A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
The end of the list has been reached or no journals were found for your choice.
Similar Journals
Journal Cover
Uniciencia
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1011-0275 - ISSN (Online) 2215-3470
Published by Universidad Nacional Costa Rica Homepage  [25 journals]
  • Structure and composition of a mangrove forest on the Central Pacific
           coast of Costa Rica: population of mollusks of commercial interest

    • Authors: Milagro Carvajal-Oses, Junior Pastor Pérez-Molina, Ángel Herrera-Ulloa, Christian Moreira-Segura
      Pages: 1 - 19
      Abstract: [Objective]. The floristic composition and populations of associated molluscs of commercial interest of the Chacarita mangrove forest on the Central Pacific of Costa Rica were evaluated to guide proposals for sustainable exploitation activities in the mangrove forest. [Methodology]. Monthly visits to the study area were conducted for one year to establish a floristic baseline of mangrove trees and measure carbon storage. Additionally, bivalve molluscs were collected to analyze the state of their populations based on the abundances of organisms found, as well as other characteristics such as length and mass. Data regarding the mangrove trees included their diameter at breast height (DBH, cm), height (m), importance value index (IVI), and carbon reserves (Mg C·ha-1). Four mollusc species of commercial interest were analyzed, using data on their length (cm), weight (g), and gonadosomatic index. Economic evaluations were also conducted using data obtained from the mangrove forest, as well as tourism and historical fishing data for the collection of Chacarita. [Results]. Five species of mangroves were identified: Rhizophora mangle, Rizophora racemosa, Laguncularia racemosa, Avicennia germinans, and Pelliciera rhizophorae, while P. rhizophorae had the highest importance value index. The study revealed a carbon storage equivalent to 78.49 Mg C·ha-1. A total of 357 organisms were counted, with Anadara similis accounting for 18% of the total count, followed by Anadara tuberculosa (37.5%), Leukoma spp. (41.46%), and Mytella guyanensis (3.08%). When considering the economic value of carbon stocks and the bivalve molluscs obtained from the samples, economic valuations of 9,812.63 USD·ha-1 and 28 USD·ha-1 were determined, respectively. [Conclusions]. The low population densities of molluscs, particularly those belonging to the Anadara genus, necessitate the establishment of management measures to facilitate the recovery of these mollusk populations. This research proposes sustainable use activities such as community tourism for educational and cultural purposes.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.6
      Issue No: Vol. 38, No. 1 (2024)
       
  • Potential for Saving Drinking Water Through the Use of Rainwater in Social
           Housing in Vi├žosa-Brazil

    • Authors: Juan Esteban Sánchez-Galvis, María José Sánchez-Galvis, Iván Andrés Sánchez-Ortiz
      Pages: 1 - 16
      Abstract: [Objective] The main objective of this research was to evaluate the potential for saving drinking water by using rainwater as a source of supply for non-potable purposes in two neighborhoods with social housing in the municipality of Viçosa, Minas Gerais, Brazil. [Methodology] The consumption statistics for each month of 2020 were used for each of the homes comprising the Benjamin José Cardoso and Sol Nascente Housing Complexes, and the fraction of drinking water that is destined in homes for non-potable purposes was estimated. The information corresponding to the monthly rainfall records of the last 50 years was analyzed and the monthly volume of rainwater that could be harvested in each house was calculated. [Results] The average monthly volume of rainwater that could be captured through the roof area of each dwelling is 3.39 m3. During the rainy months of the year, it would be feasible to save a higher percentage of water than that allocated for non-potable purposes. Sizing a rainwater reservoir that exceeds the monthly needs for non-potable purposes would allow the surplus of collected water to supply the liquid during the dry season. [Conclusions] Since the average percentage of savings in drinking water for both neighborhoods exceeded 53%, the saving of the monthly consumption can contribute to the reduction of payments for the drinking water service and the consumption of the liquid in the municipality, particularly during drought months.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.3
      Issue No: Vol. 38, No. 1 (2024)
       
  • Personal meanings in the formulation and argumentation of conjectures by
           high school students

    • Authors: María Elisa Giayetto, María Elena Markiewicz, Silvia Catalina Etchegaray
      Pages: 1 - 21
      Abstract: [Objective] This paper discusses an investigation of the meaning of “conjecture” for secondary school students, and disparities between personal meanings and those acquired in a mathematical institution. [Methodology] The methodology used is qualitative. A case study was carried out to improve understanding of the personal meanings of conjecture to students in the initial years of secondary education in the city of Río Cuarto, Argentina (15-16 years old). The responses of a group of students to assignments including three problems that involve the creation, contrasting, reformulation and/or validation of conjectures were analyzed, including interviews with the students. These analyses were carried out using tools from the ontosemiotic approach, determining configurations of primary objects and cognitive processes in the students’ personal practices. [Results] It was possible to identify semiotic conflicts in these practices, particularly disparities between personal meanings of the concept of conjecture and the meaning intended to be imparted by the mathematical institution, providing empirical indicators of the epistemic value given by students to emerging propositions in their argumentation. This made it less likely that students would learn to doubt the scope of their initial statements and recognize the need to propose another type of argument, as was intended by the mathematical institution. [Conclusions] The results of this investigation showed the importance of revealing the ontosemiotic complexity of personal practices related to the formulation and validation of conjectures, and revealing the cognitive semiotic conflicts linked to personal meanings.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.1
      Issue No: Vol. 38, No. 1 (2024)
       
