Using pivot signs to reach an inclusive definition of squares and rectangles

We present some fragments of a teaching experiment realized in a first grade classroom, to sow the seeds for a mathematical definition of rectangles that includes squares. Within the paradigm of semiotic mediation, we studied the emergence of pivot signs, which were exploited by the teacher to pave the way towards an inclusive definition of rectangles and squares. This was done to favor overcoming children's spontaneous distinction of these figures into distinct categories, reinforced by everyday language. The experiment is an example of an approach towards the theoretical dimension of mathematics in early childhood

Buone pratiche didattiche per prevenire falsi positivi nelle diagnosi di discalculia: il progetto PerContare

To contrast the phenomenon of false positives in the diagnoses of dyscalculia in Italy, among 3rd grade children, a 3-year project (2011-2014), built upon a collaboration between psychologists and mathematics educators, was carried out. Within the project specific teaching strategies for preventing and addressing learning difficulties in arithmetic arising at the beginning of primary school were designed and tested in schools nation wide. This paper presents the project's background and the theoretical foundations of the didactical material designed, providing also some examples. In particular, prototypical examples will show how the activities, grounded within a kinesthetic-tactile and visual-spatial approach, are designed to lead to students' interiorization of part-whole relations, and to their thinking about multiplication through structured diagrams. Qualitative data confirming effectiveness of the proposed didactical strategies will also be discussed.Comment: in Italia

Febrile rhabdomyolysis of unknown origin in refugees coming from West Africa through the Mediterranean

Abstract Objectives Cases of undiagnosed severe febrile rhabdomyolysis in refugees coming from West Africa, mainly from Nigeria, has been observed since May 2014. The aim of this study was to describe this phenomenon. Methods This was a multicentre retrospective observational study of cases of febrile rhabdomyolysis reported from May 2014 to December 2016 in 12 Italian centres. Results A total of 48 cases were observed, mainly in young males. The mean time interval between the day of departure from Libya and symptom onset was 26.2 days. An average 8.3 further days elapsed before medical care was sought. All patients were hospitalized with fever and very intense muscle aches. Creatine phosphokinase, aspartate aminotransferase, and lactate dehydrogenase values were abnormal in all cases. The rhabdomyolysis was ascribed to an infective agent in 16 (33.3%) cases. In the remaining cases, the aetiology was undefined. Four out of seven patients tested had sickle cell trait. No alcohol abuse or drug intake was reported, apart from a single reported case of khat ingestion. Conclusions The long incubation period does not support a mechanical cause of rhabdomyolysis. Furthermore, viral infections such as those caused by coxsackievirus are rarely associated with such a severe clinical presentation. It is hypothesized that other predisposing conditions like genetic factors, unknown infections, or unreported non-conventional remedies may be involved. Targeted surveillance of rhabdomyolysis cases is warranted

COVID-19 in the tonsillectomised population

Objective: Interactions between SARS-CoV-2 and pharyngeal associated lymphoid tissue are thought to influence the manifestations of COVID-19. We aimed to determine whether a previous history of tonsillectomy, as a surrogate indicator of a dysfunctional pharyngeal associated lymphoid tissue, could predict the presentation and course of COVID-19. Methods: Multicentric cross-sectional observational study involving seven hospitals in Northern and Central Italy. Data on the clinical course and signs and symptoms of the infection were collected from 779 adults who tested positive for SARS-CoV-2, and analysed in relation to previous tonsillectomy, together with demographic and anamnestic data. Results: Patients with previous tonsillectomy showed a greater risk of fever, temperature higher than 39°C, chills and malaise. No significant differences in hospital admissions were found. Conclusions: A previous history of tonsillectomy, as a surrogate indicator of immunological dysfunction of the pharyngeal associated lymphoid tissue, could predict a more intense systemic manifestation of COVID-19. These results could provide a simple clinical marker to discriminate suspected carriers and to delineate more precise prognostic models

Conformationally rigid nucleoside probes help understand the role of sugar pucker and nucleobase orientation in the thrombin-binding aptamer

Modified thrombin-binding aptamers carrying 2′-deoxyguanine (dG) residues with locked North- or South-bicyclo[3.1.0]hexane pseudosugars were synthesized. Individual 2′-deoxyguanosines at positions dG5, dG10, dG14 and dG15 of the aptamer were replaced by these analogues where the North/anti and South/syn conformational states were confined. It was found that the global structure of the DNA aptamer was, for the most part, very accommodating. The substitution at positions 5, 10 and 14 with a locked South/syn-dG nucleoside produced aptamers with the same stability and global structure as the innate, unmodified one. Replacing position 15 with the same South/syn-dG nucleoside induced a strong destabilization of the aptamer, while the antipodal North/anti-dG nucleoside was less destabilizing. Remarkably, the insertion of a North/anti-dG nucleoside at position 14, where both pseudosugar conformation and glycosyl torsion angle are opposite with respect to the native structure, led to the complete disruption of the G-tetraplex structure as detected by NMR and confirmed by extensive molecular dynamics simulations. We conclude that conformationally locked bicyclo[3.1.0]hexane nucleosides appear to be excellent tools for studying the role of key conformational parameters that are critical for the formation of a stable, antiparallel G-tetrad DNA structures

Whole number thinking, learning and development: neuro-cognitive, cognitive and developmental approaches

The participants of working group 2 presented a broad range of studies, 11 papers in total, related to whole number learning representing research groups from 11 countries as follows. Two large cross-sectional studies focused on developmental aspects of young children’s number learning provide a lens for re-examining ‘traditional’ features of number acquisition. van den Heuvel-Panhuizen (the Netherlands) presented a co-authored paper with Elia (Cyprus; Elia and van den Heuvel-Panhuizen 2015) on a cross-cultural study of kindergartners’ number competence focused on counting, additive and multiplicative thinking. Second, Milinković (2015) examined the development of young Serbian children’s initial understanding of representations of whole numbers and counting strategies in a large study of 3- to 7-year-olds. Children’s invented (formal) representations such as set representation and the number line were found to be limited in their recordings. In a South African study focused on early counting and addition, Roberts (2015) directs attention to the role of teachers by providing a framework to support teachers’ interpretation of young disadvantaged learners’ representations of number when engaging with whole number additive tasks. Some papers reflected the increasing role of neuroscientific concepts and methodologies utilised in research on WNA learning and development. Sinclair and Coles (2015) drew upon neuroscientific research to highlight the significant role of symbol-to-symbol connections and the use of fingers and touch counting exempli- fied by the TouchCounts iPad app. Gould (2015) reported aspects of a large Australian large study of children in the first years of schooling aimed at improving numeracy and literacy in disadvantaged communities. A case study exemplified how numerals were identified by relying on a mental number line by using location to retrieve number names. This raised the question addressed in the neuroscientific work of Dehaene and other papers focused on individual differences in how the brain processes numbers. The Italian PerContare1 project (Baccaglini-Frank 2015) built upon the collaboration between cognitive psychologists and mathematics educators, aimed at developing teaching strategies for preventing and addressing early low achievement in arithmetic. It takes an innovative approach to the development of number sense that is grounded upon a kinaesthetic and visual-spatial approach to part-whole relationships. Mulligan and Woolcott (2015) provided a discussion paper on the underlying nature of number. They presented a broader view of mathematics learning (including WNA) as linked to spatial interaction with the environment; the concept of connectivity across concepts and the development of underlying pattern and structural relationships are central to their approach

Cupricyclins, Novel Redox-Active Metallopeptides Based on Conotoxins Scaffold

Highly stable natural scaffolds which tolerate multiple amino acid substitutions represent the ideal starting point for the application of rational redesign strategies to develop new catalysts of potential biomedical and biotechnological interest. The knottins family of disulphide-constrained peptides display the desired characteristics, being highly stable and characterized by hypervariability of the inter-cysteine loops. The potential of knottins as scaffolds for the design of novel copper-based biocatalysts has been tested by engineering a metal binding site on two different variants of an ω-conotoxin, a neurotoxic peptide belonging to the knottins family. The binding site has been designed by computational modelling and the redesigned peptides have been synthesized and characterized by optical, fluorescence, electron spin resonance and nuclear magnetic resonance spectroscopy. The novel peptides, named Cupricyclin-1 and -2, bind one Cu2+ ion per molecule with nanomolar affinity. Cupricyclins display redox activity and catalyze the dismutation of superoxide anions with an activity comparable to that of non-peptidic superoxide dismutase mimics. We thus propose knottins as a novel scaffold for the design of catalytically-active mini metalloproteins

The PerContare Project: Proposed Teaching Strategies and Some Developed Materials

PerContare is a 3-year project aimed at developing effective inclusive teaching strategies and materials to help primary school teachers (in grades 1, 2, and 3) address learning difficulties, especially those of students who are potentially at risk of being diagnosed with developmental dyscalculia. The teaching strategies and materials developed involved the use of digital and physical artifacts to help students construct mathematical meanings in a solid way. Each year the materials developed are pilot tested in 15 experimental classrooms, and tested the year after in 5 new experimental classrooms whose results are compared with those of control classrooms. In this poster we describe some of the proposed teaching strategies and material that has been developed within the project

Using pivot signs to reach an inclusive definition of rectangles and squares

International audienceWe present some fragments of a teaching experiment realized in a first grade classroom, to sow the seeds for a mathematical definition of rectangles that includes squares. Within the paradigm of semiotic mediation, we studied the emergence of pivot signs, which were exploited by the teacher to pave the way towards an inclusive definition of rectangles and squares. This was done to favor overcoming children's spontaneous distinction of these figures into distinct categories, reinforced by everyday language. The experiment is an example of an approach towards the theoretical dimension of mathematics in early childhood

Una strategia BIM applicata alla gestione dei costi | A BIM strategy applied to cost management

La crescente adozione del BIM nel contesto nazionale italiano ha generato una serie di considerazioni sulla progressiva transizione digitale delle pubbliche amministrazioni con il decreto DM 560/2017. Tale fase prevede la trasformazione del processo edilizio tradizionale mediante l’adozione di metodi e strumenti innovativi BIM-based. Il contributo affronta il tema della definizione di una strategia BIM basata sulla relazione tra i contesti normativo, tecnologico e procedurale. Attraverso l'analisi e la correlazione dei tre domini, è stata esplorata una metodologia operativa applicata alla gestione dei costi per identificare i punti di forza e di debolezza del processo 5D BIM. Lo studio ha permesso di identificare, attraverso il concetto di livello di fabbisogno informativo, i contenuti grafici e alfanumerici di un modello BIM sulla base dei Model Uses specifici della commessa. L’approccio seguito intende valorizzare il ruolo della modellazione informativa, dell’interoperabilità e della visualizzazione dei prodotti ottenuti dal processo BIM. Lo studio pone in evidenza la necessità di adeguare gli standard procedurali tradizionali a quelli introdotti dall’innovazione tecnologica. | The increasing adoption of BIM in the Italian national context has generated a series of considerations on the progressive digital transition of public administrations with the DM 560/2017 decree. This phase involves the transformation of the traditional building process through the adoption of innovative BIM-based methods and tools. The paper faces the definition of a BIM strategy based on the relationship between the regulatory, technological and procedural domains. Through the analysis and correlation of the three domains, an operational methodology applied to cost management was explored to identify strengths and weaknesses of the 5D BIM process. Graphic and alphanumeric contents of a BIM model were identified through the concept of level of information needs, starting from specific Model Uses of the process procurement. The followed approach aims at enhancing the role of information modeling, interoperability and visualization of deliverables from the BIM process. The study highlights the need to gear traditional procedural standards to those introduced by innovation technology