363 research outputs found
As relações de equivalência como critério de análise da pertinência científica de categorias analíticas
El objetivo del presente trabajo es proponer las relaciones de equivalencia como criterio estructural o de ordenamiento analítico mediante el cual se puedan delimitar las funciones del conocimiento requeridas en una actividad científica. Se parte de considerar al conocimiento como un fenómeno estudiado por la psicología y cuya explicación requiere de dar cuenta de la manera en que se establecen, organizan y actualizan las funciones conductuales o del conocimiento. De este modo, se considera que las tareas de igualación a la muestra permiten comprender el modo de abstraer las categorías analíticas que estructuran científicamente el conocimiento de la realidad. Cuando se usan estos procedimiento, se derivan nuevas relaciones sin la necesidad de un entrenamiento directo y que no pueden explicarse con base en principios de generalización de estímulos, sino, más bien, como relaciones equivalentes diferenciadas mediante los entrenamientos previos y que adquieren un cierre en una categoría analítica cuando se abstraen los criterios categoriales o, si se quiere, cuando estas relaciones se nominan. Así, al categorizarse o nominarse, estas trascienden la situación -porque nominar se entiende como un ajuste a criterios convencionales- y una vez que las interacciones situacionales se nominan, regulan todas las prácticas sociales, incluidas las prácticas del conocimiento científico.O objetivo deste trabalho é propor as relações de equivalência como critério estrutural ou de ordenamento analítico pelo qual possam ser delimitadas as funções do conhecimento requeridas numa atividade científica. Parte-se de considerar o conhecimento como um fenômeno estudado pela psicologia e cuja explicação requer evidenciar a maneira na qual são estabelecidas, organizadas e atualizadas as funções comportamentais ou do conhecimento. Desse modo, considera-se que as tarefas de igualação à amostra permitem compreender o modo de abstrair as categorias analíticas que estruturam cientificamente o conhecimento da realidade. Quando são usados esses procedimentos, são derivadas novas relações que, sem a necessidade de um treinamento direto, não podem ser explicadas com base em princípios de generalização de estímulos, mas sim como relações equivalentes diferenciadas mediante os treinamentos prévios e que adquirem uma delimitação numa categoria analítica quando são abstraídos os critérios categoriais ou, se se quiser, quando essas relações são nominadas. Assim, ao serem categorizadas ou nominadas, elas transcendem a situação -porque nominar se entende como um ajuste a critérios convencionais- e, uma vez que as interações situacionais são nominadas, regulam todas as práticas sociais, incluídas as práticas do conhecimento científico.The aim of this paper is to propose equivalence relations as a structural criterion or analytical order, through which the functions of knowledge required in a scientific activity are delimited. It begins by considering knowledge as a phenomenon studied by psychology, whose explanation requires giving an account of the way in which such behavioral or knowledge functions are established, organized and updated. It is considered that the procedures of matching-to-sample allow understanding the way of abstracting the analytical categories that scientifically structure the knowledge of reality. When using these procedures, new relationships are derived that without the need for direct training, cannot be explained based on principles of stimulus generalization, but rather as equivalent relations differentiated through previous training. They get a closure in an analytical category, once the categorical criteria are abstracted or if desired, when these relationships are nominated. And when categorized or nominated, they transcend the situation, since nominating is understood as an adjustment to conventional criteria. Once situational interactions are nominated, they regulate all social practices, including practices of scientific knowledge
La evolución de la agrometeorología hacia el siglo XXI
En la presente comunicación se analiza el desarrollo de la agrometeorología como ciencia, sus aplicaciones y evolución actual.Academia Nacional de Agronomía y Veterinari
Shock compression and spallation of single crystal tantalum
We present molecular dynamics simulations of shock-induced plasticity and spall damage in single crystal Ta described by a recently developed embedded-atom-method (EAM) potential and a volumedependent qEAM potential. We use impact or Hugoniotstat simulations to investigate the Hugoniots, deformation and spallation. Both EAM and qEAM are accurate in predicting, e.g., the Hugoniots and γ - surfaces. Deformation and spall damage are anisotropic for Ta single crystals. Our preliminary results show that twinning is dominant for [100] and [110] shock loading, and dislocation, for [111]. Spallation initiates with void nucleation at defective sites from remnant compressional deformation or tensile plasticity. Spall strength decreases with increasing shock strength, while its rate dependence remains to be explored
La evolución de la agrometeorología hacia el siglo XXI
En la presente comunicación se analiza el desarrollo de la agrometeorología como ciencia, sus aplicaciones y evolución actual.Academia Nacional de Agronomía y Veterinari
Large-scale molecular dynamics simulations of shock induced plasticity in tantalum single crystals
We report on large-scale non-equilibrium molecular dynamics (NEMD) simulations of shock wave compression in Ta single crystals. The atomic interactions are modeled via a recently developed and optimized embedded-atom method (EAM) potential for Ta, which reproduces the equation of state up to 200 GPa. We examined the elastic-plastic transition and shock wave structure for wave propagation along the low index directions: (100), (110) and (111). Shock waves along (100) and (111) exhibit an elastic precursor followed by a plastic wave for particle velocities below 1.1 km/s for (100) and 1.4 km/s for (111). The nature of the plastic deformation along (110) is dominated by twinning for pressures above 41 GPa
El rol del editor y la visibilidad del conocimiento en las publicaciones científicas seriadas
Investigation of correlations between clinical signs and pathological findings in cats and dogs with inflammatory bowel disease
This paper compares the correlation between the clinical signs and the histopathological observations of the entire intestine in cats and dogs with inflammatory bowel disease (IBD). To perform this study, hospital records of 53 dogs and 20 cats of different sex, ages, and breed diagnosed with IBD following the histopathological criteria of the World Small Animal Veterinary Association (WSAVA) were evaluated. The results obtained in this study did show correlations between some clinical signs and the histopathological assessment of dogs and cats with IBD. Therefore, a slight association between diarrhea and lacteal dilation in the small bowel, and diarrhea and desquamation in the large bowel of dogs with IBD was seen, but no other associations were found between the rest of the lesions and symptoms. In contrast, cats only showed a correlation between anorexia with villous stunting and villous epithelial injury, without correspondence among other clinical signs and lesions. The results of this study propose that the evaluation of IBD can be complicated, especially with the use of retrospective records of archived intestinal biopsies and subjective clinical and histopathologic decisions
Design and validation of a tool to assess motor coordination in primary
La coordinación motriz es un proceso evolutivo complejo de adquisición progresiva. La edad óptima para la adquisición de esos procesos coordinativos es de 6 a 11 años (Educación Primaria). El objetivo del presente estudio es diseñar y validar un instrumento que permita evaluar el nivel de coordinación motriz del alumnado
Método: Los sujetos son alumnado de Primaria en centros públicos. Muestreo por conveniencia, con una muestra total de 2512 sujetos. Instrumento: Test cualitativo de observación y evaluación objetiva de la ejecución de la habilidad desarrollada en 7 tareas.
Resultados: La Consistencia interna (Alfa de Cronbach 0.827), estabilidad temporal (coeficiente correlación: 0.99) y concordancia inter-observadores (coeficiente correlación: 0.95). La validez se comprobó mediante la opinión intuitiva de expertos, siendo la opinión mayoritariamente favorable.
Conclusión: El test 3JS es un instrumento fiable, válido y eficaz para medir el desarrollo de la coordinación motriz en el alumnado de 6 a 12 añosMotor coordination is a complex evolutionary process which is gradually acquired. The optimum age for the achievement of these coordination processes is between 6 and 11 years old (Primary Education).
The aim of this study is to design and validate a tool which will allow assessing the motor coordination level of the students.
Method: Subjects and Sample. Students from Primary Education public schools. ‘Convenience’ sampling, with a total of 2512 subjects.
Tool: Qualitative observation test and objective evaluation of the implementation of the abilities developed in 7 tasks.
Results: Reliability: Internal Consistency (Cronbach Alpha 0.827), test-retest reliability (correlation coefficient; 0.99) and inter-observer agreement (correlation coefficient; 0.95). Validity has been verified by the experts’ intuitive perception, issuing a largely favourable opinion.
Conclusion: The 3JS test is a reliable, valid and effective tool for measuring the motor coordination development in students between 6 and 12 years ol
Shock-induced plasticity in nanocrystalline iron: Large-scale molecular dynamics simulations
Large-scale nonequilibrium molecular dynamics (MD) simulations of shock waves in nanocrystalline iron show evidence of plasticity before the polymorphic transformation takes place. The atomistic structure in the shock direction shows an elastic precursor, plastic deformation, and shock-induced phase transformation from bcc to hcp iron. In this Rapid Communication, large-scale MD models show that the shock response of iron is highly related to the ramp time of the applied shocks. For long ramp times we observe significant plastic relaxation and formation of microstructure defects. Pressure-induced phase transformations in iron are accompanied by stress relaxation achieving almost fully relaxed three-dimensional hydrostatic final states. The evolution of the stress relaxation is in agreement with theory and experiments. Analysis of the x-ray diffraction patterns calculated from the atomistic structure using the Debye equation revealed pronounced anisotropy of the line broadening that is caused by stacking faults in hcp Fe and by dislocations in bcc Fe.Fil: Luu, Hoang Thien. Clausthal University of Applied Technology; AlemaniaFil: Ravelo, Ramón. University of Texas at El Paso; Estados UnidosFil: Rudolph, Martin. TU Bergakademie Freiberg; AlemaniaFil: Bringa, Eduardo Marcial. Universidad de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Germann, Timothy C.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Rafaja, David. TU Bergakademie Freiberg; AlemaniaFil: Gunkelmann, Nina. Clausthal University of Applied Technology; Alemani
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