RESUMEN Las limitaciones de los modelos teóricos del proceso de solución de problemas que se sustentan en la asunción de la comprensión como una fase previa, han conducido a la adopción del enfoque transversal de la comprensión en la solución de problemas aritméticos verbales, el cual concibe a estos últimos como textos y, a su solución como proceso de comprensión textual. A tono con este último enfoque, el objetivo del artículo residió en ofrecer una estructuración didáctica de la comprensión en la solución de problemas aritméticos verbales. Para ello fue de utilidad el empleo de métodos teóricos, tales como el análisis-síntesis, la inducción-deducción y la modelación sistémica estructural funcional. La nueva propuesta, en términos generales, reside en el redimensionamiento de los subprocesos de la comprensión a la solución de problemas aritméticos verbales, lo que genera que devenga en una valiosa herramienta para docentes y estudiantes, en tanto, enriquece la concepción e instrumentación del proceso y de la clase de solución de problemas aritméticos verbales.

ABSTRACT The research starts from recognizing the limitations of the approach that explains understanding as a phase of the word problems solving, an epistemological position from which the theoretical models, more accepted and disseminated internationally, have been built and, in which it is structured didactically each of the phases that compose it. From the assumption of the transversal approach to understanding when word problems solving, which conceives the latter as texts and, to their solution as a process of textual comprehension, the didactic structuring that is offered was elaborated. For this, the use of theoretical methods was useful, such as analysis-synthesis, induction-deduction and functional structural systemic modeling. The new proposal, in general terms, resides in the resizing of the sub-processes of understanding to the word problems solving, which generates that it becomes a valuable tool for teachers and students, while enriching the conception and instrumentation of the process and the class of words problems solving.

Abstract: This study focuses on the research question: How do prospective elementary school teachers (FT) make decisions when considering the algebraic thinking of 9-year-old children? A specific type of noticing was used to describe the decisions of 21 FT when observing the strategies employed by 3 children to solve the equation 6+4= +5. The FT participated in a six-session course on the teaching and learning of algebra, based on video analysis as a means to approach teaching practice. Focusing on sessions 1 and 2, the written responses of the FT to two distinct questions were examined. The main results show that, although the FT’s decisions frequently lacked evidential support, their reasoning aligned with specific aspects of algebraic thinking and research covered during the course. Finally, two positions adopted by the FT in decision making were identified: a) arithmetic, centred on the calculations that children should follow, and (b) relational, focused on the interplay of operations through the equals sign. The role of noticing and video analysis as tools to bring future primary school teachers closer to the practice of teaching algebra in primary education was discussed.

Resumen: En esta investigación se abordó la pregunta: ¿Cómo son las decisiones de futuros profesores de primaria (FP) al considerar el pensamiento algebraico de niños de 9 años? Se partió de un tipo específico de noticing para describir las decisiones de 21 FP al observar las estrategias empleadas por 3 niños para resolver la igualdad 6+4= +5. Los FP participaron en un curso de seis sesiones sobre enseñanza y aprendizaje del álgebra basado en el análisis de videos como vía para aproximarse a la práctica docente. Centrándose en las sesiones 1 y 2, se examinaron las respuestas escritas de los FP ante dos situaciones distintas. Los principales resultados muestran que, aunque las decisiones de los FP a menudo carecían de evidencias, sus razonamientos coincidían con aspectos específicos del pensamiento algebraico y la investigación tratada durante el curso. Finalmente, se identificaron dos posturas adoptadas por los FP al decidir: a) aritmética, centrada en los cálculos que deben seguir los niños, y b) relacional, enfocada en la relación de operaciones mediante el signo igual. Se discutió sobre el rol del noticing y el análisis de videos como herramientas para aproximar a FP a la práctica de enseñar álgebra en la educación primaria.

The political and social environments in which learners with disabilities live often cause more limitation on the individual abilities of these learners than the disability itself (Capri et al., 2018:2). Likewise, mathematical thinking for learners who are severely mentally disabled is often limited to concretisation or memorisation, which tends to undermine mathematical number sense. This study was undertaken against the background of a lack of methodological guidelines for the teaching of mathematics in the new adapted curriculum for learners who are severely intellectually disabled. Context-rich mathematics tasks for the development of mathematical thinking in learners who are severely intellectually disabled were used during the study. A qualitative research approach was followed in which empirical data were generated through three action research cycles. Data were collected through in-depth discussions, field notes, a literature review and learner work. Vygotsky's (1978:6) sociocultural theory was used as a theoretical framework because it highlights the importance of social interactions and mediated learning. The Reality, Abstraction, Mathematics and Reflection (RAMR) framework of Cooper and Carter (2016:177) is used as a didactic framework for a practical approach to mathematics education in the study. According to the data from in-depth discussions with five educators, learners with intellectual disability are perceived to have limited number sense knowledge. These educators also indicated that their choice of learning tasks only included number facts, arithmetic fluency, memorisation, and teaching with concrete apparatus. Data from the in-depth discussions with two mathematics subject advisors working in special education pointed out educators'limited didactical knowledge for teaching mathematics to learners who are severely intellectually disabled. Based on these data, a teaching intervention was designed and implemented for six months. The purpose was to investigate the effect on participation and learning of changing the researcher's practice to focus on mathematical reasoning in context rich tasks. The lived experiences of the ten learners who were involved in the teaching intervention were included as a background to mathematics problems to design context-rich tasks. The guidelines from the research entail that real-life contexts in which mathematical problem types are embedded are conducive to learning experiences that are rich in discussion for learners who are severely intellectually disabled. Such an approach has the potential to make mathematics more meaningful to learners who are severely intellectually disabled, improve their mastery of contexts, and develop critical thinking. Findings from the action research process can be adapted to similar mathematics teaching practices.

