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O objetivo deste estudo era determinar a incidência de hidatidose suína em suínos abatidos na área costeira. Utilizamos 300 porcos de vários cantões próximos, selecionando 12 porcos por dia, através de inspeção diária no momento do abate. A presença de cistos, a razão do estudo e as lesões causadas por eles foram identificadas macroscopicamente. As vísceras foram inspecionadas: fígados, pulmões e rins, onde o parasita tem o maior apetite para produzir a doença. A inspeção foi realizada primeiro visualmente e depois os órgãos afetados pelos quistos, o motivo do estudo, foram apreendidos e levados ao laboratório em caixas refrigeradas para continuar com o estudo microscópico. Foram realizados testes de laboratório utilizando o método analítico para determinar a presença de ovos parasitas e sua fertilidade. Durante a avaliação dos dados, o Método Percentual foi aplicado para determinar em porcentagem quantos casos são positivos ou negativos em hidatidoses em suínos. Foram avaliadas as seguintes variáveis: seleção de animais inspecionados post-mortem de diferentes idades, raças, sexo, porcentagem de porcos positivos para cistos hidatidos, origem dos porcos positivos para cistos hidatidos e determinação da fertilidade dos cistos. Através da análise dos resultados foi determinado que há uma incidência de 5,7% de hidatidose em suínos abatidos no matadouro municipal de Babahoyo Canton; uma maior incidência de cistos hidatidos foi encontrada em fêmeas 3,7%, sem que isso signifique que o sexo seja determinante na presença da doença; uma maior incidência foi observada em suínos crioulos 13. 8%, embora eu não acredite que as raças sejam um determinante na incidência da doença, mas as condições de manejo na produção de suínos; o órgão de maior preferência pelo parasita são os rins que encontram 82,4% de incidência; a fertilidade dos cistos hidatidos encontrados foi de 41,2%, o que significa que se eles forem ingeridos por um hospedeiro intermediário eles têm um alto risco de transmissão da doença.

O objetivo desta pesquisa era determinar a freqüência de fêmeas bovinas grávidas no abate e sua incidência na produção animal. O estudo foi realizado na cidade de Ventanas, Província de Los Rios. A fórmula foi aplicada para calcular o tamanho da amostra correspondente a uma população específica e foi determinada uma amostragem de 357 casos. A metodologia utilizada no exame post-mortem determinou as fêmeas em gestação e também calculou a idade, local de origem e data da amostragem. Uma vez abatidas as fêmeas, o útero foi separado da carcaça para ser examinado fora da carcaça, que foi aberta com uma tesoura, separando as membranas fetais e procedendo à extração do feto, para calcular a idade aproximada do feto, usando um gráfico de crescimento RICTER E GOETZE. Além disso, todas as informações acima mencionadas foram registradas em tabelas preparadas para este fim. Para a presente investigação, foi aplicado o método percentual. Foram avaliadas as seguintes variáveis: Percentual de fêmeas grávidas abatidas, tempo e idade de gestação, raça e origem das fêmeas abatidas. Os resultados obtidos com os 357 casos amostrados, 159 vacas prenhas foram encontradas no abatedouro municipal a serem abatidas, o que representou 44,5%, e 198 vacas foram encontradas vazias (55,5%), a análise de sensibilidade determinou que havia significância estatística. De acordo com o tempo de gestação das vacas prenhes encontradas para abate no abatedouro Municipal da cidade de Ventanas, na faixa de 0-3 meses foram encontrados 64 casos (40,3%), na faixa de 3-6 meses foram detectados 83 casos (52,2%), esta é a faixa com maior número de vacas prenhes e na faixa de 6-9 meses foram encontradas 12 vacas prenhes (7,5%), a análise do quadrado Chi mostrou que há significância estatística. De acordo com a origem das vacas encontradas prenhas que foram abatidas no abatedouro municipal da cidade de Ventanas, foi encontrado o seguinte Em Moraspungo foram encontrados 29 casos (18,24%), em San Luis foram detectados 15 casos (9,43%), em Caluma e Pueblo Viejo o número de vacas prenhas foi de 13 respectivamente (8,18%). A análise qui-quadrada mostrou significância estatística. Dos 173 casos amostrados, 47,8% correspondiam à raça Brahman. Dos 127 casos amostrados, a raça cruzada representou 35,2%, seguida pelas raças Jersey, Charolais e Holstein. A análise qui-quadrada mostrou significância estatística.

