Comparing Teaching Approaches About Maxwell’s Displacement Current     

Ricardo Karam  Debora Coimbra  Maurício Pietrocola 《Science & Education》2014,23(8):1637-1661

Due to its fundamental role for the consolidation of Maxwell’s equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory–experiment relationship). Despite the consensus among physics educators concerning the relevance of the topic, there are many possible ways to interpret and justify the need for the displacement current term. With the goal of understanding the didactical transposition of this topic more deeply, we investigate three of its domains: (1) The historical development of Maxwell’s reasoning; (2) Different approaches to justify the term insertion in physics textbooks; and (3) Four lectures devoted to introduce the topic in undergraduate level given by four different professors. By reflecting on the differences between these three domains, significant evidence for the knowledge transformation caused by the didactization of this episode is provided. The main purpose of this comparative analysis is to assist physics educators in developing an epistemological surveillance regarding the teaching and learning of the displacement current.  相似文献   

Safety and Efficacy of Mobility Interventions in Patients with Femoral Catheters in the ICU: A Prospective Observational Study     

Christiane Perme  Theresa Nalty  Chris Winkelman  Ricardo Kenji Nawa  Faisal Masud 《Cardiopulmonary Physical Therapy Journal》2013,24(2):12-17

Introduction

There are limited data describing mobility interventions provided to patients with femoral catheters. The purpose of this study was to examine the incidence of femoral catheter related adverse effects during physical therapy (PT) sessions in a cardiovascular intensive care unit (ICU).

Methods

This was a prospective, observational study and included patients with at least one femoral catheter. Data were collected after each PT session.

Results

There were 77 subjects with a total of 92 femoral catheters (50 arterial, 15 central venous, and 27 dialysis) treated. A total of 210 separate PT sessions occurred with 630 mobility activities including sitting on side of bed, standing at the bedside, transfers to stretcher chair or regular chair, and walking. There were no catheter related mechanical or thrombotic complications during any of the PT sessions.

Conclusions

Physical therapy sessions, including standing and walking were feasible and safe in cardiovascular ICU patients with femoral catheters who met the criteria for mobility interventions. The results from this study support the hypothesis that early mobilization in patients with femoral catheters is important to minimize functional decline and provide evidence that the presence of femoral catheters alone should not be a reason to limit progressive mobility interventions.Key Words: physical therapy, ICU, early mobilization, femoral catheter  相似文献   

Effect of different inter-repetition rest intervals across four load intensities on velocity loss and blood lactate concentration during full squat exercise     

Ricardo Mora-Custodio  David Rodríguez-Rosell  Juan Manuel Yáñez-García  Miguel Sánchez-Moreno  Fernando Pareja-Blanco  Juan José González-Badillo 《Journal of sports sciences》2013,31(24):2856-2864

ABSTRACT

This study aimed to analyze the acute effect of inter-repetition rest (IRR) intervals on mechanical and metabolic response during four resistance exercise protocols (REPs). Thirty resistance-trained men were randomly assigned to: continuous repetitions (CR), 10 s (IRR10) or 20 s (IRR20) inter-repetition rest. The REPs consisted of 3 sets of 6, 5, 4 and 3 repetitions against 60, 70, 75 and 80% 1RM, respectively, in the full squat exercise. Muscle fatigue was assessed using: percentage of velocity loss over three sets, percentage of velocity loss against the ~1 m·s^?1 load (V1 m·s^?1), and loss of countermovement jump (CMJ) height pre-post exercise. Blood lactate was measured before and after exercise. The percentage of velocity loss over three sets and lactate concentration were significantly lower (P < 0.05) for IRR groups compared to CR in all REPs. The CR group showed a significantly higher (P < 0.05) velocity loss against V1 m·s^?1 load and loss of CMJ height pre-post exercise than IRR groups in REP against 60% 1RM. In conclusion, both IRR groups produced a significant lower degree of fatigue compared to CR group. However, no significant differences were found in any measured variables between IRR configurations.  相似文献   

Cognitive Neuroscience Perspectives on Motivation and Learning: Revisiting Self‐Determination Theory     

Ela Luria  Maya Shalom  Daniel A. Levy 《Mind, Brain, and Education》2021,15(1):5-17

The Self‐Determination Theory of motivation (SDT) has significantly guided educational policy and research. It maintains that learning succeeds when brought about by autonomous rather than controlled motivation, and that extrinsic reward motivation cannot engender effective learning. We present an alternative approach, rooted in recent insights from the neurobiology of memory. In exploring environments to reap rewards, people pursue interrogative goals, accompanied by dopamine‐based hippocampus activation, leading to the formation of rich relational memories. In contrast, seeking to avoid punishment or loss involves imperative goals, with amygdala activation driving the perirhinal cortex to form disjoint item memories. We suggest that structuring learning and evaluation to diminish failure and increase repeated opportunities for successful performance, as in gamification, may engender effective learning incorporating broad perspectives and rich associations. This may occur even in the absence of intrinsic motivation to master a particular subject. Employing this insight in instructional design may benefit many educational frameworks.  相似文献   

The Evolutionary Thought of Jean-Baptiste Lamarck     

Noguera-Solano  Ricardo  Rodríguez-Caso  Juan Manuel  Ruiz-Gutiérrez  Rosaura 《Science & Education》2021,30(4):909-929

Science & Education - The name Lamarck is very well known in the teaching of biology, being associated with an early effort to explain evolution. Nevertheless, when evolution is taught in the...  相似文献   

Facilitating Grounded Online Interactions in Video-Case-Based Teacher Professional Development     

Nemirovsky  Ricardo  Galvis  Alvaro 《Journal of Science Education and Technology》2004,13(1):67-79

The use of interactive video cases for teacher professional development is an emergent medium inspired by case study methods used extensively in law, management, and medicine, and by the advent of multimedia technology available to support online discussions. This paper focuses on Web-based grounded discussions—in which the participants base their contributions on specific events portrayed in the case—and the role facilitators play in these online interactions. This paper analyzes the online exchange of messages in one school district that participated in a video-case-based program of teacher professional development and derives principles that will help facilitators lead grounded online interactions.  相似文献   

On Mathematical Visualization and the Place Where We Live     

Ricardo Nemirovsky  Tracy Noble 《Educational Studies in Mathematics》1997,33(2):99-131

This paper is a case study of how a high school student, whom we call Karen, used a computer-based tool, the Contour Analyzer, to create graphs of height vs. distance and slope vs. distance for a flat board that she positioned with different slants and orientations. With the Contour Analyzer one can generate, on a computer screen, graphs representing functions of height and slope vs. distance corresponding to a line traced along the surface of a real object. Karen was interviewed for three one-hour sessions in an individual teaching experiment. In this paper, our focus is on how Karen came to recognize by visual inspection the mathematical behavior of the slope vs. distance function corresponding to contours traced on a flat board. Karen strove to organize her visual experience by distinguishing which aspects of the board are to be noticed and which ones are to be ignored, as well as by determining the point of view that one should adopt in order to see the variation of slope along an object. We have found it inspiring to use Winnicott's (1971) ideas about transitional objects to examine the role of the graphing instrument for Karen. This theoretical background helped us to articulate a perspective on mathematical visualization that goes beyond the dualism between internal and external representations frequently assumed in the literature, and focuses on the lived-in space that Karen experienced which encompassed at once physical attributes of the tool and human possibilities of action.This revised version was published online in September 2005 with corrections to the Cover Date.  相似文献   

Field dimension and skill level constrain team tactical behaviours in small-sided and conditioned games in football     

Pedro Silva  Ricardo Duarte  Jaime Sampaio  Paulo Aguiar  Keith Davids  Duarte Araújo 《Journal of sports sciences》2014,32(20):1888-1896

Abstract

This study analysed the influence of field dimension and players’ skill level on collective tactical behaviours during small-sided and conditioned games (SSCGs). Positioning and displacement data were collected using global positioning systems (15 Hz) during SSCGs (Gk+4 v. 4+Gk) played by two groups of participants (NLP- national-level and RLP-regional-level players) on different field dimensions (small: 36.8 × 23.8 m; intermediate: 47.3 × 30.6 and large: 57.8 × 37.4 m). Team tactical performance was assessed through established dynamic team variables (effective playing space, playing length per width ratio and team separateness) and nonlinear signal processing techniques (sample entropy of distances to nearest opponents and the teams’ centroids’ mutual information). Results showed that the effective playing space and team separateness increased significantly with pitch size regardless of participant skill level (P < 0.001, η² = 0.78 and P < 0.001, η² = 0.65, respectively). Playing length per width ratio increased with pitch size for the NLP but was maintained at a relatively constant level by RLP across treatments indicating different playing shapes. There was significantly more irregularity in distances to nearest opponents for the NLP in small (P = 0.003) and intermediate fields (P = 0.01). Findings suggest that tactical behaviours in SSCGs are constrained by field size and skill level, which need to be considered by coaches when designing training practices.  相似文献