Irregularidade do ciclo menstrual no Menacme como marcador para fatores de risco cardiovasculares na pós-menopausa

A associação entre fatores de risco cardiovascular (FRCV) na pósmenopausa e o antecedente de irregularidade menstrual no menacme foi avaliado em estudo caso-controle envolvendo 414 mulheres na pósmenopausa com idade de 60,4 ± 5,5 anos e IMC de 25,3 ± 4,7 kg/m2. As variáveis consideradas foram: caracterização do ciclo menstrual entre 20 e 35 anos (independente) e relato atual sobre ocorrência de hipertensão arterial, dislipidemia, diabetes mellitus e doença arterial coronariana (dependentes). Utilizou-se o teste qui-quadrado e modelos de regressão logística, ajustados para outras variáveis implicadas no risco para doenças CV, com nível de significância 5%. Observou-se que mulheres que relataram irregularidade menstrual prévia estiveram associadas com risco aumentado para ocorrência de algum FRCV [odds ratio ajustado (OR)= 2,14; IC-95%= 1,02–4,48], quando comparadas àquelas com ciclos regulares. Análise estratificada demonstrou as seguintes associações significativas com o antecedente de irregularidade menstrual: hipertensão arterial (OR= 2,4; 95% IC= 1,39–5,41), hipercolesterolemia (OR= 2,32; 95% IC= 1,17–4,59), hipertrigliceridemia (OR= 2,09; 95% IC= 1,10–4,33) e angioplastia coronariana (OR= 6,82; 95% IC= 1,44–32,18). Os dados sugerem que o antecedente de irregularidade menstrual, indicativo da ocorrência da síndrome dos ovários policísticos na idade reprodutiva, pode estar relacionado com aumento do risco para doenças CV na pós-menopausa __________________________________________________ABSTRACT Menstrual Cycle Irregularity as a Marker of Cardiovascular Risk Factors at Postmenopausal Years.To evaluate the association between cardiovascular risk factors (CVRF)during postmenopausal years and previous menstrual irregularity during reproductive years, we performed a case-control study in 414 postmenopausal women (mean age 60.4 ± 5.5 years; BMI 25.3 ± 4.7 kg/m2). The variables assessed were: menstrual cycle characteristics at age 20–35y (independent) and records of arterial hypertension, dyslipidemia, diabetes mellitus, and coronary heart disease (dependent). Statistical analysis used the chi-square test and logistic regression, adjusting for potential confounders for cardiovascular risk, with significance set at 5%. Women reporting previous menstrual irregularity were associated with increased risk for some CVRF [adjusted odds ratio (OR) 2.14; CI-95%= 1.02–4.48], when compared with those reporting regular menstrual cycles. Stratified analysis demonstrated significant associations of previous menstrual irregularity with: arterial hypertension [OR= 2.74; CI-95%= 1.39–5.41), hypercholesterolemia (OR= 2.32; CI-95%= 1.17–4.59), hypertriglyceridemia (OR= 2.09; CI-95%=1.10–4.33), and coronary angioplasty (OR= 6.82; CI-95%= 1.44–32.18). These data suggest that a prior history of menstrual irregularity, as indicative of polycystic ovary syndrome, may be related to increased risk for CVD during postmenopausal years

Effect of trypsin inhibitor from Crotalaria pallida seeds on Callosobruchus maculatus (cowpea weevil) and Ceratitis capitata (fruit fly)

GOMES, Carlos E. M. et al. Effect of trypsin inhibitor from Crotalaria pallida seeds on Callosobruchus maculatus (cowpea weevil) and Ceratitis capitata (fruit fly). Plant Physiology and Biochemistry (Paris), v. 43, n. 12, p. 1095-1102, 2005.ISSN 0981-9428. DOI:10.1016/j.plaphy.2005.11.004.

Eutrofização do reservatório Engenheiro Armando Ribeiro Gonçalves, no Rio Grande do Norte: implicações para o abastecimento público e para a piscicultura intensiva em tanques-rede

This study aimed to describe the spatial and temporal patterns of variation in trophic state and its relation with the structure and dynamics of planktonic community of a large reservoir located in semi-arid tropical region of Northeast Brazil. The reservoir Armando Ribeiro Gonçalves is the biggest reservoir of the Rio Grande do Norte State and is responsible for about 53% of all surface water accumulated in the State. The samples of water and plankton were taken monthly in 10 points distributed throughout the longitudinal axis of the reservoir and over a full hydrological cycle. The samples were collected to determine concentrations of total phosphorus, total nitrogen, chlorophyll a and suspended solids (fixed and volatile) and for determining the composition and abundance of phytoplanktonic and zooplanktonic species. During the study period, the reservoir was characterized as eutrophic and there was no trend of increasing the trophic state of the reservoir in the period of drought. The concentrations of total phosphorus and suspended fixed solids decreased towards the dam while the N:P ratios increased in the same direction due to the reduction in the phosphorus concentrations and relative constancy in the nitrogen concentrations. The N:P ratios observed were indicative of greater limitation by phosphorus than by nitrogen. However, as concentrations of both nutrients were high and the water transparency was very low, with secchi depth usually lower than one meter, it seems likely that the planktonic primary production of the reservoir is more limited by the availability of light than the availability of nutrients. High nutrient concentrations coupled with low availability of light may explain the continuing dominance of filamentous cyanobacteria such as Cylindrospermopsis raciborskii in the plankton of the reservoir.These cyanobacteria are potentially toxic and pose a serious environmental problem because it compromises the water quality for public supply, recreation and fishing when present in high densities as in this study. The mesozooplankton of the reservoir was dominated by the calanoid Notodiaptomus cearensis and the cladoceran Diaphanosoma spinulosum. In general, the structure of zooplankton community seems to be particularly influenced by the spatial variation of cyanobacteria. The results of the regression analyses show that both the chlorophyll a concentrations and the cyanobacteria biovolume were more strongly correlated with the nitrogen than with phosphorus and that the water transparency was more strongly correlated with algal biomass than with other sources of turbidity. The maximum load of phosphorus to attain the maximum permissible concentration of total P in the reservoir was estimated in 63.2 tonnes P/ year. The current external P load to the reservoir is estimated in 324 tonnes P / year and must be severely reduced to improve the water quality for water supply and allow the implementation of aquaculture projects that could contribute to the socio-economic development of the region

Uma Lectina D-lactose específica da esponja marinha Cinachyrella apion: purificação, caracterização e interação com Leishmania chagasi

Four different sponge species were screened using Ouchterlony agarose gel and immunodiffusion tests to identify cross-reactivity with the polyclonal antibody IgG anti-deglicosilated CvL, a lectin from Cliona varians. Crude extract from the sponge Cinachyrella apion showed cross-reactivity and also a strong haemmaglutinating activity towards human erythrocytes of all ABO groups. Thus, it was submitted to acetone fractionation, IgG anti-deglicosilated CvL Sepharose affinity chromatography, and Fast Protein Liquid Chromatography (FPLC-AKTA) gel filtration on a Superose 6 10 300 column to purify a novel lectin. C. apion lectin (CaL) agglutinated all types of human erythrocytes with preference for papainized type A and O erythrocytes. The haemagglutinating activity is independent of Ca2+, Mg2+ and Mn2+ ions, and it was strongly inhibited by the disaccharide D-lactose, up to a minimum concentration of 6.25 mM. CaL molecular mass determined by FPLC-AKTA gel filtration on a Superose 12 10 300 column and SDS gel electrophoresis was approximately 124 kDa, consisting of eight subunits of 15.5 kDa, assembled by hydrophobic interactions. The lectin was relatively heat- and pH-stable. Leishmania chagasi romastigotes were agglutinated by CaL, indicating that lactose receptors could be presented in this parasite stage. These findings are indicative of the physiological defense roles of CaL and its possible use in the antibiosis of pathogenic protozoa

Purificação, caracterização e atividade bioinseticida de um inibidor de tripsina de sementes de Crotalaria pallida

A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulphate fractionation, affinity chromatography on immobilized Trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named ITC, had Mr of 32.5 kDa by SDS-PAGE and was composed by two subunits with 27.7 and 5.6 kDa linked by disulphide bridges, a typical characteristic of Kunitz-Inhibitor family. ITC was stable until 50°C, and at 100°C its residual activity was of about 60%. Also, ITC was stable at pHs 2 to 12. The inhibition of trypsin by ITC was non-competitive, with a Ki of 8,8 x 10-7M. ITC inhibits weakly other serine proteinases such as chymotrypsin and elastase. The inhibition of papain (44% of inhibition), a cysteine proteinase was an indicative of the bi-functionality of ITC. In vitro assays against digestive proteinases from several Lepdoptera, Diptera and Coleoptera pests were made. ITC inhibited in 100% digestive enzymes of Ceratitis capitata (fruit fly), Spodoptera frugiperda and Alabama argillacea, the last one being a cotton pest. It also inhibited in 74.4% Callosobruchus maculatus (bean weevil) digestive enzymes, a Coleoptera pest. ITC, when added in artificial diet models, affected weakly the development of C. capitata larvae and it had a WD50 of 2.65% to C. maculatus larvae

Caracterização físico-química e ações farmacológicas hepatoprotetora, antiinflamatória, pró-angiogênica, antioxidante e anticoagulante da fração rica em fucana 0,8FRF 0,8 da alga marrom Lobophora variegata

This study examines the physical and chemical composition and the pharmacological effects of brown seaweed FRF 0.8 Lobophora variegata. Fractionation of the crude extract was done with the concentration of 0.8 volumes of acetone, obtaining the FRF 0.8. The physicochemical characterization showed that it was a fucana sulfated. Anti-inflammatory activity was assessed by paw edema model by the high rates of inhibition of the edema and the best results were in the fourth hour after induction (100 ± 1.4% at the dose of 75 mg / kg) and by the strong inhibitory activity of the enzyme myeloperoxidase (91.45% at the dose of 25 mg / kg). The hepataproteção was demonstrated by measurements of enzymatic and metabolic parameters indicative of liver damage, such as bilirubin (reduction in 68.81%, 70.68% and 68.21% for bilirubin total, direct and indirect, respectively at a dose of 75 mg / kg), ALT, AST and γ-GT (decrease of 76.93%, 44.58% and 50% respectively at a dose of 75 mg / kg) by analysis of histological slides of liver tissue, confirming that hepatoprotective effect the polymers of carbohydrates, showing a reduction in tissue damage caused by CCl4 and the inhibition of the enzyme complex of cytochrome P 450 (increasing sleep time in 54.6% and reducing the latency time in 71.43%). The effectiveness of the FRF 0.8 angiogenesis was examined in chorioallantoic membrane (CAM) of fertilized eggs, with the density of capillaries evaluated and scored, showing an effect proangigênico at all concentrations tested FRF (10 mg- 1000 mg). The FRF showed antioxidant activity on free radicals (by inhibiting Superoxide Radical in 55.62 ± 2.10%, Lipid Peroxidation in 100.15 ± 0.01%, Hydroxyl Radical in 41.84 ± 0.001% and 71.47 Peroxide in ± 2.69% at concentration of 0.62 mg / mL). The anticoagulant activity was observed with prolongation of activated partial thromboplastin time (aPTT) at 50 mg (> 240 s), showing that its action occurs in the intrinsic pathway of the coagulation cascade. Thus, our results indicate that these sulfated polysaccharides are an important pharmacological target

Avaliação da ação bioinseticida de SBTI e vicilina de Erythrina velutina em enzimas digestivas e membrana peritrófica de larvas de Plodia interpunctella (Lepidoptera: Pyralidae)

