Exposições em museus de ciências: reflexões e critérios para análise

Hoje, no que diz respeito à sua interface direta com o público, os museus são considerados, em teoria, instituições com objetivos variados, como educação, lazer, informação e inclusão social. Neste contexto, as exposições aparecem como elemento fundamental da relação entre museus e sociedade, e a expografia torna-se, portanto, ferramenta de comunicação essencial para a efetividade do processo de divulgação. Mas, como se dá a comunicação nestes espaços? Trata-se o presente, de uma reflexão acerca das estratégias de comunicação nas exposições em museus de ciências e sua eficácia. Foram selecionadas três temáticas, a primeira delas é a dos tipos de exposição, e entre as numerosas possibilidades de categorização, optou-se por aquelas descritas por Dean (2003) e Davallon (1986 e 1989). Outra questão discutida é a do uso do objeto, tido, dentre as diferentes mídias a que se pode recorrer em uma exposição, como o diferencial do museu. Por fim, discute-se a questão da interatividade, por vezes reduzida à manipulação, a partir dos níveis propostos por Wagensberg (2000). Apontam-se exemplificações dessas temáticas na exposição de longa duração Pesquisa em Zoologia: a biodiversidade sob o olhar do zoólogo, inaugurada pelo Museu de Zoologia da Universidade de São Paulo em setembro de 2002.

Uma coleção de história em um museu de ciências naturais: o Museu Paulista de Hermann von Ihering

Instalado em um edifício-Monumento, data de 1895 a inauguração do Museu Paulista. Seu primeiro diretor, o zoólogo Hermann Von Ihering (1895-1916), teve a tarefa de organizar suas vastas coleções, as quais possuíam objetos de diversos ramos do conhecimento, entre eles, a História. Este artigo tem a intenção de entender a dimensão, dinâmica e concepção desta coleção de História, que recebeu pouca atenção da Historiografia relativa ao tema.

Study of mural paintings by Fulvio Pennacchi in São Paulo City by mineralogical techniques

The present research deals with two mural paintings made in 1947 with the fresco technique by Fulvio Pennacchi in the Catholic Chapel of the Hospital das Clínicas (São Paulo City, Brazil), namely the Virgin Annunciation and the Supper at Emmaus. This study regards the materials and painting techniques used by the artist, based on historical research,on in situ observations and laboratory analytical techniques (stereomicroscopy,scanning electron microscopy with an energy dispersive spectrometer, X-ray diffractometry, electron microprobe, images obtained with UV-light), aiming to improve the methods of characterization of objects of our cultural heritage, and to enhance its preservation accordingly. The results lead to the identification of the plaster components and of distinct layers in the frescoes, besides further information on grain size, impurities and textures, composition of pigments, and features of deterioration, such as efflorescences. The degree of degradation of the murals painting was assessed by this way. Our data suggest that a single layer of plaster was used by Pennacchi, as a common mortar with fine- and medium-grained aggregates. Differences in texture were obtained by adding gypsum to the plaster.

Diferenças culturais e de gênero em conflitos de pré-escolares

O estudo compara episódios de conflitos entre crianças de quatro a cinco anos de idade, pertencentes a dois grupos culturais: um de uma grande metrópole (São Paulo) e outro de uma pequena comunidade praiana do estado de São Paulo (Ubatuba). Foram observadas 39 crianças (20 meninas e 19 meninos). Analisaram-se os motivos, as estratégias de oposição, as reações à oposição e o desenlace de conflitos. Nos dois grupos e gêneros, o motivo mais freqüente para os conflitos foi a disputa por brinquedos e as estratégias de resolução pró-sociais mesclaram-se com as coercitivas. Algumas diferenças comportamentais de gênero encontradas nas crianças de São Paulo, diferentemente do que se observou em Ubatuba, assemelharam-se às verificadas em estudos europeus e norte-americanos: os meninos se mostraram mais agressivos e as meninas, mais conciliadoras. As crianças paulistanas apresentaram maior número de táticas verbais, enquanto as estratégias diretas e proximais predominaram entre as ubatubanas. O estudo evidencia a importância de considerar as influências culturais na resolução de conflitos entre crianças.