Zearalenone (ZEA), a mycotoxin recognized with estrogenic effects, has a contaminant prevalence in corn, sorghum and wheat, mainly being produced by fungi: Fusarium graminearum, and other species such as culmorum and tricintum. Zearalenone effects are estrogenic. Being swine one of the most sensitive animals. Gilts often present hyperestrogenism and manifest as vulvovaginitis and mammary glands enlargement. The objective of this study was to assess ZEA toxic effects in gilts, during 52 days period, consuming naturally contaminated feed, using 1200 ppb levels (ZEA) and verify two commercial toxin binders efficiency to reduce their potential detrimental effects. 24 recently weaned gilts were selected; first seven days were for adaptation, then each gilt was assigned within one of the four experimental groups identified as: 1) control diet without ZEA, 2) positive control diet with 1,200 ppb of ZEA, 3) challenge diet with 1,200 ppb of ZEA and 1.5 kg / t of organoaluminosilicate, 4) challenge diet with 1,200 ppb of ZEA and 1.5 kg / t of Aluminosilicate + yeast cell walls. The obtained information was analyzed through the statistical software SYSTAT, by the Tukey test where the difference of means was defined. The significance value was based on a p < 0.05. There were statistically significant differences in reproductive tract weight and length, vulva volume and cervix width between treatments.

espanolEn el ano 2019 se llevaron a cabo en Lima los XVIII Juegos Panamericanos y Sextos Juegos Parapanamericanos. Este fue el mayor evento deportivo multidisciplinario organizado por el Peru. Este evento fue un gran reto para el Peru, tanto por su complejidad como por el corto tiempo con el que se contaba para su ejecucion. Para cumplir sus objetivos, el Proyecto Especial a cargo de la organizacion de los Juegos empleo diferentes mecanismos de contratacion y herramientas de gestion novedosos, dentro del marco de un contrato de Gobierno a Gobierno con el Reino Unido. En este contexto, estas experiencias han sido replicadas en un nuevo Modelo de Ejecucion de Inversiones Publicas que puede ser empleado por los Proyectos Especiales de Inversion Publica. Lo que se busca mediante este nuevo esquema es destrabar las inversiones publicas, gestionandolas y ejecutandolas eficientemente, empleando altos estandares internacionales.La regulacion de estos Proyectos Especiales de Inversion Publica se ha venido desarrollando progresivamente en el ultimo ano, incorporando incluso la posibilidad de celebrar contratos de Gobierno a Gobierno. A la fecha, se encuentra en operacion el Proyecto de Inversion Publica, denominado “Escuelas Bicentenario”, que permitira analizar el funcionamiento de este nuevo Modelo de Ejecucion de Inversiones Publicas. Actualmente, en medio de constantes anuncios de modificacion de la Ley de Contrataciones del Estado, se ha puesto sobre la mesa la discusion de la oportunidad y pertinencia de implementar varias de las herramientas del Modelo de Ejecucion de Inversiones en la normativa de contrataciones del Estado, a efectos de mejorar la ejecucion de las obras publicas. En este escenario, es importante conocer estas herramientas comprendidas en el Modelo de Ejecucion de Inversiones Publicas como punto de partida para evaluar posibles propuestas de mejora a la normativa de contrataciones del Estado, ya sea para prever nuevas figuras o para mejorar la regulacion existente. Para dicho fin, en el presente articulo se resenan algunas de las principales herramientas del Modelo de Ejecucion de Inversiones Publicas, asi como los beneficios que estas podrian aportar para la ejecucion de las obras publicas. EnglishAfter the XVIII Pan American Games and Sixth Parapan American Games were held between July and September 2019, the largest sporting event organized and executed by Peru, which involved the deployment of novel contracting and management mechanisms, the Government has sought replicate this experience in a new investment management model. In this context, the Special Public Investment Projects were created, with the aim of applying this new investment management model for the execution of public investment projects, a package of projects or a portfolio of projects.The regulation of these Special Public Investment Projects has been progressively developed in the last year, adopting even the mechanism of Government-to-Government contracts. This regulatory development has led to the creation of the first Public Investment Project, “Escuelas Bicentenario”. With the constant announcements of modification of the Government Procurement Law, the discussion of the opportunity and relevance of implementing the tools enabled for Special Public Investment Projects in the general regulation of public contracts has been raised, in order to improve the execution of public works. In this scenario, it is important to study the tools considered in the investment execution model envisaged in Emergency Decree 021-2020, as a starting point to evaluate the proposals for improvement to the Government Procurement Law. In this article the main tools of the Investment Execution Model are reviewed, as well as the benefits these tools provide for the execution of important infrastructure projects in Peru.

The Covid‐19 pandemia has many other undesirable consequences apart of virus infection. Less people is hospitalized due to acute coronary syndrome and the delay to seek medical attention has increased. Patients with ST segment elevation myocardial infarction arrive at the hospital too late to be timely treated and we have recently seen mechanical complications that were more frequent in the past decades before the use of reperfusion strategies. In this report we describe the presentation, evolution and detailed imaging evaluation of two patients with unusual presentations of cardiac rupture: left ventricular pseudoaneurysm and left ventricular intramyocardial dissecting hematoma.

Politische Werbung in sozialen Netzwerken spielt eine immer größere Rolle: Durch die Auswertung und Analyse der in sozialen Netzwerken befindlichen, personenbeziehbaren Nutzerdaten (dem sog. Microtargeting) lassen sich individualisierte Werbebotschaften und Anzeigen erstellen, die auf unterschiedlichste Nutzergruppen zugeschnitten werden können. Während in den USA Microtargeting bereits seit geraumer Zeit von Politikern und Parteien in Wahlkämpfen eingesetzt wird, steht Deutschland bei dieser Entwicklung erst am Anfang. Neben Parteien und Politikern vertreten jedoch auch andere Institutionen, Organisationen und Nutzer politische oder gesellschaftlich relevante Standpunkte und bewerben diese in sozialen Netzwerken. Hinsichtlich bezahlter Werbeanzeigen sind in Deutschland die Gewerkschaften und die Arbeitgeberverbände kontinuierlich aktiv. Daher stellt sich die Frage, ob sich bei der politischen Werbung dieser Organisationen bereits Hinweise für ein Nutzertargeting finden lassen? Auf Basis unserer Daten aus der Facebook Ad Library soll im Artikel dieser Frage nachgegangen werden. Mit seiner Ad Library sammelt und veröffentlicht das Unternehmen Facebook seit 2019 nach eigenen Angaben alle politisch und gesellschaftlich relevanten Werbeanzeigen, für die Werbetreibende bezahlt haben. Vor diesem Hintergrund werden die unterschiedlichen Werbestrategien der deutschen Gewerkschaften und Arbeitgeberverbände im ersten Teil des Artikels anhand der Anzeigenanzahl, der Werbekosten und der Reichweite der bezahlten Werbung innerhalb des Beobachtungszeitraums März 2019 bis Juni 2020 verglichen. Im zweiten Teil wird versucht, mögliche Targeting-Strategien anhand der demographischen und der räumlichen Verteilung der Facebook - Nutzern nachzuzeichnen, denen die Werbung angezeigt worden ist.

espanolEn este informe de investigacion se presenta una experiencia de uso de situaciones adidacticas conforme al fundamento teorico de las Situaciones Didacticas de Guy Brousseau y la teoria de los campos conceptuales de Vergnaud, referentes que se usaron en el analisis de la indagacion respecto de la conceptualizacion de los numeros negativos, en una estudiante de cuarto ano de Ensenanza Basica en una escuela de Valparaiso-Chile. Usando como recurso el entorno de Scratch, se crearon situaciones, con la intencion de que la estudiante extendiera su conceptualizacion respecto de estos numeros y sin tener conocimientos previos de los aspectos formales de estos. Como resultado de ello, se evidencio que la estudiante extendio su conceptualizacion. Es una investigacion cualitativa, en la que se utilizaron como instrumentos la entrevista y el registro de las producciones escritas de la estudiante para realizar el analisis, mediante este proceso ha sido posible reconocer las condiciones en las que se alcanza la extension numerica para el caso estudiado, las cuales son: reconocimiento de los distintos niveles de conceptualizacion de los numeros negativos, dualidad del signo menos y aceptacion de la sustraccion de enteros, y explorar las dificultades que tuvo para aprender conceptos de numeros negativos. EnglishThis research report presents an experience of the use of non-didactic situations according to the theoretical foundation of Guy Brousseau’s Didactic Situations and Vergnaud’s theory of conceptual fields, theoretical references that were used in the analysis of inquiry regarding conceptualization of the negative numbers, in a fourth year student of Basic Education in a school in Valparaiso-Chile. Using the Scratch environment as a resource, situations were created, with the intention that the student extends her conceptualization regarding these numbers and without prior knowledge of the formal aspects of these. As a result, it was evident that the student extended his conceptualization. It is a qualitative investigation, which used as instruments the interview and the recording of the student’s written productions to carry out the analysis, through this process it has been possible to recognize the conditions in which the numerical extension is reached for the case studied, which They are: recognition of the different levels of conceptualization of negative numbers, duality of the minus sign and acceptance of integer subtraction, and exploring the difficulties he had in learning concepts of negative numbers.

Gold nanoparticles dispersed on MnOx/TiO2 were used to perform the oxidation of carbon monoxide at low temperatures. Remarkable dispersion of gold nanoparticles under hydrogen treatment was obtained, mainly in Au–MnOx/TiO2 catalysts with 2 wt% Au and 5 wt% Mn, where the Au nanoparticles displayed average sizes of 1–3 nm. The addition of Au nanoparticles to the MnOx/TiO2 catalysts promoted both the CO oxidation from 0 °C and stability at room temperature. This behavior could be attributed to the synergistic interactions between Au0/Au1+ and Mn3+/Mn4+ on the Au–MnOx/TiO2 catalyst surface.

Desde la recesión financiera del 2007-2009 y hasta el día de hoy, los principales bancos centrales han utilizado a instrumentos de política no tradicionales para estimular la actividad económica. Un ejemplo muy característico fue la expansión de sus hojas de balance a través de la compra de títulos de deuda gubernamental de largo plazo. En este artículo analizo el efecto de esta herramienta “no convencional” en los mercados de crédito y lo comparo con aquel de instrumentos convencionales tales como las operaciones de mercado abierto. Nuestros resultados sugieren que las compras de títulos de deuda gubernamental de largo plazo estimulan la actividad en los mercados de crédito y reducen los costos de financiamiento tanto privado como público sólo cuando existe un régimen con tasas de interés bajas y deuda fiscal limitada. De otra manera, esta política incrementa el costo del servicio a la deuda, lo que resulta en una contracción del crédito. Por otro lado, las operaciones de mercado abierto facilitan la disponibilidad de crédito pero afectan negativamente la compartición del riesgo en la economía.

A novel approach is presented to determine four bisphenols in water and urine samples, employing magnetic dispersive solid‐phase extraction combined with liquid chromatography and diode array detection. A modified zeolite‐based magnetic composite was used as an efficient sorbent, combining the advantages of magnetic materials with the remarkable properties of zeolites. A multivariate optimization design was employed to optimize some experimental factors affecting magnetic dispersive solid‐phase extraction. The method was evaluated under optimized conditions (i.e., amount of sorbent, 50 mg; sample pH, unadjusted; NaCl concentration, 1.25%; extraction and elution time, 2 min; eluent solvent, ethanol; eluent solvent volume, 400 µL), obtaining good linearity with correlation coefficients ranging between 0.995 and 0.999 (N = 5) (from 2 to 250 µg/L for bisphenol A, bisphenol AP, and bisphenol P and from 5 to 250 µg/L for bisphenol AF). Method repeatability was assessed obtaining coefficients of variation between 3 and 11% (n = 6). Finally, the method was applied to spiked real samples, obtaining for water samples relative recoveries between 83 and 105%, and for urine samples between 81 and 108% for bisphenol A, bisphenol AP, and bisphenol AF, and between 47 and 59% for bisphenol P. The authors would like to thank the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project no. CTQ2016-79991-R) and Generalitat Valenciana (Spain) (project no. PROMETEO/2018/087) for the financial support. P. Baile also thanks Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).

Introduction. The roles of angiotensin II (Ang II) in the brain are still under investigation. In this study, we investigated if Ang II influences differentiation of human neuroblastoma cells with simultaneous activation of NADPH oxidase and reactive oxygen species (ROS). Moreover, we investigated the Ang II receptor type involved during differentiation. Methods. Human neuroblastoma cells (SH-SY5Y; 5 × 10 5 cells) were exposed to Ang II (600 nM) for 24 h. Differentiation was monitored by measuring MAP2 and NF-H levels. Cell size and ROS were analyzed by flow cytometry, and NADPH oxidase activation was assayed using apocynin (500 μM). Ang II receptors (ATR) activation was assayed using ATR blockers or Ang II metabolism inhibitors (10-7 M). Results. (1) Cell size decreased significantly in Ang II-treated cells; (2) MAP2 and ROS increased significantly in Ang II-treated cells with no changes in viability; (3) MAP2 and ROS decreased significantly in cells incubated with Ang II plus apocynin. (4) A significant decrease in MAP2 was observed in cells exposed to Ang II plus PD123.319 (AT2R blocker). Conclusion. Our findings suggest that Ang II influences differentiation of SH-SY5Y by increasing MAP2 through the AT2R. The increase in MAP2 and ROS were also mediated through NADPH oxidase with no cell death.

The academic community of the department of Risaralda, in its permanent interest in evidencing the results of the research processes that are carried out from the Higher Education Institutions and as a product of the VI meeting of researchers of the department of Risaralda held in November 2021 presents its work: “The journey of research as a challenge towards new trends”, which reflects the result of the latest research and advances in different lines of knowledge in Agricultural Sciences, Health Sciences, Social Sciences and Technology and Information Sciences, which seek to solve and meet the demands of the different sectors. This work would not have been possible without the help of each of the teachers, researchers and authors who presented their articles that make up each of the chapters of the book, to them our gratitude for their commitment, dedication and commitment, since their sole purpose is to contribute from the academy and science to scientific and technological development in the search for the solution of problems and thus contribute to transform the reality of our society and communities. We also wish to extend our gratitude to the institutions of the Network that made this publication possible: UTP, UCP, UNAD, UNIREMINGTON; UNISARC, CIAF, Universidad Libre, Uniclaretiana, Fundación Universitaria Comfamiliar and UNIMINUTO, institutions that in one way or another allowed this work to become a reality, which we hope will be of interest to you. Preface............................................................................................................................7 Chapter 1. Technologies and Engineering Towards a humanization in Engineering using soft skills in training in Engineers.............................................................................................................11 Omar Iván Trejos Buriticá1, Luis Eduardo Muñoz Guerrero Innovative materials in construction: review from a bibliometric analysis....................................................................................................................27 Cristian Osorio Gómez, Daniel Aristizábal Torres, Alejandro Alzate Buitrago, Cristhian Camilo Amariles López Bibliometric review of disaster risk management: progress, trends, and challenges.........................................................................................................51 Alejandro Alzate Buitrago, Gloria Milena Molina Vinasco. Incidence of land coverage and geology, in the unstability of lands of the micro-basin of the Combia creek, Pereira, Risaralda....................................73 Alejandro Alzate Buitrago, Daniel Aristizábal Torres. Chapter 2. Arts, Humanities, and Social Sciences Training experience with teachers teaching mathematics using the inquiry methodology ...............................................................................................95 Vivian Libeth Uzuriaga López, Héctor Gerardo Sánchez Bedoya. Interpretation of the multiple representations of the fears associated to the boarding of limited visual patients in the elective I students’ written productions and low vision ...................................................................................113 Eliana Bermúdez Cardona, Ana María Agudelo Guevara, Caterine Villamarín Acosta. The relevance of local knowledge in social sciences............................................131 Alberto Antonio Berón Ospina, Isabel Cristina Castillo Quintero. Basic education students’ conceptions of conflict a view from the peace for the education....................................................................................................143 Astrid Milena Calderón Cárdenas,Carolina Aguirre Arias, Carolina Franco Ossa, Martha Cecilia Gutiérrez Giraldo, Orfa Buitrago. Comprehensive risk prevention in educational settings: an interdisciplinary and socio-educational approach ............................................................................163 Olga María Henao Trujillo, Claudia María López Ortiz. Chapter 3. Natural and Agricultural Sciences Physicochemical characterization of three substrates used in the deep bedding system in swine .......................................................................................175 Juan Manuel Sánchez Rubio, Andrés Felipe Arias Roldan, Jesús Arturo Rincón Sanz, Jaime Andrés Betancourt Vásquez. Periodic solutions in AFM models........................................................................187 Daniel Cortés Zapata, Alexander Gutiérrez Gutiérrez. Phenology in flower and fruit of Rubus glaucus benth. Cv. Thornless in Risaralda: elements for phytosanitary management .........................................199 Shirley Palacios Castro, Andrés Alfonso Patiño Martínez, James Montoya Lerma, Ricardo Flórez, Harry Josué Pérez. Socio-economic and technical characterization of the cultivation of avocado (Persea americana) in Risaralda..............................................................217 Andrés Alfonso Patiño Martínez, Kelly Saudith Castañez Poveda, Eliana Gómez Correa. Biosecurity management in backyard systems in Santa Rosa de Cabal, Risaralda................................................................................................................227 Julia Victoria Arredondo Botero, Jaiver Estiben Ocampo Jaramillo, Juan Sebastián Mera Vallejo, Álvaro de Jesús Aranzazu Hernández. CONTENTS Physical-chemical diagnosis of soils in hillside areas with predominance of Lulo CV. La Selva production system in the department of Risaralda.............241 Adriana Patricia Restrepo Gallón, María Paula Landinez Montes, Jimena Tobón López. Digestibility of three concentrates used in canine feeding....................................271 María Fernanda Mejía Silva, Valentina Noreña Sánchez, Gastón Adolfo Castaño Jiménez. Chapter 4. Economic, Administrative, and Accounting Sciences Financial inclusion in households from socioeconomic strata 1 and 2 in the city of Pereira ..................................................................................................285 Lindy Neth Perea Mosquera, Marlen Isabel Redondo Ramírez, Angélica Viviana Morales. Internal marketing strategies as a competitive advantage for the company Mobilautos SAS de Dosquebradas........................................................................303 Inés Montoya Sánchez, Sandra Patricia Viana Bolaños, Ana María Barrera Rodríguez. Uses of tourist marketing in the tourist sector of the municipality of Belén de Umbría, Risaralda.............................................................................................319 Ana María Barrera Rodríguez, Paola Andrea Echeverri Gutiérrez, María Camila Parra Buitrago, Paola Andrea Martín Muñoz, Angy Paola Ángel Vélez, Luisa Natalia Trejos Ospina. Territorial prospective of Risaralda department (Colombia), based on the SDGS...............................................................................................................333 Juan Guillermo Gil García, Samanta Londoño Velásquez. Chapter 5. Health and Sports Sciences Performance evaluation in times of pandemic. What do medical students think?.......................................................................................................353 Samuel Eduardo Trujillo Henao, Rodolfo A. Cabrales Vega, Germán Alberto Moreno Gómez. The relevance of the therapist’s self and self-reference in the training of psychologists.....................................................................................................371 Maria Paula Marmolejo Lozano, Mireya Ospina Botero. Habits related to oral health which influence lifestyle of elder people in a wellness center for the elderly in Pereira 2020. .............................................387 Isadora Blanco Pérez, Olga Patricia Ramírez Rodríguez, Ángela María Rincón Hurtado. Analysis of the suicide trend in the Coffee Region in Colombia during the years 2012-2018 ..............................................................................................405 Germán Alberto Moreno Gómez, Jennifer Nessim Salazar, Jairo Franco Londoño, Juan Carlos Medina Osorio. Hind limb long bone fractures in canines and felines...........................................419 María Camila Cruz Vélez, Valentina Herrera Morales, Alba Nydia Restrepo Jiménez, Lina Marcela Palomino, Gabriel Rodolfo Izquierdo Bravo. Prevalence of overweight and obesity in children in the rural and urban area of Risaralda....................................................................................................439 Angela María Álvarez López, Angela Liceth Pérez Rendón, Alejandro Gómez Rodas, Luis Enrique Isaza Velásquez. Chapter 6. Architecture, Design and Advertising The artisan crafts of Risaralda, characteristics, importance, and risks within the Colombian Coffee Cultural Landscape, CCCL....................................457 Yaffa Nahir Ivette Gómez Barrera, Javier Alfonso López Morales.

