Resumen En la actualidad, los compuestos bioactivos de las plantas representan un gran potencial para descubrir un fármaco novedoso que pueda actuar en el tratamiento del cáncer. Se ha informado que diferentes especies de pino y roble poseen actividades citotóxicas contra varias líneas celulares cancerosas. En el presente estudio, se evaluó el perfil fenólico y las actividades citotóxicas de extractos crudos y orgánicos de la corteza de P. durangensis y Q. sideroxyla. Algunos compuestos, como la taxifolina y dimeros de procianidina, fueron identificados en extractos de ambas especies mediante ESI-MS. La actividad citotóxica se realizó en MDA-MB-231 (cáncer de mama), HeLa (cáncer de cuello uterino), MCF-10A (células no tumorales de mama) y HSF-1184 (células de fibroblastos de piel humana) mediante ensayo MTT. Todos los extractos mostraron un efecto citotóxico dependiente de la dosis contra las líneas celulares cancerosas y poca o ninguna actividad contra las no tumorales. Los resultados proporcionan información importante sobre la actividad citotóxica de extractos de corteza de P. durangensis y Q. sideroxyla. Este fuerte efecto citotóxico representa una oportunidad para la valorización de un subproducto de la industria de la madera.

Abstract Nowadays, plants bioactive compounds represent a great potential for discovering novel drugs that could act in cancer treatment. Previous word reports that different pine and oak species possess cytotoxic activities against various cancer cell lines. The present study evaluated the phenolic profile and cytotoxic activities of crude and organic extracts from P. durangensis and Q. sideroxyla bark. Among ESI-MS identified compounds in extracts from both species, are taxifolin and procyanidin dimers. The cytotoxic activity was performed on MDA-MB-231 (breast cancer), HeLa (cervix cancer), MCF-10A (breast non-tumorous cell), and HSF-1184 (human skin fibroblast cells) by MTT assay. All extracts showed a dose-dependent cytotoxic effect against cancer cell lines and small or no activity against the non-tumorous cells. The results provide important information about the cytotoxic activity of bark extracts from P. durangensis and Q. sideroxyla. This strong cytotoxic effect represents an opportunity for the valorization of a by-product of the wood industry.

Abstract The complexity of the current problems in the Colombian countryside puts at risk the sustainability of family Agricultural Production Units (UPA for its acronym in Spanish). Consequently, it becomes a fundamental study area for the improvement of the rural economy. For this reason, a documentary, field investigation was developed on a case study located in Lebrija, Colombia, for the systemic analysis of economic sustainability in 10 UPAS promoters of sustainable agriculture. The results allowed to establish the effectiveness of the ES in the Characterization of UPAs. It was identified that the lack of investment in infrastructure and appropriate technologies has made the UPAs to allocate 50% of its total area for inadequate grazing. This distribution of land threatens the sustainability of the economy of local families, given that the production and profitability of livestock are not enough for their livelihood and the maintenance of pastures. The inadequate grazing generates large amounts of manure that pollutes the environment. The above affects the congruence between the productive activities and the philosophical principles of the UPAs.

Resumen La complejidad de los problemas actuales del campo colombiano pone en riesgo la sostenibilidad de las Unidades de Producción Agropecuaria (UPA) familiares. En consecuencia, se convierte en un área de estudio fundamental para el mejoramiento de la economía rural. Debido a ello, se desarrolló una investigación documental y de campo sobre un caso de estudio ubicado en Lebrija, Colombia, para el análisis sistémico de la sostenibilidad económica en 10 UPAS promotoras de la agricultura sostenible. Los resultados permitieron establecer la efectividad del ES en la caracterización de UPAs. Se identificó que la falta de inversión en infraestructura y tecnologías apropiadas han hecho que las UPAs destinen más del 50% de su área total para el inadecuado pastoreo de bovinos. Esta distribución de la tierra amenaza la sostenibilidad de la economía de las familias locales, dado que la producción y rentabilidad de la ganadería no son suficientes para su sustento y el mantenimiento de los potreros. El inadecuado pastoreo genera grandes cantidades de estiércol que contamina el medio ambiente. Lo anterior afecta la congruencia entre las actividades productivas y los principios filosóficos de las UPAs.