  • Didactic Suitability Assessment Guide of Educational Processes for the
           Differential

    • Authors: Manuel Alejandro Verón, Belén Giacomone, Luis Roberto Pino-Fan
      Pages: 1 - 22
      Abstract: [Objective] This article describes the process of preparing a Guide for the Assessment of Didactic Suitability of a process for studying the concept of the differential of a function. The objective of this exercise was to propose an instrument to promote, guide and support teachers’ analysis of, and reflection on, teaching and learning processes of the differential concept. [Methodology] The research method used was content analysis, and its starting point was a systematic review of didactic-mathematical knowledge in key research. The analysis was guided by the dimensions or facets that characterize an educational process – epistemic, cognitive, affective, instructional and ecological – whose components and criteria are based on the notion of didactic suitability proposed in the Onto-semiotic Approach to Mathematical Knowledge and Instruction (OSA). [Results] The construction of the Didactic Suitability Assessment Guide introduced a methodology for the reconstruction of the reference meaning for the study of various facets of the differential. In addition, this guide represents a powerful tool for teachers at the time of designing, implementing. and evaluating study processes, taking into account the various meanings of the differential, its connections, its potential semiotic conflicts and its relationships with other concepts. [Conclusions] In line with the theoretical reference framework, it is concluded that its ideal use would allow teachers to make informed decisions about management of the didactic process, taking into account its educational context.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.2
      Issue No: Vol. 38, No. 1 (2024)
       
  • Analysis of the School Climate Scale in University Environments (ECEAU)

    • Authors: José Andrey Zamora-Araya, Karolayn Duarte-Abarca, Darcy Quesada-Varela, Mónica Prado-Abarca
      Pages: 1 - 21
      Abstract: [Objective] The aim of this paper is to verify the factorial structure of the School Climate Scale in University Environments (ECEAU) through structural equation models (SEM). [Methodology] A non-experimental cross-sectional study was carried out with a random sample of 381 students of the Universidad Nacional de Costa Rica (UNA), to whom the ECEAU was applied. A SEM model was proposed to confirm the factor structure of the scale and an exploratory factor analysis (EFA) was used to provide the basis for an alternative SEM model with a different structure. The reliability of scales was determined using McDonald’s omega, and the goodness of fit indexes used for the SEM models were the RMSEA, the CFI, the TLI and the GFI. The analysis was carried out using R software. [Results] The reliability of the scales in both models was adequate (w >0.70), although the metrics in the proposed model produced better results. The AFE suggested a different structure for the ECEAU, keeping some dimensions of the original structure and modifying and eliminating others. The goodness of fit indexes in both models were almost identical, with RMSEA=0.02, CFI=0.99, TLI=0.99 and GFI=0.98, which provides supporting evidence for the factorial structures proposed. [Conclusions] The original structure of the ECEAU was confirmed, while the differences in the results of the estimation and rotation methods generated another equally valid factorial structure for measuring the school climate construct in this university, and could be applied to other similar contexts.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.4
      Issue No: Vol. 38, No. 1 (2024)
       
  • Specialized Knowledge of Prospective Mathematics Teachers on the Concept
           of Mathematical Proof

    • Authors: Christian Roberto Alfaro-Carvajal, Jennifer Fonseca-Castro
      Pages: 1 - 16
      Abstract: [Objetivo] En este artículo, se presentan los resultados de una investigación cualitativa de carácter descriptivo que tiene como objetivo caracterizar el conocimiento especializado de los profesores de matemáticas en formación inicial de la Universidad Nacional en Costa Rica (UNA), sobre el concepto de la demostración matemática, mediante el modelo Mathematics Teacher’s Specialized Knowledge (MTSK). [Metodología] La investigación se posiciona en el paradigma interpretativo y tiene un enfoque cualitativo. Se aplicó un cuestionario, durante el primer semestre del 2021, a 42 profesores de matemáticas en formación inicial de cuarto y quinto año de la carrera Bachillerato y Licenciatura en Enseñanza de la Matemática de la Universidad Nacional de Costa Rica. Para examinar la información, se empleó el análisis de contenido y se hicieron agrupaciones de las respuestas, con el propósito de generar ideas centrales sobre el concepto de demostración. [Resultados] De los resultados se desprenden cuatro ideas centrales sobre lo que es una demostración matemática para los sujetos de la investigación, cercanas a aspectos formales lógico-sintácticos y matemáticos (ALSM) o aspectos informales semánticos (AIS). Se encontraron evidencias de las cinco funciones de De Villiers (1993) para la demostración y surgieron nuevas funciones relacionadas con esta en las matemáticas y en las matemáticas escolares. [Conclusiones] Los resultados brindan insumos a formadores de profesores de matemáticas e investigadores, en la revisión y análisis de programas de formación docente, y contribuyen en la búsqueda de nuevas áreas de investigación relacionadas con el tema.
      PubDate: 2024-01-01
      DOI: 10.15359/ru.38-1.5
      Issue No: Vol. 38, No. 1 (2024)
       
