.2%, 0.4%, 0.6% y 0.8%.
Los resultados de los ensayos indicaron que las fibras de acero mejoran significativamente el comportamiento de las vigas con aberturas. Permiten que las vigas mantengan su capacidad última de flexión a pesar de la presencia de aberturas, logrando mejoras significativas en comparación con la viga de referencia: un aumento del 34.69% en la carga de primera fisura, un incremento del 39% en la capacidad última y un aumento del 56% en la energía absorbida. Además, al aumentar el contenido de fibras, es posible cambiar el modo de fallo cortante de tipo marco a tipo viga
O eu neoliberal na era das plataformas digitais: Entre autonomia e precariedade
No full textThis study provides a comprehensive analysis of how digital platforms such as Uber, Glovo, and Airbnb influence labor dynamics through discourses that praise autonomy and flexibility. Using a qualitative methodology based on 73 in-depth interviews conducted with workers during the pandemic, the analysis reveals a clear contradiction between the independence promoted by these companies and the daily reality of workers: insecure jobs, intense algorithmic control, and a notable lack of social protection. The research conducts a critical analysis of corporate discourses and shows how they influence the construction of work identity and how workers reinterpret and reshape this logic to negotiate better conditions. Significant patterns of resistance and adaptation are identified that actively challenge the prevailing logic of individualization and self-exploitation. The concept of the neoliberal self is critically scrutinized and it is shown that its manifestation is neither uniform nor inevitable, but varies considerably depending on the socioeconomic context and the individual and collective strategies of workers. The study concludes that while platforms systematically hinder collective action, organic support networks and innovative organizing strategies are emerging that fundamentally challenge this model and open up crucial debates about new forms of resistance in today’s digital economy.Este estudio ofrece un análisis exhaustivo de cómo las plataformas digitales como Uber, Glovo y Airbnb configuran las dinámicas laborales mediante discursos que ensalzan la autonomía y la flexibilidad. A partir de una metodología cualitativa –basada en 73 entrevistas en profundidad realizadas durante la pandemia a trabajadores–, el análisis muestra una marcada contradicción entre la independencia promovida por estas compañías y las realidades cotidianas de los trabajadores: precarización laboral, un control algorítmico intensivo y una notable falta de protección social. Se realiza un análisis crítico de los discursos corporativos, examinando cómo influyen en la construcción de la identidad laboral y cómo los trabajadores los reinterpretan y transforman para negociar mejores condiciones. Se identifican patrones significativos de resistencia y adaptación que desafían activamente la lógica dominante de la individualización y la autoexplotación, y se cuestiona de forma crítica el concepto del yo neoliberal, demostrando que su manifestación no es uniforme ni inevitable, sino que varía considerablemente según el contexto socioeconómico y las estrategias individuales y colectivas de los trabajadores. Se concluye que, aunque las plataformas obstaculizan sistemáticamente la acción colectiva, surgen redes de apoyo orgánico y estrategias organizativas innovadoras que cuestionan de raíz este modelo y abren debates cruciales sobre nuevas formas de resistencia en la economía digital contemporánea.Este estudo apresenta uma análise exaustiva sobre como plataformas digitais como Uber, Glovo e Airbnb moldam as dinâmicas laborais através de discursos que exaltam a autonomia e a flexibilidade. A partir de uma metodologia qualitativa — baseada em 73 entrevistas detalhadas realizadas a trabalhadores durante a pandemia —, a análise evidencia uma contradição marcante entre a independência promovida por essas empresas e a realidade cotidiana dos trabalhadores: precariedade laboral, controle algorítmico intensivo e notável falta de proteção social. Realiza-se uma análise crítica dos discursos corporativos, mostrando como eles influenciam a construção da identidade laboral, assim como a forma pela qual os trabalhadores reinterpretam e transformam essas lógicas para negociar melhores condições. São identificados padrões significativos de resistência e adaptação que desafiam ativamente a lógica dominante da individualização e da autoexploração. O estudo questiona criticamente o conceito do eu neoliberal, demonstrando que a sua manifestação não é uniforme nem inevitável, variando consideravelmente em função do contexto socioeconômico e das estratégias individuais e coletivas dos trabalhadores. Conclui-se que, apesar das plataformas dificultarem sistematicamente a ação coletiva, emergem as redes de apoio orgânicas e estratégias organizacionais inovadoras que desafiam a raíz esse modelo, abrindo debates cruciais sobre novas formas de resistência na economia digital contemporânea
Diseño y contenido de aplicaciones móviles sobre el número para la educación infantil
