123 research outputs found
Prospective Elementary Teachers’ Pedagogical Knowledge for Mathematical Problem Solving
This research was funded by Ministry of Science, Innovation and Universities (Spain) who financed the research project PGC2018-095765-B-I00 (PROFESTEM), and a Ph.D. grant awarded by Chile's ANID (folio 72170314).Research on mathematics teachers’ knowledge has generally focused more on mathematics
concepts than mathematical processes. This paper addresses the latter with a focus on mathematical
problem solving (PS). It reports on a study that investigated the pedagogical knowledge for PS of
prospective elementary school teachers of mathematics (PTs). Participants were 149 PTs at a university
in Spain. They were at the end of their teacher education program. Data sources consisted of
a questionnaire on knowledge of learning PS and a questionnaire on knowledge of teaching PS.
Findings indicated that the PTs held combination of different levels of knowledge of PS learning
and teaching. Many of them demonstrated appropriate knowledge of many characteristics for (1) PS
learning consisting of student as a problem-solver, PS as a worthwhile task, non-cognitive factor
related to PS, and (2) PS teaching consisting of PS teaching approaches, discourse in PS, intervention
during stuck state in PS, PS assessment, and PS resources. However, there were also contradictions
and limitations to their knowledge with implications for teacher education. These combination of
appropriate and inappropriate knowledge resulted in some conflicts that are related to teaching
actions and would limit student’ learning of PS.Ministry of Science, Innovation and Universities (Spain) PGC2018-095765-B-I00
folio 7217031
Presencia, uso e influencia de los diputados del Parlamento de Galicia en Twitter
The emergence of Internet and Information and Communication Technologies in the field of politics has led to a transformation of its main characteristics. In 2.0 contexts, subjects and structures of politics must to adapt a new environment, a digital one, where new rules for participation and social interaction are settle down. In this sense, the present study aims to analyze the possibilities for participation of Members of the Galician Parliament through Twitter as a social network.La irrupción de Internet y de las Tecnologías de la Información y la Comunicación en el ámbito de la política ha conllevado una transformación de algunos de sus aspectos más característicos. En el ámbito 2.0 los sujetos y estructuras de la política convencional han tenido que adaptarse a un nuevo entorno, el digital, en el que se establecen nuevas reglas para la interacción social y la participación. En este sentido, el presente estudio ha tenido por objeto analizar las posibilidades para la participación que los agentes del Parlamento de Galicia brindan a la ciudadanía a través de la plataforma social Twitter
Resultados PISA y resolución de problemas matemáticos en los currículos de Educación Primaria
The results of successive PISA assessments show substantial differences between countries. In this context, we wonder if these differences are related to levels of specificity in solving problems of curricula of these countries. Particularly, in this paper we present a comparative study of curricula for primary education from six countries, which have received high, middle and lower scores in PISA 2012. Through a content analysis, we describe how problem solving competency is set to these curricula. The results reveal different levels of explicitness in each document and dichotomies what is explicit as a concept of problem solving and what requires school. We conclude that countries with curricula with higher levels of explicitness not necessarily correspond with those who obtained the highest score in the PISA study.Los resultados de las sucesivas evaluaciones PISA muestran diferencias sustanciales entre países. En este contexto, nos preguntamos si estas diferencias están relacionadas con los niveles de concreción en resolución de problemas de los currículos de estos países. Particularmente, en el presente trabajo mostramos un estudio comparativo de los currículos de Educación Primaria de seis países los cuales han recibido puntajes altos, medios y bajos en el estudio PISA 2012. Mediante un análisis de contenido describimos cómo se configura la competencia de resolver problemas en estos currículos. Los resultados revelan diferentes niveles de explicitación en cada documento y dicotomías sobre lo que se explicita como una concepción de la resolución de problemas y lo que se exige a los escolares. Se concluye que los países que presentan currículos con mayor nivel de explicitación no se corresponden necesariamente con aquellos que obtuvieron mayor puntaje en el estudio PISA
Teacher knowledge components for teaching problem solving in primary education
La importancia que presenta la resolución de problemas en la enseñanza y aprendizaje de la matemática es una premisa aceptada en la comunidad de educadores matemáticos. No obstante, los marcos que describen o caracterizan el conocimiento de los profesores sobre las matemáticas escolares han dado poca relevancia a este proceso. Partiendo de revisiones curriculares y teóricas, presentamos una organización del conocimiento del profesor de educación primaria sobre la resolución de problemas de matemáticas. En ella diferenciamos un conocimiento sobre la resolución de problemas del que emergen los componentes relativos al concepto de problema, proceso de resolución y disposición para afrontar un problema; y un conocimiento pedagógico sobre la resolución de problemas en el que distinguimos un componente referido al aprendizaje y otro a la enseñanza. Nuestra reflexión ratifica la idea que la naturaleza distinta de un proceso como la resolución de problemas provoca un conocimiento que los modelos han omitido.Problem solving is central in teaching and learning of mathematics, an accepted premise in the community of mathematics educators. However, the frameworks that describe or characterize teachers' knowledge have given little relevance to this process. Starting from curricular and theoretical revisions, we present a proposal of organization for the knowledge of primary teacher about problem solving. We differentiate a knowledge of the process from which the components related to the concept of problem, resolution process and disposition to face a problem emerge; and a pedagogical knowledge where we distinguish a component referring to learning and another to the teaching of problem solving. Our reflection confirms the idea that the different nature of a process such as problem solving, causes a knowledge that the models have omitted.Este trabajo se enmarca en el Plan Nacional de I+D+I del Ministerio de Ciencia e Innovación, financiado bajo el proyecto EDU2015-70565-P; y la Comisión Nacional de Investigación Científica y Tecnológica del Gobierno de Chile (CONICYT), mediante una beca de doctorado en el extranjero (Folio 72170314)
Vapor-liquid interfacial properties of rigid-linear Lennard-Jones chains
We have obtained the interfacial properties of short rigid-linear chains formed from tangentially bonded Lennard-Jones monomeric units from direct simulation of the vapour-liquid interface. The full long-range tails of the potential are accounted for by means of an improved version of the inhomogeneous long-range corrections of Janecek [J. Phys. Chem. B 110, 6264–6269 (2006)] proposed recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] valid for spherical as well as for rigid and flexible molecular systems. Three different model systems comprising of 3, 4, and 5 monomers per molecule are considered. The simulations are performed in the canonical ensemble, and the vapor-liquid interfacial tension is evaluated using the test-area method. In addition to the sur- face tension, we also obtain density profiles, coexistence densities, critical temperature and density, and interfacial thickness as functions of temperature, paying particular attention to the effect of the chain length and rigidity on these properties. According to our results, the main effect of increasing the chain length (at fixed temperature) is to sharpen the vapor-liquid interface and to increase the width of the biphasic coexistence region. As a result, the interfacial thickness decreases and the sur- face tension increases as the molecular chains get longer. The surface tension has been scaled by critical properties and represented as a function of the difference between coexistence densities relative to the critical density.The authors would like to acknowledge helpful discus- sions with F. J. Martínez-Ruiz, E. de Miguel, C. Vega, and A. Galindo. This work was supported by Ministerio de Ciencia e Innovación (MICINN, Spain) through Grant Nos. FIS2010- 14866 (F.J.B.), FIS2009-07923 (J.M.M. and M.M.P.) and FIS2010-22047-C05-05 (L.G.M.D.). J.M.M. also acknowledges Ministerio de Ciencia e Innovación for the FPU Grant with reference AP2007-02172. Further financial support from Proyecto de Excelencia from Junta de Andalucía (Grant No. P07-FQM02884), Consellería de Educacion e Ordenacion Universitaria (Xunta de Galicia), Comunidad Autónoma de Madrid (Grant No. MODELICO-P2009/EPS-1691), and Universidad de Huelva are also acknowledged
Precave: Immediate neoadjuvant instillation of chemotherapy for the prevention of non-muscle invasive bladder carcinoma recurrence: A prospective randomized clinical trial protocol
Introduction and objectives: Recurrence rates for patients presenting with non-muscle invasive bladder
carcinoma (NMIBC) can be as high as 60% during the first year after a transurethral resection of bladder
tumor (TURBT). Currently, an immediate postoperative instillation of chemotherapy (IPOIC) is recommended
for the prevention of recurrences in patients with low to intermediate risk disease. Although
in real clinical practice this specific instillation of chemotherapy has many difficulties to be standardized,
including its contraindications (suspected or confirmed bladder perforation, wide or extensive resection
and, continuous bladder irrigation requirement), which will only make it feasible for around 30% of
patients.
We propose in this controlled study, to administer an immediate neoadjuvant instillation of
chemotherapy (INAIC), which can be applied technically to all patients, no matter the surgical outcomes
and compare it with a control group. We expect to find a reduction in the recurrence rate in the experimental
group of at least 15%.
Methods: We designed a phase IV, randomized, controlled, open label clinical trial. Main inclusion criteria
are: patients with a clinical diagnosis of localized, papillary-type bladder cancer (suspected low to intermediate
risk) with a disease-free interval of at least 6 months. Eligible patients will be allocated into
group A (INAIC plus TURBT) or group B (TURBT) using a computer-generated block randomization
sequence/ratio 1:1. Time to recurrence of both groups will be analyzed and compared using Kaplan-
Meier estimates, log-rank tests and, Cox-regression. Univariate and multivariate analyzes will be performed
to determine factors which influence recurrence. The study has received the approval of
the Ethics Committee for Drug Research (CEIm) of La Paz University Hospital and the Spanish Agency for Medicines and Health ProductsThis study received funding from grants ‘‘Rafael Molla y
Rodrigo” from the Foundation for Research in Urology (Spanish
Urological Association) and Immunothercan-CM(B2017/BM
D3733) from the Local Government of the Community of Madrid,
Madrid, Spain
The effect of neoadjuvant chemotherapy among patients undergoing radical cystectomy for variant histology bladder cancer: A systematic review
Objective: To systematically review the evidence about the effect of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) with pure urothelial carcinoma (pUC) in radical cystectomy (RC) candidates affected by variant histology (VH) bladder cancer. Methods: A review of the current literature was conducted through the Medline and National Center for Biotechnology Information (NCBI) PubMed, Scopus databases in May 2020. The updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed for this systematic review. Keywords used were ‘bladder cancer’, ‘bladder carcinoma’, ‘bladder tumour’ and ‘bladder cancer variants’ and ‘neoadjuvant chemotherapy’. Only original articles in English published after 2000 and reporting oncological outcomes a series of more than five patients with VH were included. We excluded series in which the oncological outcomes of patients with pUC and VH were undistinguishable. Results: The literature search identified 2231 articles. A total of 51 full-text articles were assessed for eligibility, with 17 eventually considered for systematic review, for a cohort of 450,367 patients, of which 5010 underwent NAC + RC. The median age at initial diagnosis ranged from 61 to 71 years. Most patients received cisplatin-gemcitabine, methotrexate-vinblastine-adriamycin-cisplatin, or carboplatin-based chemotherapy. Only one study reported results of neoadjuvant immunotherapy. The median follow-up ranged from 1 to 120 months. The results showed that squamous cell carcinoma (SCC) is less sensitive to NAC than pUC and that SCC predicts poorer prognosis. NAC was found to be a valid approach in treating small cell carcinoma and may have potential benefit in micropapillary carcinoma. Conclusions: NAC showed the best oncological outcomes in small cell variants and micropapillary carcinoma, while NAC survival benefit for SCC and adenocarcinoma variants needs further studies. Drawing definite considerations on the efficacy of NAC in VH is complicated due to the heterogeneity of present literature. Present results need to be confirmed in randomised controlled trial
Current Incidence and risk factors of fecal incontinence after acute stroke affecting functionally independent people
Background: Previously published retrospective series show a high prevalence of fecal incontinence (FI) in stroke patients. We aimed to analyze in a prospective series the current incidence of FI in acute stroke in functionally independent patients and its evolution over time and the patient characteristics associated with the appearance of FI in acute stroke. Methods: We included consecutive patients with acute stroke admitted in our stroke unit who fulfilled the following inclusion criteria: a first episode of stroke, aged >18 years, with no previous functional dependency [modified Rankin Scale (mRS) = 2] and without previous known FI. FI was assessed by a multidisciplinary trained team using dedicated questionnaires at 72 ± 24 h (acute phase) and at 90 ± 15 days (chronic phase). Demographic, medical history, clinical and stroke features, mortality, and mRS at 7 days were collected. Results: Three hundred fifty-nine (48.3%) of 749 patients (mean age 65.9 ± 10, 64% male, 84.1% ischemic) fulfilled the inclusion criteria and were prospectively included during a 20-month period. FI was identified in 23 patients (6.4%) at 72 ± 24 h and in 7 (1.9%) at 90 days ± 15 days after stroke onset. FI was more frequent in hemorrhagic strokes (18 vs. 5%, p 0.007) and in more severe strokes [median National Institute of Health Stroke Scale (NIHSS) 18 (14–22) vs. 5 (3–13), p < 0.0001]. No differences were found regarding age, sex, vascular risk factors, or other comorbidities, or affected hemisphere. Patients with NIHSS =12 (AUC 0.81, 95% CI 0.71 to 0.89) had a 17-fold increase for the risk of FI (OR 16.9, IC 95% 4.7–60.1) adjusted for covariates.Peer ReviewedPostprint (published version
WHF IASC Roadmap on Chagas Disease
Background: Chagas Disease is a neglected tropical disease caused by the protozoan Trypanosoma
cruzi, with some of the most serious manifestations affecting the cardiovascular system. It is a
chronic, stigmatizing condition, closely associated with poverty and affecting close to 6 million
people globally. Although historically the disease was limited to endemic areas of Latin America
recent years have seen an increasing global spread. In addition to the morbidity and mortality associated with the disease, the social and economic burdens on individuals and society are substantial.
Often called the ‘silent killer’, Chagas disease is characterized by a long, asymptomatic phase in
affected individuals. Approximately 30% then go on develop chronic Chagas cardiomyopathy and
other serious cardiac complications such as stroke, rhythm disturbances and severe heart failure.
Methods: In a collaboration of the World Hearth Federation (WHF) and the Inter-American
Society of Cardiology (IASC) a writing group consisting of 20 diverse experts on Chagas disease
(CD) was convened. The group provided up to date expert knowledge based on their area of
expertise. An extensive review of the literature describing obstacles to diagnosis and treatment of CD along with proposed solutions was conducted. A survey was sent to all WHF Members
and, using snowball sampling to widen the consultation, to a variety of health care professionals working in the CD global health community. The results were analyzed, open comments were
reviewed and consolidated, and the findings were incorporated into this document, thus ensuring
a consensus representation.
Results: The WHF IASC Roadmap on Chagas Disease offers a comprehensive summary of current
knowledge on prevention, diagnosis and management of the disease. In providing an analysis of
‘roadblocks’ in access to comprehensive care for Chagas disease patients, the document serves
as a framework from which strategies for implementation such as national plans can be formulated. Several dimensions are considered in the analysis: healthcare system capabilities, governance, financing, community awareness and advocacy.
Conclusion: The WHF IASC Roadmap proposes strategies and evidence-based solutions for
healthcare professionals, health authorities and governments to help overcome the barriers to
comprehensive care for Chagas disease patients. This roadmap describes an ideal patient care
pathway, and explores the roadblocks along the way, offering potential solutions based on available research and examples in practice. It represents a call to action to decision-makers and
health care professionals to step up efforts to eradicate Chagas disease
Ojos que no ven… ¿Qué podemos hacer para incluir más a la fracción subterránea en estudios de vegetación?
Conocer la estructura y el funcionamiento de la fracción subterránea de la vegetación es fundamental para comprender numerosos procesos que ocurren en distintos niveles de organización. Sin embargo, dicha fracción fue menos estudiada que su contraparte aérea, principalmente por el gran esfuerzo que demanda muestrearla a campo y procesarla en el laboratorio. En la XXVIII Reunión Argentina de Ecología (Mar del Plata, 2018) se realizaron dos simposios sobre la importancia de conocer las raíces en estudios ecológicos. De los simposios surgió la necesidad de 1) cuantificar los estudios que hayan evaluado las fracciones subterránea y aérea de la vegetación, y 2) determinar las metodologías empleadas y las variables de la fracción subterránea registradas en sistemas naturales (i.e., pastizales, estepas, bosques, arbustales y desierto) y antropizados (i.e., pasturas y cultivos) en seis provincias fitogeográficas de la Argentina y en dos regiones geomorfológicas de Uruguay. Se registraron 933 estudios publicados entre 1990 y 2019. El 57% y el 23% correspondieron a estudios exclusivos de la fracción aérea y de la subterránea, respectivamente, con un incremento exponencial en el tiempo de ambas fracciones. En la actualidad existe una tendencia a incorporar el compartimiento subterráneo en estudios ecológicos. Mediante un análisis sistemático se encontró que se emplearon seis métodos de muestreo (barreno, ruleros, planta entera, monolitos, rhizotron y estimación de la biomasa subterránea a partir de la biomasa aérea) para evaluar cuatro variables (biomasa subterránea, productividad primaria neta subterránea, algunos atributos radicales y tasa de descomposición radical). El método más empleado fue el del barreno y la variable más evaluada fue la biomasa subterránea. Proponemos fomentar la colaboración entre equipos de investigación y establecer comparaciones metodológicas para comprender los alcances de los resultados y obtener estimaciones más confiables sobre las consecuencias del cambio en el uso del suelo.To know the structure and functioning of the belowground vegetation compartment is essential to understand numerous processes that occur at different organization levels. However, the belowground vegetation compartment has traditionally been less studied than the above layer due to the great effort required for field sampling and laboratory processing. In the XXVIII Reunión Argentina de Ecología, Mar del Plata 2018, two symposia about the importance of root knowledge in ecological studies were conducted. From this exchange arose the need to 1) quantify studies that include data of belowground and aboveground vegetation, and 2) determine the methodologies and the variables of the belowground compartment recorded in natural (grasslands, steppes, forests, shrubs, and desert) and human modified systems (pastures, crops) in six Argentinean phytogeographic provinces and in two Uruguayan geomorphological regions. There were 933 published studies from 1990 to 2019. The 57% and 23% corresponded to exclusive studies of the above and belowground compartments respectively, with an exponential increase in the time of both fractions. Currently, there is a tendency to incorporate the underground compartment in ecological studies. Through systematic analysis, it was found that six sampling methods were used (soil core, ingrowth cores, trench, monoliths, rhizotron and belowground biomass estimation from aboveground biomass) where four variables of the belowground vegetation compartment were recorded (belowground biomass, belowground net primary productivity, root traits, and roots decomposition rate). Obtaining soil volumes by soil core was the most used method, while belowground biomass was the most evaluated variable. We propose to encourage collaboration between research teams and establish methodological comparisons to understand the scope of the results and obtain better estimates about the consequences of land-use change.EEA Santa CruzFil: López Mársico, Luis. Universidad de la República. Facultad de Ciencias. Instituto de Ecología y Ciencias Ambientales; UruguayFil: Pestoni, Sofía. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Conti, Georgina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Pérez-Harguindeguy, Natalia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Pinto, Priscila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Sarquis, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Reyes, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad Nacional del Comahue. Facultad de Ambiente y Salud. Laboratorio de Rehabilitación y Restauración de Ecosistemas Áridos y Semiáridos (LARREA); ArgentinaFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Universidad Nacional de la Patagonia Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piñeiro, Gervasio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de la República. Facultad de Agronomía. Departamento de Sistemas Ambientales; Urugua
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