  • Exploratory teaching of geometry using dynamic geometry software and
           learning of mathematics teachers: A systematic review

    • Authors: Rafael Enrique Gutiérrez-Araujo, Vinícius Pazuch
      Pages: 1 - 22
      Abstract: [Objective] This article analyzes the literature related to research on continuing training processes of mathematics teachers, whose objectives are teacher learning, the study of exploratory teaching, or the links between the use of dynamic geometry software (DGS) and professional education. [Methodology] A meta-ethnography of 18 studies published in the period 2001-2021, encountered through searches in databases and mathematics education journals, was carried out. The analysis consisted of three stages: interpretative syntheses of each study; integrative syntheses, based on the recognition of convergences and divergences; and a final synthesis. [Results] In general terms, the review revealed that: (a) the predominant conception of teacher learning is related to participation of teachers in communities of practice; (b) exploratory teaching is compatible with the use of DGS, and its promotion in educational processes usually takes into account the interaction between theoretical and practical activities; and (c) teachers who begin to incorporate DGS into classroom activities may fail to take full advantage of the potential of this instrument for teaching, due to the emergence of unexpected situations during the class, or because of their convictions about the pedagogical use of digital technologies. [Conclusions] Among the most important conclusions, it is clear that incorporation of DGS in the classroom can be successfully achieved through teachers’ progressive and critical awareness of the pedagogical knowledge that supports exploratory teaching as an educational practice.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.27
       
  • The Use of the Arm Circumference as a Measure to Detect Underweight in
           Individuals Aged 60 Years or Older Living in Costa Rica

    • Authors: Eduardo Aguilar-Fernández, Xinia Fernández-Rojas
      Pages: 1 - 12
      Abstract: [Objective]: This investigation focuses on the association between arm circumference and body mass index, and the estimation of cutoff values of this arm measurement for identifying low weight in Costa Rican residents aged 60 years and over. [Methods]: The study included a total of 2514 persons 60 years old or older who participated in the project “Costa Rica: Study of Longevity and Healthy Aging.” The analysis included calculation of Spearman’s correlation coefficient between arm circumference and the body mass index, the area under the Receiver Operating Characteristic (ROC) curve, and sensitivity and specificity values for measurements of arm circumference corresponding to a body mass index lower than 22 kg/m2. [Results]: The Spearman’s correlation coefficient between the body mass index and the arm circumference was 0.794 (0.774 for men and 0.806 for women). The optimum cutoff point was estimated at 26.5 cm, with a Youden’s Index of 0.7256, a sensitivity of 87.79 %, and a specificity of 84.77 %. Specific cutoff points for men and women were 26.5 cm and 25.9 cm, respectively. [Conclusions]: There is a strong relationship between arm circumference and body mass index in Costa Rican residents aged 60 years and over. A first approach was established to determine an adequate cutoff point in the measurement of arm circumference that will allow the detection of persons with low weight and greater nutritional risk in this population.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.24
       
  • Workshop on non-routine problem solving for students aged 8 to 9: A case
           study

    • Authors: Miguel Rodríguez Jara, Andrea Vergara-Gómez, Alejandra Mondaca-Saavedra, Pablo Gregori Huerta
      Pages: 1 - 23
      Abstract: [Objective] This article describes heuristics used by 8 and 9 year-old students to solve four non-routine problems that promote the development of arithmetic thinking from two perspectives: number distribution under a graphical representation, and use of arithmetic operations in the positional decimal system. [Methodology] The analysis included the formulation of categories that made it possible to characterize a priori the heuristics that could arise when solving each problem. These categories were used in the implementation of a mixed methodological approach with an exploratory and descriptive orientation. Qualitative analysis was carried out through a case study that helped to identify key actions based on written results provided by students. Quantitative analysis was carried out using implicative analysis, which includes a similarity tree and identification of significant classes. [Results] The results point to the importance of using simple heuristics in finding solutions to non-routine arithmetic problems, and confirm the presence of some characteristics of heuristic reasoning, such as attention, reduction, and change of assumptions. Likewise, implicative relationships were identified among some heuristics that share common characteristics, depending on the type of problem. [Conclusions] The results of this study show that, even in incorrect or incomplete answers, it is possible to recognize logical processes for the elaboration of partial answers and intuitive approaches, which are consistent with the action of simplifying or facilitating the search for a solution.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.28
       
  • Sensitivity of Hydra attenuata and Hydra viridis to diuron and ethoprophos
           pesticides, Costa Rica

    • Authors: Caroline Jones, María del Rocío Ugalde, Katherine Jiménez, Freylan Mena, Seiling Vargas
      Pages: 1 - 31
      Abstract: [Objective] The objective was to determine which of the two hydra species (Hydra attenuata or Hydra viridis) was more sensitive to two pesticides, and then use the most sensitive species as part of the battery of test organisms of the Ecotoxicological Studies Laboratory (ECOTOX). [Methodology] For this purpose, dilutions of two of the most commonly used pesticides in pineapple cultivation in Costa Rica which were detected in water samples were used: the herbicide diuron and the insecticide ethoprophos. Toxicity bioassays were conducted with each of these substances and with a mixture of these substances. The morphological state of the hydras was recorded. In addition, the mean effective concentration (EC50), mean lethal concentration (LC50) and toxicity interactions were evaluated in terms of three possibilities: antagonistic, additive or synergistic. [Results] H. attenuata was the most sensitive species to both pesticides, with an LC50s of 16.84 mg/L and 103.01 mg/L, and an EC50s of 4.24 mg/L and 23.4 mg/L for diuron and ethoprophos, respectively. Furthermore, H. viridis had an LC50s of 36.94 mg/L and 103.01 mg/L, with an EC50s of 13.64 mg/L and 53.12 mg/L, also for diuron and ethoprophos, respectively. Exposure to the pesticide mixture only caused mortality in H. viridis and had a synergistic effect on both species. [Conclusions] These results suggest that H. attenuata is the most appropriate species for the evaluation of pesticide effects, but further studies should be conducted on the interactions of contaminants in mixtures, since these may modify their toxicity for different species.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.29
       
  • Mathematical work of students in technical-professional education in an
           interdisciplinary context

    • Authors: Carolina Henríquez Rivas, Paula Verdugo Hernández, Yocelyn Valenzuela Barrera
      Pages: 1 - 24
      Abstract: [Objective] This study is intended to characterize the mathematical work of secondary education students in technical-professional education (TP), who participate in a didactic program that integrates mathematical learning and a specialization in administration. [Methodology] This is a qualitative investigation based on a case study that analyzes mathematical work in the classroom by students in the final year of their TP education. The theoretical foundation considers aspects related to interdisciplinarity and the theory of Mathematical Work Spaces. [Results] Results of this investigation show the distance between the analyses expected and what the students actually did, which is expressed in the presence of the [Sem-Ins] plane above the others. Student results were organized according to the type of answers they provided: standard, incomplete, and blocking or difficulty. [Conclusions] Results of this investigation showed that the first sub-task was carried out in a standard manner with activation of the [Sem-Ins] plane and in a part of it the discursive genesis, while the results of the following sub-tasks corresponded to incompletion and blocking or difficulty, respectively, in which only the presence of the semiotic genesis was observed. Finally, it can be concluded that knowledge of the concepts of the specialization were not an obstacle when they were related to mathematical work. However, from a mathematical perspective, difficulties were identified with respect to the communication of discursive reasoning, associated with discursive genesis and the interpretation of graphs, which suggests the need to work on activities that integrate mathematics with the TP area of specialization – in this case, administration.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.25
       
  • Antimicrobial resistance in the main aquaculture resources of the
           departments of Tumbes, Piura, San Martin and Puno

    • Authors: Carla D Calizaya, Erick H Reátegui, José C Silva, Rodolfo Velazco, Liliana Rodríguez, Derly R Angulo, Carlos A Llontop, Luis A Salcedo, Carla A Villena
      Pages: 1 - 16
      Abstract: [Objective] The objective of this study was to analyze antimicrobial resistance in Peruvian aquaculture. [Methodology] An observational, descriptive study was carried out. Samples of Argopecten purpuratus, Oncorhynchus mykiss, Oreochromis niloticus and Litopenaeus vannamei were included. The bacteria Enterococcus spp., Salmonella spp., Escherichia coli, Vibrio parahaemolyticus, Aeromonas spp., and Flavobacterium psychrophilum were isolated. Antibiotic resistance was evaluated using antibiograms, and resistant samples were sequenced to identify antimicrobial resistance genes. Absolute and percentage frequencies were calculated. In addition, Wald, Clopper-Pearson, and pooled prevalence confidence intervals were estimated. [Results] In the case of A. purpuratus, 22.2% (95% CI:2.81-60.00) of the E. coli samples were resistant to oxytetracycline. Resistant samples were found in 4.44% (n=2) of the aquaculture production centers (APCs). In O. mykiss, 88.89% (95% CI:51.16-99.72) of the Enterococcus spp. were resistant to fosfomycin and oxytetracycline. Resistant samples were found in12.96% of the APCs (n=7). Regarding O. niloticus, 47.31% (95% CI: 37.16-57.46) of the E. coli samples were resistant to oxytetracycline>ampicilline>chloramphenicol>fosfomycin and azithromycin. Resistant samples were encountered in 50% of the APCs (n=19). In addition, 89.36% (95% CI:80.55-98.18) of the Enterococcus spp. were resistant to Fosfomycin> chloranphenicol and colistin> oxytetracycline>azithromycin>ampicilline; resistant samples were found in 36.84% of the APCs (n=14). In L. vannamei, 87.11% (95% CI:83.00-91.21) of the Enterococcus spp. samples were resistant to Fosfomycin> colistin> oxytetracycline> azithromycin>ampicilline and resistant samples were found in 100% of the APCs (n=33). Likewise, 35.05% (95% CI:29.74-40.23) of the V. parahaemolyticus samples were resistant to ampicilline>fosfomycin>oxytetracycline>azithromycin>eritromicine>enrofloxacin> ampicilline> chloranfhenicol. Resistant samples were found in 78.79% (n=26) of the APCs. [Conclusions] The percentage of APCs with O. niloticus and L. vannamei showed that antimicrobial resistance was high.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.30
       
  • Isolation, identification, and characterization of bacterial strains with
           potential for degradation of the pesticides chlorothalonil and
           chlorpyrifos

    • Authors: Joyce Estrada-Gamboa, Rodolfo Umaña-Castro, Carolina Sancho-Blanco, Martha Orozco-Aceves
      Pages: 1 - 16
      Abstract: Indiscriminate use of highly toxic pesticides in agriculture has produced soil contamination and deterioration of ecosystems. A promising solution to this environmental problem is bioremediation, which includes the use of bacteria to degrade contaminating substances. [Objective] The objective of this work was to isolate, identify, and characterize bacterial strains capable of degrading the pesticides chlorothalonil and chlorpyrifos to determine their potential use in bioremediation of contaminated soils. [Methodology] The strains were isolated from agricultural soils using enrichment cultures containing chlorothalonil or chlorpyrifos (20 mg/L) as the sole carbon source. The isolated strains were characterized by their morphology, by their physiological responses to 48 biochemical tests and sensitivity to 15 antibiotics, by their growth kinetics, and in molecular terms (amplification of the gene rDNA 16S). [Results] In total, three strains were isolated, one capable of using (and degrading) chlorpyrifos, identified as Stenotrophomonas maltophilia, and two bacterial strains with a partial ability to use chlorothalonil as a carbon source, identified as Enterobacter cloacae and Ochrobactrum anthropi. The three bacterial species are Gram-negative bacilli and have diverse physiological characteristics, including variable resistance to certain antibiotics. [Conclusion] It is concluded that the isolated bacteria have biotechnological potential to be incorporated into a bioremediation strategy for contaminated soils, especially for the elimination of chlorpyrifos. Finally, further research perspectives are proposed to determine more efficient processes of chlorothalonil degradation by cometabolism.  
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-09-01
      DOI: 10.15359/ru.37-1.26
       
  • The Effects of sexism against women on men's self-efficacy and performance
           in Mathematics: structural equation models from the theory of ambivalent
           sexism

    • Authors: Steven García-Goñi, Antonio Loría-García, Hazel Quesada-Leitón
      Pages: 1 - 21
      Abstract: [Objective] This study is intended to explain the performance in mathematics tests of men at the high school and college levels, majoring in Social Sciences, Humanities and STEM, using a SEM model based on the theory of ambivalent sexism towards women. [Methodology] Data was obtained from high school boys in urban areas (2015), as well as college men majoring in the careers mentioned before. A structural equation model was estimated using maximum likelihood and generalized least squares estimation methods. Given non-compliance with the assumptions, estimates were made using Bayesian statistical methods. Finally, goodness-of-fit measures were evaluated. [Results] In the three groups studied, the relationships matched initial expectations. For high school boys, the relationship between hostile sexism and perceived equality in mathematics was not significant (coefficient: -0.02). In the case of college men majoring in Social Sciences and Humanities, the relationship between benevolent sexism and perceived equality in mathematics was also not significant (coefficient: 0.00). In the three cases, the higher the perception of equality, the higher the level of self-efficacy of the male students, which generates better performance in mathematical tests. Likewise, the higher the level of reasoning skills of the students, the higher their levels of self-efficacy. [Conclusions] Sexist ideologies negatively influence the perception of equality in mathematical contexts. Higher levels of perception of equality are related to higher levels of performance in Mathematics tests. The importance of reasoning skills in mathematical contexts was shown by the fact that all the estimated models showed such skills to be highly positively related to mathematical test results.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-22
      DOI: 10.15359/ru.37-1.19
       
  • Comparative tomographic and histological investigation of two biomaterials
           for preservation of the alveolar ridge

    • Authors: María Catalina Castaño-Granada, Jorge Alberto Arismendi-Echavarria, María Isabel Pérez-Cano, Andrea Julieth Gómez-Yali, Sara Sanchez- Gómez
      Pages: 1 - 17
      Abstract: [Objective] This investigation evaluates tomographic dimensional changes and histological changes after extraction with the use of two graft materials: Bio-Oss® xenograft and Bio-Gide® resorbable collagen membrane, and Puros® allograft and Biomed Extend® resorbable collagen membrane for the preservation of the alveolar ridge. [Materials and Methods] This is an experimental study in which 20-single tooth extractions were performed and two different biomaterials randomly assigned in two groups were compared. Members of Group A received xenograft-type material (Bio-Oss and Bio-Gide®), while members of group B received allograft-type material (Puros and Biomed®). Tomographic measurements were carried out on Day 0 and Day 210 after extraction. On Day 210 tissue samples were taken for histological analysis. [Results] Tomographic measurements did not show statistically significant variations except in the case of maximum width of the bone crest, which was smaller in the allograft group on day 210 with a value of p<0.05. Histological results show similarity between the two groups in cellular response, osteoid tissue, and mineralized new bone. Differences were observed in the amount of remaining material, with the highest presence of material found in the xenograft group. [Conclusion] The results of this study are similar to those found in the literature, and adequate preservation of the height and width of the bone ridge after an extraction was observed when xenograft or allograft bone substitute materials were employed, with very slight changes during the time of evaluation.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-22
      DOI: 10.15359/ru.37-1.18
       