Sugar and total energy content of household food purchases in Brazil

Objective To study the role of energy derived from sugar (both table sugar and sugar added to processed foods) in the total energy content of food purchases in Brazil.Design Food purchase data were collected during a national household budget survey carried out between June 2002 and July 2003 on a probabilistic sample representative of all households in the country. The amount of food purchased in this 12-month period was transformed into energy and energy from sugar using food composition tables. Multiple linear regression models were used to study the association between amount of energy from sugar and total energy content of food purchases, controlling for sociodemographic variables and potential interactions between these variables and sugar purchases.Results There was a positive and significant association between energy from sugar and total household energy purchases. A 1 kJ increase in sugar purchase corresponded to a 3·637 kJ increase in total energy. In the absence of expenditure on meals outside the home, i.e. when household food purchases tend to approximate actual food consumption by household members, sugar purchase of 1926·35 kJ/d (the 90th percentile of the distribution of sugar purchases in Brazil) was associated, depending on income strata, with total energy purchase over 40\201360 per cent of the recommended daily value for energy intake in Brazil.Conclusions The present results corroborate the recommendations of the WHO and the Brazilian Ministry of Health regarding limiting the consumption of sugar

Sensory analysis of hydrolysed meat preparations

A utilização de hidrolisados de carne em dietas melhora seu conteúdo protéico, de vitaminas e minerais. O objetivo do presente trabalho foi avaliar a aceitação de hidrolisados de carne. Quatro preparações foram desenvolvidas com três tipos de hidrolisados em condições similares às domésticas. . A aceitação foi avaliada com uso de escala hedônica de 9 pontos. Os testes foram realizados em três sessões (de acordo com o tipo de hidrolisado) e, incluiu-se na ficha de avaliação informações de idade. A análise estatística foi realizada por ANOVA e teste de Tukey. As preparações mais aceitas foram os bolinhos com hidrolisados de peru e frango. Os hidrolisados podem ser utilizados em diversas preparações, sendo necessário o conhecimento da faixa etária a qual se destinam, suas características sensoriais e físico-químicas, para garantir o sabor e a aparência do produto final

The relationship between birth weight and insulin resistance in childhood

Chronic diseases that are typical of adulthood may originate in intra-uterine life through inadequate fetal development. The present epidemiological cohort study of 506 healthy children aged 5\20138 years evaluated the relationship between birth weight and insulin resistance in an age group that has been assessed in few similar studies. Insulin concentration was determined by chemiluminescence and insulin resistance by the homeostasis model assessment (HOMA). Blood glucose, total cholesterol and fractions (LDL cholesterol and HDL cholesterol) and TAG concentrations were determined by automated enzymatic methods. Linear regression analysis investigated the relationship between birth weight (assessed as a continuous variable and in three categories: small for gestational age, SGA; adequate for gestational age and large for gestational age) and the HOMA index, using backward stepwise selection and biological models to explain the causal pathway of the relationship. There were negativeassociations between birth weight (P < 0·001), SGA (P = 0·027) and the HOMA index, and a positive association between waist circumference (P < 0·001) and the HOMA index. Considering the significant associations between birth weight and waist circumference (P < 0·001) and waist circumference and insulin resistance (P < 0·001), we can probably suspect that lower birth weight is a common cause of higher waist circumference and insulin resistance. In summary, the results of the present study showed increased insulin resistance in apparently healthy, young children, who had lower weight at birth and higher measurements of waist circumference. There is a need to develop public health policies that adopt preventive measures to promote adequate maternal-fetal and child development and enable early diagnosis of metabolic abnormalities

Conhecimento contraceptivo no puerpério precoce e seu uso efetivo após seis meses

Objetivo: Avaliar o conhecimento sobre métodos anticoncepcionais em mulheres no puerpério, bem como analisar a escolha e seu uso efetivo decorrido seis meses do parto. Método: Estudo prospectivo, transversal, realizado por entrevistas no puerpério precoce e após seis meses, com 107 mulheres internadas que aceitaram participar do estudo após a leitura do consentimento livre e esclarecido. Avaliaram-se os indicadores socioeconômicos, o conhecimento em anticoncepção, a orientação recebida, a oferta e uso de contraceptivos após seis meses do parto. Resultados: Os métodos anticoncepcionais mais conhecidos de forma espontânea foram a pílula (89%) e o condom masculino (65%). O DIU com hormônio foi o menos lembrado espontaneamente. Perto de 95% das puérperas referiram desejar evitar nova gravidez. Os métodos mais escolhidos foram a pílula (24%) e a ligadura tubária (18%). Ao se perguntar sobre o interesse em outros métodos contraceptivos após o questionário, 48% demonstraram interesse, sendo o mais citado o DIU (26%). Apenas um quarto das mulheres que disseram conhecer o DIU, faria a opção pelo método. Após seis meses, apenas 47 mulheres foram contatadas, e somente 31 delas haviam recebido orientação sobre anticoncepção (em média sobre três métodos diferentes). Houve apenas uma inserção de DIU de cobre, e três mulheres estavam grávidas naquele momento. Conclusões: O conhecimento da anticoncepção pelas mulheres no puerpério foi alto e melhorou após a estimulação. A avaliação dos resultados parece indicar que a simples leitura dos métodos anticoncepcionais disponíveis contribui para a escolha por métodos não relatados espontaneamente

Nutrition and health: the issue is not food, nor nutrients, so much as processing [Invited commentary]

Orthodox teaching and practice on nutrition and health almost always focuses on nutrients, or else on foods and drinks. Thus, diets that are high in folate and in green leafy vegetables are recommended, whereas diets high in saturated fat and in full-fat milk and other dairy products are not recommended. Food guides such as the US Food Guide Pyramid are designed to encourage consumption of healthier foods, by which is usually meant those higher in vitamins, minerals and other nutrients seen as desirable.What is generally overlooked in such approaches, which currently dominate official and other authoritative information and education programmes, and also food and nutrition public health policies, is food processing. It is now generally acknowledged that the current pandemic of obesity and related chronic diseases has as one of its important causes increased consumption of convenience including pre-prepared foods(1,2). However, the issue of food processing is largely ignored or minimised in education and information about food, nutrition and health, and also in public health policies.A short commentary cannot be comprehensive, and a general proposal such as that made here is bound to have some problems and exceptions. Also, the social, cultural, economic and environmental consequences of food processing are not discussed here. Readers comments and queries are invited

A SEARCH FOR FIELD HORIZONTAL-BRANCH STARS NEAR THE SOUTH GALACTIC POLE

Searches for field horizontal-branch (FHB) stars in the halo of the Galaxy in the past have been carried out by several techniques, such as objective-prism surveys and visual or infrared photometric surveys. By choosing adequate color criteria, it is possible to improve the efficiency of identifying bona fide FHB stars among the other objects that exhibit similar characteristics, such as main-sequence A-stars, blue stragglers, subdwarfs, etc. In this work, we report the results of a spectroscopic survey carried out near the south Galactic pole intended to validate FHB stars originally selected from the HK objective-prism survey of Beers and colleagues, based on near-infrared color indices. A comparison between the stellar spectra obtained in this survey with theoretical stellar atmosphere models allows us to determine T(eff), log g, and [Fe/H] for 13 stars in the sample. Stellar temperatures were calculated from measured (B-V)(o), when this measurement was available (16 stars). The color index criteria adopted in this work are shown to correctly classify 30% of the sample as FHB, 25% as non-FHB (main-sequence stars and subdwarfes), whereas 40% could not be distinguished between FHB and main-sequence stars. We compare the efficacy of different color criteria in the literature intended to select FHB stars, and discuss the use of the Mg II 4481 line to estimate the metallicity.

FILTERING TECHNIQUES APPLIED ON RAW CARRIER PHASE FOR GPS DETECTING SMALL DYNAMIC DISPLACEMENTS

This work is part of a research under construction since 2000, in which the main objective is to measure small dynamic displacements by using L1 GPS receivers. A very sensible way to detect millimetric periodic displacements is based on the Phase Residual Method (PRM). This method is based on the frequency domain analysis of the phase residuals resulted from the L1 double difference static data processing of two satellites in almost orthogonal elevation angle. In this article, it is proposed to obtain the phase residuals directly from the raw phase observable collected in a short baseline during a limited time span, in lieu of obtaining the residual data file from regular GPS processing programs which not always allow the choice of the aimed satellites. In order to improve the ability to detect millimetric oscillations, two filtering techniques are introduced. One is auto-correlation which reduces the phase noise with random time behavior. The other is the running mean to separate low frequency from the high frequency phase sources. Two trials have been carried out to verify the proposed method and filtering techniques. One simulates a 2.5 millimeter vertical antenna displacement and the second uses the GPS data collected during a bridge load test. The results have shown a good consistency to detect millimetric oscillations.

