1,516 research outputs found
ESTUDIO EXPLORATORIO SOBRE EL DESARROLLO DE LAS HABILIDADES DEL PENSAMIENTO GEOMÉTRICO ESPACIAL EN ESTUDIANTES DE LA EDUCACIÓN PREUNIVERSITARIA
Desarrollar el pensamiento geométrico espacial en los estudiantes de la educación preuniversitaria en Cuba, como uno de los componentes del pensamiento matemático, es un imperativo en el proceso de enseñanza-aprendizaje de la asignatura Matemática en este nivel educativo. La mayoría de los estudiantes que promueven al duodécimo grado e incluso los que cursan la educación superior, en no pocas ocasiones, presentan dificultades en demostrar que poseen algún desarrollo de las habilidades relacionadas con el pensamiento geométrico espacial. En este trabajo, a partir del análisis crítico de investigaciones de diferentes autores sobre el tema, así como de la utilización de métodos tales como: analítico-sintético, inductivo-deductivo, encuesta, análisis de frecuencias, dócimas de bondad de ajuste para una población como pruebas de significación estadística; se realizó un estudio exploratorio de la situación actual del desarrollo de las habilidades del pensamiento geométrico espacial en los estudiantes y profesores de la asignatura Matemática del Instituto Preuniversitario Urbano “Mártires del Porvenir” del municipio de Diez de Octubre en la provincia de La Habana. Estos resultados obtenidos permitieron realizar varias reflexiones que arrojaron inconsistencias tanto en estos estudiantes como en sus profesores en el ya mencionado nivel educativo en el Sistema Nacional de Educación en la República de Cuba.
ABSTRACT
Developing spatial geometric thinking in students of Pre-University education in Cuba, as one of the components of mathematical thinking, is an imperative in the teaching-learning process of the mathematics subject at this level educational. The majority of students who promoted to twelfth grade and even those who are studying higher education, not infrequently, present difficulties in demonstrating that they possess some development skills related to spatial geometric thinking. In this work, from the critical analysis of research of different authors on the subject, as well as the use of methods such as: analytical - synthetic, inductive - deductive , survey, analysis of frequency, goodness of fit for a docimas population as tests of statistical significance; was an exploratory study of the current situation of the development of the spatial geometric thinking skills in students and teachers of the subject mathematics of the urban pre-University Institute "Martyrs of el Porvenir" of the municipality of 10 October in the province of Havana. These results allowed to make several reflections which showed inconsistencies in these students and their teachers in the aforementioned level of education in the national education system in the Republic of Cuba.
KEY WORDS: spatial geometric thinking, abilities of spatial geometric thinking, development of skills
PRE-EXPERIMENTO PARA CONSTATAR CAMBIOS AL APLICAR UN RESULTADO CIENTÍFICO. EJEMPLO PRÁCTICO DE UNA METODOLOGÍA PARA MEJORAR EL DESARROLLO DE HABILIDADES DEL PENSAMIENTO GEOMÉTRICO ESPACIAL
En el trabajo se exponen algunas características de los diseños experimentales en la investigación educativa. Se explican distintas tipologías de los diseños pre-experimentales, tales como el diseño de solo pos prueba con un grupo, el de pre prueba- pos prueba con un grupo y el de solo pos prueba con dos grupos no equivalentes. Para el diseño pre-experimental de pre prueba- pos prueba con un grupo se presenta un ejemplo práctico con los datos de campo de una investigación educativa aplicada. También se destaca la importancia, en el mencionado ejemplo, de la utilización de herramientas estadísticas tanto descriptivas univariables como la prueba de los signos como dócima de una muestra medida dos veces y obtenida por medio de pares replicados en este tipo de diseño pre-experimental, para poder constatar que la intervención de una metodología elaborada, sustentada en el enfoque desarrollador y en la enseñanza basada en la resolución de problemas, contribuye a provocar cambios positivos al estado actual del desarrollo de las habilidades del pensamiento geométrico espacial en estudiantes de la educación preuniversitaria en la provincia de La Habana
EL DESARROLLO DE LAS HABILIDADES DEL PENSAMIENTO GEOMÉTRICO ESPACIAL: UNA MIRADA DESDE EL ENFOQUE DESARROLLADOR Y LA ENSEÑANZA BASADA EN LA RESOLUCIÓN DE PROBLEMAS
THE DEVELOPMENT OF SPATIAL GEOMETRIC THINKING SKILLS: A VIEW FROM THE DEVELOPER APPROACH AND TEACHING BASED ON PROBLEM SOLVING
RESUMEN
Los estudiantes de la educación preuniversitaria en Cuba presentan limitaciones en la resolución de problemas geométricos de la geometría del espacio debido al bajo nivel de desarrollo de sus habilidades del pensamiento geométrico. Entre las causas que provocan tales limitaciones está en la insuficiente preparación teórica y didáctica de los profesores de Matemática de esta educación para guiar a sus estudiantes en el desarrollo de las mismas. En este trabajo se analiza y fundamenta cómo desde el enfoque desarrollador y la enseñanza basada en la resolución de problemas, se puede crear esas bases teóricas y didácticas para que los profesores de Matemática conduzcan el proceso de desarrollo de las habilidades del pensamiento geométrico espacial en sus estudiantes de la educación preuniversitaria.
PALABRAS CLAVE: pensamiento geométrico espacial; habilidades; enseñanza basada en problemas; proceso de enseñanza-aprendizaje desarrollador; problemas geométricos.
ABSTRACT
The students of preuniversity education in Cuba have limitations in solving geometric problems of the geometry of the space due to the low level of development of geometric thinking skills. Among the causes that provoke such limitations is in insufficient theoretical and didactic preparation of teachers of mathematics in education to guide students in the development of the same. This study analyzed and based how from a developer perspective and teaching based on problem solving, you can create these theoretical and didactic bases so that teachers of mathematics will lead the process of developing the skills of the spatial geometrical thinking in their students of pre-university education.
KEYWORDS: spatial geometric thinking; abilities of spatial geometric thinking; teaching based on problems; process of teaching - learning developer; geometric problems
Aperiodic modulation of graphene driven by oxygen-induced reconstruction of Rh(110)
Artificial nanostructuring of graphene has served as a platform to induce variations in its structural and electronic properties, fostering the experimental observation of a wide and fascinating phenomenology. Here, we present an approach to graphene tuning, based on Rh(110) surface reconstruction induced by oxygen atoms intercalation. The resulting nanostructured graphene has been characterized by scanning tunneling microscopy (STM) complemented by low-energy electron microscopy (LEEM), micro low-energy electron diffraction (μ-LEED), micro angle-resolved photoemission spectroscopy (μ-ARPES), and micro X-ray photoelectron spectroscopy (μ-XPS) measurements under ultrahigh vacuum (UHV) conditions at room temperature (RT). It is found that by fine-tuning the O2 exposure amount, a mixture of missing row surface reconstructions of the metal surface below the graphene layer can be induced. This atomic rearrangement under the graphene layer results in aperiodic patterning of the two-dimensional (2D) material. The electronic structure of the resulting nanostructured graphene is dominated by a linear dispersion of the Dirac quasiparticles, characteristic of its free-standing state but with a p-doping character. The local effects of the underlying missing rows on the interfacial chemistry and on the quasiparticle scattering processes in graphene are studied using atomically resolved STM images. The possibilities offered by this nanostructuring approach, which consists in inducing surface reconstructions under graphene, could provide a novel tuning strategy for this 2D materialSpanish MINECO (Ref: MAT2016-77852-C2-2-R). Spanish
MICINN (Ref: PID2020-116619GA-C22). Spanish MICINN
(Ref: PID2021-123295NB-I00) Comunidad de Madrid and
Universidad Autonoma ́ de Madrid (Ref: SI3/PJI/2021-00500
Dirac cones in graphene grown on a half-filled 4d-band transition metal
New opportunities for structural and electronic properties engineering of graphene can be achieved by tuning the
interfacial interaction, which is ruled by the interplay between d-band filling and geometry of the support. Here,
is demonstrated the growth of graphene, featuring Dirac cones around the Fermi level, on the rectangular (110)
surfaces of Rh, a half-filled 4d-band transition metal element. The analysis of the structural properties by low
energy electron diffraction (LEED) and scanning tunneling microscopy (STM) shows that domains with a continuum of possible graphene-substrate orientations with angular scatter of around 10◦ coexist in graphene/Rh
(110) surfaces. Within each domain, surface structure is characterized by a distinct stripe-like moir´e pattern. The
interfacial chemistry analysis, by microprobeX-ray photoelectron spectroscopy (μ-XPS), of all the rotational
domains studied, demonstrates the existence of two main levels of interfacial interaction strength, similar to
previously reported graphene-metal systems characterized by the absence of Dirac cones around the Fermi level.