The Webquest is a type of didactic activity based on constructivist assumptions of the teaching - learning process. This research, in the context of innovation, proposes a didactic experience for three groups of teachers, to design, develop and implement webquest for the teaching of science. It is guided by a guided indagatory methodology that promotes meaningful learning and improves academic performance. The methodological teaching proposal is theoretically based on the significant learning of Ausubel, on cognitive developments of Piaget, zone of proximal development of Vygotsky and the cooperative work of Jonhson and Jonhson. The research is experimental, essentially quantitative, with an exploratory, descriptive study. The results ensure an important advance between the pretest and posttest of each work group, with a tangible product that can be used in the science classrooms. La Webquest es un tipo de actividad didáctica basada en presupuestos constructivistas del proceso enseñanza – aprendizaje. La presente investigación, en el contexto de la innovación, propone una experiencia didáctica para a tres grupos de profesores, para diseñar, elaborar y poner en práctica webquest para la enseñanza de las ciencias. Se orienta en una metodología indagatoria guiada y que promueva aprendizaje significativo, y que mejore los rendimientos académicos. La propuesta metodológica de enseñanza se sustenta teóricamente en el aprendizaje significativo de Ausubel, en desarrollos cognitivos de Piaget zona de desarrollo próximo de Vygotsky y el trabajo cooperativo de Jonhson y Jonhson. La investigación es de tipo experimental, esencialmente cuantitativa, con un estudio exploratorio, descriptivo. Los resultados aseguran un avance importante entre el pretest y postest de cada grupo de trabajo, con un producto tangible que puede ser utilizado en las aulas de ciencias.