Plodia interpunctella (Indian meal moth) is a cosmopolitan pest that attacks not only a wide range of stored grain as well other food products. Due to its economic importance several researches have focused in a method with ability to control this pest with few or no damage to the environment. The study of digestive enzymes inhibitors, lectins and chitin-binding proteins, has often been proposed as an alternative to reduce insect damage. In this study we report the major classes of digestive enzymes during larval growth in P. Interpunctella, being those proteinases actives at pH 9.5 and optimum temperature of 50 oC to both larvae of the 3rd instar and pre-pupal stage of development. In vitro and zymogram assays presented the effects of several inhibitors, such as SBTI, TLCK and PMSF to intestinal homogenate of 3rd instar larvae of 62%, 92% and 87% of inhibition and In pre-pupal stage of 87%, 62 % and 55% of inhibition, respectively. Zymograms showed inhibition of two low molecular masses protein bands by TLCK and that in presence of SBTI were retarded. These results are indicative of predominance of digestive serine proteinases in gut homogenate from Plodia interpunctella larvae. This serine proteinase was then used as a target to evaluate the effect of SBTI on larvae in in vivo assay. Effect of SBTI on mortality and larval mass was not observed at until 4% of concentration (w/w) in diets. Chitin, another target to insecticidal proteins, was observed by chemical method. Moreover, optic microscopy confirmed the presence of a peritrophic membrane. Established this target, in vivo effect of EvV, a chitin binding vicilin, evaluated during the larval development of P. interpunctella and was obtained a LD50 of 0,23% and WD50 of 0,27% to this protein. Mechanism of action was proposed through of the in vivo digestibility of EvV methodology. During the passage through the larval digestive tract was observed that EvV was susceptible to digestive enzymes and a reactive fragment, visualized by Western blotting, produced by digestion was recovered after dissociation of the peritrophic membrane. The bound of EvV to peritrophic membrane was confirmed by immunohystochemical assays that showed strong immunofluorescent signal of EvV-FITC binding and peritrophic membrane. These results are a indicative that vicilins could be utilized as potential insecticide to Plodia interpunctella and a control methods using EvV as bioinsecticide should be studied to reduce lost caused by storage insect pests

Mutagênese induzida por flavonóides presentes do decocto das cascas da aroeira (Schinus terebinthifolius, Raddi)

The decoction of Brazilian pepper tree barks (Schinus terebinthifolius, Raddi), is used in medicine as wound healing and antiinflamatory. Once extracts from this plant are used for acceleration of scar s process, it is important to study their mutagenic and genotoxic potential. In previous works in our laboratory, it was observed mutagenicity caused by the decoction when in high concentrations. Among the chemical compounds of this plant that could be able to induce mutation, the flavonoids were the only group that was referred to have either an oxidant or antioxidant potential. The flavonoids were isolated, purified and quantified by adsorptive column chromatography under silica gel, bacterial and in vitro genotoxic tests were realized to determine if the flavonoids were the responsible agents for this mutagenicity found. The tests realized with plasmidial DNA were indicative that the flavonoids are probably genotoxic, due to the presence of correlation between increase of the flavonoid concentration and in plasmidial DNA double strand breakage visualized in agarose gel, as well as they were capable to generated abasic sites shown by the in vitro treatment with exonuclease III. The same tests with plasmidial DNA in the presence of copper [10 µM] and of a Tris-HCl pH 7.5 [10 µM] buffer were realized with the isolated flavonoids to determine if there would be or not participation of reactive oxygen species (ROS). The transformation of plasmidial DNA in different bacterial strains proficient and deficient in DNA repair enzymes in the presence or not of a Tris-HCl buffer, suggests that the enzymes that repair oxidative lesions are necessary to repair the lesions generated by the flavonoids and that ROS are generated and are necessary to promote the lesions. Bacterial tests with Escherichia coli strains of the CC collection (deficient or not for DNA repair enzymes), showed that the flavonoids are able to increase the frequency of mutations, mainly in strains mutated in repair enzymes (MutM, MutY-glicosylases and double mutant), suggesting that these agents are responsible for the enhancement in the mutation rate. In order to determine the mutation spectrum caused by the flavonoids of the Brazilian pepper tree stem bark, plasmidial DNA previously treated with the flavonoids were transformed in bacterial strains deficient and proficient in the DNA repair enzymes, followed by a blue-white selection with X-gal, DNA amplification by PCR and sequencing the positive mutant clones. Analysis of the mutants obtained from strains CC104, CC104mutM, CC104mutY, CC104mutMmutY, BW9101, BW9109 indicated a predominance of some mutations like G:C to C:G that can be correlated with the origin of 8-oxoG, due to oxidative lesions caused by the flavonoids. So it can concluded that the flavonoid isolated or in fractions enriched on them are genotoxic and mutagenic, and their mutations are predominantly oxidative, mediated by ROS, and the lesions are recognized by the BER system. In this way it is proposed that the flavonoids can act in two different ways to generate the DNA lesion: 1. in a Fenton-like reaction, when the flavonoid are in the presence of metal ions and that together with the water generate ROS that promotes the DNA lesions; 2. in another way the lesions can be generated by the formation of ROS due to the internal chemical structure of the flavonoid molecule due to the quantity and location of hydroxyl groups, and so producing the DNA lesions, those lesions can be directly (suggested by the in vitro experiments) or indirectly done (supported by the experiments using the CC bacterial strains)

Níveis de homocisteína e desempenho cognitivo em uma amostra populacional de idosos da cidade do Natal-RN

The imprecision of the frontier that separates those cognitive deficits inherent to the human physiological aging process from those which represent the early signs of nervous system degenerative pathologies ,very prevalent among the elderly, has brought attention to the need of studies aiming to establish clinical and/or laboratorial criteria to allow this differentiation. Elderly people living in poor and developing countries are frequently exposed to precarious socioeconomic conditions which facilitate the development of an array of pathologies which have metabolic and nutritional dysfunctions as the established or proposed etiological agents. The levels of certain micronutrients, such as the vitamins B12 and B9 (folic acid), and of some intermediary metabolites, such as homocysteine are being thought of as etiological factors and/or as biological markers of a group of alterations which affect the normal functioning of the nervous system with important reflexes upon cognitive performance. This study aims to investigate the influence of homocysteine, B12 vitamin and folic acid levels on the cognitive performance of the low income elderly population. This transversal study took place in Natal, Rio Grande do Norte State, Brazil, and involved 205 dwelling elderly people, users of the Programa de Saúde da Família, a public healthcare program, maintained by the city s health authorities. A multidimensional questionnaire was used to assess the socio-demographic aspects and the overall health and nutrition conditions. The cognitive performance was measured by the use of the Portuguese version of the Mini Mental State Exam (MMSE). The serum levels of homocysteine, B12 vitamin and folic acid were determined by chemiluminescence. The association between the socio-demographic and serum levels of Hcy, B12 vitamin and folic acid was determined by multiple linear regression. Serum levels higher than 13.5 μmol/l, indicative of hyperhomocysteinemia (HHcy), were found on 25.4% of the sample, being more prevalent in men (p<0.05). Deficitary levels of folic acid (<5ng/mol) and of B12 vitamin (<193 pg/ml) were found on 3.9% and 10.2% of the sample respectively. A negative correlation was found between cognitive performance with both age and HHcy and a positive correlation was found between cognitive performance and schooling. The isolated HHcy R2 values were an explanation to only 4% of the variance of the MMSE scores. However, when associated with schooling and age, this model explains about 25% of this association

Avaliação da genotoxicidade e da qualidade das águas do açude de Lucrécia/RN

The occurrence of human cancer in the municipality of Lucrécia (RN, Brazil) has shown high frequencies (INCA, 2007). Tests of micronucleus (MN) and nuclear abnormalities (NA) were performed to assess the genotoxic potential of water from the Lucrécia dam, which is located in a semi-arid region under the influence of crop irrigation and irregular rainfall. Water samples were collected in this source for analyzing the concentration of cyanobacteria, metals and radioactivity. Erythrocytes of Nile tilapia (Oreochromis niloticus) were collected in dam and cells of human oral mucosa in the urban area of this municipality for the bioassays of MN and NA. In fish were also analyzed concentrations of metals in samples of liver and gills. The genotoxicity tests with biological samples of fish and humans have shown significant increases in the frequencies of MN and NA (p ≤ 0.05) and are indicative of increased DNA damage in relation to the control groups. In conclusion, the results obtained from water samples and biological municipality of Lucrécia indicates that the presence of chemical and microbiological pollutants, and increase of genotoxic in human of this municipality. We suggest the implementation of advanced water treatment, to prevent further degradation of the aquatic environment and decrease in the life quality. This research of environmental quality assessment was performed in order to contemplate a multi and interdisciplinary character of this water resource and that can induce genotoxic damage in the organisms in this study region

Valores de referência para cobre e zinco no plasma e no eritrócito em adultos universitários na cidade de Natal-RN

This study aimed builds reference values for copper and zinc, of healthy adults in Natal-RN, and to identify the influence of the gender, age, body mass index (BMI) and diet, on those values. They were assessed 123 healthy students of the Universidade Federal do Rio Grande do Norte (UFRN), both genders, with age between 19 and 41 years. The project was approved by the Ethics Committee in Research of UFRN. BMI was determined and the food consume was accomplished through a 24h recordatory. Dietary was evaluated as the energy, macronutrients, copper and zinc, according to the recommendations of National Academy of Sciences (2001; 2002). Analyses of the copper and zinc concentrations in the plasma and erythrocytes were accomplished by flame atomic absorption spectrometry. The casuistic came quite homogeneous as for the distribution for gender and age, being the largest number of individuals between the 19 and 24 years old. Most of the volunteers presented anthropometric nutritional state inside of the normality patterns. Chronic diseases family antecedents and sedentarysm were observed. Diet was characterized with low consumption of zinc, appropriate of copper and of lipids. Average concentrations of plasma copper (p=0,002), erythrocyte copper (μg/dL, p=0,036; μg/gHb, p=0,038), and plasma zinc (p=0,022) were different among the genders, what was demonstrated by the largest values of copper in the female gender and larger of zinc in the masculine. Plasma copper values still suffered interference of the variables: energy, carbohydrate and copper consumption, all classified in agreement with the median, besides the protein classified according to the percentage contribution for the dietary total energy. The study allowed to establish reference values for erythrocyte zinc (1.261,6-1.344,0 μg/dL e 51,0-54,3 μg/gHb) and to suggest "indicative" of reference values for plasma (108,4 130,2 μg/dL) and erythrocyte (female = 85,0 91,4 μg/dL; masculine = 80,2 86,5 μg/dL) copper and plasma zinc (female = 98,8 105,8 μg/dL; masculine = 104,6 111,6 μg/dL)

Compor e educar para descolonizar

Industrialization, accelerated urbanization, increased material wealth, expansion of the consumer society, incentive to competition and environmental degradation represent multiple dimensions of the development existing in Brazil over the last forty years. Upon reflecting about this process, this thesis is based on the understanding that eagerness for development is indicative of the existence of a self-colonized imaginary, as Serge Latouche says, among considerable portions of Brazilian people. Understanding that art creates a deeper and truer knowledge on the essence of the world, according to the comprehension announced by Arthur Schopenhauer, I point out that Brazilian composers, upon seeing beforehand the symptoms of the evil of civilization expressed under the sign of development, spread ideas which poetically decolonize our imaginary. Being convinced that we can and must get out of the line, invent new ways, announce a forbidden knowledge, discuss implausible hypotheses, unfinished ideas, as Maria da Conceição de Almeida states, I present the notion of DESdesenvolvimento as a cognitive operator which potentializes the imaginary decolonization revealed by several songs by Brazilian composers

Histórias de idosos: sementes para cultivarmos uam educação para uma velhice bem-sucedida

We understand that the successful old age is not confined only in the analysis of quantitative aspects concerning the economic situation of the subject that gets old, but this special way of aging is related to other values, such as dignity, happiness, self-esteem, willingness, autonomy, independence, social involvement with family and friends, among others. Thus, this study aimed to investigate the human aging process, considering the history of life of ten seniors who fit the profile of successful old age, seeking to identify elements that contribute to educational thinking in order to get a successful aging. In this perspective, we argue in this study, the idea that we need to learn to engage in experiences that more than providing satisfaction and well-being in the moment in which we conducted, serve as a potentiating to a successful old age. Thus, throughout this thesis we question: what are the present indicative in the histories of life of elderly people, considered successful, which may contribute to an education that people experiencing their age more satisfactorily. This is a qualitative study, that took as universe a methodological oral history, in which we used as a technique of research a semistructured interview as a part of their life history, with emphasis on consideration of the following categories: diary routine, with emphasis on social harmony in the family, at work and in friendship groups of leisure and physical activity, self-knowledge and the learning experiences throughout life. To get the objectives outlined, as well as lectured on the categories analyzed, we support our reflection on the theory of the course of life, which includes human aging as a historical and cultural contextual reality. Our research revealed, among other things, that successful aging is coupled to an active lifestyle, where the involvement in physical activities, recreational and social experiences throughout life is important for increasing self-esteem, autonomy and joy of living, conditions that enable successful old age. Our study also revealed that the educationfor successful old age is linked with the consumption along the life, educational activities which broaden the possibilities of social interaction between people, even among different generations, since the interaction is important to learn and accept our possibilities and limits.