No full textMobile applications (apps) have rapidly spread in homes and schools, where they coexist with traditional teaching materials and diversify learning contexts and resources. In this sense, math-related apps present numerical information in different forms and offer the possibility to combine numerical signs and symbols with different actions and procedures. Thus, they contribute to the conceptualization of quantitative properties and relationships, as well as to the abstraction of numbers, even the smallest ones. However, research on number-focused apps available in Spanish remains scarce. This study examines the design and content features of 26 apps with numerical activities intended for Spanish-speaking preschool children. After applying the constant comparison method and descriptive statistics, the results show a predominance of quantification activities based on the application of counting, and recognition and tracing of numerals activities, with direct negative feedback, use of rewards, and instructions that often misalign with users’ evolutionary-educational stage. In this context, number learning does not emerge from the exploration of a meaningful problem space field; but rather from a lack of challenges and an oversimplification of arithmetic learning. There is still a need for apps grounded in educational and research-based advances that support the development of numerical skills from kindergarten education and foster children’s ability to learn and communicate numbers.Las aplicaciones móviles (apps) se han difundido rápidamente en los hogares y las escuelas, donde coexisten con materiales didácticos tradicionales y diversifican contextos y recursos de aprendizaje. En ese sentido, las apps sobre matemáticas presentan información numérica de distintas formas y ofrecen la posibilidad de combinar signos y símbolos numéricos con diferentes acciones y procedimientos. Así, contribuyen a la conceptualización de propiedades y relaciones cuantitativas; al igual que a la abstracción de números, incluso de los más pequeños. Sin embargo, las investigaciones sobre aplicaciones centradas en números y disponibles en castellano son todavía escasas. El presente estudio examina las características de diseño y de contenido de 26 apps con actividades numéricas destinadas a niños y niñas castellanohablantes de escuela infantil. Tras aplicar el método comparativo constante y estadística descriptiva, los resultados muestran un predominio de actividades de cuantificación basadas en la aplicación del conteo y de actividades de reconocimiento y trazado de numerales, con retroalimentación negativa directa, uso de recompensas e instrucciones en poca sintonía con la etapa evolutiva-educativa de los usuarios. En ese escenario, el aprendizaje del número no aparece como producto de la exploración de un campo de problemas que le otorgue sentido, sino que predominan la escasez de desafíos y una sobre-simplificación del aprendizaje de la aritmética. Aún hacen falta aplicaciones basadas en avances investigativos y educacionales pertinentes para las competencias numéricas a desplegar desde la escuela infantil y que impacten en la capacidad de niños y niñas para aprender y comunicar los números
Asociación entre el humor del docente y el disfrute estudiantil en clase de matemáticas: el rol mediador de la diversión percibida
No full textHumor in the classroom has been considered a positive pedagogical strategy for easing classroom tension because it brings educators and students emotionally closer. However, it can also be associated with adverse effects depending on how it is employed. This study explores the possibility that perceiving the teacher as fun mediates the functional relationship between the type of humor used by the teacher in mathematics class and the enjoyment experienced by the students. Through an exploratory study based on observable variables analysis, 679 Colombian high school students were evaluated in order to identify how much they enjoyed mathematics class, and three types of teacher humor: offensive, related and unrelated to the class. The model showed that the association between teacher humor and student enjoyment is mediated by the perception of the teacher's type of humor. This mediation is partial-negative for offensive humor, and total-positive for class-related and non-class-related humor. Students' assessments of their teachers' personality traits seem to play an important role in how humorous messages are associated with classroom enjoyment, whereas offensive treatment is linked to a negative experience. These exploratory findings require longitudinal studies to establish robust patterns of relationships among the studied variables.El humor en el aula se considera una estrategia pedagógica positiva para la distensión en clases porque acerca emocionalmente a educadores y estudiantes. Sin embargo, también puede asociarse con efectos adversos, según cómo se emplee. Esta investigación explora la posibilidad de que la percepción del profesor como divertido medie en la relación entre el tipo de humor que este usa en clase de matemáticas y el disfrute en el aula que experimentan sus estudiantes. Mediante un estudio exploratorio, basado en análisis de variables observables, se evaluaron 679 escolares colombianos de secundaria, con el fin de identificar cuánto disfrutaban de la clase de matemáticas mediada por tres tipos de humor docente: ofensivo, relacionado y no relacionado con la clase. El modelo aplicado mostró que la asociación entre el humor del docente y el disfrute estudiantil están mediados por la percepción del grado de diversión del educador. Esta mediación es parcial-negativa para el humor ofensivo y total-positiva para el humor relacionado y el no relacionado con la clase. La valoración de los estudiantes sobre los aspectos personológicos de sus docentes parece desempeñar un papel importante en la forma como los mensajes humorísticos se asocian con el disfrute de la clase, mientras que el trato ofensivo se vincula con una experiencia negativa. Estos hallazgos exploratorios requieren de estudios longitudinales que permitan establecer patrones sólidos de relación entre las variables estudiadas
In vitro: Effectiveness of Laurus nobilis extract against Hymenolepis nana Eggs
No full textBackground: Parasites are among the most widespread disorders affecting various organisms. The worm Hymenolepis nana is a common intestinal parasite of Mus musculus and Rattus norvegicus, widely dispersed. The well-being of laboratory mice is essential for the effectiveness of research that produces trustworthy outcomes. The study aims to investigate the impact that the Laurus nobilis extract has on the worm Hymenolepis nana eggs.