A frequency approach to identifying asteroid families II. Families interacting with nonlinear secular resonances and low-order mean-motion resonances

Aims. In an earlier paper we introduced a new method for determining asteroid families where families were identified in the proper frequency domain (n, g, g + s) ( where n is the mean-motion, and g and s are the secular frequencies of the longitude of pericenter and nodes, respectively), rather than in the proper element domain (a, e, sin(i)) (semi-major axis, eccentricity, and inclination). Here we improve our techniques for reliably identifying members of families that interact with nonlinear secular resonances of argument other than g or g + s and for asteroids near or in mean-motion resonant configurations. Methods. We introduce several new distance metrics in the frequency space optimal for determining the diffusion in secular resonances of argument 2g - s, 3g - s, g - s, s, and 2s. We also regularize the dependence of the g frequency as a function of the n frequency (Vesta family) or of the eccentricity e (Hansa family). Results. Our new approaches allow us to recognize as family members objects that were lost with previous methods, while keeping the advantages of the Carruba & Michtchenko (2007, A& A, 475, 1145) approach. More important, an analysis in the frequency domain permits a deeper understanding of the dynamical evolution of asteroid families not always obtainable with an analysis in the proper element domain.

Fossil groups in the Millennium Simulation Evolution of the brightest galaxies

Aims. We create a catalogue of simulated fossil groups and study their properties, in particular the merging histories of their first-ranked galaxies. We compare the simulated fossil group properties with those of both simulated non-fossil and observed fossil groups. Methods. Using simulations and a mock galaxy catalogue, we searched for massive (>5 x 10(13) h(-1) M-circle dot) fossil groups in the Millennium Simulation Galaxy Catalogue. In addition, we attempted to identify observed fossil groups in the Sloan Digital Sky Survey Data Release 6 using identical selection criteria. Results. Our predictions on the basis of the simulation data are: (a) fossil groups comprise about 5.5% of the total population of groups/clusters with masses larger than 5 x 10(13) h(-1) M-circle dot. This fraction is consistent with the fraction of fossil groups identified in the SDSS, after all observational biases have been taken into account; (b) about 88% of the dominant central objects in fossil groups are elliptical galaxies that have a median R-band absolute magnitude of similar to-23.5-5 log h, which is typical of the observed fossil groups known in the literature; (c) first-ranked galaxies of systems with M > 5 x 10(13) h(-1) M-circle dot, regardless of whether they are either fossil or non-fossil, are mainly formed by gas-poor mergers; (d) although fossil groups, in general, assembled most of their virial masses at higher redshifts in comparison with non-fossil groups, first-ranked galaxies in fossil groups merged later, i.e. at lower redshifts, compared with their non-fossil-group counterparts. Conclusions. We therefore expect to observe a number of luminous galaxies in the centres of fossil groups that show signs of a recent major merger.

Physical and dynamical characterization of (5201) Ferraz-Mello, a possible extinct Jupiter family comet

Context. The subject of asteroids in cometary orbits (ACOs) has been of growing interest lately. These objects have the orbital characteristics typical of comets, but are asteroidal in appearance, i.e., show no signs of a coma at any part of their orbits. At least a fraction of these objects are thought to be comets that have either exhausted all their volatile content or developed a refractory crust that prevents sublimation. In particular, the asteroid ( 5201) Ferraz-Mello has, since its discovery, been suspected to be an extinct Jupiter family comet due to the peculiar nature of its orbit. Aims. The aim of this work is to put constraints on the possible origin of ( 5201) Ferraz-Mello by means of spectroscopic characterization and a study of the dynamics of this asteroid. Methods. We used the SOAR Optical Imager (SOI) to obtain observations of ( 5201) Ferraz-Mello using four SDSS filters. These observations were compared to asteroids listed in the Sloan Moving objects catalog and also to photometry of cometary nuclei, Centaurs, and TNOs. The orbital evolution of ( 5201) Ferraz-Mello and of a sample of asteroids and comets that are close to that object in the a - e plane were simulated using a pure N-body code for 4 000 years forward and 4 000 years backward in time. Results. The reflectance spectrum obtained from its colors in the SDSS system is unusual, with a steep spectral gradient that is comparable to TNOs and Centaurs, but with an increase in the reflectance in the g band that is not common in those populations. A similar behavior is seen in cometary nuclei that were observed in the presence of a faint dust coma. The dynamical results confirm the very chaotic evolution found previously and its dynamical similarity to the chaotic evolution of some comets. The asteroid is situated in the very stochastic layer at the border of the 2/1 resonance, and it has a very short Lyapunov time ( 30 - 40) years. Together, the spectral characteristcs and the dynamical evolution suggest that ( 5201) Ferraz-Mello is a dormant or extinct comet.