Validaciones perceptivas y deductivas en geometría: un estudio con docentes en formación continua

La comunicación breve evidencia resultados parciales del proyecto de investigación Processo de Ensino e Aprendizagem em Matemática em ambientes tecnológicos desarrollado por investigadores del grupo Didáctica de las Matemáticas (DIMAT) de la Pontificia Universidad Católica del Perú y del grupo Processo de Ensino e Aprendizagem em Matemática (PEA-MAT) de la Pontificia Universidad Católica de Sao Paulo/Brasil. Presentamos uno de los cuatro encuentros de la formación en geometría que realizamos con dieciséis docentes peruanos de Educación Básica Regular-nivel secundario. Analizamos una tarea de la secuencia basados en el Enfoque de Parzysz que determina los procesos y mecanismos relacionados con la enseñanza y con el aprendizaje de la geometría y propone una clasificación o tipos de geometría que considera los objetos como físicos o teóricos y los modos de validación perceptiva y deductiva. En la tarea que analizamos, los docentes utilizan diversas estrategias de resolución y realizan un análisis matemático y didáctico la misma. En cuanto a los resultados, observamos que los docentes utilizan estrategias de resolución del tipo G1-geometría concreta y G2 geometría protoaxiomática, en el sentido de Parzysz, sin embargo muestran dificultad en identificar qué tipo de validaciones están utilizando y se les hace difícil elaborar una estrategia en G0

Abordagem instrumental: uma revisão da literatura no Peru e no Brasil dos anos 2013 a 2017

Este estudo é um levantamento de dissertações e teses produzidas no Peru e no Brasil de 2013 a 2017. Tem como objetivo apresentar um panorama das pesquisas que usam a Abordagem Instrumental como quadro teórico, tendo como critérios: as instituições das pesquisas, o objeto matemático, o tipo de artefato usado, os sujeitos envolvidos, e as fases da Gênese Instrumental usadas. A metodologia foi uma pesquisa bibliográfica do tipo estado da arte. Concluímos que as pesquisas no Brasil usam diversos artefatos, em diferentes níveis de ensino e utilizam as duas fases das Gênese Instrumental. Enquanto no Peru, usam artefatos simbólicos, são do nível médio e superior e maioritariamente usam uma das fases

LOS CUADRILÁTEROS COMO SABER A ENSEÑAR EN EL CURRÍCULO PERUANO

El presente artículo tiene como objetivo presentar un análisis de los cuadriláteros como saber a enseñar en el currículo de Perú. Los elementos teóricos en que nos basamos están sustentados por la Teoría Antropológica de lo Didáctico (TAD) y en su perspectiva ecológica. Realizamos un estudio del sistema Educativo Peruano, de las reformas curriculares y luego analizamos cómo y porqué está presente el estudio de los cuadriláteros en el sistema escolar peruano. Como resultados, obtuvimos que, en el currículo de peruano, existe atomización de los contenidos, específicamente enGeometría, es decir, los contenidos son propuestos para ser enseñados de manera separada sin interrelacionarse, por lo cual se pudo dilucidar que, en el caso de los cuadriláteros, se da el fenómeno del autismo temático, que quiere decir que existe un encierro en el nivel temático dentro de la escalade codeterminación didáctica

The secreted triose phosphate isomerase of Brugia malayi is required to sustain microfilaria production in vivo

Human lymphatic filariasis is a major tropical disease transmitted through mosquito vectors which take up microfilarial larvae from the blood of infected subjects. Microfilariae are produced by long-lived adult parasites, which also release a suite of excretory-secretory products that have recently been subject to in-depth proteomic analysis. Surprisingly, the most abundant secreted protein of adult Brugia malayi is triose phosphate isomerase (TPI), a glycolytic enzyme usually associated with the cytosol. We now show that while TPI is a prominent target of the antibody response to infection, there is little antibody-mediated inhibition of catalytic activity by polyclonal sera. We generated a panel of twenty-three anti-TPI monoclonal antibodies and found only two were able to block TPI enzymatic activity. Immunisation of jirds with B. malayi TPI, or mice with the homologous protein from the rodent filaria Litomosoides sigmodontis, failed to induce neutralising antibodies or protective immunity. In contrast, passive transfer of neutralising monoclonal antibody to mice prior to implantation with adult B. malayi resulted in 60–70% reductions in microfilarial levels in vivo and both oocyte and microfilarial production by individual adult females. The loss of fecundity was accompanied by reduced IFNγ expression by CD4+ T cells and a higher proportion of macrophages at the site of infection. Thus, enzymatically active TPI plays an important role in the transmission cycle of B. malayi filarial parasites and is identified as a potential target for immunological and pharmacological intervention against filarial infections