Como vão se formando os professores em física e química: embates entre o ser, o ter e o fazer na formação de licenciandos da UFRN sob a perspectiva da teoria das representações sociais

The purpose of this work is to approach and understand the Social Representations (SR) (MOSCOVICI, 2003) about Physics and Chemistry from people who are major in these courses, as well as their Social Representations about teaching . We took as principle that approaching these representations it would be possible to relate their symbolic contents, in order to show how people who are following the first segments of bachelor degree courses in Physics and Chemistry become teachers, taking into account a psychosocial view. Two source of data was used during this research: Free-association Technique FA (ABRIC, 1994); and Multiple Classification Procedure (MCP) (ROAZZI, 1995). The analytical treatment of the collected data from FA was done according to the proposition of Grize, Vergés and Silem (1987 apud ABRIC, 1994, p. 66). MCP data were analyzed through MSA (Multidimensional Scalogram Analysis) and SSA (Singular Spectrum Analysis) methods associated with the Facet Theory (BILSKY, 2003). The discourses of MCP discussing groups at the moment of explanations were studied by Content Analysis as it was proposed by Bardin (1977) and Franco (2005). Indicative of an approach to the relations with knowledge (CHARLOT, 2000), the connections which aroused from the analyses showed that the group of future majors in Physics thought that this scientific field was based on a rationalist conception, influencing the idealization sense of the phenomena to be explained by Physics. Thus, Physics as school content started to require the student of the fundamental and high school to think abstractly as a cognitive skill of learning. The identifying elements observed in the relations between SR about Physics and Teaching aroused from the antagonism between future majors and their teacher, as well as from the speculation between their fundamental and high school students and themselves, mainly when they had to face the act of teaching due to the obstacles imposed by the own educational system, and by the weakness of the initial preparation. The group of future majors in Chemistry, through its discourses, showed these relations when they conceived empiricist Chemistry and said that teaching was the way of transmission of this knowledge, and didactics of Chemistry teaching was the direction to learning through pedagogic methods in order to lead the students to discoveries. The psychosocial contents which were built and showed from the symbolic relations in the studied SR achieved the relation of identity. This relation revealed identifying elements for these people, resulting from the traffic between their condition as students of Chemistry, and as teachers regarding their work, what placed the current relational contents in the teaching space, named as Knowledge changing and Adaptability . In order to study emerging questions in the discussing environment about formation and teaching professionalization, we focused the psychosocial view on this traffic and managed to observe epistemological practical and pedagogic obstacles that limited a configuration of the teaching work as a professional activity, especially from the particular conditions which led the relations of senses to Physics , Chemistry and Teaching ; and Chemistry and Physics as it was seen in this research. Generally speaking, we noted that these obstacles can denounce such obstacles concerning to the pedagogic doings which mainly impair the learning process of fundamental and high school students

Construção, calibração e análise de desempenho de um piranômetro de baixo custo, baseado no modelo Kimball-Hobbs

In this work a pyrometer using the classic model of Kimball-Hobbs was developed, tested and calibrated. The solar radiation is verified through the temperature difference between the sensible elements covered by absorbing (black) and reflecting (white) pigmentations of the incoming radiation. The photoacoustic technique was used to optimize the choice of the pigments. Methodologies associated with linearity, thermo-variation, sensibility, response time and distance are also presented. To correctly classify the results, the international standard ISO 9060 as well as indicative parameters of World Meteorological Organization (WMO) are used. In addition a system of data acquisition of two channels with 12 bits, constructed during the this time, was used to measure the global solar radiation on the ground by the pyrometer and also by another pyrometer certified in the case of Keep & zonen. The results statistically show, through the hypothesis test presented here, that both equipments find population average with 95% of correctness