  • Diagnostic evaluation of Mathematics for the fourth grade in a Costa Rican
           

    • Authors: Ricardo Poveda-Vásquez, Marianela Zumbado-Castro
      Pages: 1 - 14
      Abstract: [Objective] The objective of the diagnostic test was to determine the level of progress of an institutional curricular reform during the pandemic and post-pandemic periods to make immediate decisions for the 2022 school year. [Methodology] The type of research is inferential-exploratory, with a quantitative approach. Fifty-one (51) fourth grade students participated. The individual written test consisting of 19 items, was applied simultaneously in November 2021 for 60 minutes. Its preparation was based on teachers’ opinions and propositions. The Classical Test Theory (CTT) was used to interpret the results and SPSS 28.0.1.0 and its programming language, as well as the R environment were used. [Results] Analysis of the test results produced a Cronbach’s alpha value of 0.79, with three very difficult items and one very easy item. The grades that were located in the first quartile were subjected to a personalized analysis. The mathematical areas in which the test takers displayed the greatest mastery were Measurement, and Statistics and Probability, while they showed the least mastery of Geometry. For the second problem involving the development of a solution, almost 14% of the students obtained a perfect score and 40% did not obtain any points. [Conclusions] In the area of Numbers it was clear that the presentation of abbreviated multiplication should be strengthened. In the case of Geometry, it was determined that students were too dependent on memorization, while in the area of Relations and Algebra, results showed that it was necessary to vary the type of sequences used. In Statistics and Probability, it was observed that students can read information from a graph. Finally, it was determined that Problem Solving should be emphasized more in the classroom to guarantee better results in the development of solutions.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-22
      DOI: 10.15359/ru.37-1.20
       
  • Model 5E and teaching thermodynamics. Design and evaluation of a
           teaching-learning sequence

    • Authors: Ramón Zárate-Moedano, Jorge Manuel Suárez-Medellín, Rosa Luz Pérez-Hernández
      Pages: 1 - 19
      Abstract: [Objective] The objective of this investigation is to document the design, implementation and evaluation process of a teaching-learning sequence based on the 5E model for teaching the concepts of heat and temperature. [Methodology] Using a design-based research methodology, the implementation of a teaching-learning sequence was designed, implemented, and evaluated with secondary school students between 13 to 15 years old. Nineteen (19) students from two Mexican schools participated, organized into two groups, one from each school. Using a pretest –  posttest experimental design, quantitative data were recorded related to the students' knowledge about the use of the concepts of heat and temperature to explain natural phenomena, as well as qualitative data obtained during sessions with the students.  Quantitative data were analyzed using the Shapiro-Wilk test and two-factor ANOVA using JASP with p≤0.05. In addition, a triangulation with qualitative data was performed to support the conclusions. [Results] The results obtained showed positive effects related to the knowledge that students achieved during implementation of the sequence. Positive effects were also found in the qualitative evidence, where it was observed that the conceptual integration displayed by the students was sufficient to explain, in a coherent and complex way, the natural phenomena related to the concepts of heat and temperature. [Conclusions] The teaching-learning sequence achieved the proposed learning goals related to the concepts of heat and temperature. A list of design principles is included that is intended as a guide for other teachers interested in adapting this experience to their local contexts.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-22
      DOI: 10.15359/ru.37-1.22
       
  • A Comparative Study of Proportional reasoning of Costa Rican and Spanish
           students in ratio comparison problems

    • Authors: Luis Armando Hernández-Solís, Carmen Batanero
      Pages: 1 - 20
      Abstract: Abstract [Objective] This study seeks to evaluate the level of proportional reasoning and strategies in ratio comparison problems of Costa Rican and Spanish students between 11 and 16 years old. [Methodology] Using an interpretative research approach, 704 students were given one of two questionnaires with three items on ratio comparison (a total of six different levels of proportional reasoning, according to Noelting). The percentage of correct answers and levels of proportional reasoning, and the result of a content analysis of correct and incorrect strategies are presented. [Results] The majority of students correctly answered the problems with the lowest Noelting proportional reasoning level (IA to IIA), with this proportion decreasing in grades 6 to 8 of General Basic Education as the proportional reasoning level of the problem increased. Similar results were obtained with respect to correct strategies. The most frequent incorrect strategies were the comparison of the first terms of ratios and additive comparisons. Virtually all students reached the first two proportional reasoning levels of Noelting, and as the course progressed, a higher proportion attained the following levels of reasoning, but few students achieved level IIIA, corresponding to formal operations, even in the highest grade (grade 10). [Conclusions] It was concluded that it is necessary to reinforce the teaching of reasoning about comparison of ratios, and to take it into account in the mathematical topics based on this reasoning.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.21
       