Die politiese en sosiale omgewings waarin leerders met gestremdhede leef, veroorsaak dikwels meer beperking van die individuele vermoëns van dié leerders as die gestremdheid self (Capri et al., 2018:2). Eweneens word wiskundige denke vir leerders wat verstandelik erg gestremd is dikwels tot konkretisering en memorisering beperk, wat neig om begrip te ondermyn. Hierdie studie is onderneem teen die agtergrond van 'n tekort aan metodologiese riglyne vir die onderrig van wiskunde in die nuwe aangepaste kurrikulum vir leerders wat verstandelik erg gestremd is. Konteksryke wiskundetake ter ontwikkeling van wiskundige denke by leerders wat verstandelik erg gestremd is, is tydens die studie gebruik. 'n Kwalitatiewe navorsingsbenadering is gevolg waarin empiriese data gegenereer is deur middel van drie aksienavorsingsiklusse. Data is deur semi-gestruktureerde fokusgroep-onderhoude, veldnotas, 'n literatuuroorsig en leerderwerk ingesamel. Die literatuuroorsig is onderneem om 'n onderrig- en teoretiese raamwerk vir die studie te skep. Vygotsky (1978:6) se sosiokulturele teorie is as teoretiese raamwerk gebruik omdat dit die belangrikheid van sosiale interaksies en bemiddelde leer uitlig. Die Realiteit, Abstraksie, Wiskunde en Refleksie (RAWR)-onderrigraamwerk van Cooper en Carter (2016:177) word as didaktiese raamwerk vir 'n praktiese aanslag tot wiskundeonderrig in die studie aangewend. Volgens die data van die fokusgroeponderhoud met vyf opvoeders, beskik leerders met intellektuele gestremdheid oor beperkte getalbegripkennis. Dié opvoeders het ook aangedui dat hul keuse van leertake slegs getalfeite, rekenvlotheid, memorisering en onderrig met konkrete apparaat insluit. Data uit die fokusgroeponderhoud met twee wiskundespesialiste wat in spesiale onderwys werksaam is, het opvoeders in die navorsingskool se beperkte didaktiese kennis vir wiskundeonderrig aan leerders wat verstandelik erg gestremd is, uitgewys. Gebaseer op hierdie data is 'n onderrigingreep ontwerp en vir ses maande geïmplementeer. Die tien leerders wat by die onderrigingreep betrek is, se geleefde ervaringe is as agtergrond by wiskundeprobleme ingesluit om konteksryke take te ontwerp. Die riglyne wat uit die navorsing spruit, het tot gevolg dat lewensegte kontekste waarin wiskundige probleemtipes ingebed is, nuttig gebruik kan word in gespreksryke leerervarings vir leerders wat verstandelik erg gestremd is. Só 'n benadering het die potensiaal om wiskunde vir leerders wat verstandelik erg gestremd is meer betekenisvol te maak, hulle beheersing van kontekste te verbeter, en kritiese denke te ontwikkel. Bevindinge uit die aksienavorsingsproses kan aangepas word vir soortgelyke wiskundeonderrigpraktyke.

ABSTRACT: Mathematics teaching is one of the fundamental pillars of early childhood education. Several studies have highlighted that adequate approach at early levels can positively influence future school performance and other cognitive domains. In Chile, mathematics education is an area of concern due to local evidence and observed gaps following the pandemic. In this context, educators and educational assistance professionals are challenged to provide equal teaching opportunities for all, including preschoolers with Developmental Language Disorder, who usually only receive support in language area. This review aims to update the literature on the math skills of students with Developmental Language Disorder and to establish their possible impact on the mathematics curriculum. The main findings include identifying barriers in counting and arithmetic tasks. Finally, the learning objectives that could require more attention for their approach were recorded, and studies were identified that highlighted the potential of visual and gestural representation as a way to favor the teaching-learning of these children. Thus, the approach to early mathematical skills can contribute to the inclusion and equalization of opportunities for these students.

RESUMEN: La enseñanza de las matemáticas es uno de los ejes fundamentales de la educación parvularia. Diversos estudios han destacado que un abordaje adecuado en niveles tempranos puede influir positivamente en el rendimiento escolar futuro y en otros dominios cognitivos. En Chile, la educación matemática representa un área de preocupación debido a los hallazgos locales y a las brechas observadas después de la pandemia. En este contexto, las educadoras y profesionales asistentes de la educación tienen el desafío de equiparar las oportunidades de enseñanza para todas y todos, incluyendo a los preescolares con Trastorno Específico del Lenguaje, quienes usualmente solo reciben apoyos en el área de lenguaje. Esta revisión tuvo como objetivo actualizar la literatura sobre las habilidades matemáticas de estudiantes con Trastorno Específico del Lenguaje y establecer su posible incidencia en el currículum matemático. Como principales resultados se hallaron obstáculos en tareas de conteo y aritmética. Por último, se registraron los objetivos de aprendizaje que podrían requerir mayor atención para su abordaje y se identificaron estudios que destacaban el potencial de la representación visual y gestual como forma de favorecer la enseñanza-aprendizaje de estos niños. Así, el abordaje de las habilidades matemáticas tempranas puede contribuir a la inclusión y equiparación de oportunidades para estos estudiantes.

ABSTRACT Lessonia nigrescens and L. trabeculata are economically important kelp species in northern Chile. Despite their considerable value, the genetic diversity of these kelp has received limited attention in the Atacama region. This study aimed to analyze genetic diversity, establish genetic relationships, and identify diagnostic DNA markers in the Atacama region's L. nigrescens and L. trabeculata. Both species' Inter-sequence simple repeat (ISSR) band patterns showed high reproducibility and reliability. Among 17 ISSRs, 161 polymorphic bands were identified in Lessonia spp. Parameters, such as percentage polymorphism, number of alleles per locus, effective number of alleles, and Shannon information index, indicated that L. nigrescens had slightly higher genetic diversity than L. trabeculata. The Unweighted pair group method with arithmetic average (UPGMA) cluster analysis revealed two main clusters: one containing L. nigrescens and the other containing L. trabeculata. Additionally, four species diagnostic ISSR markers were identified for L. nigrescens and L. trabeculata. The ISSR markers proved valuable in detecting genetic diversity in L. nigrescens and L. trabeculata. This information is particularly important for marine management strategies and ensuring successful conservation.

Resumen Las herramientas TIC han incrementado su uso en las entidades educativas como estrategia pedagógica para mejorar el proceso de enseñanza aprendizaje en las distintas áreas académicas de una manera interactiva y motivadora, lo que plantea el desafío de la inserción de dichas herramientas en aula. Este estudio consistió en realizar un diagnóstico de la efectividad del uso de la herramienta Math Cilenia de las operaciones básicas en el nivel de básica elemental de la Unidad Educativa Fiscal Las Mercedes de 24 de Mayo-Manabí. El enfoque investigación-acción guio este estudio, combinando el análisis de información cualitativa y cuantitativa para el procesamiento de resultados, las actividades cumplidas fueron: i) Diagnóstico del problema; ii) Plan de acción de la solución; iii) Implementación en aula; y iv) Evaluación de resultados. Los resultados evidenciaron mejora en los procesos de aprendizaje de las operaciones básicas, confrontado con el método tradicional. Se concluye que el uso de herramienta TIC mejoran la motivación y la capacidad de aprendizaje de los estudiantes, futuras investigaciones llevan a ejecutar un nuevo ciclo de aprendizaje del plan de acción con nuevas operaciones básicas usando Math Cilenia.

Abstract ICT tools have increased their use in educational institutions as a pedagogical strategy to improve the teaching-learning process in different academic areas in an interactive and motivating way, which poses the challenge of inserting these tools in the classroom. This study consisted of a diagnosis of the effectiveness of the use of the Math Cilenia tool for basic operations at the elementary basic level of the Unidad Educativa Fiscal Las Mercedes de 24 de Mayo-Manabí. The action-research approach guided this study, combining the analysis of qualitative and quantitative information for the processing of results, the activities carried out were: i) Diagnosis of the problem; ii) Action plan of the solution; iii) Implementation in the classroom; and iv) Evaluation of results. The results showed improvement in the learning processes of basic operations, compared to the traditional method. It is concluded that the use of ICT tools improves the motivation and learning capacity of students. Future research will lead to the execution of a new learning cycle of the action plan with new basic operations using Math Cilenia.

Resumo O uso do inglês é uma necessidade nos dias de hoje. Na educação, desenvolver a competência comunicativa em inglês é um desafio para professores e alunos; mais ainda num ambiente que não seja de sala de aula. O avanço da tecnologia é um aliado neste contexto. Este estudo visa determinar o impacto das ferramentas tecnológicas no domínio da língua inglesa em estudantes universitários. O desenho do projeto foi quase experimental, e a amostra esteve constituída por 62 estudantes: 31 no Grupo de Controle e 31 no Grupo Experimental numa universidade nacional no Peru. Foram aplicados um pré-teste e um pós-teste de competência comunicativa em inglês e um questionário sobre o uso de ferramentas tecnológicas. A média aritmética mostra uma melhoria em pontos 5.13 utilizando as ferramentas tecnológicas, após comparar o pré-teste com o pós-teste. A conclusão é uma melhoria significativa na competência comunicativa em inglês.

