The modern math movement(s): an essay on how elementary school teachers in Brazil gave meaning to it

The main goal of this paper is to discuss the production of meaning of the Modern Math Movement. The main sources were data available in school archives and interviews with former teachers that we use in order to focus on the diversity of perspectives -that complement it or oppose it-, which comes up when teachers refer to the Movement. Using this process of signification, teachers whether accept it, invalidate it or adapt it to guidelines imposed to them in their teaching activities. We establish a methodology by following the premises of Oral History to gather oral testimonies. The theoretical foundations in which this article is written are the guidelines of Paul Ricoeur's Hermeneutics, John Thompson's Depth Hermeneutics and Bolivar's narrative analysis.

Investigation of the effect of movement and irrigation systems on temperature in the conventional drilling of cortical bone

We have compared the results of the external irrigation technique with those of a double irrigation technique with continuous intermittent movement. Maximum thermal measurements were made in the cortical part of 10 samples of bovine ribs during osteotomy to simulate the preparation of a surgical bed for the installation of dental implants at a depth of 10 mm Twenty specimens were drilled for each group: external irrigation and continuous movement (control group 1, CG1); external irrigation and intermittent movement (control group 2, CG2); double irrigation and continuous movement (test group 1, TG1); and double irrigation and intermittent movement (test group 2, TG2). The double irrigation technique gave significantly better results regardless of the drilling movement used. Thermal increases between samples was 19.2% in group CG1, 10.4% in CG2, 5.4% in TG1, and 3.4% in TG2. The double irrigation technique produced a significantly smaller increase in temperature in the cortical bone during both types of drilling (p = 0.001), which illustrated its greater efficiency compared with that of the external irrigation technique. (C) 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Reproductive migration of fish and movement in a series of reservoirs in the Upper Parana River basin, Brazil

AbstractThis study evaluates the effectiveness of two fish passes at two hydropower dams (Canoas I and II) in the Upper Parana basin, which form part of a cascade of three reservoirs. Fish from 12 migratory species (3089 specimens) were captured during their ascending, reproductive migration and were tagged with hydrostatic tags. The recapture data (294 specimens over two consecutive years) showed that there is a strong tendency for the maintenance of ascending migration through reservoirs with fish passes but with differences in migratory activity within the same species. No eggs, larvae or juveniles of these species were found in samples collected over 5 years in the reservoirs above the fish passes. These data suggest that fish passes have contributed to the restoration of the migratory routes of adult fish but that in the absence of suitable spawning or nursery habitats for these species; they probably act as ecological traps and do not contribute to the recruitment of the species.

Finite-time synchronization of tunnel-diode-based chaotic oscillators

This paper addresses the problem of finite-time synchronization of tunnel diode based chaotic oscillators. After a brief investigation of its chaotic dynamics, we propose an active adaptive feedback coupling which accomplishes the synchronization of tunnel-diode-based chaotic systems with and without the presence of delay(s), basing ourselves on Lyapunov and on Krasovskii-Lyapunov stability theories. This feedback coupling could be applied to many other chaotic systems. A finite horizon can be arbitrarily established by ensuring that chaos synchronization is achieved at a pre-established time. An advantage of the proposed feedback coupling is that it is simple and easy to implement. Both mathematical investigations and numerical simulations followed by PSPICE experiment are presented to show the feasibility of the proposed method.

A family of dissipative two-dimensional mappings: Chaotic, regular and steady state dynamics investigation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phase space properties and chaotic transport for a particle moving in a time dependent step potential well

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The importance of sensing one's movement in the world for the sense of personal identity

Within philosophy and cognitive science, the focus in relation to the problem of personal identity has been almost exclusively on the brain. We submit that the resulting neglect of the body and of bodily movements in the world has been detrimental in understanding how organisms develop a sense of identity. We examine the importance of sensing one’s own movements for the development of a basic, nonconceptual sense of self. More specifically, we argue that the origin of the sense of self stems from the sensitivity to spontaneous movements. Based on this, the organism develops a sense of “I move” and, finally, a sense of “I can move”. Proprioception and kinesthesis are essential in this development. At the same time, we argue against the traditional dichotomy between so-called external and internal senses, agreeing with Gibson that perception of the self and of the environment invariably go together. We discuss a traditional distinction between two aspects of bodily self: the body sense and the body image. We suggest that they capture different aspects of the sense of self. We argue that especially the body sense is of great importance to our nonconceptual sense of self. Finally, we attempt to draw some consequences for research in cognitive science, specifically in the area of robotics, by examining a case of missing proprioception. We make a plea for robots to be equipped not just with external perceptual and motor abilities but also with a sense of proprioception. This, we submit, would constitute one further step towards understanding creatures acting in the world with a sense of themselves.

