O papel de um instrumento de apoio à comunicação matemática numa turma do 4.º ano

Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1.º e 2.º Ciclos do Ensino BásicoA criação de ambientes de sala de aula onde os alunos são agentes efetivos da sua aprendizagem e têm espaço para participar e expor os seus conhecimentos, sabendo que vão ser ouvidos pelo professor e colegas, é, cada vez mais, uma recomendação curricular da atualidade e objeto de estudo. Este relatório dá conta da intervenção realizada numa turma do 4.º ano de escolaridade, com o propósito de promover a aprendizagem, valorizando, sistematicamente, a comunicação. Em simultâneo, explana-se a investigação realizada nesta turma, que envolveu a avaliação do impacto da construção de um instrumento de apoio aos momentos de Comunicação Matemática, no contexto de uma rotina semanal da turma, a Apresentação do Problema da Semana. Com a pretensão de dar resposta às questões (i) quais os contributos de um instrumento de apoio à organização e estruturação dos momentos de comunicação matemática? e (ii) de que forma esse mesmo instrumento contribui para o desenvolvimento de estratégias de resolução de problemas?, investigou-se a evolução da turma quanto à comunicação das resoluções dos problemas e à variedade das estratégias utilizadas, antes e após a construção coletiva do instrumento de apoio. A análise de resultados, feita através da análise das produções dos alunos e das respostas a um questionário que instigou a reflexão sobre o papel do instrumento de apoio ao longo das várias apresentações do problema da semana, permitiu perceber uma crescente variedade de estratégias utilizadas e uma maior preocupação, por parte dos alunos, em organizar e estruturar os momentos de comunicação matemática, bem como em mobilizar um discurso com correção matemática. Este é um estudo que se limita a uma turma, não sendo as suas conclusões generalizáveis, mas que pode contribuir com uma estratégia para melhorar a comunicação matemática dos alunos, de uma forma que os envolve de forma direta e que prevê a sua participação e papel ativo na aprendizagem.ABSTRACT Creating classroom environments where students are effective agents of their learning process and have space to participate and exhibit their skills, knowing that they will be heard by the teacher and classmates, is an increasingly curricular recomendation and object of stdy nowadays. This report gives an account of the intervention carried out on a 4th grade level class, with the purpose of promoting learning, valuing, systematically, the communication. At the same time, explains research performed in this class, which involved the evaluation of the impact of the construction of an instrument in support of Mathematical Communication moments, in the context of a weekly routine of the class, The Presentation of rhe Problem of the Week. With the pretense of responding to questions (i) what are the contributions of an instrument of support to the organization and structuring of moments of mathematical communication? and (ii) how this same instrument contributes to the development of problem solving strategies?, it was investigated the evolution of the class regarding the communication of the resolutions of the problems and the variety of strategies used in problem solving, before and after the collective construction of the instrument. The analysis of results, through the analysis of students’ productions and the replies to a questionnaire that instigated the reflection about the role of the instrument of support along the various presentations of the problem of the week, allowed to realize a growing variety of strategies used and greater concern, on the part of students, to organise and structure the moments of mathematical communication as well as in mobilizing a discourse with mathematical correction. This is a study that is limited to a class, which makes its conclusions not generalizable, but that can contribute with a strategy to improve students’ math communication, in a way that involves them directly and provides their participation and active role in their own learning process.N/

Anticoagulant and fibrinogenolytic properties of the venom of Polybia occidentalis social wasp

Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway). The venom inhibited platelet aggregation and degraded plasma fibrinogen, possibly containing metal-dependent metalloproteases that specifically cleave the B beta-chain of fibrinogen. In conclusion, fibrinogenolytic and anticoagulant properties of this wasp venom find a potential application in drug development for the treatment of thrombotic disorders. For that, further studies should be carried out in order to identify and isolate the active compounds responsible for these effects. Blood Coagul Fibrinolysis 21: 653-659 (c) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)UFF/PROPPConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Para (FAPESPA

Biochemical and functional properties of a thrombin-like enzyme isolated from Bothrops pauloensis snake venom

In the present study, a thrombin-like enzyme named BpSP-I was isolated from Bothrops pauloensis snake venom and its biochemical, enzymatic and pharmacological characteristics were determined. BpSP-I is a glycoprotein that contains both N-linked carbohydrates and sialic acid in its structure, with M(r) = 34,000 under reducing conditions and pI similar to 6.4. The N-terminal sequence of the enzyme (VIGGDECDINEHPFL) showed high similarity with other thrombin-like enzymes from snake venoms. BpSP-I showed high clotting activity upon bovine and human plasma and was inhibited by PMSF, benzamidine and leupeptin. Moreover, this enzyme showed stability when examined at different temperatures (-70 to 37 degrees C), pH values (3-9) or in the presence of divalent metal ions (Ca(2+), Mg(2+), Zn(2+) and Mn(2+)). BpSP-I showed high catalytic activity upon substrates, such as fibrinogen, TAME, S-2238 and S-2288. It also showed kallikrein-like activity, but was unable to act upon factor Xa and plasmin substrates. Indeed, the enzyme did not induce hemorrhage, myotoxicity or edema. Taken together, our data showed that BpSP-I is in fact a thrombin-like enzyme isoform isolated from Bothrops pauloensis snake venom. (C) 2009 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa dos Estados de Minas Gerais (FAPEMIG)Sao Paulo (FAPESP)Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq

BjussuSP-I: A new thrombin-like enzyme isolated from Bothrops jararacussu snake venom

A thrombin-like enzyme named BjussuSP-I, isolated from B. jararacussu snake venom, is an acidic single chain glycoprotein with approximately 6% sugar, Mr = 61,000 under reducing conditions and pI similar to 3.8, representing 1.09% of the chromatographic A(280) recovery. BjussuSP-I is a glycosylated scrine protease containing both N-linked carbohydrates and sialic acid in its structure. BjussuSP-I showed a high clotting activity upon human plasma, which was inhibited by PMSF, leupeptin, heparin and 1,10-phenantroline. This enzyme showed high stability regarding coagulant activity when analyzed at different temperatures (-70 to 37 degrees C), pHs (4.5 to 8.0), and presence of two divalent metal ions (Ca2+ and Mg2+). It also displayed TAME esterase and proteolytic activities toward natural (fibrinogen and fibrin) and synthetic (BAPNA) substrates, respectively, being also inhibited by PMSF and leupeptin. BjussuSP-I can induce production of polyclonal antibodies able to inhibit its clotting activity, but unable to inhibit its proteolytic activity on fibrinogen. The enzyme also showed crossed immunoreactivity against I I venom samples of Bothrops, I of Crotalus, and I of Calloselasma snakes, in addition of LAAO isolated from B. moojeni venom. It displayed neither hemorrhagic, myotoxic, edema-inducing profiles nor proteolytic activity on casein. BjussuSP-I showed an N-terminal sequence (VLGGDECDfNEHPFLA FLYS) similar to other thrombin-like enzymes from snake venoms. Based on its biochemical, enzymatic and pharmacological characteristics, BjussuSP-I was identified as a new thrombin-like enzyme isoform from Bothrops jararacussu snake venom. (C) 2007 Elsevier Inc. All rights reserved

Molecular Characterization of Lys49 and Asp49 Phospholipases A2 from Snake Venom and Their Antiviral Activities against Dengue virus

