Body Mass Index: A Scientific Evidence-Based Inquiry

OBJECTVE: To objectively and critically assess body mass index and to propose alternatives for relating body weight and height that are evidence-based and that eliminate or reduce the limitations of the body mass index. METHODS: To analyze the relations involving weight and height, we used 2 databases as follows: 1) children and adolescents from Brazil, the United States, and Switzerland; and 2) 538 university students. We performed mathematical simulations with height data ranging from 115 to 190 cm and weight data ranging from 25 to 105 kg. We selected 3 methods to analyze the relation of weight and height as follows: body mass index - weight (kg)/height (m²); reciprocal of the ponderal index - height (cm)/weight1/3 (kg); and ectomorphy. Using the normal range from 20 to 25 kg/m² for the body mass index in the reference height of 170 cm, we identified the corresponding ranges of 41 to 44 cm/kg1/3 for the reciprocal of the ponderal index, and of 1.45 to 3.60 for ectomorphy. RESULTS: The mathematical simulations showed a strong association among the 3 methods with an absolute concordance to a height of 170 cm, but with a tendency towards discrepancy in the normal ranges, which had already been observed for the heights of 165 and 175 cm. This made the direct convertibility between the indices unfeasible. The reciprocal of the ponderal index and ectomorphy with their cut points comprised a larger age range in children and adolescents and a wider and more central range in the university students, both for the reported (current) and desired weights. CONCLUSION: The reciprocal of the ponderal index and ectomorphy are stronger and are more mathematically logical than body mass index; in addition, they may be applied with the same cut points for normal from the age of 5 ½ years on.

Para além das fronteiras da química: relações entre filosofia, psicologia e ensino de química

The concepts of molecule and of molecular structure are so central to understand chemical phenomena that seems to be no doubt about the uniqueness of its meanings. Nevertheless, the idea that the world exhibits a multiform structure and that to different spheres of the world correspond different ways of knowing (Berger & Luckmann, 1967) has received support from different areas of scientific inquiry. Bachelard (1940, 1982) showed that a single philosophical doctrine is not enough to describe all the different ways of thinking when we try to explain a single concept. Wooley's question about the possibility of deducing the concept of molecular structure from quantum theory (Wooley, 1978) strengthened the feasibility of thinking the concept of molecule as a profile that encompasses different meanings. Moreover, research on students' learning of scientific concepts have brought to light that students use several ideas to explain scientific and everyday phenomena which are different from those learned in formal schooling. These ideas are not extinguished or replaced by scientific concepts, despite the efforts to do so in science classes. The common sense and scientific ways of understanding and talking about reality seems to be complementary in the same sense of the Bohr's complementarity (Halliday & Martin, 1993). So, we have to include in our profile of the concept of molecule not only scientific but also common sense zones. Drawing from Bachelard's notion of epistemological profile, from the history of science and from the research on children's ideas in science, we have developed the idea of a conceptual profile and used it to analyse basic scientific concepts, such as the concepts of matter and physical states of matter (Mortimer, 1995) and to investigate new ways to teach them. In the present paper, we will discuss the zones that might constitute a conceptual profile of molecule. The need of complementary views to account for the molecular structure in different contexts bring important issues for understanding and teaching chemistry, which will be discussed further in the article.

Laboratory projects using inquiry-based learning: an application to a practical inorganic course

This paper reports how laboratory projects (LP) coupled to inquiry-based learning (IBL) were implemented in a practical inorganic chemistry course. Several coordination compounds have been successfully synthesised by students according to the proposed topics by the LP-IBL junction, and the chemistry of a number of metals has been studied. Qualitative data were collected from written reports, oral presentations, lab-notebook reviews and personal discussions with the students through an experimental course with undergraduate second-year students at the Universidad Nacional de Colombia during the last 5 years. Positive skills production was observed by combining LP and IBL. Conceptual, practical, interpretational, constructional (questions, explanations, hypotheses), communicational, environmental and application abilities were revealed by the students throughout the experimental course.

Dinâmicas de inquiry no estudo de perturbações a um estado de equilíbrio químico

Educational institutions are not being effective, because they do not give individuals what they need to integrate into postmodern society, nor produce citizens that postmodern society needs. Shortcomings include the scientific literacy and cognitive domain levels attained, with an aggravating waning interest in science among pre-university students. We present an inquiry module, an inquiry dynamic, as an education resource for the study of perturbations of a chemical equilibrium state by pre-university or university students of basic chemistry, to contribute to the relevance and popularity of science, potentiation of science literacy and development of cognition. Here we describe an investigation with pre-university students.

THE SKEPTICAL CARTESIAN BACKGROUND OF HUME'S "OF THE ACADEMICAL OR SCEPTICAL PHILOSOPHY" (FIRST INQUIRY, SECTION 12)

ABSTRACT In section XII of the First Inquiry, Hume refers to the two Hellenistic schools of skepticism (Academic and Pyrrhonian) to present his own view of skepticism, which, however, depends on the ancient skeptics mainly indirectly. Hume's view of skepticism depends crucially on Descartes and post-Cartesian philosophers such as Pascal, Huet, Foucher and Bayle, who reacted skeptically to major Cartesian doctrines but followed one version or other of Descartes's methodical doubt. Although all these post-Cartesian philosophers are relevant in section XII, I focus on the topics in which Descartes himself-besides his skeptical followers-seems directly relevant. After an introductory section (I) on Julia Annas' and Richard Popkin's views of Hume's relation to, respectively, ancient and modern skepticism, I turn to section XII and examine what Hume calls (II) "consequent skepticism about the senses," (III) "antecedent skepticism," and (IV) "Academic skepticism."

Escaping the flybottle: solipsism and method in Wittgenstein's Philosophical Remarks

The paper supports a dialectical interpretation of Wittgenstein's method focusing on the analysis of the conditions of experience presented in his Philosophical Remarks. By means of a close reading of some key passages dealing with solipsism I will try to lay bare their self-subverting character: the fact that they amount to miniature dialectical exercises offering specific directions to pass from particular pieces of disguised nonsense to corresponding pieces of patent nonsense. Yet, in order to follow those directions one needs to allow oneself to become simultaneously tempted by and suspicious of their all-too-evident "metaphysical tone" - a tone which, as we shall see, is particularly manifest in those claims purporting to state what can or cannot be the case, and, still more particularly, those purporting to state what can or cannot be done in language or thought, thus leading to the view that there are some (determinate) things which are ineffable or unthinkable. I conclude by suggesting that in writing those remarks Wittgenstein was still moved by an ethical project, which gets conspicuously displayed in these reiterations of his attempts to cure the readers (and himself) from some of the temptations expressed by solipsism.

TOWARDS A PHILOSOPHICAL UNDERSTANDING OF THE LOGICS OF FORMAL INCONSISTENCY

Abstract In this paper we present a philosophical motivation for the logics of formal inconsistency , a family of paraconsistent logics whose distinctive feature is that of having resources for expressing the notion of consistency within the object language in such a way that consistency may be logically independent of non-contradiction. We defend the view according to which logics of formal inconsistency may be interpreted as theories of logical consequence of an epistemological character. We also argue that in order to philosophically justify paraconsistency there is no need to endorse dialetheism, the thesis that there are true contradictions. Furthermore, we show that mbC , a logic of formal inconsistency based on classical logic, may be enhanced in order to express the basic ideas of an intuitive interpretation of contradictions as conflicting evidence.

A Critical Analysis of the Philosophical-Political Element of the Master-Slave Dialectic

ABSTRACT:The section “Lordship and Bondage” in Hegel’s Phenomenology of Spirit offers us, through the criticism of slavery, some indications regarding Hegel’s conception of human nature. In this paper some consequences of this conception for Hegel’s political philosophy are identified and presented. The analysis shows problems may emerge when we analyze some fundamental Hegelian concepts – “recognition” and shows that some “men” – if we take into consideration the way these concepts were defined in the master-slave dialectic. In light of these problems it is pointed out that Hegel’s political philosophy, and also his position regarding slavery, become less cogent and more susceptible to criticism. The last part of the text analyzes some consequences of problems related to the possibility of defining the concepts “recognition” and “men” in terms of Hegel’s model of state.