A theoretical model for organizing and understanding teacher learning opportunities to teach mathematics

Understanding how teacher learning is constituted is an important research area in teacher education with many open questions to be investigated yet. Thereby, in this paper, we present a theoretical model whose main purpose is to enable the design of teacher education programs as well as to guide the understanding of professional learning opportunities for teachers. Based on our research outcomes on teaching and learning algebra and on a literature review, we describe how the model was elaborated and bring some illustrative situations to indicate the model “in action” throughout the teacher education process. The architecture of the program enabled teachers to experience professional learning opportunities linked to mathematical and didactical knowledge regarding patterns and regularities, as well as the opportunity to learn from and with each other, overcoming the isolation caused by daily work in their schools and leading them to explore practices close to their own school reality.info:eu-repo/semantics/publishedVersio

Professional learning opportunities in a practice-based teacher education programme about the concept of function

This article aims to identify professional learning opportunities (PLO) experienced by mathematics teachers during an in-service course regarding their mathematical and didactical knowledge on the concept of function. The conceptual framework distinguishes between mathematical and didactical knowledge and characterises teacher learning and professional learning tasks. The research methodology is qualitative, using participant observation with audio and video recording and document collection. The results show that the professional learning tasks proposed enabled to identify PLO regarding mathematical knowledge of function, involving different ways of representing this concept by means of numeric tables and algebraic notation. Regarding didactical knowledge, there were also PLO supporting reflection about difficulties that the students find with the concept of function and about teaching resources and strategies to overcome those difficulties

Mathematical and didactical knowledge about patterns and regularities mobilized by teachers in a professional learning task

Congresso realizado de 6 a 10 de Fevereiro de 2019, na Universidade de Utrecht, HolandaInvestigating teachers’ knowledge for teaching mathematics has been an important theme in mathematics teacher education. In this paper we aim to analyze which mathematical and didactical knowledge secondary mathematics teachers have about patterns and regularities. For this, we developed a teacher education process with mathematics teachers in Brazil during 15 weeks using professional learning tasks (PLT) specially built for this purpose. The research is qualitative-interpretative and data were collected by audio and video recording, with gathering of written documents. The results show that PLT allowed to recognize what mathematical and didactical knowledge teachers had in the begging of the teacher education process, and how the PLT enabled the development of new professional teacher knowledge.info:eu-repo/semantics/publishedVersio

Hacia un enfoque para el desarrollo profesional de los docentes: cómo trabajar con el pensamiento algebraico en los primeros años

This article received national funding from the FCT - Fundação para a Ciência e a Tecnologia, IP, within the scope of the UIDEF - Unidade de Investigação e Desenvolvimento em Educação e Formação - UIDB/04107/2020.This article presents the first intervention cycle of a design-based research program on teacher professional development. The study aims to understand how the formative process helped teachers to understand what algebraic thinking means and how to work with it in the early years. Data analysis was based on three principles of design: teacher’s role and actions, professional learning tasks for teachers, and discursive interactions among participants. The results suggest that these design principles contributed to teachers’ understanding of the meaning of algebraic thinking and how to promote it in elementary students.Este artículo presenta el primer ciclo de intervención de una investigación basada en el diseño del desarrollo profesional docente. Su objetivo es comprender cómo el proceso formativo ayudó a los maestros a comprender qué significa el pensamiento algebraico y cómo trabajar con él en los primeros. El análisis de datos se basó en tres principios de diseño, papel y acciones del formador de docentes, tareas de aprendizaje profesional para los docentes e interacciones discursivas entre los participantes. Los resultados sugieren que los principios de diseño contribuyeron a la comprensión del significado del pensamiento algebraico y cómo promoverlo en los estudiantes de primaria.FCT - Fundação para a Ciência e a Tecnologia UIDB/04107/202

Conhecimento matemático e didático de professores da escola básica acerca de padrões e regularidades em um processo formativo ancorado na prática

O presente artigo discute resultados de uma pesquisa realizada a partir de um processo formativo ancorado na prática envolvendo professores da escola básica e tematizando o ensino de álgebra por meio de padrões e regularidades. Utilizando tarefas de aprendizagem profissional especialmente elaboradas para a formação, objetiva-se investigar o conhecimento matemático e didático mobilizado e aprofundado por professores de Matemática ao preparar, desenvolver e analisar coletivamente uma aula sobre padrões e regularidades em uma turma do Ensino Médio. Trata-se de uma pesquisa qualitativa-interpretativa, cujos dados foram recolhidos por meio de protocolos e gravações em áudio e vídeo. Os resultados mostram que os professores participantes mobilizaram e ampliaram seus conhecimentos sobre a interpretação de diferentes formas de generalizar um padrão matemático, assim como ampliaram seus próprios conhecimentos matemáticos acerca de um importante tema a ser discutido na escola básica

Prática profissional de professores dos anos iniciais e o pensamento algébrico: contribuições a partir de uma formação continuada

Neste artigo analisamos como dois professores dos anos iniciais do ensino fundamental planejaram e conduziram uma aula considerando aspectos do pensamento algébrico a partir de uma abordagem de ensino exploratório, tendo em conta sua participação em uma formação continuada. O estudo enquadra-se em uma perspectiva qualitativa-interpretativa de pesquisa, em que a recolha de dados foi proveniente do planejamento dos professores, de registros em áudio das aulas, com sua subsequente transcrição, e registro fotográfico das tarefas matemáticas realizadas pelos alunos. Os resultados mostram que como consequência da formação realizada, as ações de planejamento e condução das aulas dos professores consideraram as fases do ensino exploratório, bem como aspectos do pensamento algébrico

Fast blood impedance measurements as quality indicators in the pre-analytical phase to prevent laboratory errors

In clinical laboratories, the major proportion of errors regarding blood analyses occurs in the pre-analytical phase. Pre-analytical conditions are key, necessary factors in maintaining the high quality of specimens, limiting day-to-day and batch variations, and guaranteeing the absolute reliability and accuracy of clinical results and related diagnoses. The quality of serum samples must be very high in order to avoid interferences due to hemolysis, thereby preventing measurement errors. In addition, the quality of the blood should always be fast monitored to identify inadequacies and guarantee their complete usability in transfusion procedures. In the near future, the solution could be to supply laboratories with smart and portable devices that are able to perform fast quality tests for every sample. Electrical impedance has relevant potential in analyzing and monitoring blood quality. We propose a new, simple impedancebased biosensor that can perform accurate and efficient single and multi-frequency impedance measurements in the pre-analytical phase and to check the quality of blood samples using quantitative thresholds as useful indicators to ensure the reliability of results and thereby prevent laboratory errors. The proposed sensor allows for discriminating different blood components, identifying hemolysis in serum, evaluating blood quality, and rapidly quantifying its hematocrit

Improved GMP compliant approach to manipulate lipoaspirates, to cryopreserve stromal vascular fraction, and to expand adipose stem cells in xeno-free media

Abstract Background The stromal vascular fraction (SVF) derived from adipose tissue contains adipose-derived stromal/stem cells (ASC) and can be used for regenerative applications. Thus, a validated protocol for SVF isolation, freezing, and thawing is required to manage product administration. To comply with Good Manufacturing Practice (GMP), fetal bovine serum (FBS), used to expand ASC in vitro, could be replaced by growth factors from platelet concentrates. Methods Throughout each protocol, GMP-compliant reagents and devices were used. SVF cells were isolated from lipoaspirates by a standardized enzymatic protocol. Cells were cryopreserved in solutions containing different albumin or serum and dimethylsulfoxide (DMSO) concentrations. Before and after cryopreservation, we analyzed: cell viability (by Trypan blue); immunophenotype (by flow cytometry); colony-forming unit-fibroblast (CFU-F) formation; and differentiation potential. ASC, seeded at different densities, were expanded in presence of 10% FBS or 5% supernatant rich in growth factors (SRGF) from platelets. The differentiation potential and cell transformation grade were tested in expanded ASC. Results We demonstrated that SVF can be obtained with a consistent yield (about 185 × 103 cells/ml lipoaspirate) and viability (about 82%). Lipoaspirate manipulation after overnight storage at +4 °C reduced cell viability (−11.6%). The relative abundance of ASC (CD34+CD45−CD31–) and endothelial precursors (CD34+CD45−CD31+) in the SVF product was about 59% and 42%, respectively. A period of 2 months cryostorage in autologous serum with added DMSO minimally affected post-thaw SVF cell viability as well as clonogenic and differentiation potentials. Viability was negatively affected when SVF was frozen at a cell concentration below 1.3 × 106 cells/ml. Cell viability was not significantly affected after a freezing period of 1 year. Independent of seeding density, ASC cultured in 5% SRGF exhibited higher growth rates when compared with 10% FBS. ASC expanded in both media showed unaltered identity (by flow cytometry) and were exempt from genetic lesions. Both 5% SRGF- and 10% FBS-expanded ASC efficiently differentiated to adipocytes, osteocytes, and chondrocytes. Conclusions This paper reports a GMP-compliant approach for freezing SVF cells isolated from adipose tissue by a standardized protocol. Moreover, an ASC expansion method in controlled culture conditions and without involvement of animal-derived additives was reported

Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder

Background: Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries. Methods: Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun’s electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries). Results: This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01. Conclusion: A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival