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1.
An. acad. bras. ciênc ; 89(1,supl): 757-771, May. 2017. graf
Article in English | LILACS | ID: biblio-886668

ABSTRACT

ABSTRACT Fostering innovation and creativity is a priority in the science and education policy agenda of most countries, which have advocated that innovative minds and processes will boost scientific and economic growth. While our knowledge society has embraced this view, fostering creativity is among the major challenges faced by educators and policymakers. For example, plagiarism, which may be considered a form of imitation and repetition, is a global concern at schools and universities. However, most discussions focus on academic integrity, which, we believe, leaves some gaps in the approach to the problem. As part of an ongoing project on plagiarism, science and education policy, we show results from a survey sent to 143 high-school science teachers at one of the most highly regarded federal schools in Brazil. Among respondents (n=42), about 50% admit that students plagiarize in assignments. Additionally, many of these educators suggest that the way biology, chemistry and physics are taught at school stimulates more repetition than creativity. Our findings are consistent with the need for a broader perspective on plagiarism and with initiatives to stimulate creativity and critical thinking among students. Although we offer a perspective from Brazil, it may illuminate current discussions on plagiarism, particularly in emerging countries.


Subject(s)
Humans , Publications/ethics , Science/education , Plagiarism , Brazil , Scientific Misconduct , Ethics, Research
2.
Mem. Inst. Oswaldo Cruz ; 108(4): 494-500, jun. 2013. tab, graf
Article in English | LILACS | ID: lil-678285

ABSTRACT

In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL) are transferred to the haemolymphatic lipophorin (Lp) and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80%) and NL (20%). The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.


Subject(s)
Animals , Female , Digestive System/metabolism , Lipid Metabolism/physiology , Phospholipids/metabolism , Rhodnius/metabolism , Membrane Lipids/metabolism , Rhodnius/physiology
3.
An. acad. bras. ciênc ; 77(3): 405-430, Sept. 2005. ilus
Article in English | LILACS | ID: lil-406222

ABSTRACT

Em triatomíneos, assim como em outros insetos, o acúmulo de vitelo é um processo no qual um tecido extraovariano, o corpo gorduroso, produz proteínas que são empacotadas no interior de um ovo. A principal proteína, sintetizada pelo corpo gorduroso, que é acumulada no interior de um ovócito, é a vitelogenina. Este processo é também conhecido por vitelogênese. Existem crescentes evidências em triatomíneos, que além do corpo gorduroso, o ovário também produz proteínas de vitelo. A forma como estas proteínas de vitelo entram nos ovócitos será aqui comentada. O vitelo é um material complexo composto por proteínas, lipídeos, carboidratos e outros compostos minoritários que são empacotados de uma maneira organizada no interior dos ovócitos. A fertilização dispara a embriogênese, um processo que culmina com o desenvolvimento do embrião. Durante a embriogênese o vitelo será utilizado para a construção de um novo indivíduo, a ninfa de primeiro estádio. O desafio para a próxima década é entender onde e como estas proteínas de vitelo são utilizadas junto com os seus componentes não protéicos, em compasso com o programa genético do embrião, que comanda a diferenciação celular (fase inicial da embriogênese) e diferenciação do embrião (fase final da embriogênese) no interior do ovo.


Subject(s)
Animals , Female , Oogenesis/physiology , Ovum/growth & development , Triatominae/embryology , Vitellogenesis/physiology , Ovum/chemistry , Triatominae/metabolism , Triatominae/physiology , Vitellogenins/metabolism , Vitellogenins/physiology
4.
Mem. Inst. Oswaldo Cruz ; 82(supl.3): 89-92, 1987. tab
Article in English | LILACS | ID: lil-623744

ABSTRACT

The fates of purified 32P-vitellin and 32P-lipophorin were followed in vitellogenic females of Rhodnius prolixus. While the radioactivity from 32P-vitellin 6 hours after injection was found almost exclusively in the ovary, the radioactivity from injected 32P-lipophorin was found distributed among several organs. In the ovary, the radioactivity from 32P-vitellin was associated with the contents of the yolk granules. 32P-lipophorin delivered a great amount of radioactive phospholipids to the ovary with no accumulation of its protein moiety, as observed after its iodination with 131I. The delivery of phospholipids was inhibited at 0ºC and by the metabolic inhibitors, sodium azide and sodium fluoride. Comparison of the radioactivity incorporation from 32P-lipophorin with that of 14C-inulin suggests that the 32P-phospholipids from lipophorin are not taken up by fluid phase endocytosis. The data presented here are compatible with the concept of lipophorin as a carrier of lipids in insects and provide evidence that lipophorin transports phospholipids as shown previously for other classes of lipids. The utilization by the oocytes of the phospholipids transported by lipophorin is discussed.


Subject(s)
Humans , Rhodnius , Mannheimia haemolytica , Oogenesis , Lipoproteins
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