Cinética química y analogías: un análisis de las propuestas de enseñanza

Un supuesto altamente consensuado en los procesos de enseñanza-aprendizaje en ciencias naturales radica en relacionar los conceptos y contenidos abstractos con la realidad concreta y cotidiana. Investigaciones en el ámbito de la psicología y las ciencias cognitivas, indican que apropiarse de cualquier aspecto de la realidad supone poder elaborar una “representación” del mismo, es decir, construir un modelo mental de esa realidad (Izquierdo, 1999; Dagher, 1995). El modelo está presente en nuestra vida cotidiana, científica y escolar, y facilita la comprensión y el entendimiento de los mensajes que se reciben desde los diferentes campos. En este contexto, son de especial importancia, los modelos en la Didáctica de las Ciencias y, en particular, las analogías (Dagher, 1995; Treagust, 1992). Cualquier analogía que se plantee, por muy sugerente y útil que sea, presenta relaciones comunes entre el objeto y el análogo, pero también relaciones que difieren de un fenómeno a otro. Estas ocasiones se podrían canalizar transformándolas en invitaciones a los alumnos a la reflexión y desarrollo de su espíritu crítico. A continuación mostramos los resultados de la revisión de algunos textos escolares pertenecientes al nivel Polimodal y de textos universitarios y textos escolares utilizados en la educación media (estos últimos, empleados durante las décadas del `80 y `90, previo a la implementación de la Reforma Educativa en la Pcia. de Buenos Aires.Sección Naturales.Departamento de Ciencias Exactas y Naturale

Representaciones sociales en el aula de ciencias. El lugar del alumno

Las investigaciones en didáctica de las ciencias han focalizado los estudios sobre los problemas de aprendizaje en la estructura psicológica del alumno que aprende, en la lógica de los contenidos, o en las preconcepciones de los alumnos acerca de los contenidos, no tomando en cuenta la influencia las variables sociales en la comunidad del aula. En este trabajo se propone, desde un marco socio histórico, la incorporación de las representaciones sociales de los alumnos respecto de su lugar en el aula como un elemento central para la comprensión de la dinámica del aula y para un desarrollo de estrategias meta-cognitivas en los alumnos

Representaciones sociales en el aula de ciencias. El lugar del alumno

Las investigaciones en didáctica de las ciencias han focalizado los estudios sobre los problemas de aprendizaje en la estructura psicológica del alumno que aprende, en la lógica de los contenidos, o en las preconcepciones de los alumnos acerca de los contenidos, no tomando en cuenta la influencia las variables sociales en la comunidad del aula. En este trabajo se propone, desde un marco socio histórico, la incorporación de las representaciones sociales de los alumnos respecto de su lugar en el aula como un elemento central para la comprensión de la dinámica del aula y para un desarrollo de estrategias meta-cognitivas en los alumnos

Optimal Byzantine Resilient Convergence in Asynchronous Robot Networks

We propose the first deterministic algorithm that tolerates up to $f$ byzantine faults in $3f+1$-sized networks and performs in the asynchronous CORDA model. Our solution matches the previously established lower bound for the semi-synchronous ATOM model on the number of tolerated Byzantine robots. Our algorithm works under bounded scheduling assumptions for oblivious robots moving in a uni-dimensional space

Repurposing NGO data for better research outcomes: A scoping review of the use and secondary analysis of NGO data in health policy and systems research

Background Non-government organisations (NGOs) collect and generate vast amounts of potentially rich data, most of which are not used for research purposes. Secondary analysis of NGO data (their use and analysis in a study for which they were not originally collected) presents an important but largely unrealised opportunity to provide new research insights in critical areas including the evaluation of health policy and programmes. Methods A scoping review of the published literature was performed to identify the extent to which secondary analysis of NGO data has been used in health policy and systems research (HPSR). A tiered analytic approach provided a comprehensive overview and descriptive analyses of the studies which: 1) used data produced or collected by or about NGOs; 2) performed secondary analysis of the NGO data (beyond use of an NGO report as a supporting reference); 3) used NGO-collected clinical data. Results Of the 156 studies which performed secondary analysis of NGO-produced or collected data, 64% (n=100) used NGO-produced reports (e.g. to critique NGO activities and as a contextual reference) and 8% (n=13) analysed NGO-collected clinical data.. Of the studies, 55% investigated service delivery research topics, with 48% undertaken in developing countries and 17% in both developing and developed. NGO-collected clinical data enabled HPSR within marginalised groups (e.g. migrants, people in conflict-affected areas), with some limitations such as inconsistencies and missing data. Conclusion We found evidence that NGO-collected and produced data are most commonly perceived as a source of supporting evidence for HPSR and not as primary source data. However, these data can facilitate research in under-researched marginalised groups and in contexts that are hard to reach by academics, such as conflict-affected areas. NGO–academic collaboration could help address issues of NGO data quality to facilitate their more widespread use in research. Their use could enable relevant and timely research in the areas of health policy, programme evaluation and advocacy to improve health and reduce health inequalities, especially in marginalised groups and developing countries

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Representaciones sociales en el aula de ciencias. El lugar del alumno

Las investigaciones en didáctica de las ciencias han focalizado los estudios sobre los problemas de aprendizaje en la estructura psicológica del alumno que aprende, en la lógica de los contenidos, o en las preconcepciones de los alumnos acerca de los contenidos, no tomando en cuenta la influencia las variables sociales en la comunidad del aula. En este trabajo se propone, desde un marco socio histórico, la incorporación de las representaciones sociales de los alumnos respecto de su lugar en el aula como un elemento central para la comprensión de la dinámica del aula y para un desarrollo de estrategias meta-cognitivas en los alumnos

Cinética química y analogías : Un análisis de las propuestas de enseñanza

Un supuesto altamente consensuado en los procesos de enseñanza-aprendizaje en ciencias naturales radica en relacionar los conceptos y contenidos abstractos con la realidad concreta y cotidiana. Investigaciones en el ámbito de la psicología y las ciencias cognitivas, indican que apropiarse de cualquier aspecto de la realidad supone poder elaborar una “representación” del mismo, es decir, construir un modelo mental de esa realidad (Izquierdo, 1999; Dagher, 1995). El modelo está presente en nuestra vida cotidiana, científica y escolar, y facilita la comprensión y el entendimiento de los mensajes que se reciben desde los diferentes campos. En este contexto, son de especial importancia, los modelos en la Didáctica de las Ciencias y, en particular, las analogías (Dagher, 1995; Treagust, 1992). Cualquier analogía que se plantee, por muy sugerente y útil que sea, presenta relaciones comunes entre el objeto y el análogo, pero también relaciones que difieren de un fenómeno a otro. Estas ocasiones se podrían canalizar transformándolas en invitaciones a los alumnos a la reflexión y desarrollo de su espíritu crítico. A continuación mostramos los resultados de la revisión de algunos textos escolares pertenecientes al nivel Polimodal y de textos universitarios y textos escolares utilizados en la educación media (estos últimos, empleados durante las décadas del `80 y `90, previo a la implementación de la Reforma Educativa en la Pcia. de Buenos Aires.Sección Naturales.Departamento de Ciencias Exactas y Naturale