  • Sentiment Analysis of Russia-Ukraine Conflict Tweets Using RoBERTa

    • Authors: Leo Ramos, Oscar Chang
      Pages: 1 - 11
      Abstract: [Objective] The moment Russia officially invaded Ukraine, the world experienced a period of tension and uncertainty. As a social release valve digital communication, channels increased their number of users and activity, generating a large amount of data. Twitter, in particular, being one of the most popular channels for sharing information and opinions, exploded with activities related to this historical moment. And as with many other social events, such as COVID-19, this social network became one of the main sources of information, opinion, and knowledge. This paper analyzes sentiments in tweets related to the armed conflict between Russia and Ukraine. [Methodology] The analyzed dataset contains tweets from January 1, 2022, through March 3, 2022, and was collected using event-related hashtags. In total, 603,552 tweets in English and 1,664 in Russian were analyzed. To perform emotion classification, DistilRoBERTa variant and the pre-trained XLM-RoBERTa-Base model were used, respectively. English tweets were classified into seven emotions: anger, disgust, fear, joy, neutral, sadness, and surprise. Russian tweets were classified into positive negative, and neutral polarities. [Results] The results showed that most English tweets convey fear and anger as predominant feelings, reaching 32.08% and 15.18% of the total tweets analyzed, respectively. Regarding tweets in Russian, the majority presented negative polarity, with 86.83% of the total. Some of the most recurrent phrases in the analysis allude to support for Ukraine and call for a halt to the war. Likewise, phrases of concern for the crisis, weapons, and fatalities are recurrent. [Conclusion] As expected, most people were concerned about the armed conflict and upset and angry about its consequences. Future works could use more tweets to improve the analysis and increase the time range to be studied. The analysis could also be segmented to study the sentiments of tweets according to different groupings and compare them with other societies, for instance, tweets could be segmented by country and analyzed accordingly.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.23
       
  • Insecticidal activity of ethanolic plant extracts on Aedes aegypti larvae

    • Authors: Victor Alvarez-Valverde, Gerardo Rodríguez, Silvia Argüello Vargas
      Pages: 1 - 11
      Abstract: [Objective] The objective of this study was to determine the larvicidal activity against A. aegypti of ethanolic extracts of plants commonly found in Costa Rica. [Methodology] Larvicidal activity of ethanolic extracts of plants was determined in this study using the WHO/VBC/81.807: WHO/VBC/81. from 1981. An analysis PROBID for dose response was conducted to determine LC50 of the most prominent extracts. [Results] A total of six extracts with the highest toxicity were chosen, with the stem extract of Ipomoea cairica having the lowest LC50 of 0.0341 mg/mL, followed by I. cairica leaf extract with an LC50 of 0.121 mg/mL. The larvicidal activity of ethanolic extracts of plants was determined in this study, with an emphasis on the larvicidal potential of I. cairica as an environmentally friendly alternative for the control of A. aegypti. [Conclusions] The larvicidal activity for ethanolic extracts of different plants, with an emphasis on the larvicidal potential of I. cairica as an environmentally friendly alternative for the control of A. aegypti.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.17
       
  • Design and implementation of an educational experience on linear variation
           for prospective mathematics teachers

    • Authors: Karina Herrera-García, Teresa Dávila-Araiza, Pablo Beltrán-Pellicer, Belén Giacomone
      Pages: 1 - 23
      Abstract: [Objective] This paper discusses the design, implementation, and analysis of an educational experience focused on linear variation, aimed at prospective secondary school mathematics teachers. The objective of this experience is to improve the prospective teachers’ didactic-mathematical knowledge and to contribute to the development of their onto-semiotic analytical skills. Linear variation is an important topic because it is present in different educational moments through multiple approaches and meanings – arithmetic, algebraic, and functional. As a complex mathematical object, it can generate teaching and learning conflicts, which can be studied to provide useful information about improvement of educational activities. [Methodology] This is a qualitative investigation, based on the preliminary study, design, implementation, and analysis of 5 didactic activities according to the theoretical principles of the Onto-semiotic Approach. The data gathered for the investigation included video recordings of classes, field notes and written answers provided by nine prospective teachers in the eighth semester of a Licentiate’s Degree in Secondary Education program, specializing in Mathematics. [Results] The results indicate that linear variation is indeed a complex issue, and deficiencies were found in the didactic-mathematical knowledge of prospective teachers. Likewise, difficulties in terms of knowledge and skills were found when participants were asked to analyze hypothetical responses to tasks related to the concept of linear variation. [Conclusions] The results of this investigation indicate that experiences such as these can be a valuable resource in educational programs for teachers to acquire knowledge and skills for the appropriate treatment of mathematical content.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.16
       
  • Analysis of returnee association websites: architecture and navigability

    • Authors: Oihane Korres, Erlantz Velasco, Visitación Pereda-Herrero
      Pages: 1 - 18
      Abstract: [Objective] This investigation analyzed the attributes of architecture and navigability of web sites intended to provide information to Spanish returnees. [Methodology] This is an exploratory empirical study which uses a qualitative design with a statistical-descriptive basis, and makes use of absolute and relative frequencies. The qualitative analysis was carried out by means of a manual examination supported by the Atlas.Ti tool, guided by a theoretical model with empirical foundations. Data from 16 websites related to associations and federations of Spanish returnees active during the years 2019-2021 were analyzed. [Results] The websites analyzed were similar in terms of structure, interface and navigability. They use formats similar to those of current blogs, but their content was infrequently updated. They contain large amounts of information structured using hyperlink formats or attached documentation. [Conclusions] It is concluded that the architecture and navigability of web pages of Spanish associations and federations of returnees are much more notable for their similarities than for their differences. The investigation opens the way for further comparative and relational studies that will allow analysis of similarities and differences between websites, as well as the characterization of their communicative structures.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.15
       