However, the band structures of these domains probed by micro angle resolved photoelectron spectroscopy
(μ-ARPES) present Dirac cones, with Fermi velocities comparable with those previously reported on weakly
coupled graphene layers. Both the unique properties of graphene/Rh(110) surfaces and the prospect to obtain
novel graphene-metal interfaces through the interplay between d-band filling and geometry, are expected to
open new opportunities to study phenomena up to now masked behind the interaction with the substrateFinancial support from the
Spanish MINECO under project MAT2016-77852-C2-2-R, from the
“María de Maeztu” program for units of excellence in R&D (grant
number CEX2018-000805-M) is gratefully acknowledged. A. J. M.-G.
acknowledges funding from the Spanish MICINN through Project No.
PID2020-116619 GA-C22, and from the Comunidad de Madrid and the
Universidad Autonoma ´ de Madrid through project SI3/PJI/2021-00500.
E. G. M. acknowledges funding from the Spanish MICINN through
Project No. PID2021-123295NB-I00. The research leading to this result
has been supported by the project CALIPSOplus under Grant Agreement
730872 from the EU Framework Programme for Research and Innovation HORIZON 202
Accurate band mapping via photoemission from thin films
Electron bands in solids can be determined in angle-resolved photoemission experiments from thin films, where the perpendicular wave vector (k⊥) uncertainty that characterizes photoemission from bulk crystals is removed. However, the comparison with state-of-the-art quasiparticle band-structure calculations has never been done. In this work we have mapped both initial-state (occupied) and final-state (empty) E(k⊥) bands along the A axis of aluminum, from photon-energy- and thickness-dependent quantum-well spectra of aluminum films. For final states the best fit is obtained with inverse low-energy electron diffraction band structure calculations. For initial-state bands of Cu and Al, thin-film data display excellent agreement with bulk quasiparticle theory, suggesting the use of thin films as model systems to investigate fine effects in the crystal band structure.This work has been supported in part by the Universidad del País Vasco (A.Mu. and J.E.O. under Contract No. 00057.240-EA-13668/2001, and A.Ma., A.R., and F.J.G.A. under Contract No. 00206.215-13639/2001), the European Community (EC) research training network NANOPHASE [A.Ma. and A.R. (Grant No. HPRN-CT-2000-00167)], and the Spanish Ministerio de Ciencia y Tecnología [A.Ma., A.R., and F.J.G.A. (Grant No. MAT2001-0946), and J.L. and E.G.M. (BFM2001-0244)].Peer Reviewe
An approach for data mining of electronic health record data for suicide risk management: Database analysis for clinical decision support
Background: In an electronic health context, combining traditional structured clinical assessment methods and routine electronic health-based data capture may be a reliable method to build a dynamic clinical decision-support system (CDSS) for suicide prevention. Objective: The aim of this study was to describe the data mining module of a Web-based CDSS and to identify suicide repetition risk in a sample of suicide attempters. Methods: We analyzed a database of 2802 suicide attempters. Clustering methods were used to identify groups of similar patients, and regression trees were applied to estimate the number of suicide attempts among these patients. Results: We identified 3 groups of patients using clustering methods. In addition, relevant risk factors explaining the number of suicide attempts were highlighted by regression trees. Conclusions: Data mining techniques can help to identify different groups of patients at risk of suicide reattempt. The findings of this study can be combined with Web-based and smartphone-based data to improve dynamic decision making for clinicians.This study received a Hospital Clinical Research Grant (PHRC 2009) from the French Health Ministry. None of the funding
sources had any involvement in the study design; collection, analysis, or interpretation of data; writing of the report; or the decision
to submit the paper for publication. This study was funded partially by Instituto de Salud Carlos III (ISCIII PI13/02200; PI16/01852),
Delegación del Gobierno para el Plan Nacional de Drogas (20151073), and the American Foundation for Suicide Prevention (LSRG-1-005-16)
LA INTEGRACIÓN DE SABERES DE SEGURIDAD Y DEFENSA NACIONAL EN LA FORMACIÓN INICIAL DEL LICENCIADO EN EDUCACIÓN PREESCOLAR: LA INTEGRACIÓN DE SABERES DE SEGURIDAD Y DEFENSA NACIONAL
This research addresses the general foundations of the importance and social need for the development of professional ways of action related to the Security and Defense of the Cuban nation, in the initial training process of the Preschool Education professional. This training responds to that of an educator who provides comprehensive educational care to children from 0-6 years of age, for which the comprehensive preparation of the professionals of this career is required, committed to the future progress of the country and to the solution, through their personal and professional initiatives, of the problems that arise in their sphere of action. Its objective is the elaboration of systematic actions, contextualized to the object of the profession for the integration of knowledge of the Discipline Preparation for Defense with the rest of the career that allow the development of professional performance ways in initial training process of the graduate in Preschool Education. All this through the implementation of the Preparation for Defense strategy and the development of scientific-methodological work in terms of strengthening these ways of action. The results achieved in the students of the Bachelor's Degree in Preschool Education of the University of Las Tunas, where the research was applied, were satisfactory, which is reflected in their ways of professional performance, ascertained in a strong scientific-technical preparation and solid development of their ethical, professional and moral values tinged by a high social commitment to the defense of the country.La presente investigación aborda fundamentos generales de la importancia y necesidad social del desarrollo de modos de actuación profesional relacionados con la Seguridad y la Defensa de la nación cubana, en el proceso de formación inicial del profesional de la Educación Preescolar. Esta formación responde a la de un educador que brinda atención educativa integral a niños de 0-6 años, para ello se requiere de la preparación integral de los profesionales de esta carrera, comprometidos con el progreso futuro del país y con la solución, a través de sus iniciativas personales y profesionales, de los problemas que se les presenten en su esfera de actuación. Tiene como objetivo la elaboración de acciones sistemáticas, contextualizadas al objeto de la profesión para la integración de saberes de la Disciplina Preparación para la Defensa con las restantes de la carrera que permitan el desarrollo de modos de actuación profesional en el proceso de formación inicial del licenciado en Educación Preescolar. Todo ello a través de la implementación de la estrategia de Preparación para la Defensa y el desarrollo del trabajo científico-metodológico en función del fortalecimiento de dichos modos de actuación. Los resultados alcanzados en los estudiantes de la licenciatura en Educación Preescolar de la Universidad de Las Tunas, donde fue aplicada la investigación, fueron satisfactorios, lo que se refleja en sus modos de actuación profesional, constatados en una fuerte preparación científico- técnica y sólido desarrollo de sus valores éticos, profesionales y morales matizados por un elevado compromiso social ante la defensa del país
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Landscape of Genome-Wide DNA Methylation of Colorectal Cancer Metastasis.
Colorectal cancer is a heterogeneous disease caused by both genetic and epigenetics factors. Analysing DNA methylation changes occurring during colorectal cancer progression and metastasis formation is crucial for the identification of novel epigenetic markers of patient prognosis. Genome-wide methylation sequencing of paired samples of colon (normal adjacent, primary tumour and lymph node metastasis) showed global hypomethylation and CpG island (CGI) hypermethylation of primary tumours compared to normal. In metastasis we observed high global and non-CGI regions methylation, but lower CGI methylation, compared to primary tumours. Gene ontology analysis showed shared biological processes between hypermethylated CGIs in metastasis and primary tumours. After complementary analysis with The Cancer Genome Atlas (TCGA) cohort, FIGN, HTRA3, BDNF, HCN4 and STAC2 genes were found associated with poor survival. We mapped the methylation landscape of colon normal tissues, primary tumours and lymph node metastasis, being capable of identified methylation changes throughout the genome. Furthermore, we found five genes with potential for methylation biomarkers of poor prognosis in colorectal cancer patients
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