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.

INFLUENCE OF INFORMATION ABOUT THE BENEFITS OF CONSUMING FRUIT ON CONSUMER PREFERENCES IN TEMUCO, REGION OF THE ARAUCANÍA

ABSTRACT With the aim of identifying strategies to increase fruit consumption in Temuco, consumer segments were classified according to the importance and preference of theattributes type of fruit, package/ brand, benefit associated with fruit consumption and price. A survey was applied to 400 people in Temuco,Chile, distributed using a simple allocation: 200 working adults and 200university students. The questionnaire included the SWFL (Satisfaction with Food-related Life) scale, respondents’ fruit consumption habits and their characteristics. Using conjoint and cluster analyses, three segments were distinguished: Group 1 (22.0%) gave greatest importance to the package/brand and preferred themessage “prevents diseases” and “without information”; Group 2 (47.5%) gave greatest importance to the package/brand and preferred the message “prevents diseases”; Group 3 (30.5%) assigned greatest importance to the price and preferred the message “contains antioxidants”. The segments differed in their level of satisfaction with food-related life, self-declared lifestyle, age and presence of university students. The results provide input to promote fruit consumption in working adults and university students.

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.

Propuesta de un test para determinar el conocimiento conceptual de estudiantes universitarios sobre la constante de equilibrio químico y su aplicación en estudiantes españoles

This article outlines a procedure that was used to develop a written test for evaluating the conceptual knowledge of chemical equilibrium constant among university students. The concepts in the subject matter were carefully defined through propositional statements. Students' understanding of the topic was determined through interviews. These data were used to produce nine multiple choice questions. Each question was designed to identify misconceptions related to the chemical equilibrium constant. The test was evaluated by foure associate professors and was administred to a total of 196 spanish university students. This test has a Cronbach's alpha reliability of 0.63 and its content validity values ranged from 3.7 to 5.

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.

Uso de língua bovina na prática de técnicas de sutura

The authors present a method of teaching of suture techniques being used instrumental surgical and bovine tongue used in the evaluation of the graduation students' learning. The evaluation of the technique, used since January 2000, considering students' motivation, learning curve, practical applicability, quality of the biological material used and similarity to the human tegument. The acceptance for the students was very good and the bovine tongue was shown material of easy acquisition and extremely useful in the teaching of suture techniques. The presented method is simple, easily reproductible and interesting. The bovine tongue is similar to the skin and the subcutaneous tissue, providing more enlightening and stimulants practical lessons.

The control of deliberate waiting strategies in a stop-signal task

To inhibit an ongoing flow of thoughts or actions has been largely considered to be a crucial executive function, and the stop-signal paradigm makes inhibitory control measurable. Stop-signal tasks usually combine two concurrent tasks, i.e., manual responses to a primary task (go-task) are occasionally countermanded by a stimulus which signals participants to inhibit their response in that trial (stop-task). Participants are always instructed not to wait for the stop-signal, since waiting strategies cause the response times to be unstable, invalidating the data. The aim of the present study was to experimentally control the strategies of waiting deliberately for the stop-signal in a stop-task by means of an algorithm that measured the variation in the reaction times to go-stimuli on-line, and displayed a warning legend urging participants to be faster when their reaction times were more than two standard deviations of the mean. Thirty-four university students performed a stop-task with go- and stop-stimuli, both of which were delivered in the visual modality and were lateralized within the visual field. The participants were divided into two groups (group A, without the algorithm, vs group B, with the algorithm). Group B exhibited lower variability of reaction times to go-stimuli, whereas no significant between-group differences were found in any of the measures of inhibitory control, showing that the algorithm succeeded in controlling the deliberate waiting strategies. Differences between deliberate and unintentional waiting strategies, and anxiety as a probable factor responsible for individual differences in deliberate waiting behavior, are discussed.

A high-carbohydrate diet enhances the adverse effect of the S2 allele of APOC3 SstI polymorphism on the TG/HDL-C ratio only in young Chinese females

Both genetic background and diet have profound effects on plasma lipid profiles. We hypothesized that a high-carbohydrate (high-CHO) diet may affect the ratios of serum lipids and apolipoproteins (apo) differently in subjects with different genotypes of the SstI polymorphism in the apoCIII gene (APOC3). Fifty-six healthy university students (27 males and 29 females, 22.89 ± 1.80 years) were given a washout diet of 54% carbohydrate for 7 days, followed by a high-CHO diet of 70% carbohydrate for 6 days without total energy restriction. Serum triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apoB100, apoAI, and the APOC3 SstI polymorphism were analyzed. The ratios of serum lipids and apoB100/apoAI were calculated. At baseline, the TG/HDL-C ratio was significantly higher in females, but not in males, with the S2 allele. The differences in the TG/HDL-C ratio between genotypes remained the same after the washout and the high-CHO diet in females. When compared with those before the high-CHO diet, the TC/HDL-C (male S2 carriers: 3.13 ± 1.00 vs 2.36 ± 0.65, P = 0.000; male subjects with the S1S1 genotype: 2.97 ± 0.74 vs 2.09 ± 0.55, P = 0.000; female S2 carriers: 2.68 ± 0.36 vs 2.24 ± 0.37, P = 0.004; female subjects with the S1S1 genotype: 2.69 ± 0.41 vs 2.09 ± 0.31, P = 0.000) and LDL-C/HDL-C (male S2 carriers: 1.44 ± 0.71 vs 1.06 ± 0.26, P = 0.012; male subjects with the S1S1 genotype: 1.35 ± 0.61 vs 1.01 ± 0.29, P = 0.005; female S2 carriers: 1.18 ± 0.33 vs 1.00 ± 0.18, P = 0.049; female subjects with the S1S1 genotype: 1.18 ± 0.35 vs 1.04 ± 0.19, P = 0.026) ratios were significantly decreased after the high-CHO diet regardless of gender and of genotype of the APOC3 SstI polymorphism. However, in female S2 carriers, the TG/HDL-C (1.38 ± 0.46 vs 1.63 ± 0.70, P = 0.039) ratio was significantly increased after the high-CHO diet. In conclusion, the high-CHO diet has favorable effects on the TC/HDL-C and LDL-C/HDL-C ratios regardless of gender and of genotype of the APOC3 SstI polymorphism. Somehow, it enhanced the adverse effect of the S2 allele on the TG/HDL-C ratio only in females.

Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70% one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R.