Search results for " Complement"

Integrazione e apprendimento: un’esperienza laboratoriale tra Lingua e Matematica alla Scuola dell’Infanzia

2017

Drawings, Gestures and Discourses: A Case Study with Kindergarten Students Discovering Lego Bricks

2020

This paper presents a study aimed at investigating the didactic potentiality of the use of an artefact, useful to construct mathematical meanings concerning the coordination of different points of view, in the observation of a real object/toy. In our view, the process of meaning construction can be fostered by the use of adequate artefacts, but it requires a teaching/learning model, which explicitly takes care of the evolution of meanings, from those personal, emerging through the activities, to the mathematical ones, aims of the teaching intervention. The main hypothesis of this study is that the alternation between different semiotic systems, graphical system, verbal system and system of …

The Histidinol Phosphate Phosphatase Involved in Histidine Biosynthetic Pathway Is Encoded by SCO5208 (hisN) in Streptomyces coelicolor A3(2)

2008

Through the screening of a Streptomyces coelicolor genomic library, carried out in a histidinol phosphate phosphatase (HolPase) deficient strain, SCO5208 was identified as the last unknown gene involved in histidine biosynthesis. SCO5208 is a phosphatase, and it can restore the growth in minimal medium in this HolPase deficient strain when cloned in a high or low copy number vector. Moreover, it shares sequence homology with other HolPases recently identified in Actinobacteria. During this work a second phosphatase, SCO2771, sharing no homologies with SCO5208 and all so far described phosphatases was identified. It can complement HolPase activity mutation only at high copy number. Sequence …

Host-Nonspecific Iron Acquisition Systems and Virulence in the Zoonotic Serovar of Vibrio vulnificus

2014

ABSTRACT The zoonotic serovar of Vibrio vulnificus (known as biotype 2 serovar E) is the etiological agent of human and fish vibriosis. The aim of the present work was to discover the role of the vulnibactin- and hemin-dependent iron acquisition systems in the pathogenicity of this zoonotic serovar under the hypothesis that both are host-nonspecific virulence factors. To this end, we selected three genes for three outer membrane receptors ( vuuA , a receptor for ferric vulnibactin, and hupA and hutR , two hemin receptors), obtained single and multiple mutants as well as complemented strains, and tested them in a series of in vitro and in vivo assays, using eels and mice as animal models. Th…

Trophic and spatial complementarity on seed dispersal services by birds, wild mammals, and cattle in a Mediterranean woodland pasture

2021

Made available in DSpace on 2022-05-01T09:47:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Università degli Studi di Palermo CYTED Ciencia y Tecnología para el Desarrollo Federación Española de Enfermedades Raras Most earth surfaces have undergone intensive land-use changes, creating habitat mosaics. Seed dispersal by animals is a crucial process in such mosaics, but community-wide studies comparing the functional complementarity and response to man-imposed habitat heterogeneity are rare. Here, we investigate the trophic and spatial seed dispersal networks underpinning a strong, woody vegetation expansion over a pastureland inside the largest forest remnant in western Sici…

Dense Geometry of Music and Visual Arts: Vanishing Points, Continuous Tonnetz, and Theremin Performance

2018

The dualism between continuous and discrete is relevant in music theory as well as in performance practice of musical instruments. Geometry has been used since longtime to represent relationships between notes and chords in tonal system. Moreover, in the field of mathematics itself, it has been shown that the continuity of real numbers can arise from geometrical observations and reasoning. Here, we consider a geometrical approach to generalize representations used in music theory introducing continuous pitch. Such a theoretical framework can be applied to instrument playing where continuous pitch can be naturally performed. Geometry and visual representations of concepts of music theory and…

An Inquiry-Based Approach to a Pedagogical Laboratory for Primary School Teacher Education

2017

In questo articolo vengono presentati e di- scussi alcuni risultati relativi alla sperimen- tazione di due esperienze di didattica laboratoriale della fisica, una basata su me- todi di indagine scientifica e l’altra su meto- dologie didattiche più “tradizionali”, svolte durante l’A.A. 2014-15 con studenti del CdL in Scienze della Formazione Primaria del- l’Università di Palermo. I dati, analizzati tra- mite metodi quantitativi, sono stati ricavati dalla somministrazione prima, durante e do- po le attività laboratoriali, di un questionario finalizzato a comprendere gli stili di insegna- mento preferiti dagli studenti, la motivazio- ne di questi all’apprendimento/insegna- mento delle scienze …

Multidimensional Scaling in Cluster Analysis: examples in Science and Mathematics Education

2021

Several researches in STEM education research highlight the advantages of an inte- grated approach to these disciplines that relates knowledge and know-how, design and implementation, theoretical and practical problems [5, 4, 6]. In some researches, the effectiveness of these approaches on students conceptual understanding and motivation and has been studied through the use of quantitative analysis tools such as cluster analysis (CLA) [1, 7]. Through CLA it is possible to characterize students analyzing the strategies they deploy to tackle, for example, questionnaires built so as to investigate the lines of reasoning implemented by them when they are proposed with problematic situations. In…

A Phenomenological Study About the Effect of Covid-19 Pandemic on the Use of Teaching Resources in Mathematics

2023

In this contribution, we discuss phenomenological research related to a pilot study carried out by the Consortium of the MaTeK Horizon 2020 project during the 2020–21 academic year. The research aims to analyse the effects of the Covid-19 pandemic on the use of teaching resources in mathematics in five coun- tries. A questionnaire made of seven questions was administered to a data sample made of teachers of all grades. The answers coming from the questionnaire were quantitatively and qualitatively analysed. Closed-ended questions were analysed by using a clustering methodology called k-means. Open-ended questions were qualitatively analysed. The results show that almost all the teachers are…

Italian Primary School prospective teachers beliefs about knowledge construction: a case study about models

2012

In this paper we discuss a study on the approaches to modeling of students of the 4-year Primary School Teacher program at the University of Palermo, Italy. The answers to a specially designed questionnaire are analyzed on the basis of an a-priori analysis made using a general scheme of reference on the epistemology of mathematics and physics. The study is performed by using quantitative data analysis methods, i.e. analysis of implicative and similarity trees. Dans ce papier, nous menons une étude relative à l’approche de la notion de modélisation par des étudiants de 4ème année de formation à la fonction de professeur d’école primaire à l’Université de Palerme, Italie. Les réponses à un qu…