Functionalized biodegradable electrospun scaffolds and nanoengineered particles as innovative tools for vascular medicine

In the Western World, atherosclerosis-related diseases, including coronary and peripheral arterial pathologies, are one of the most common cause of morbidity and mortality. In some cases, in order to restore the blood flow, preserving all the functions of the downstream tissue, is necessary to introduce an arterial bypass or substitute in the patient. If autologous veins or artery are not available for different reasons (previous harvest, anatomical defects and anomalies, disease progression, other vascular problems etc.), artificial vascular constructs are required

Matematical Language and Advanced Mathematics Learning

This paper is concerned with the role of language in mathematics learning at college level. Its main aim is to provide a perspective on mathematical language appropriate to effectively interpret students’ linguistic behaviors in mathematics and to suggest new teaching ideas. Examples are given to show that the explanation of students’ behaviors requires to take into account the role of context. Some ideas from functional linguistics are outlined and some features of the texts usually produced by students are discussed and compared to the corresponding features of standard mathematical texts. Some teaching implications are discussed as well

Language in argumentation and solution of problems with graphs

Il lavoro indaga le argomentazioni degli studenti universitari prodotte allo scopo di giustificare le loro risposte a problemi introduttivi di analisi matematica che richiedano il riconoscimento di relazioni fra grafici, testi verbali e formule. L'esame dei testi argomentativi prodotti in un ampio arco di tempo mette in luce serie difficolt\ue0 linguistiche e suggerisce che non possiamo escludere che il linguaggio possa essere un fattore determinante per la qualit\ue0 degli argomenti. L'obiettivo principale dello studio \ue8 il raggiungimento di una migliore comprensione di come le difficolt\ue0 linguistiche influenzino le argomentazioni

Developing language through communication and conversion of semiotic systems

This paper investigates the use of language by 2 classes of 7th graders in a context involving linguistic exchanges and conversions between representation systems in mathematical setting. The pupils were given tasks requiring the verbal description of a figure by means of a written text with no drawings for one class, and the interpretation of the text for the other. Both the tasks have been dealt with through discussion. The constraints involved in the experiment (communication with people not sharing the same context of situation; conversions between figures, written and spoken texts) have been designed in order to promote the acquisition of linguistic skills suitable for the learning of mathematics

Interpreting symbolic statements as texts: an exploratory study

This paper is devoted to the problem of the interpretation of mathematical texts . Some ideas on mathematical language are shortly discussed with the help of some constructs from functional linguistics. Some evidence regarding the interpretation processes of a symbolic text by groups of 10-graders, including both written answers and the transcriptions of spoken interactions is presented and discussed. The outcomes of this study show that students often try to interpret mathematical statements according to everyday-life schemes. This suggests that in school practice mathematical expressions should be dealt with as texts (rather than as abbreviations or local conventions) and that metalinguistic awareness should become one of the the goals of both linguistic and mathematical education

Cortical Motor Organization, Mirror Neurons, and Embodied Language: An Evolutionary Perspective

The recent conceptual achievement that the cortical motor system plays a crucial role not only in motor control but also in higher cognitive functions has given a new perspective also on the involvement of motor cortex in language perception and production. In particular, there is evidence that the matching mechanism based on mirror neurons can be involved in both pho-nological recognition and retrieval of meaning, especially for action word categories, thus suggesting a contribution of an action–perception mechanism to the automatic comprehension of semantics. Furthermore, a compari-son of the anatomo-functional properties of the frontal motor cortex among different primates and their communicative modalities indicates that the combination of the voluntary control of the gestural communication systems and of the vocal apparatus has been the critical factor in the transition from a gestural-based communication into a predominantly speech-based system. Finally, considering that the monkey and human premotor-parietal motor system, plus the prefrontal cortex, are involved in the sequential motor organization of actions and in the hierarchical combination of motor elements, we propose that elements of such motor organization have been exploited in other domains, including some aspects of the syntactic structure of language

On prospective teachers' evaluations of freshman students' written arguments

n this paper we present a qualitative study in which we analyse how a group of prospective mathematics teachers evaluates written arguments produced by freshman students solving a problem involving graphs. The prospective teachers were attending a course of Mathematics Education for the second year of a master degree in Mathematics. In particular we focus on how prospective teachers in their evaluations look at mathematical content, language, and argumentative structure. The outcomes show, on the one hand, a certain attention to some linguistic aspects, on the other hand, a greater attention to the content than to the argumentative structure of the texts. We suggest that prospective teachers' models for linguistic education are often the standard ones, based on conformity to grammar or style rather than on adequacy with respect to goals

L'interpretazione dei testi matematici tra processi cooperativi e modelli logici: il caso dei connettivi

Il tema delle competenze logiche richieste per capire la matematica è stato quasi sempre oggetto di controversie sul piano educativo, tra i sostenitori dell'insegnamento della logica come disciplina e quelli che la guardano come una competenza trasversale. Il problema viene spesso sollevato nel corso della scuola secondaria di secondo grado e all'inizio dei corsi universitari. In questo contributo si discutono i processi di interpretazione dei testi matematici in linguaggio verbale, e il potenziale conflitto tra i meccanismi interpretativi propri delle notazioni simboliche della matematica e quelli usuali delle lingue. Viene affrontato in particolare il tema dell'interpretazione dei condizionali, anche attraverso l'esame di due teorie opposte. Vengono poi illustrati alcuni esempi a proposito di altri connettivi proposizionali. La conclusione è che la diversità dei processi interpretativi tra lingua e linguaggi della logica sconsiglia di proporre attività che richiedono l'interpretazione logica di testi verbali al di fuori dei contesti in cui questa sia giustificata

Cued repetition of self-directed behaviors in macaques (Macaca nemestrina)

Two macaques were trained to perform three self-directed behaviors on signal, and to repeat behaviors after a ‘repeat’ signal. The cognitive processes underlying the monkeys’ repeat performance were evaluated using multiple repetitions of the repeat signal, extended delay periods between target behavior and repeat signal, and by transferring the repeat signal to novel behaviors. The monkeys appear to have used representations of their own past behaviors as a basis for repetition performance, but they mostly failed to correctly repeat target behaviors after extended delays and during transfer tasks. Implications for episodic memory abilities are discussed

Small diameter vascular grafts coated with gelatin

In the field of tissue engineering, there is an increased demand for small diameter vascular grafts to treat peripheral vascular pathologies and ischemic heart diseases. The limited availability of suitable autogenous veins and the drawbacks related to the use of synthetic materials, such as polyethylene terephthalate (Dacron\uc2\uae) and expanded polytetrafluoroethylene (ePTFE), especially when they are used as substitutes for small diameter vessels, have attracted several investigators turning their attention toward the fabrication of alternative biocompatible grafts. In this study, small diameter tubular grafts (2 mm), made of poly (\ucf\ub5-caprolactone) (PCL) and poly (glycerol sebacate) (PGS) at a ratio of 1:1 (v/v) were obtained by electrospinning. With the aim to reduce water permeability, their surface was modified by dynamic coating of gelatin at 37 \uc2\ub0C for 1 h, followed by UV-irradiation. Thickness, fiber diameters, porosity, mass loss, fluid uptake, water permeability, gelatin release, mechanical properties, cytotoxicity, and hemocompatibility of gelatin-coated electrospun scaffolds (GCS) were studied and compared with uncoated scaffolds (UCS). Scanning electron microscopy (SEM) images showed that the gelatin surface modification did not affect the 3D structure and pore interconnectivity of the scaffolds. A significant decrease in the water permeability was noticed when gelatin was used as coating agent. The results of this study highlighted the importance of a very low cost surface treatment with gelatin to improve the properties of PCL:PGS electrospun grafts. In conclusion, these gelatin-coated prostheses could be considered as a good candidate for vascular replacement in tissue engineering