Resumen El uso del inglés es una necesidad en la actualidad. En el ámbito educativo, desarrollar la competencia comunicativa en inglés es un reto para docentes y estudiantes; es aún más desafiante en un contexto de educación no presencial. El avance de la tecnología es una aliada en este contexto. Este estudio pretende determinar el impacto de las Herramientas Tecnológicas en la Competencia Comunicativa en inglés en estudiantes universitarios. El diseño fue cuasi-experimental, y la muestra de 62 estudiantes: 31 del Grupo Control y 31 del Grupo Experimental en una universidad nacional del Perú. Se aplicó un pre-test y un post-test respecto a la competencia comunicativa en inglés y un cuestionario sobre el uso de las herramientas tecnológicas. La media aritmética muestra una mejora en 5.13 puntos utilizando las herramientas tecnológicas, tras comparar el pre-test y post-test. Se concluye en una mejora significativa en la competencia comunicativa del inglés.

Abstract The use of English is a necessity today. In education, developing communicative competence in English is a challenge for teachers and students; it is even more challenging in a non-face-to-face education context. The advancement of technology is an ally in this context. This study aims to determine the impact of technological tools on English communicative competence in university students. The design was quasi-experimental, and the sample of 62 students: 31 from the Control Group and 31 from the Experimental Group in a national university in Peru. A pre-test and a post-test on communicative competence in English and a questionnaire on the use of technological tools were applied. The arithmetic mean shows an improvement in 5.13 points using the technological tools, after comparing the pre-test and post-test. It is concluded in a significant improvement in English communicative competence among university students.

ABSTRACT Although soybean is one of the most important agricultural commodities in the world, it has been losing genetic diversity in recent decades, due to the intense breeding process and reproduction method. Thus, the objective of this study was to evaluate the agronomic performance and estimate the genetic diversity among inbred lines, and identify promising crossings. A total of 66 soybean genotypes were evaluated, 61 of which were pre-commercial lines, and five commercial cultivars (AS3797, DESAFIO, M7110, M7739, M8210) as controls. The experimental design consisted of randomized blocks with three replicates. The distance matrix between the inbred lines was calculated by Mahalanobis distance and grouping by the unweighted pair group method with arithmetic mean (UPGMA). The maximum distance was 1,776.26 between cultivar M7110 and the G23 inbred line, and the minimum 1.50 between inbred lines G13 and G36, with an average distance of 364.40, demonstrating genetic diversity. The traits that contributed most to genetic divergence were number of days to flowering (66.7%) and physiological maturation (28.55%). Inbred lines G60 (higher grain yield), G51 and G33 (lower physiological maturation) and cultivar M7110 (greater divergence) stood out. Four groups were formed, with G1 having the highest grain yield and fewest days to flowering and physiological maturation. The indicated crossings are between G60, G57, CD2728, M7110, G33 and G32 (group G1) and G47 (group G4). world decades Thus 6 evaluated precommercial pre AS3797, AS3797 AS (AS3797 DESAFIO M M7739 M8210 controls replicates UPGMA. UPGMA . (UPGMA) 177626 1 776 26 1,776.2 M711 G G2 line 150 50 1.5 G36 36440 364 40 364.40 66.7% 667 7 (66.7% 28.55%. 2855 28.55% 28 55 (28.55%) G6 higher yield, , yield) G5 G3 lower greater out formed G57 CD2728 CD G4 G4. G4) AS379 (AS379 M773 M821 (UPGMA 17762 77 2 1,776. M71 15 5 1. 3644 36 4 364.4 66.7 (66.7 285 28.55 (28.55% CD272 AS37 (AS37 M77 M82 1776 1,776 M7 3 364. 66. (66. 28.5 (28.55 CD27 AS3 (AS3 M8 177 1,77 (66 28. (28.5 CD2 (AS 17 1,7 (6 (28. 1, ( (28 (2

RESUMO A soja é uma das mais importantes comodities agrícolas mundiais, no entanto, devido ao intenso processo de melhoramento e sua forma de reprodução, vem perdendo diversidade genética ao longo das últimas décadas. Assim, o objetivo deste estudo foi avaliar o desempenho agronômico, estimar a diversidade genética entre as linhagens e identificar cruzamentos promissores. Para isto, foram avaliados 66 genótipos de soja, sendo 61 linhagens pré-comerciais e cinco cultivares comerciais (AS3797, DESAFIO, M7110, M7739, M8210) como controles. O delineamento experimental foi o de blocos ao acaso com três repetições. A matriz de distância entre as linhagens foi calculada pela distância de Mahalanobis e o agrupamento pelo método da ligação média entre grupos (UPGMA). A distância máxima foi de 1.776,26 entre as linhagens M7110 e G23, e a mínima de 1,50 entre as linhagens G13 e G36, sendo a distância média de 364,40, demonstrando a existência de diversidade genética. Os caracteres que mais contribuíram para a divergência genética foram número de dias para o florescimento (66,7%) e maturação fisiológica (28,55%). As linhagens G60 (maior produtividade de grãos), G51 e G33 (menor maturação fisiológica) e a cultivar M7110 (maior divergência) se destacaram. Formaram-se quatro grupos, sendo o grupo G1 com maior produtividade de grãos e menor número de dias para o florescimento e maturação fisiológica. Os cruzamentos indicados são entre G60, G57, CD2728, M7110, G33 e G32 (grupo G1) com a G47 (grupo G4). mundiais entanto reprodução décadas Assim agronômico promissores isto 6 précomerciais pré AS3797, AS3797 AS (AS3797 DESAFIO M M7739 M8210 controles repetições UPGMA. UPGMA . (UPGMA) 177626 1 776 26 1.776,2 M711 G23 G 150 50 1,5 G36 36440 364 40 364,40 66,7% 667 7 (66,7% 28,55%. 2855 28,55% 28 55 (28,55%) G6 grãos, , grãos) G5 G3 destacaram Formaramse Formaram G57 CD2728 CD G4 G4. G4) AS379 (AS379 M773 M821 (UPGMA 17762 77 2 1.776, M71 G2 15 5 1, 3644 36 4 364,4 66,7 (66,7 285 28,55 (28,55% CD272 AS37 (AS37 M77 M82 1776 1.776 M7 3 364, 66, (66, 28,5 (28,55 CD27 AS3 (AS3 M8 177 1.77 (66 28, (28,5 CD2 (AS 17 1.7 (6 (28, 1. ( (28 (2

ABSTRACT Introduction: Basic demographic indicators constitute a statistical operation, conformed by a collection of indicators that allow analyzing the incidence of the basic demographic phenomena in a society. Objective: To design an indicator, taking the masculinity index as a starting point, for the evaluation of population ageing through a hierarchical scale. Methods: An ecological study was carried out that included any population with existent information, from the age 0 to a final open group of 75 years and over, subdivided by five-year groups and sex. The sample was selected by random simple sampling. The mean arithmetic, medium arithmetic, typical deviation and percentiles were among the descriptive measures; also, the Kolmogorov-Smirnov test for goodness of fit, the receiver operating characteristic curve, Youden index, Pearson correlation coefficient, kappa coefficient as a measure of concordance and chi-square test of independence were applied. Results: A good or high concordance existed with the Sundbarg index and a high correlation with all the aging indicators, except the dependence index. Conclusion: The pondered masculinity ratio provides an excellent measuring of the aging degree in a population, whenever the final age interval is 75 years and over.

RESUMEN Introducción: Los indicadores demográficos básicos constituyen una operación estadística, conformada por una colección de indicadores que permiten analizar la incidencia de los fenómenos demográficos básicos en una sociedad. Objetivo: Diseñar un indicador, a partir del índice de masculinidad, para la evaluación del envejecimiento poblacional a través de una escala jerárquica. Métodos: Se realizó un estudio ecológico, que incluyó a cualquier población con información existente desde la edad 0 hasta un grupo abierto final de 75 y más años, subdivididos por grupos quinquenales y sexo. La muestra fue seleccionada por muestreo simple aleatorio. Entre las medidas descriptivas figuraron la media aritmética, la mediana, la desviación típica y los percentiles; asimismo, fueron aplicadas la prueba de bondad de ajuste de Kolmogorov-Smirnov, la curva de la característica operativa del receptor, el índice de Youden, el coeficiente de correlación de Pearson, el coeficiente kappa como medida de concordancia y la prueba de la Χ2 de independencia. Resultados: Existió una concordancia buena o elevada con el índice de Sundbarg y una alta correlación con todos los indicadores de envejecimiento, excepto con el índice de dependencia. Conclusiones: La razón de masculinidad ponderada proporciona una excelente medición del grado de envejecimiento de una población, siempre que el intervalo de edad final sea de 75 años y más.

Resumo Os poluentes ambientais podem frequentemente alterar os componentes genéticos das populações naturais. Neste estudo, metais pesados e diversidade genética em caramujos terrestres (Achatina achatina) de três populações do sudoeste da Nigéria foram investigados, usando a tecnologia de espectrometria de absorção atômica e sequenciamento de DNA, respectivamente. A análise dos metais revelou que os caramujos acumularam chumbo (Pb) e níquel (Ni) em altas concentrações em dois dos três estados, enquanto o cádmio (Cd) foi o menos detectado. A edição e o alinhamento das sequências de todos os acessos de caramujos geraram uma faixa de 384pb a 419pb. A análise de variância molecular (AMOVA) em todos os 18 acessos foi baixa em apenas 16%. A cobertura da consulta (QC) variou entre 96% e 100%, com 14 (77,8%) dos 18 acessos apresentando 100% de identidade. A comparação pareada dos acessos estudados também mostrou alta similaridade genética. O método de grupo de pares não ponderados com média aritmética (UPGMA) gerou dois clusters principais. O cluster I era único e contém uma amostra (AaOy06), enquanto o outro cluster está intimamente relacionado e pode ser subdividido em subclusters. O índice de similaridade entre os clusters é 0,5357. A grande semelhança entre os acessos pode ser devido à proximidade geográfica dos três estados. A singularidade do acesso AaOy06 em comparação com outros acessos pode ser devido à influência negativa de metais pesados, particularmente chumbo. A determinação das relações evolutivas entre as populações de caramujos pode ser útil para os esforços de reprodução da espécie na Nigéria.

Abstract Environmental pollutants may often alter the genetic components of natural populations. In this study, heavy metals and genetic diversity in land snail (Achatina achatina) from three populations of south-western Nigeria were investigated, using the Atomic Absorption Spectrometry and DNA Sequencing technology respectively. Metal analysis revealed that the snails accumulated lead (Pb) and nickel (Ni) in high concentrations in two of the three states, while cadmium (Cd) was the least detected. Editing and alignment of the sequences of all snail accessions generated a range of 384bp to 419 bp. Analysis of Molecular Variance (AMOVA) in all 18 accessions was low at only 16%. The query coverage (QC) ranged between 96% and 100%, with 14 (77.8%) of the 18 accessions showing 100% identity. Pairwise comparison of the accessions studied also showed a high genetic similarity. The unweighted pair group method with arithmetic mean (UPGMA) generated two main clusters. Cluster I was unique and contain one sample (AaOy06) while the other cluster are very closely related and can be further sub-divided into sub-clusters. The similarity index of between the clusters is 0.5357. The close similarity among the accessions may be due to the geographical proximity of the three states. The uniqueness of accession AaOy06 in comparison to other accessions might be due to the negative influence of heavy metal, particularly lead. The determination of evolutionary relationships among snail populations may be useful towards the breeding efforts of the species in Nigeria.

Abstract In this exploratory study, we focused on identifying first-year university students' prior conceptions regarding the concepts of linear equations and the system of linear equations (SLE) with two unknowns. The knowledge of these conceptions will serve to understand what students are learning and as a starting point for planning the teaching of the SLE content of m x n. For this, 24 engineering students who were studying Linear Algebra answered a questionnaire with open questions about the graphic representation of a linear equation with two unknowns and a 3 x 2 SLE, the number of solutions of a linear equation and a SLE, a particular solution of a SLE and what they understand by the solution of a SLE. Later we analyzed their written protocols based on the thinking modes of Linear Algebra: synthetic-geometric, analytical-arithmetic, and analytical-structural. Our results revealed that the students identified the linear equation with a straight line. However, misconceptions predominate regarding a linear equation's number of solutions or the quantity a SLE with two unknowns can have. In addition, we observed that in the students' arguments, the analytic-arithmetic mode prevails, and they express difficulty in transitioning to the synthetic-geometric mode when the task is presented in a different mode. study firstyear first year (SLE n syntheticgeometric, syntheticgeometric synthetic geometric, geometric analyticalarithmetic, analyticalarithmetic analytical arithmetic, arithmetic analytical-arithmetic analyticalstructural. analyticalstructural structural. structural analytical-structural line However s have addition arguments analyticarithmetic analytic prevails

Resumen En este estudio exploratorio, nos enfocamos en identificar las concepciones previas que tienen los estudiantes de primer año de universidad con respecto a los conceptos de ecuación lineal y sistema de ecuaciones lineales (SEL) con dos incógnitas. El conocimiento de dichas concepciones servirá para conocer lo que están aprendiendo los estudiantes y como punto de partida para la planificación de la enseñanza del contenido de SEL de m x n. Con este propósito, aplicamos un cuestionario con preguntas abiertas a 24 estudiantes de ingeniería que estaban cursando Álgebra Lineal. Este cuestionario contenía preguntas sobre la representación gráfica de una ecuación lineal con dos incógnitas y de un SEL de 3 x 2, la cantidad de soluciones de una ecuación lineal y de un SEL, una solución particular de un SEL y lo qué entienden por solución de un SEL. Posteriormente, analizamos sus protocolos escritos en función de los modos de pensamiento del Álgebra Lineal: sintético-geométrico, analítico-aritmético y analítico-estructural. Nuestros resultados revelaron que los estudiantes identifican la ecuación lineal con una recta. Sin embargo, predominan las concepciones erróneas referente a la cantidad de soluciones que tiene una ecuación lineal o que puede tener un SEL con dos incógnitas. Además, observamos que en los argumentos de los estudiantes prevalece el modo analítico-aritmético y manifiestan dificultad para transitar al modo sintético-geométrico cuando la tarea se plantea en un modo diferente. exploratorio (SEL n propósito 2 Lineal Posteriormente sintéticogeométrico, sintéticogeométrico sintético geométrico, geométrico analíticoaritmético analítico aritmético analíticoestructural. analíticoestructural estructural. estructural analítico-estructural recta embargo Además diferente

ABSTRACT Shade-tolerant soybean genotypes will allow their greater adoption for use in agroforestry or intercropped systems in tropical and subtropical regions. These genotypes can be obtained from the selection of existing superior genotypes or through breeding programs. This study, was verified such genetic variability and select those genotypes with cultivation potential at reduced levels of photosynthetically active radiation (PAR). Morphophysiological and yield characteristics of 16 soybean genotypes were evaluated in two experiments conducted in a controlled environment and laid in a randomized block design with three replications. Genetic parameters, correlations and genetic diversity were estimated and path analysis was performed. The soybean cultivars used showed genetic variability with a high variation index and heritability, which is advantageous for the selection of superior cultivars. Leaf area showed genotypic correlation and had a direct effect on seed weight per plant, regardless of shading. Additionally, the number of pods, hypocotyl diameter, and leaf area, all indirectly contributed to seed weight per plant regardless of shading. Seven genotypes (NS7780, NS8338, NS7667, NS7901, RK8115, CZ37B43 and 8579RSF) were selected based on genetic gain obtained by the Mulamba and Mock index at the two levels of PAR reduction tested. Furthermore, five of these genotypes (CZ37B43, RK8115, NS7901, NS8338 and 8579RSF) were identified by the Unweighted Pair-Group method Arithmetic Mean, as suitable either as a shaded crop or, as parental materials in breeding programs. Shadetolerant Shade tolerant regions programs study PAR. . (PAR) 1 replications parameters performed heritability shading Additionally pods diameter NS7780, NS7780 NS (NS7780 NS7667 NS7901 RK8115 RK CZB CZ B CZ37B4 8579RSF RSF tested Furthermore CZ37B43, (CZ37B43 NS833 PairGroup Pair Group Mean (PAR NS778 (NS778 NS766 NS790 RK811 CZ37B (CZ37B4 NS83 NS77 (NS77 NS76 NS79 RK81 (CZ37B NS8 NS7 (NS7 RK8 (NS

Abstract At school, the mathematical literacy initiated by the development of arithmetic skills in the four operations, and reading and writing skills, plays a fundamental role in children’s cognitive development and their socializing. The literature points to phonological and visuospatial working memory, number sense, and linguistic skills as some of the cognitive aspects that mediate arithmetic skills. The present study aimed to (1) characterize the performance in solving arithmetic operations and investigate whether this arithmetic performance is different between children with and without reading difficulties; (2) investigate whether the way of registering the resolution (written or mental) is associated with correct answers in this arithmetic operations; and finally, (3) verifying the association of this arithmetic performance with tests that assess number sense and phonological and visuospatial working memory. Participants were 131 students of elementary school with and without reading difficulties. The results indicate that these children have a deficit in arithmetic performance compared to what is expected by the curriculum of their respective school grades. This study also showed that both the performance in arithmetic and the number sense and working memory are lower in the group with reading difficulty. The way of registering the resolution was related to the correct answers only for the addition with 2 digits. Finally, it was found an association between the evaluated cognitive functions and the arithmetic performance, this association varied according to the different school grades. childrens s socializing 1 (1 difficulties (2 written mental finally 3 (3 13 grades difficulty digits Finally (

Resumo Na escola, a alfabetização matemática, iniciada pelo desenvolvimento de habilidades aritméticas nas quatro operações, ao lado da leitura e escrita, constitui um papel de fundamental importância no desenvolvimento cognitivo da criança e na sua inserção na sociedade. A literatura da área aponta a memória operacional fonológica e visuoespacial, além do senso numérico e habilidades linguísticas como sendo alguns dos aspectos cognitivos que mediam o desempenho aritmético. O presente estudo teve como objetivos: (1) caracterizar o desempenho na resolução de operações aritméticas e investigar se esse desempenho é diferente entre crianças com e sem dificuldade de leitura; (2) investigar se o modo de registro da resolução (escrito ou mental) se associa com os acertos nas operações aritméticas; e (3) verificar a associação desse desempenho aritmético com testes que avaliam senso numérico e memória operacional fonológica e visuoespacial. Os participantes foram 131 alunos dos Anos Iniciais do Ensino Fundamental com e sem dificuldades de leitura. Os resultados indicam que as crianças da amostra possuem defasagem no desempenho aritmético comparando com o esperado pelo currículo das respectivas séries escolares. O estudo mostrou também que tanto o desempenho em aritmética quanto o senso numérico e memória operacional foram menores no grupo com dificuldade em leitura. O uso dos diferentes modos de registro das resoluções identificados teve relação com os acertos em aritmética apenas para a adição de 2 dígitos. Encontrou-se também uma associação entre as funções cognitivas avaliadas e o desempenho aritmético, essa associação variou conforme os diferentes anos escolares. escola matemática escrita sociedade visuoespacial objetivos 1 (1 (2 escrito mental 3 (3 13 escolares dígitos Encontrouse Encontrou (

ABSTRACT The objective of this study was to assess the genetic variability of 63 garlic accessions grown in two environments in the state of São Paulo, Brazil. A randomized block design with replications was used. Agromorphological evaluations were conducted based on descriptors defined by the International Plant Genetic Resources Institute (IPGRI), currently Bioversity International, encompassing 18 characteristics. The obtained data consisted of the mode of each variable and genetic distances from the complement arithmetic of the Jaccard coefficient. Cluster analysis was carried out using Tocher optimization and UPGMA methods; Mantel test was used to assess the correlation of genetic distances between locations. Garlic accessions exhibited genetic diversity for the studied qualitative variables. Correlations between distances of the evaluated accessions were found in both locations, although of low magnitude. Garlic characteristics vary according to growth environment, indicating divergence among accessions. This may be attributed to the plasticity of the species and genotype-environment interaction factors. Phenotypic variability of garlic germplasm observed in a particular environment cannot be extrapolated to other locations. 6 Paulo Brazil IPGRI, IPGRI , (IPGRI) 1 coefficient methods locations variables magnitude genotypeenvironment genotype factors (IPGRI

RESUMO O objetivo deste trabalho foi avaliar a diversidade genética de 63 acessos de alho semi-nobre avaliados em dois ambientes no estado de São Paulo. Utilizou-se o delineamento de blocos casualizados, com repetições. As avaliações agromorfológicas foram realizadas com base nos descritores do Plant Genetic Resources Institute (IPGRI), atualmente Bioversity International, e totalizaram 18 características. Os dados foram obtidos pela moda de cada variável, sendo que a medida de divergência utilizada foi o complemento aritmético de Jaccard. As análises de agrupamento aplicadas foram o método de otimização de Tocher e UPGMA; bem como o teste de Mantel para avaliar a correlação das distâncias genéticas entre os locais. Os acessos apresentaram diversidade genética para as variáveis qualitativas estudadas. A correlação entre as distâncias dos acessos avaliados nos dois locais existiu, porém, sua magnitude foi baixa. As características do alho modificam-se de acordo com o ambiente, portanto, a divergência entre os acessos. Isso pode ser atribuído a plasticidade da espécie e aos fatores de interação genótipo-ambiente. A variabilidade fenotípica de germoplasma de alho observada em um determinando ambiente não pode ser extrapolado para outros locais. 6 seminobre semi nobre Paulo Utilizouse Utilizou se casualizados repetições IPGRI, IPGRI , (IPGRI) International 1 variável Jaccard UPGMA estudadas existiu porém baixa modificamse modificam portanto genótipoambiente. genótipoambiente genótipo ambiente. genótipo-ambiente (IPGRI

Abstract This article reports on research based on literature in mathematics education to identify, present, and discuss superficialities, biases, and misunderstandings of different orders and various origins concerning the theme of teaching and learning fractions. We produced the research data using a variant of snowballing. After reading one or more relevant articles about our theme, we selected additional articles referenced in the consulted articles that potentially contain relevant information. We grouped the identified superficialities, biases, and misunderstandings into seven categories, each encompassing one or more difficulties. Consequently, we observed that these problematic issues are intertwined with the concepts involved in the subject of fractions when thought of as school mathematical content and are related from the different meanings manifested by fractions in the real world to its notational form, to its existence as a number, to how it is represented physically and pictorially, to the complexity of introducing new and numerous rules regarding its arithmetic, to the forms of conduct preferred by teachers when in the act of teaching. By observing many problematic issues related to the teaching and learning of fractions, we conclude that this theme is an essential front for further theoretical and empirical studies. identify present superficialities biases snowballing information categories difficulties Consequently form number pictorially arithmetic studies

Resumo Esse texto relata uma pesquisa que objetivou, a partir de estudo da literatura específica, identificar, apresentar e discutir superficialidades, parcialidades e equívocos de diferentes ordens e variadas origens, ligadas ao ensino e aprendizagem das frações. Para levantar os dados, utilizamos uma variação da metodologia bola de neve, que, a partir da leitura de um ou mais textos notáveis acerca do tema desejado, são elencados novos textos que podem conter informações relevantes. As superficialidades, parcialidades e equívocos identificados foram agrupados em sete categorias, cada qual abrigando uma ou mais dificuldades, fato que revelou que essas questões problemáticas encontram-se, de certo modo, entrelaçadas aos conceitos envolvidos no tema frações quando pensadas como conteúdo matemático escolar, e relacionam-se, desde os diferentes significados manifestados pelas frações no mundo real, passando por sua forma notacional de escrita, por sua existência enquanto número, pelas formas com as quais são representadas física e pictoricamente, pela complexidade da introdução de novas e numerosas regras quanto à sua aritmética, até as formas de condução preferidas por professores quando do ato de ensino. Ao observarmos quantidade significativa de questões problemáticas relacionadas ao ensino e à aprendizagem de frações, concluímos que essa temática se constitui em uma frente importante para estudos teóricos e empíricos adicionais. objetivou específica identificar superficialidades origens dados neve desejado relevantes categorias dificuldades encontramse, encontramse encontram se, encontram-se modo escolar relacionamse, relacionamse relacionam relacionam-se real escrita número pictoricamente aritmética adicionais