  • Creation of proportionality problems for the training of prospective
           primary school teachers

    • Authors: María Burgos, Jorhan Chaverri Hernández
      Pages: 1 - 24
      Abstract: [Objective] This article presents a description and analysis of an educational experience with prospective primary school teachers, aimed at developing their skills to create proportionality problems by modifying an initial problem to reflect a didactic-mathematical orientation. [Methodology] This is a qualitative and interpretative investigation that adopted an engineering or design approach to teaching in its research methodology. Theoretical and methodological tools of the Onto-semiotic Approach were used in both the design of the experience, and in the content analysis of participants’ responses. The investigation was carried out with a group of 127 Primary Education students of the University of Granada, Spain, organized in 33 teams to answer two problem-creation tasks. [Results] It was found that the participants most frequently created relevant problems by modifying a given problem, but that they did not manage to create problems that specifically allowed them to distinguish proportional from additive situations that are consistent with didactic-mathematical requirements. [Conclusions] Prospective teachers did not display sufficient didactic and mathematical knowledge to be able to successfully create proportionality problems. Training programs should therefore strengthen their strategies to develop this knowledge, incorporating it as a didactic resource in the teaching process to assist in improving the skills of prospective teachers in the analysis of mathematical activities.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.14
       
  • Functional Education as a Nexus between Agricultural and Industrial
           Revolution: An Epidemiological Modeling Approach

    • Authors: Abayomi Ayotunde Ayoade, Srinivasarao Thota
      Pages: 1 - 16
      Abstract: Education has been regarded as a major route to economic prosperity. Its potentials, if properly exploited, have the tendency to revolutionize a nation’s productivity, income, and development. [Objetive] In this work, a mathematical model was formulated, and an epidemiological modeling approach was explored to derive the necessary and sufficient conditions for agricultural and industrial transformation in Nigeria in terms of education. The use of mathematics to quantify such a phenomenon is relatively new. [Methodology] Ample mathematics theorems were employed to test for the existence, boundedness, and positivity of the model’s solutions which are basic features of a valid epidemiological model. The model was solved to derive the equilibrium points, and the analytic threshold that governed revolution in industry and agriculture in terms of education was derived. Stability and sensitivity analyses were conducted via the stability theory of nonlinear differential equations and normalized forward sensitivity index, respectively. Simulations were later conducted using the Maple software to validate the analytical results.  [Results] A government expenditure of 25% on education with or without corruption did not make education functional. Also, an increase in expenditure on education to 65% but with corruption of more than 30% retarded functional education. In general, education became functional when government investment in education attained 60%, with corruption levels lower than 20%. [Conclusions] Both the analytical and numerical results linked agricultural transformation and industrial revolution through functional education to massive investment in education and victory over corruption.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.12
       
  • Mathematical connections skills associated with the concept of quadratic
           equation established by prospective Mexican mathematics teachers

    • Authors: Magali Edaena Hernández-Yañez, Javier García-García, Karen Gisel Campo-Meneses
      Pages: 1 - 26
      Abstract: [Objective] This investigation seeks to identify the mathematical connections established by prospective mathematics teachers related to the concept of the quadratic equation. [Methodology] A focal group interview was used to collect information. It consisted of assigning five tasks to eight prospective mathematics teachers who are pursuing a Licentiate’s degree in Mathematics in the area of Educational Mathematics. The participants are from the city of Chilpancingo in the state of Guerrero in Mexico, and were from 21 to 23 years old. Due to the COVID-19 pandemic, the four group sessions were held virtually, each lasting 80 minutes. Data were analyzed using a thematic approach. [Results] The written and verbal responses of prospective mathematics teachers indicated that each of them used mathematical connections skills in a different way. In general, the most frequent skills were related to procedures, characteristics, and meaning, and less frequently to part-whole, modeling, and implication. These connections correspond to those specified in the theoretical framework; therefore, it can be argued that this framework is valid and relevant for exploring the mathematical connections among prospective mathematics teachers when solving mathematical tasks. [Conclusions] The participants assigned meaning to the concept of quadratic equation in terms of what it represents in real contexts, and were able to present the quadratic function in different forms in the algebraic and graphical terms. However, most of them did not make the intended mathematical connections.
      Keywords: Original scientific papers (evaluated by academic peers) ; PubDate: 2023-06-01
      DOI: 10.15359/ru.37-1.13
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 35.175.201.191
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-
JournalTOCs
 
 

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
The end of the list has been reached or no journals were found for your choice.
Similar Journals
Similar Journals
HOME > Browse the 73 Subjects covered by JournalTOCs  
SubjectTotal Journals
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 35.175.201.191
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-