A case of eosinophilic granuloma of the skull in an adult man: a case report

Eosinophilic granuloma is very rare benign bone tumor which presents in more than 90% in children under the age of ten. There is predominance for males. It is usually found at flat and long bones. The skull and vertebral spine is often affected. We report a case of 57 year-old man who gradually developed local pain at his skull and orbit. A soft, movable, palpable and tender mass was found at the left temporal bone. The pain deteriorated after an accidental injury at skull and remained so. The clinical examination revealed no pathological findings. The patient was a doctor who smoked and consumed alcohol daily. He had a history of cardial infraction and psoriatic arthritis. X-rays and CT revealed a round lytic defect at the skull. Its borders were sharp and its size was 1.6 × 1.8 cm. No periostic reaction or bone formation was noted. Scintigraphy depicted a lytic lesion without radionuclide enhancement. Thus we suspected an eosinophilic granuloma. An attempt to excise the tumor failed as it had already eroded the underlying temporal bone. The external meninga was affected but not the internal one. Histological diagnosis with dominance of Langerhans cells set the diagnosis. A second surgery was done and the eosinophilic granuloma was extracted. After eight months the gap was bridged with plastic heterologous transplant. After the curettage the patient received antibiotics and five cycles of radiotherapy. The aesthetic result was excellent. The patient's head has a normal hairy appearance. No tenderness, swelling or recurrence is recorded until now

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

Two new rapid SNP-typing methods for classifying Mycobacterium tuberculosis complex into the main phylogenetic lineages

There is increasing evidence that strain variation in Mycobacterium tuberculosis complex (MTBC) might influence the outcome of tuberculosis infection and disease. To assess genotype-phenotype associations, phylogenetically robust molecular markers and appropriate genotyping tools are required. Most current genotyping methods for MTBC are based on mobile or repetitive DNA elements. Because these elements are prone to convergent evolution, the corresponding genotyping techniques are suboptimal for phylogenetic studies and strain classification. By contrast, single nucleotide polymorphisms (SNP) are ideal markers for classifying MTBC into phylogenetic lineages, as they exhibit very low degrees of homoplasy. In this study, we developed two complementary SNP-based genotyping methods to classify strains into the six main human-associated lineages of MTBC, the 'Beijing' sublineage, and the clade comprising Mycobacterium bovis and Mycobacterium caprae. Phylogenetically informative SNPs were obtained from 22 MTBC whole-genome sequences. The first assay, referred to as MOL-PCR, is a ligation-dependent PCR with signal detection by fluorescent microspheres and a Luminex flow cytometer, which simultaneously interrogates eight SNPs. The second assay is based on six individual TaqMan real-time PCR assays for singleplex SNP-typing. We compared MOL-PCR and TaqMan results in two panels of clinical MTBC isolates. Both methods agreed fully when assigning 36 well-characterized strains into the main phylogenetic lineages. The sensitivity in allele-calling was 98.6% and 98.8% for MOL-PCR and TaqMan, respectively. Typing of an additional panel of 78 unknown clinical isolates revealed 99.2% and 100% sensitivity in allele-calling, respectively, and 100% agreement in lineage assignment between both methods. While MOL-PCR and TaqMan are both highly sensitive and specific, MOL-PCR is ideal for classification of isolates with no previous information, whereas TaqMan is faster for confirmation. Furthermore, both methods are rapid, flexible and comparably inexpensive