Construcción del concepto múltiplo común en el dominio de los números naturales

El objetivo de esta investigación fue caracterizar el proceso de construcción del concepto de múltiplo común de dos números naturales como parte del esquema de divisibilidad en estudiantes de educación secundaria. A partir de un análisis cualitativo de entrevistas clínicas en las que los estudiantes resolvían y justificaban su proceso de resolución de un problema, identificamos dos momentos cognitivos en el proceso constructivo del concepto de múltiplo común generado durante la resolución del problema. Estos momentos fueron caracterizados teniendo en cuenta cómo los estudiantes generaban casos particulares y coordinaban o no la información procedente de éstos. Esta caracterización proporciona información sobre cómo los estudiantes empiezan a concebir que un número pueda adoptar diferentes papeles en las relaciones multiplicativas del esquema de divisibilidad como parte constituyente del aprendizaje de los números.The purpose of this research was to characterize the construction process of common multiple of two whole numbers as a part of divisibility scheme in Secondary School students. From the analysis of clinical interviews with Secondary School students when solving a word-problem and justifying their decisions, we identify two cognitive moments in the constructive process generated in some cases in the context of problem solving. These cognitive moments were characterized regarding how students generated particular cases and were or were not able to coordinate the information arising from them. The characterization provides us with information about the way in which students begin to conceive that a number can play different roles in the divisibility scheme

Habitatge buit i altres situacions anòmales del Parc d'habitatge: diagnosi i estratègies d'actuació: el cas de Molins de Rei: pla de treball

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Habitatge buit i altres situacions anòmales del Parc d'habitatge: diagnosi i estratègies d'actuació: el cas de Molins de Rei. Part I: Infrahabitatge

Preprin

Habitatge buit i altres situacions anòmales del Parc d'habitatge: diagnosi i estratègies d'actuació: el cas de Molins de Rei. Part II: Parc vacant

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Habitatge buit i altres situacions anòmales del Parc d'habitatge: diagnosi i estratègies d'actuació: el cas de Molins de Rei. Part III: Parc sobreocupació

Preprin

A configurational approach to innovation performance: The role of creativity

In this study, we analyze new ways of conceptualizing improvements in firms’ innovation by implementing the “right-factors configuration,” illustrated through an analog of a recipe and its ingredients. Specifically, we research the multiple combinations of three ingredients (creativity, innovation networks, and resources) required to accomplish the innovation recipe. Using a sample of firms from a Spanish science and technology park, we apply qualitative comparative analysis (QCA)—specifically, fuzzy-set QCA (fsQCA)—to test the importance of each component in technological and non-technological innovation. First, the results suggest a map of combinations of innovative ingredients with eight possible patterns. Second, they show that the only ingredient needed is the combination of a creative climate and creative intensity. Finally, the methods of obtaining technological and non-technological innovations differ. The implications for management and policymakers are discussed, and directions for future research are highlighted

Failure of ProTaper rotary Ni-Ti instruments used by undergraduate students

Objective: To evaluate the effect of number of uses, angle and radius of curvature and type of instrument on the fracture of ProTaper rotary instruments when used by undergraduate students. Study design: Three hundred and seventy-six molars, with a total of 1114 root canals, extracted were instrumented by undergraduate students using ProTaper instruments according to the manufacturer´s recommendations. When fracture occurred, data were collected concerning the number of uses, type of instrument, level of fracture, angle and radius of curvature. ANOVA test were used to determine the influence of type of instrument in the incidence of instrument fracture. Logistic regression model was used to determine the influence of number of uses, angle and radius of curvature in the incidence of instrument fracture. Significance was set at p< 0.05. Results: A total of 37 Ni-Ti rotary instruments fractured during the treatment. Fracture occurred in 9.84% (37/376) of the teeth treated and 3.32% of the canals prepared with Ni-Ti rotary instruments (37/1114). A decrease in the radius of curvature of the canal significantly increased the likelihood of fracture (p=0.0001). Instrument fracture significantly increased as the number of uses increased (p=0.0037). No significant differences were found between the 6 types of ProTaper instruments (p=0.8). A reduction in the angle of curvature did not produce a significant decrease in the incidence of instrument separation (p=0.08). Conclusions: The results of this study imply that instrument fracture is linked to radius of curvature and number of uses

Development and validation of a new methodological platform to measure behavioral, cognitive, and physiological responses to food interventions in real time

To fully understand the causes and mechanisms involved in overeating and obesity, measures of both cognitive and physiological determinants of eating behavior need to be integrated. Effectively synchronizing behavioral measures such as meal micro-structure (e.g., eating speed), cognitive processing of sensory stimuli, and metabolic parameters, can be complex. However, this step is central to understanding the impact of food interventions on body weight. In this paper, we provide an overview of the existing gaps in eating behavior research and describe the development and validation of a new methodological platform to address some of these issues. As part of a controlled trial, 76 men and women self-served and consumed food from a buffet, using a portion-control plate with visual stimuli for appropriate amounts of main food groups, or a conventional plate, on two different days, in a random order. In both sessions participants completed behavioral and cognitive tests using a novel methodological platform that measured gaze movement (as a proxy for visual attention), eating rate and bite size, memory for portion sizes, subjective appetite and portion-size perceptions. In a sub-sample of women, hormonal secretion in response to the meal was also measured. The novel platform showed a significant improvement in meal micro-structure measures from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.85; 90% CI 0.74, 0.92). This trial was registered at Clinical Trials.gov with Identifier NCT03610776. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.3758/s13428-021-01745-9