RESUMO JUSTIFICATIVA E OBJETIVOS: Dor crônica acarreta incapacidade funcional e social, impactando emocionalmente os indivíduos. O objetivo deste estudo foi descrever os principais comprometimentos das atividades de vida diária, sintomas ansiosos e depressivos e qualidade de vida em pacientes com dor crônica. MÉTODOS: Estudo transversal com pacientes de ambulatório de dor crônica. Análise das variáveis clínicas e sociodemográficas, assim como das atividades de vida diária. Avaliação de dor, de sintomas ansiosos e depressivos pela Hospital Anxiety and Depression Scale, de qualidade de vida pelo questionário Medical Outcomes Study 36 - Item Short Form Health Survey e a análise dos dados no programa estatístico SPSS. RESULTADOS: Foi evidenciada limitação para o trabalho, movimento, lazer e atividade domiciliar, qualidade de vida abaixo da mediana e pior para os domínios aspectos físicos e emocionais. O sono foi muito comprometido, seguido de dificuldade parcial para apetite e atividade sexual. Embora apresentassem sintomas ansiosos e depressivos, a maioria dos participantes estavam moderadamente satisfeitos com o tratamento. CONCLUSÃO: A dor crônica impacta de forma muito significativa na qualidade de vida, comprometendo e limitando as atividades diárias de modo mais intenso nos portadores de sintomas ansiosos e depressivos.

ABSTRACT BACKGROUND AND OBJECTIVES: Chronic pain causes functional and social disability, resulting in emotional impact. This study’s objective was to describe the main impairments of activities of daily living, anxious and depressive symptoms, and quality of life in patients with chronic pain. METHODS: Cross-sectional study with chronic pain outpatients. Analysis of clinical and sociodemographic variables, as well as activities of daily living. Assessment of pain, anxious and depressive symptoms by the Hospital Anxiety and Depression Scale, quality of life by the Medical Outcomes Study 36 - Item Short Form Health Survey questionnaire and data analysis by the SPSS statistical software. RESULTS: The study observed limitations in work, movement, leisure and home activities, quality of life below the median and worse for the physical and emotional domains. Sleep was very impaired, followed by partial difficulty with appetite and sexual activity. Although they had anxious and depressive symptoms, most participants were moderately satisfied with their treatment. CONCLUSION: Chronic pain has a very significant impact on quality of life, impairing and limiting daily activities more intensely in individuals with anxious and depressive symptoms.

Wavelength dispersion X-ray fluorescence spectrometry (WDXRF) is a non-destructive technique and therefore attractive for gunshot residues (GSR) analysis. It is well known for determination of inorganic constituents of samples. However, X-ray scattering region spectral data is not commonly used, although it may provide information about organic constituents and their interactions. This work employed X-ray scattering region and inorganic elements spectral data for a better characterization of GSR. Swabs containing residues collected from the hand of people who fired (shooters group) and also from the hands of people which did not fire (control group) with guns were analyzed directly by the WDXRF. Brake pad and people who perform activities that favor the accumulation of characteristic elements of GSR on their hands were chosen to compose the control group. Principal components analysis (PCA) discriminated the GSR according to the firearm/cartridge used. However, similar GSR clustering did not occur without X-ray scatter data, showing the importance of X-ray scattering spectrum for GSR evaluation. The k-nearest neighbors (k-NN) method correctly classified all samples from shooters and control groups, employing from 1 to 5 nearest neighbors. No anomalous behavior was detected by PCA and hierarchical cluster analysis (HCA).

Resumen: Esta investigación describe el proceso de construcción colaborativa de conocimiento por parte de estudiantes virtuales de Psicología, mediante una herramienta sincrónica de representación diagramática. En este estudio mixto, los estudiantes hicieron una argumentación para representar diagramáticamente una solución. Los estudiantes se reunieron en grupos. El análisis consistió en identificar las fases de construcción del conocimiento, siguiendo estos pasos: a) organización basada en la comprensión del caso y acuerdos de participación, b) intercambio de información y argumentación, c) elaboración de construcciones y aprobación de significados, y d) diagramación de la solución del caso. Los resultados muestran la conveniencia de una herramienta sincrónica colaborativa, porque ofrece a los estudiantes interacción en tiempo real mediante la argumentación, teniendo en cuenta las implicaciones de la gestión en un entorno virtual, así como la intencionalidad formativa y la realimentación dada por el tutor. Los resultados también muestran que los estudiantes tienen interés por la organización de las actividades, el acuerdo y el acato a las normas establecidas, el intercambio de información y la elaboración de significados para producir conocimiento a través de diagramas desde la argumentación. Se puede concluir que los estudiantes pudieron establecer patrones de interacción derivados del nivel de implicación y la profundidad del diálogo durante la tarea. Finalmente, se plantean propuestas para la intervención del docente y la mejora de procesos colaborativos.

Abstract: This research describes the process of collaborative knowledge construction by virtual students of Psychology, by means of a synchronous diagrammatic representation tool. In this mixed study, students made an argument to diagrammatically represent a solution. Students gathered in groups. The analysis consisted in identifying the phases for the construction of knowledge, following these steps: a) organization based on the understanding of the case and agreements to participate, b) exchange of information and argumentation, c) elaboration of constructs and approval of meanings, and d) diagramming the solution of the case. The results show the convenience of a collaborative synchronic tool, because it offers students real-time interaction through argumentation, considering the implications of management in a virtual environment, as well as the formative intent and feedback given by the tutor. The results also show that students are interested in organizing activities, agreeing and abiding by established rules, exchanging information and elaborating meanings to produce knowledge through diagrams from the argumentation. It can be concluded that students were able to establish patterns of interaction derived from the level of involvement and the depth of dialogue during the assignment. Finally, proposals are made for teacher intervention and improvement of collaborative processes.

A acromegalia é caracterizada pelo excesso do hormônio de crescimento (GH) em adultos entre 30 e 50 anos. A doença apresenta manifestações clínicas, como crescimento das extremidades e assimetria facial. O principal objetivo do estudo foi descrever os impactos psicossociais das alterações físicas da acromegalia na autoimagem. Foi realizado um estudo retrospectivo de corte transversal em uma amostra de 71 pacientes do estado da Bahia, utilizando o questionário AcroQol (Questionário de Qualidade de Vida em Acromegalia). Foi utilizada também a técnica de grupo focal, onde a partir de uma análise de conteúdo foram explorados aspectos psicossociais. Os participantes de ambos os gêneros, em sua maioria, se veem diferentes no espelho e percebem que há partes no corpo que são demasiado grandes por conta da patologia. Já boa parte das mulheres se percebem feias e se veem horrorosas nas fotografias, enquanto mais da metade dos homens percebem o olhar do outro por conta do seu aspecto físico. Os resultados qualitativos indicaram, como maior incômodo as mudanças físicas em relação a outras manifestações clínicas, pois impactam em áreas da vida como a emocional e laboral. Foi evidenciado o impacto que a alteração na autoimagem pode trazer a nível social, psicológico e emocional na vida do acromegálico.

Acromegaly is characterized by excess growth hormone (GH) in adults between 30 and 50 years. The disease presents clinical manifestations, such as growth of the extremities and facial asymmetry. The main objective of the study was to describe the psychosocial impacts of physical alterations of acromegaly on self - image. A cross-sectional retrospective study was carried out in a sample of 71 patients from the state of Bahia, using the Acromegaly Quality of Life Questionnaire. The focus group technique was also used, from which a content analysis explored psychosocial aspects. Most participants look different in the mirror. Most women, however, perceive themselves as ugly and look awful in their photographs, while more than half of the men perceive the look of the other on account of their physical appearance. There was a significant correlation between self-concept change and mood. The qualitative results indicated that physical changes are more uncomfortable than other manifestations, since they impact on areas of life such as emotional and work. It was evidenced the impact that the alteration in the self - image can bring to the social and psychological level in the life of the acromegalic.

Abstract Introduction: in several countries, there is an increasing trend of consumers and distributors of organic food. Objective: to identify consumer motivation, a socioeconomic profile and possible sociopolitical actions for the development of public policy by the consumers of organic products supplied by 12 alternative food distribution networks in Medellín and Eastern Antioquia. Methods: qualitative study with semi-structured interviews and participant and non-participant observation. Results: the main reason for organic food consumption is personal wellbeing, specifically health, followed by care for the environment and social welfare because such consumption contributes to improving the quality of life of poor producers (farmers and indigenous people). The consumption of these foods is also in some cases a form of resistance against the food industry, agroindustry and supermarkets; however, this social awareness does not imply that consumers commit themselves to sociopolitical actions transcending to the collective sphere. Conclusion: action by local governments is required to develop strategies that consolidate the transformative potential of consumer practices regarding organic products from alternative food networks.

Resumen Introducción: el incremento de consumidores y distribuidores de alimentos y productos orgánicos constituye una tendencia en varios países. Objetivo: establecer las motivaciones para el consumo, el perfil socioeconómico y las posibles acciones de carácter sociopolítico para la construcción de políticas públicas realizadas por los consumidores de productos orgánicos de las 12 redes de distribución alternativa de alimentos que existen en Medellín y el oriente antioqueño. Métodos: estudio cualitativo con entrevistas semiestructuradas y observación participante y no participante. Resultados: se halló que la principal razón de consumo es el bienestar individual, específicamente la salud, seguido del cuidado del medio ambiente y el bienestar social porque se contribuye a mejorar la calidad de vida de los productores pobres (campesinos e indígenas). Se encontró, además, que el consumo de estos alimentos, se hace en algunos casos como forma de resistencia frente a la industria de alimentos, la agroindustria y los supermercados. Sin embargo, esta conciencia social no implica que los consumidores se comprometan con acciones sociopolíticas para trascender a la esfera colectiva. Conclusión: se requiere una acción de los gobiernos locales para desarrollar estrategias que consoliden el potencial transformador de las prácticas de los consumidores de productos orgánicos de las redes alternativas de alimentos.

Resumen Antecedentes: el abastecimiento de alimentos en las ciudades es mayoritariamente dirigido por empresas transnacionales; usa circuitos largos, estimula el uso de agroquímicos en la producción de alimentos y con frecuencia no genera precios justos. Estas características han llevado a la construcción de un sector alternativo que articule nuevos mecanismos de producción, distribución y consumo de alimentos. Objetivo: describir las principales características de las redes alimentarias alternativas de Medellín y la subregión Oriente del departamento de Antioquia, sus actores, procesos y relacionamiento entre productores, distribuidores y consumidores. Materiales y métodos: estudio cualitativo de casos colectivos; se entrevistaron personas relacionadas con 15 redes alimentarias alternativas, se realizaron entrevistas semiestructuradas, observación participante en espacios de distribución y no participante en zonas de producción. Resultados: se halló en estas iniciativas el cimiento de un sistema alimentario alternativo, fundamentado en la agroecología, el comercio justo y el consumo saludable. Al ser analizadas desde los constructos teóricos del capital social, se halló que estas redes trabajan por tender puentes entre productores y consumidores y reforzar lazos entre los primeros eslabones del sistema; sin embargo, un posicionamiento más fuerte requiere fortalecer la asociatividad. Conclusiones: el naciente sector alternativo representa una oportunidad para consolidar sistemas alimentarios que contribuyan a generar capital social como bien público colectivo.

Abstract Background: Food supply in cities is largely managed by multinational companies using widespread systems, promoting the use of agrochemicals in food production, and generating unfair pricing and access. These factors have led to the creation of an alternative sector highlighting new mechanisms of production, distribution, and consumption of foods. Objective: Describe the principle characteristics of alternative food networks in Medellin and the eastern sub-region of the state of Antioquia, highlighting the actors, processes, and relationships among producers, distributors, and consumers of said food products. Materials and Methods: Qualitative collective case study in which the participants were selected for interviews given their ties to 15 alternative food networks and systems. Semi-structured interviews were conducted, as well as active observation in distribution areas and passive observation in production zones. Results: The basis for healthy food systems was found in these alternative initiatives, which are based on agro-ecology, fair trade, and healthy consumption and consumerism. When analyzed from the theoretical constructs of social capital, it’s seen that these networks help build ties between producers and consumers, and reinforce the bonds between the first links of these systems; however, stronger positioning is needed to strengthen these association. Conclusions: The recent advent of alternative food systems represents an opportunity to consolidate food sectors that contribute to the generation of social capital for the collective good of the population.

Abstract Objective: to make a descriptive review about the influence of the dietary amino acids in gene expression. Materials and method: the bibliographic research included the following written sources: Scielo, PubMed, Medline, NCBI, Springer, Scopus, Science Direct and Elsevier, retrieved until May 2018 from critical reviews of scientific articles. One hundred and five records were found after the combination of key words. Fundamental selection criteria were taken into account (title, authors, summary and results) using Maeda's reasoned reduction and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) as a systematic review methodology. Conclusion: there are genes that are regulated in various stages including transcription, post-transcriptional processing, nuclear export and translation of mature mRNA. Amino acids can influence these processes through the activation of transcription factors. In terms of translation, amino acids can regulate protein synthesis through changes in eIF2B, phosphorylation of 4E-BP1 and S6 proteins. In addition, amino acids affect the regulation of the growth factor expression (insulin like grow factor: IGF-I) in humans.

Resumen Objetivo: realizar una revisión descriptiva sobre la influencia de aminoácidos (AA) provenientes de la dieta en la expresión génica. Materiales y métodos: la investigación bibliográfica incluyó las siguientes fuentes escritas: Scielo, PubMed, Medline, NCBI, Springer, Scopus, Science Direct y Elsevier, recuperadas hasta mayo de 2018, a partir de revisiones críticas de artículos científicos. Se encontraron 105 registros después de la combinación de palabras clave. Se tomaron en cuenta los criterios fundamentales de selección (título, autores, resumen y resultados) usando la reducción razonada de Maeda y PRISMA (elementos de informe preferidos para revisiones sistemáticas y metaanálisis) como metodología de revisión sistemática. Conclusiones: existen genes que se regulan en varias etapas: transcripción, procesado postranscripcional, exportación nuclear y traducción de los mRNA maduros. Los aminoácidos pueden tener influencia en estos procesos a través de la activación de factores de transcripción. En la traducción, los AA pueden regular la síntesis de proteínas mediante cambios en eI F2B, fosforilación de 4E-BP1 y de proteínas S6. Los AA tienen efecto en la regulación de la expresión de factores de crecimiento, como el factor de crecimiento análogo a la insulina IGF-I en el ser humano.

Abstract This study evaluated the capacity of adsorbent biochar derived from pequi husks to remove glyphosate (commercial formulation) in aqueous medium under three pH conditions (5.5, 7.0 and 8.0). This biochar presented a mean yield of 33.1% ± 2.66% and a high amount of surface particles of small dimensions endowing it with high surface area. The results showed that removal is proportional to pH increase in the range of 5.5 to 8.0. Adsorption assays performed at pH 7 and 8 fitted better to the Langmuir pseudo-first order kinetics model with fast adsorption in the first 15 to 30 minutes. The results for the acidic pH range fit none of the adopted models satisfactorily. The results obtained suggest that adsorbent can be used as an efficient and inexpensive alternative for the adsorption of glyphosate present in commercial formulations from aqueous matrices.

RESUMO Objetivo: Avaliar o efeito de remineralização do CPP-ACP sobre o esmalte dentário erodido extrinsecamente. Métodos: Sessenta dentes bovinos recém-extraídos, foram armazenados em solução de timol 0,1%, cortados em blocos de esmalte (6x6mm), desgastados com lixas de carbeto de silício (600, 800 e 1200) e polidos com feltro. Os espécimes foram distribuídos aleatoriamente em 4 grupos (n=15), variando o meio de imersão, água deionizada ou ácido cítrico; e o uso ou não do CPP-ACP (G1: água deionizada; G2: ácido cítrico; G3: água deionizada + CPP-ACP; G4: ácido cítrico + CPP-ACP). As amostras foram submetidas a 4 ciclos erosivos diários de 5 minutos de imersão em um dos meios e 2 horas de imersão em saliva artificial, durante 5 dias consecutivos. Após cada ciclo erosivo, 20 µL da pasta MI Paste foram aplicadas por 5 minutos em metade das amostras e lavadas com água deionizada. Antes e após a ciclagem erosiva as mensurações de dureza Vickers e rugosidade de superfície foram realizadas. Resultados: Os resultados foram avaliados através de testes estatísticos. Os valores de microdureza e rugosidade final não apresentaram diferença estatisticamente significante entre os grupos G2 e G4. No G4 a pasta não promoveu aumento nos valores de microdureza e nem diminuição nos valores de rugosidade. Conclusão: Concluiu-se que o CPP-ACP não foi capaz de remineralizar o esmalte submetido a erosão extrínseca, sendo ineficaz na prevenção da erosão do esmalte e na remineralização do esmalte erodido.

ABSTRACT Objective: The aim of this study was to evaluate the remineralization effect of CPP-ACP on tooth enamel that is eroded extrinsically. Methods: Sixty freshly extracted bovine teeth were stored in a solution of thymol (0.1%), cut into enamel blocks (6x6mm), abraded with silicon carbide sandpaper (600, 800 and 1200 grit) and polished with felt. The specimens were randomly divided into 4 groups (n=15), varying the immersion medium , deionized water or citric acid, and the optional use of CPP-ACP. (G1: deionized water; G2: citric acid; G3: deionized water + CPP-ACP; G4: citric acid + CPP-ACP). The samples were subjected to 4 cycles of erosion every day, comprising 5 minutes immersion in one medium and 2 hours of immersion in artificial saliva, for 5 consecutive days. After each erosive cycle, 20 uL of the MI Paste was applied for 5 minutes on one half of the samples and washed with deionized water. Before and after the erosive cycling, the measurements of Vickers hardness and surface roughness were taken. Results: The results were evaluated through statistical testing. The final hardness and roughness values showed no statistically significant difference between G2 and G4. The paste in G4 did not promote an increase in hardness values nor a decrease in roughness values. Conclusion: It was concluded that CPP-ACP was unable to remineralize enamel subjected to extrinsic erosion, being ineffective in preventing erosion of enamel and in the remineralization of the eroded enamel.

Resumen Objetivo: Presentar el proceso realizado y su aplicación para la identificación y categorización de comportamientos posturales sedentes de alumnos en clase, utilizando captura en vídeo y el desarrollo de una matriz gráfica para registro postural. Materiales y Métodos: Participaron estudiantes de segundo a once grado de escolaridad (entre 7 y 16 años de edad) pertenecientes a una institución de educación mixta en Bogotá, Colombia. Se registraron en diez vídeos las posturas sedentes de veinte estudiantes distribuidos de acuerdo a la edad, el grado de escolaridad y la dinámica escolar (individual/grupal). Las posturas observadas fueron dibujadas, categorizadas y plasmadas en una matriz gráfica utilizada como instrumento para señalarlas y luego se consolidó una base de datos. Resultados: Se identificaron 138 variaciones posturales, clasificadas en siete categorías. La matriz se aplicó para comparar la frecuencia de las posturas adoptadas durante la primera y la segunda mitad de la clase en dinámica individual, la frecuencia rotación de cuello entre las dos dinámicas escolares y la frecuencia de las categorías posturales entre las dinámicas de clase. Conclusiones: La matriz gráfica es una herramienta de tamizaje de tipo cualitativo, que con la elaboración de una base de datos posibilita calcular frecuencias de movimiento en partes del cuerpo (cuello, extremidades, tronco) y porcentajes de tiempo de permanencia en las categorías establecidas o en determinada variación postural, sin la necesidad de contar con equipos o con software especializados ni con personal técnico experto para la recolección y análisis de datos.

Abstract Objective: To present the process conducted and its application in order to identify and categorize the seated posture behavior of students in the classroom, using video capture and the development of a graphic matrix to register postures. Material and method: Students from second to eleven grade (between 7 and 16 years of age) male and female from a coeducational school in Bogotá, Colombia participated in the study. The seated postures of 20 students, distributed according to age, school grade, and school dynamics (individual / group), were recorded in ten videos. The postures observed were drawn, categorized and captured in a graphical matrix used as an instrument to identify them, and then, a database was consolidated. Results: A total of 138 posture variations were identified and classified into seven categories. The matrix was applied to compare the frequency of the postures adopted during the first and second half of the class in individual dynamics, the frequency of neck rotation between the two school dynamics, and the frequency of posture categories between class dynamics. Conclusions: The graphic matrix is a qualitative type screening tool which, with the elaboration of a database, makes it possible to calculate the frequencies of movement in the body parts (neck, extremities, and trunk) and percentages of time of permanence in the established categories or in certain posture variation, without the need for specialized equipment or software, or specialized technical staff for data collection and analysis.

Resumo Objetivo: Apresentar o processo realizado e sua aplicação para a identificação e categorização de comportamentos e como se sentam os alunos na sala de aula, utilizando captura em vídeo e o desenvolvimento de uma matriz gráfica para registro da sua expressão corporal. Materiais e Métodos: Participaram estudantes de segunda serie a oitava serie do primeiro grau e estudantes de primeira a terceira serie do segundo grau (de 7 a 16 anos de idade) pertencente a uma instituição de educação mista em Bogotá, Colômbia. Registraram se em dez vídeos dos alunos na sala de aula, de vinte estudantes distribuídos de acordo à idade, o grau de escolaridade e a dinâmica escolar (individual/grupal). A maneira de sentar - sem observadas foram desenhadas, categorizadas e plasmadas em uma matriz gráfica utilizada como instrumento para sinais e logo se consolidou uma base de dados. Resultados: Identificaram-se 138 variações da forma se sentarem-se, classificadas em sete categorias. A matriz se aplicou para comparar as fraquezas das posturas adotadas durante a primeira e a segunda metade da classe em dinâmica individual, a freqüência rotação de pescoço entre as duas dinâmicas escolares e a freqüência das categorias da forma na qual os estudantes se sentam entre as dinâmicas de classe. Conclusões: A matriz gráfica uma ferramenta de Tamisagem de tipo qualitativo, que com a elaboração de uma base de dados possibilita calcular freqüências de movimento em partes do corpo (pescoço, extremidades, tronco) e porcentagens de tempo de permanência nas categorias estabelecidas ou em determinada variação postural, sem precisar contar com equipes ou com softwares especializados nem com pessoal técnico esperto para a colheita e analise de dados.