We investigate the diffusion of conspiracy theories related to the origin of COVID-19 on social media. By analyzing third-party content on four social media platforms, we show that: (a) In contrast to conventional wisdom, mainstream sources contribute overall more to conspiracy theories diffusion than alternative and other sources; and (b) platforms’ content moderation practices are able to mitigate the spread of conspiracy theories. Nevertheless, we locate issues regarding the timeliness and magnitude of content moderation, as well as that platforms filter significantly fewer conspiracy theories coming from mainstream sources. Given this, we discuss policy steps that can contribute to the containment of conspiracy theories by media sources, platform owners, and users.

Within the main contracting mechanisms used by the Special Project in chargeof the organization and development of the X VIII Pan American Games and VI ParapanAmerican Games of 2019 for the acquisition of complex and sophisticated goods, servicesand infrastructure, considering the lack of national experience in mega sport events,we can find Government-to-Government Agreements and New Engineering Contracts.Considering the results of these contracting mechanisms, there are many public entitiesevaluating the possibility to use them to carry out their own projects. However, it is notunusual for these entities to not fully understand the scope and nature of said mechanisms.Therefore, this paper explains the main characteristics of these two contractual figures, aswell as the experience of their use in the Pan American Games, in order to appoint some considerations that public entities must take into account before deciding to use them. Entre los principales mecanismos de contratación empleados por el Proyecto Especial a cargo de la preparación y desarrollo de los Juegos Panamericanos del 2019 para abastecerse de bienes, servicios y obras complejos de manera oportuna y eficiente, considerando la falta de experiencia nacional en las contrataciones necesarias para mega eventos deportivos, se encuentran el Acuerdo de Gobierno a Gobierno y el empleo de los contratos NEC 3 - Opción F. En vista de los resultados que viene obteniendo el Proyecto Especial con el empleo de estas figuras, no son pocas las entidades que se encuentran explorando la posibilidad de utilizarlas para llevar a cabo sus propios proyectos; aunque muchas veces sin terminar de comprender el alcance y naturaleza de estos mecanismos. Por ello, en el presente artículo se desarrollan las principales características de estas dos herramientas de contratación, así como la experiencia de su empleo en los Juegos Panamericanos, a fin de concluir en algunas consideraciones que deben tomar en cuenta las entidades antes de replicar dicho esquema.

Community-based educational spaces (CBES; afterschool programs, community-based youth organizations, etc.) have a long history of interrupting patterns of educational inequity and continue to do so under the current educational policy climate. The current climate of education, marked by neoliberal education restructuring, has left community-based educational spaces vulnerable in many of the same ways as public schools. Considering the current political moment of deep insecurity within public education, this review of research illuminates the role community-based educational spaces have played in resisting forms of educational inequality and their role in the lives of minoritized youth. With a review of seminal education research on community-based spaces, we intend to capture the ways these diverse out-of-school spaces inform the educational experiences, political identity development, and organizing and activist lives of minoritized youth. Further, this piece contends that reimagining education beyond the borders of the school is a form of resistance, as community-based leaders, youth workers, and youth themselves negotiate the dialectical nature of community-based educational spaces within a capitalist and racialized neoliberal state.

Online Social Networks (OSNs) are used increasingly for political purposes. Among others, politicians externalize their views on issues, and users respond to them, initiating political discussions. Part of the discussions are shaped by hyperactive users. These are users that are over-proportionally active in relation to the mean. In this paper, we define the hyperactive user on the social media platform Facebook, both theoretically and mathematically. We apply a geometric topic modelling algorithm (GTM) on German political parties' posts and user comments to identify the topics discussed. We prove that hyperactive users have a significant role in the political discourse: They become opinion leaders, as well as set the content of discussions, thus creating an alternate picture of the public opinion. Given that, we discuss the dangers of replicating the specific bias by statistical and deep learning algorithms, which are used widely for recommendation systems and the profiling of OSN users.