Nonlinear control in an electromechanical transducer with chaotic behaviour

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Heterorhabditis amazonensis RSC5 (Rhabditida: Heterorhabditidae) movement and host recognition

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chaotic planar piecewise smooth vector fields with non-trivial minimal sets

In this paper some aspects on chaotic behavior and minimality in planar piecewise smooth vector fields theory are treated. The occurrence of non-deterministic chaos is observed and the concept of orientable minimality is introduced. Some relations between minimality and orientable minimality are also investigated and the existence of new kinds of non-trivial minimal sets in chaotic systems is observed. The approach is geometrical and involves the ordinary techniques of non-smooth systems.

Otimizando vibrações sísmicas em estruturas através de controles híbridos

Pós-graduação em Engenharia Mecânica - FEIS

Cuspal movement related to different polymerization protocols

Objective: The aim of this study to investigate the effects of different polymerization protocols on the cuspal movement in class II composite restorations. Materials and methods: Human premolar teeth were prepared with class II cavities and then restored with composite and three-step and two-step etch-and-rinse adhesive systems under different curing techniques (n = 10). It was used a lightemittingdiode curing unit and the mode of polymerization were: standard (exposure for 40 seconds at 700 mW/cm2), pulse-delay (initial exposure for 6 seconds at 350 mW/cm2 followed by a resting period of 3 minutes and a final exposure of 37 seconds at 700 mW/cm2) and soft-start curing (exposure 10 seconds at 350 mW/cm2 and 35 seconds at 700 mW/cm2). The cuspal distance (µm) was measured before and after the restorative procedure and the difference was recorded as cuspal movement. The data were submitted to two-way ANOVA and Bonferroni test (p < 0.05). Results: The type of adhesive system did not influenced the cuspal movement for all the curing methods. Standard protocol showed the highest values of cuspal movement and was statistically different from the pulse-delay and soft-start curing modes. Conclusion: Although the cuspal displacement was not completely avoided, alternative methods of photocuring should be considered to minimize the clinical consequences of composites contraction stress.

Effect of alendronate sodium on tooth movement in ovariectomized rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of mesenchymal stem cells on movement and urination of rats with spinal cord injury

Cell therapy has frequently been reported as a possible treatment for spinal trauma in humans and animals; however, without pharmacologically curative action on damage from the primary lesion. In this study, we evaluated the effect of administering human adipose-derived stem cells (hADSC) in rats after spinal cord injury. The hADSC were used between the third and fifth passages and a proportion of cells were transduced for screening in vivo after transplantation. Spinal cord injury was induced with a Fogarty catheter no. 3 inserted into the epidural space with a cuff located at T8 and filled with 80 mu L saline for 5 min. The control group A (n = 12) received culture medium (50 mu L) and group B (n = 12) received hADSC (1.2 x 10(6)) at 7 and 14 days post-injury, in the tail vein. Emptying of the bladder by massage was performed daily for 3 months. Evaluation of functional motor activity was performed daily until 3 months post-injury using the Basso-Beattie-Bresnahan scale. Subsequently, the animals were euthanized and histological analysis of the urinary bladder and spinal cord was performed. Bioluminescence analysis revealed hADSC at the application site and lungs. There was improvement of urinary bladder function in 83.3% animals in group B and 16.66% animals in group A. The analysis of functional motor activity and histology of the spinal cord and urinary bladder demonstrated no significant difference between groups A and B. The results indicate that transplanted hADSC improved urinary function via a telecrine mechanism, namely action at a distance.

Risk evaluation of diabetes mellitus by relation of chaotic globals to HRV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)