We report the detailed molecular characterization of two PLA2s, Lys49 and Asp49 isolated from Bothrops leucurus venom, and examined their effects against Dengue virus (DENV). The Bl-PLA2s, named BlK-PLA2 and BlD-PLA2, are composed of 121 and 122 amino acids determined by automated sequencing of the native proteins and peptides produced by digestion with trypsin. They contain fourteen cysteines with pIs of 9.05 and 8.18 for BlK- and BlD-PLA2s, and show a high degree of sequence similarity to homologous snake venom PLA2s, but may display different biological effects. Molecular masses of 13,689.220 (Lys49) and 13,978.386 (Asp49) were determined by mass spectrometry. DENV causes a prevalent arboviral disease in humans, and no clinically approved antiviral therapy is currently available to treat DENV infections. The maximum non-toxic concentration of the proteins to LLC-MK2 cells determined by MTT assay was 40 µg/mL for Bl-PLA2s (pool) and 20 µg/mL for each isoform. Antiviral effects of Bl-PLA2s were assessed by quantitative Real-Time PCR. Bl-PLA2s were able to reduce DENV-1, DENV-2, and DENV-3 serotypes in LLC-MK2 cells infection. Our data provide further insight into the structural properties and their antiviral activity against DENV, opening up possibilities for biotechnological applications of these Bl-PLA2s as tools of research

A new acidic myotoxic, anti-platelet and prostaglandin I(2) inductor phospholipase A(2) isolated from Bothrops moojeni snake venom

Phospholipase A(2) (PLA(2), EC 3.1.1.4), a major component of snake venoms, specifically catalyzes the hydrolysis of fatty acid ester bonds at position 2 of 1,2-diacyl-sn-3-phosphoglycerides in the presence of calcium. This article reports the purification and biochemical/functional characterization of BmooTX-I, a new myotoxic acidic phospholipase A(2) from Bothrops moojeni snake venom. The purification of the enzyme was carried out through three chromatographic steps (ion-exchange on DEAE-Sepharose, molecular exclusion on Sephadex G-75 and hydrophobic chromatography on Phenyl-Sepharose). BmooTX-I was found to be a single-chain protein of 15,000 Da and pI 4.2. The N-terminal sequence revealed a high homology with other acidic Asp49 PLA(2)S from Bothrops snake venoms. It displayed a high phospholipase activity and platelet aggregation inhibition induced by collagen or ADP. Edema and myotoxicity in vivo were also induced by BmooTX-I. Analysis of myotoxic activity was carried out by optical and ultrastructural microscopy, demonstrating high levels of leukocytary infiltrate. Previous treatment of BmooTX-1 with BPB reduced its enzymatic and myotoxic activities, as well as the effect on platelet aggregation. Acidic myotoxic PLA(2)S from Bothrops snake venoms have been little explored and the knowledge of its structural and functional features will be able to contribute for a better understanding of their action mechanism regarding enzymatic and toxic activities. (C) 2008 Elsevier Ltd. All rights reserved.Fundacao de AmparoPesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Pro-Reitoria de Pesquisa e Pos-Graduaco da Universidade Federal Fluminense (UFF/PROPP), Brazi

Molecular characterization of an acidic phospholipase A(2) from Bothrops pirajai snake venom: synthetic C-terminal peptide identifies its antiplatelet region

This paper describes a biochemical and pharmacological characterization of BpirPLA(2)-I, the first acidic Asp49-PLA(2) isolated from Bothrops pirajai. BpirPLA(2)-I caused hypotension in vivo, presented phospholipolytic activity upon artificial substrates and inhibitory effects on platelet aggregation in vitro. Moreover, a synthetic peptide of BpirPLA(2)-I, comprising residues of the C-terminal region, reproduced the antiplatelet activity of the intact protein. A cDNA fragment of 366 bp encompassing the mature form of BpirPLA(2)-I was cloned by reverse transcriptase-PCR of B. pirajai venom gland total RNA. A Bayesian phylogenetic analysis indicated that BpirPLA(2)-I forms a clade with other acid Asp49-PLA(2) enzymes from the Bothrops genus, which are characterized by the high catalytic activity associated with anticoagulant or hypotensive activity or both. Comparison of the electrostatic potential (EP) on the molecular surfaces calculated from a BpirPLA(2)-I homology model and from the crystallographic models of a group of close homologues revealed that the greatest number of charge inversions occurred on the face opposite to the active site entrance, particularly in the Ca2+ ion binding loop. This observation suggests a possible relationship between the basic or acid character of PLA(2) enzymes and the functionality of the Ca2+ ion binding loop.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Instituto Nacional de Ciencia e Tecnologia em Toxinas (INCT-Tox), BrazilUniv São Paulo, Dept Anal Clin Toxicol & Bromatol, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040903 Ribeirao Preto, SP, BrazilUniv Fed Paraiba, DBM, Ctr Ciencias Exatas & Nat, Joao Pessoa, PB, BrazilFiocruz MS, IOC, Lab Bioquim Prot & Peptideos, BR-21045900 Rio de Janeiro, BrazilUFU, Fac Ciencias Integradas Pontal, Ituiutaba, MG, BrazilUniv Fed Fluminense, Inst Biol, Dept Biol Celular & Mol GCM, Niteroi, RJ, BrazilUniversidade Federal de São Paulo, Dept Biofis, São Paulo, BrazilCtr Nacl Pesquisas Energia & Mat, Lab Nacl Biociencias, Campinas, SP, BrazilUniv Fed Sao Joao Del Rei, Divinopolis, MG, BrazilUniversidade Federal de São Paulo, Dept Biofis, São Paulo, BrazilWeb of Scienc

Myotoxic phospholipases A(2) isolated from Bothrops brazili snake venom and synthetic peptides derived from their C-terminal region: Cytotoxic effect on microorganism and tumor cells

This paper reports the purification and biochemical/pharmacological characterization of two myotoxic phospholipases A(2) (PLA(2)S) from Bothrops brazili venom, a native snake from Brazil. Both myotoxins (MTX-I and II) were purified by a single chromatographic step on a CM-Sepharose ion-exchange column up to a high purity level, showing M-r similar to 14,000 for the monomer and 28,000 Da for the dimer. The N-terminal and internal peptide amino acid sequences showed similarity with other myotoxic PLA2S from snake venoms, MTX-I belonging to Asp49 PLA(2) class, enzymatically active, and MTX-II to Lys49 PLA(2)S, catalytically inactive. Treatment of MTX-I with BPB and EDTA reduced drastically its PLA(2) and anticoagulant activities, corroborating the importance of residue His48 and Ca2+ ions for the enzymatic catalysis. Both PLA(2)S induced myotoxic activity and dose-time dependent edema similar to other isolated snake venom toxins from Bothrops and Crotalus genus. The results also demonstrated that MTXs and cationic synthetic peptides derived from their 115-129 C-terminal region displayed cytotoxic activity on human T-cell leukemia (JURKAT) lines and microbicidal effects against Escherichia coli, Candida albicans and Leishmania sp. Thus, these PLA(2) proteins and C-terminal synthetic peptides present multifunctional properties that might be of interest in the development of therapeutic strategies against parasites, bacteria and cancer. (C) 2008 Elsevier Inc. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq

Molecular characterization and phylogenetic analysis of JussuMP-I: A RGD-P-III class hemorrhagic metalloprotease from Bothrops jararacussu snake venom

Snake venom metalloproteases (SVMPs) embody zinc-dependent multidomain enzymes responsible for a relevant pathophysiology in envenomation. including local and systemic hemorrhage. The molecular features responsible for hemorrhagic potency of SVMPs have been associated with their multidomains structures which can target these proteins them to several receptors of different tissues and cellular types. BjussuMP-I. a SVMP isolated from the Bothrops jararacussu venom, has been characterized as a P-III hemorrhagic metalloprotease. The complete cDNA sequence of BjussuMP-I with 1641bp encodes open reading frames of 547 amino acid residues, which conserve the common domains of P-III high molecular weight hemorrhagic metalloproteases: (i) pre-pro-peptide, (ii) metalloprotease, (iii) disintegrin-like and (iv) rich cysteine domain. BjussuMP-I induced lyses in fibrin clots and inhibited collagen- and ADP-induced platelet aggregation. We are reporting, for the first time, the primary structure of an RGD-P-III class snake venom metalloprotease. A phylogenetic analysis of the BjussuMP-1 metalloprotease/catalytic domain was performed to get new insights into the molecular evolution of the metalloproteases. A theoretical molecular model of this domain was built through folding recognition (threading) techniques and refined by molecular dynamics simulation. Then, the final BjussuMP-I catalytic domain model was compared to other SVMPs and Reprolysin family proteins in order to identify eventual structural differences, which could help to understand the biochemical activities of these enzymes. The presence of large hydrophobic areas and some conserved surface charge-positive residues were identified as important features of the SVMPs and other metalloproteases. (C) 2006 Elsevier B.V. All rights reserved

Purification and biochemical characterization of three myotoxins from bothrops mattogrossensis snake venom with toxicity against leishmania and tumor cells

Submitted by Claudete Queiroz ([email protected]) on 2016-05-03T17:49:34Z No. of bitstreams: 1 Purification and Biochemical Characterization of Three Myotoxins from Bothrops mattogrossensis Snake Venom with Toxicity against Leishmania and Tumor Cells.pdf: 2330661 bytes, checksum: d78a494a905fcd4ee4e7b030ef32d219 (MD5)Approved for entry into archive by EMERSON LEAL ([email protected]) on 2016-05-17T13:55:08Z (GMT) No. of bitstreams: 1 Purification and Biochemical Characterization of Three Myotoxins from Bothrops mattogrossensis Snake Venom with Toxicity against Leishmania and Tumor Cells.pdf: 2330661 bytes, checksum: d78a494a905fcd4ee4e7b030ef32d219 (MD5)Made available in DSpace on 2016-05-17T13:55:08Z (GMT). No. of bitstreams: 1 Purification and Biochemical Characterization of Three Myotoxins from Bothrops mattogrossensis Snake Venom with Toxicity against Leishmania and Tumor Cells.pdf: 2330661 bytes, checksum: d78a494a905fcd4ee4e7b030ef32d219 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil. / Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brazil.Universidade Federal Fluminense. Instituto de Biologia. Departamento de Biologia Celular e Molecular. Niterói, RJ, Brazil.Universidade de São Paulo. Faculdade de Ciências Farmacêuticas. Ribeirão Preto, SP, Brazil.Universidade Federal de São João del Rei. Ouro Branco, MG, Brazil.Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil. / Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil. / Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil. / Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Fundação Oswaldo Cruz. Centro de Estudos de Biomoléculas Aplicadas à Saúde. Departamento de Medicina. Núcleo de Saúde. Universidade Federal de Rondônia. Porto Velho, RO, Brazil. / Fundação Oswaldo Cruz. Porto Velho, RO, Brazil.Bothrops mattogrossensis snake is widely distributed throughout eastern South America and is responsible for snakebites in this region. This paper reports the purification and biochemical characterization of three new phospholipases A2 (PLA2s), one of which is presumably an enzymatically active Asp49 and two are very likely enzymatically inactive Lys49 PLA2 homologues. The purification was obtained after two chromatographic steps on ion exchange and reverse phase column. The 2D SDS-PAGE analysis revealed that the proteins have pI values around 10, are each made of a single chain, and have molecular masses near 13 kDa, which was confirmed by MALDI-TOF mass spectrometry. The N-terminal similarity analysis of the sequences showed that the proteins are highly homologous with other Lys49 and Asp49 PLA2s from Bothrops species. The PLA2s isolated were named BmatTX-I (Lys49 PLA2-like), BmatTX-II (Lys49 PLA2-like), and BmatTX-III (Asp49 PLA2). The PLA2s induced cytokine release frommouse neutrophils and showed cytotoxicity towards JURKAT (leukemia T) and SK-BR-3 (breast adenocarcinoma) cell lines and promastigote forms of Leishmania amazonensis. The structural and functional elucidation of snake venoms components may contribute to a better understanding of the mechanism of action of these proteins during envenomation and their potential pharmacological and therapeutic applications