Methods: The eggs were divided into six groups, with each group consisting of 500 eggs: the control group. Treatment groups (2, 3, 4, and 5) were with 25, 50, 100, and 200 µg/ml of L. nobilis. Group 6 received treatment with the reference drug Albendazole at a concentration of 1 ml/ml. The samples were incubated at 28°C for 12, 24, 36, and 48 hours. At the conclusion of each incubation duration, 0.5 µL of the egg extract suspension was combined with 0.5 µL of 0.1% eosin dye, and the mixture was checked by a light microscope to assess viability.
Result: After 12, 24, 36, and 48 hours of incubation in a test tube, 89% and 93% of the eggs were killed with the highest concentrations of L. nobilis (200 µg/ml) and albendazole (10 µl/ml), respectively. Dead eggs turned red. At the same time, the control group lasted for long hours, and viable eggs retained their color. It was found that there were statistically significant differences (P ≤ 0.01) between the concentrations and the reference treatment (P ≤ 0.01) and between the different concentrations of the extract (µg/ml 25, 50, 100).
Conclusion: The study proved that plant extracts are effective drugs for parasitic diseases as they inhibition the eggs of tapeworms (non-viable), and their derivatives can be used in the manufacture of drugs and enhance biological activity
Thought colloquial but found formal in Jordanian Arabic vernaculars: a sociolinguistic perspective
No full textLexical borrowing can be looked at as a vital sign that a certain language or variety of a language is lively and progressive, rather than spiritless and regressive. Masquerading under the guise of colloquialism and subscribing to the view that both interlingual and intralingual lexical borrowing can be seen as a linguistic zone of contact, this paper examines the premise that Jordanian Arabic local dialects proliferate in words that have been traditionally conceived by many ‘semi-languaged’ people as being colloquial, while they are actually formal and/or standard. Analysis shows that while some examples have displayed a perfect congruence between the colloquialized forms and their ‘parent’ ones at the semantic, syntactic, phonological, and morphological levels, some other ones have undergone certain changes at one or more of these levels, in response to the sociolinguistic exigencies of human communication. Analysis also provides proselytizing support to the overarching claim that classical Arabic enjoys a sonorous signifying richness, a primacy, and an inspiring, horizontalizing, and ennobling influence and effect on the different vernaculars spoken across Jordan; rather, classical Arabic never ceases to serve a cathartic function and to play a formative role in animating such local colloquial codes.Lexical borrowing can be looked at as a vital sign that a certain language or variety of a language is lively and progressive, rather than spiritless and regressive. Masquerading under the guise of colloquialism and subscribing to the view that both interlingual and intralingual lexical borrowing can be seen as a linguistic zone of contact, this paper examines the premise that Jordanian Arabic local dialects proliferate in words that have been traditionally conceived by many ‘semi-languaged’ people as being colloquial, while they are actually formal and/or standard. Analysis shows that while some examples have displayed a perfect congruence between the colloquialized forms and their ‘parent’ ones at the semantic, syntactic, phonological, and morphological levels, some other ones have undergone certain changes at one or more of these levels, in response to the sociolinguistic exigencies of human communication. Analysis also provides proselytizing support to the overarching claim that classical Arabic enjoys a sonorous signifying richness, a primacy, and an inspiring, horizontalizing, and ennobling influence and effect on the different vernaculars spoken across Jordan; rather, classical Arabic never ceases to serve a cathartic function and to play a formative role in animating such local colloquial codes
