The inverse relation between the size and the number of parts

This study analyses children’s understanding of the inverse relationship between size and number of parts when fractions and division situations are involved. A survey by questionnaire was conducted with 42 Portuguese fourth-graders trying to address two questions: 1) How do children understand the inverse relation between size and number of parts in partitive and quotitive division situations? And 2) How do children understand the inverse relation when fractions are involved in part-whole and quotient interpretations? Results suggest that these distinct situations have different impacts on children’s understanding of the inverse relations between the size and the number of parts.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), PortugalNational Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI) with the reference POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

A compreensão das relações numéricas na aprendizagem das frações: um estudo comparativo com crianças brasileiras e portuguesas

The understanding of rational numbers is one of the major conceptual challenges faced by students in mathematics learning in basic education. Regarding fractions, to establish the inverse relationship between the numerator and the denominator becomes a key issue in concept formation. The main goals of this study were: to understand if the inverse relationship between smaller quantities than the unit in quotient and part-whole situations influences the learning of fractions; and to compare Brazilian and Portuguese students’ comprehension of the inverse relationship between quantities in fraction problems, using quotient and part-whole situations. The results indicate that students have a better grasp of the inverse relationship between the quantities in the quotient situation and also showed that Portuguese students performed significantly better than Brazilian students in the both types of situations. The discrepancy in student performance can be explained by differences in the curricula of mathematics in grade four in these countries. Implications for the teaching of mathematics in these two countries were also discussed.A compreensão dos números racionais é um dos maiores desafios conceituais enfrentados pelos estudantes na aprendizagem matemática durante a educação básica. No que diz respeito às frações, estabelecer a relação inversa entre o numerador e o denominador torna-se uma habilidade fundamental na construção do conceito. Os objetivos deste estudo foram: verificar como a compreensão da relação inversa entre quantidades menores do que a unidade, apresentadas nas situações de quociente e parte-todo, influencia na aprendizagem das frações; e perceber se existe diferença no desempenho entre alunos brasileiros e portugueses quanto à compreensão da relação inversa entre quantidades em problemas de fração. Os resultados indicam que os estudantes apresentam uma melhor compreensão da relação inversa entre quantidades na situação quociente e apontam que os desempenhos dos estudantes portugueses são significativamente melhores do que os dos estudantes brasileiros, nos diferentes tipos de situação. A discrepância no desempenho dos estudantes pode ser explicada pelas diferenças nos programas curriculares de matemática no quarto ano nesses países. Implicações no ensino da matemática nesses dois países foram discutidas.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), PortugalNational Funds through the FCT (Foundation for Science and Technology) and co-financed by European Regional Development Funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI) with the reference POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

Portuguese and Brazilian children understanding the inverse relation between quantities: the case of fractions

This study compares Portuguese and Brazilian fourth-graders (n=84) understanding of the inverse relation between quantities when fractions are presented in quotient and part-whole interpretations. It addresses three questions: 1) How do children understand this inverse relation in quotient interpretations of fractions? 2) How do children understand this inverse relation in part-whole interpretation of fractions? 3) Are there differences in performance between Brazilian and Portuguese children concerning these issues? A survey by questionnaire was applied and 16 part-whole and quotient problems were analyzed. Results indicate that quotient interpretation promotes more the understanding of this inverse relation; Portuguese and Brazilian children perform differently when solving the fraction problems.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), PortugalFundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

Mycobacterium szulgai Pulmonary Infection in an Immunocompromised Patient

Mycobacterium szulgai is a slow-growing nontuberculous mycobacterium (NTM). It was first described in 1972 and is responsible for less than 0.2% of all NTM infections. The most common presentation resembles pulmonary tuberculosis, but it may also present as an extrapulmonary disease. It primarily affects individuals with underlying lung disease or immunocompromising conditions. The increasing use of tumor necrosis factor-alpha inhibitors, such as adalimumab, is associated with an increased risk of serious infections. We report a case of Mycobacterium szulgai infection in a 23-year-old woman with a history of childhood pneumonia and Crohn's disease on adalimumab.info:eu-repo/semantics/publishedVersio

Neurological manifestations of COVID-19 in adults and children

Different neurological manifestations of coronavirus disease 2019 (COVID-19) in adults and children and their impact have not been well characterized. We aimed to determine the prevalence of neurological manifestations and in-hospital complications among hospitalized COVID-19 patients and ascertain differences between adults and children. We conducted a prospective multicentre observational study using the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) cohort across 1507 sites worldwide from 30 January 2020 to 25 May 2021. Analyses of neurological manifestations and neurological complications considered unadjusted prevalence estimates for predefined patient subgroups, and adjusted estimates as a function of patient age and time of hospitalization using generalized linear models. Overall, 161 239 patients (158 267 adults; 2972 children) hospitalized with COVID-19 and assessed for neurological manifestations and complications were included. In adults and children, the most frequent neurological manifestations at admission were fatigue (adults: 37.4%; children: 20.4%), altered consciousness (20.9%; 6.8%), myalgia (16.9%; 7.6%), dysgeusia (7.4%; 1.9%), anosmia (6.0%; 2.2%) and seizure (1.1%; 5.2%). In adults, the most frequent in-hospital neurological complications were stroke (1.5%), seizure (1%) and CNS infection (0.2%). Each occurred more frequently in intensive care unit (ICU) than in non-ICU patients. In children, seizure was the only neurological complication to occur more frequently in ICU versus non-ICU (7.1% versus 2.3%, P < 0.001). Stroke prevalence increased with increasing age, while CNS infection and seizure steadily decreased with age. There was a dramatic decrease in stroke over time during the pandemic. Hypertension, chronic neurological disease and the use of extracorporeal membrane oxygenation were associated with increased risk of stroke. Altered consciousness was associated with CNS infection, seizure and stroke. All in-hospital neurological complications were associated with increased odds of death. The likelihood of death rose with increasing age, especially after 25 years of age. In conclusion, adults and children have different neurological manifestations and in-hospital complications associated with COVID-19. Stroke risk increased with increasing age, while CNS infection and seizure risk decreased with age

Reactive oxygen species generation in peripheral blood monocytes and oxidized LDL are increased in hyperlipidemic patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Objectives: Experimental and in vitro evidences have established that reactive oxygen species (ROS) generated by vascular wall cells play a key role in atherogenesis. Here, we evaluated the rate of ROS generation by testing peripheral monocytes in naive hyperlipidemic subjects. Design and methods: Primary hypercholesterolemic, combined hyperlipidemic, and normopilidemic individuals were studied. ROS generation and the mitochondrial electrical transmembrane potential were estimated by flow cytometry. Plasma oxidized (ox) LDL levels and lipid profile were measured by ELISA and enzymatic colorimetric methods. Results: Both hyperlipidemic groups presented significantly higher rates of monocyte ROS generation and elevated plasma levels of ox-LDL. Combined hyperlipidemic subjects presented increased levels of small dense LDL and insulin. Significant positive correlations between monocyte ROS generation and ox-LDL concentrations were found in pooled data. Conclusions: These data provide evidence that ROS production by circulating monocytes from hyperlipidemic subjects may contribute to the systemic oxidative stress and possibly to atherogenesis. (C) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.421212221227Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundo de Apoio ao EnsinoPesquisa e A ExtensAo (FAEPEX/FCM/UNICAMP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq