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/

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Influence of Quaternary Conformation on the Biological Activities of the Asp49-phospholipases A(2)s from Snake Venoms

One of the main components of snake venoms are the Asp49-phospholipases A(2), also known as svPLA(2)s. The study of these toxins is a matter of great scientific interest due to their wide variety of biological effects. In this work we present strong evidences found in literature and other aspects which strengthen the importance of quaternary assembly for understanding the activities and molecular evolution of svPLA(2)s

The Intriguing Phospholipases A(2) Homologues: Relevant Structural Features on Myotoxicity and Catalytic Inactivity

Phospholipases A(2) homologues are found in the venom of Crotalinae snakes, being their main action related to myonecrosis induction. Although many studies on these toxins had already been performed, their mechanism of action remains unclear. Here, important aspects about these toxins are reviewed, including their correct biological assembly and how essential is the natural substitution D49K for their catalytic inactivity

Crystallization and preliminary X-ray diffraction analysis of a Lys49-phospholipase A(2) complexed with caffeic acid, a molecule with inhibitory properties against snake venoms

Phospholipases A(2) (PLA(2)s) are one of the main components of bothropic venoms; in addition to their phospholipid hydrolysis action, they are involved in a wide spectrum of pharmacological activities, including neurotoxicity, myotoxicity and cardiotoxicity. Caffeic acid is an inhibitor that is present in several plants and is employed for the treatment of ophidian envenomations in the folk medicine of many developing countries; as bothropic snake bites are not efficiently neutralized by conventional serum therapy, it may be useful as an antivenom. In this work, the cocrystallization and preliminary X-ray diffraction analysis of the Lys49-PLA(2) piratoxin I from Bothrops pirajai venom in the presence of the inhibitor caffeic acid (CA) are reported. The crystals diffracted X-rays to 1.65 angstrom resolution and the structure was solved by molecular-replacement techniques. The electron-density map unambiguously indicated the presence of three CA molecules that interact with the C-terminus of the protein. This is the first time a ligand has been observed bound to this region and is in agreement with various experiments previously reported in the literature.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Crotoxin: Novel activities for a classic beta-neurotoxin

Crotoxin, the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, was the first snake venom protein to be purified and crystallized. Crotoxin is a heterodimeric beta-neurotoxin that consists of a weakly toxic basic phospholipase A(2) and a nonenzymatic, non-toxic acidic component (crotapotin). The classic biological activities normally attributed to crotoxin include neurotoxicity, myotoxicity, nephrotoxicity and cardiotoxicity. However, numerous studies in recent years have shown that crotoxin also has immunomodulatory, anti-inflammatory, anti-microbial, anti-tumor and analgesic actions. In this review, we describe the historical background to the discovery of crotoxin and its main toxic activities and then discuss recent structure-function studies and investigations that have led to the identification of novel pharmacological activities for the toxin. (C) 2010 Elsevier Ltd. All rights reserved

Biophysical characterization of the recombinant importin-α from neurospora crassa

Neurospora crassa has been widely used as a model organism and contributed to the development of biochemistry and molecular biology by allowing the identification of many metabolic pathways and mechanisms responsible for gene regulation. Nuclear proteins are synthesized in the cytoplasm and need to be translocated to the nucleus to exert their functions which the importin-α receptor has a key role for the classical nuclear import pathway. In an attempt to get structural information of the nuclear transport process in N. crassa, we present herein the cloning, expression, purification and structural studies with N-terminally truncated IMPα from N. crassa (IMPα-Nc). Circular dichroism analysis revealed that the IMPα-Nc obtained is correctly folded and presents a high structural conservation compared to other importins-α. Dynamic light scattering, analytical size-exclusion chromatography experiments and molecular dynamics simulations indicated that the IMPα-Nc unbound to any ligand may present low stability in solution. The IMPα-Nc theoretical model displayed high similarity of its inner concave surface, which binds the cargo proteins containing the nuclear localization sequences, among IMPα from different species. However, the presence of non-conserved amino acids relatively close to the NLS binding region may influence the binding specificity of IMPα-Nc to cargo proteins. Copyright © 2012 Bentham Science Publishers. All Rights Reserved

Biophysical Characterization of the Recombinant Importin-alpha from Neurospora crassa

Neurospora crassa has been widely used as a model organism and contributed to the development of biochemistry and molecular biology by allowing the identification of many metabolic pathways and mechanisms responsible for gene regulation. Nuclear proteins are synthesized in the cytoplasm and need to be translocated to the nucleus to exert their functions which the importin alpha-receptor has a key role for the classical nuclear import pathway. In an attempt to get structural information of the nuclear transport process in N. crassa, we present herein the cloning, expression, purification and structural studies with N-terminally truncated IMP alpha from N. crassa (IMP alpha-Nc). Circular dichroism analysis revealed that the IMP alpha-Nc obtained is correctly folded and presents a high structural conservation compared to other importins-alpha. Dynamic light scattering, analytical size-exclusion chromatography experiments and molecular dynamics simulations indicated that the IMP alpha-Nc unbound to any ligand may present low stability in solution. The IMP alpha-Nc theoretical model displayed high similarity of its inner concave surface, which binds the cargo proteins containing the nuclear localization sequences, among IMP alpha from different species. However, the presence of non-conserved amino acids relatively close to the NLS binding region may influence the binding specificity of IMP alpha-Nc to cargo proteins.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES