306 research outputs found
A MOLECULAR EXPLANATION OF SLC25A1 DEFICIENCY RESULTING IN AGENESIS OF CORPUS CALLOSUM AND OPTIC NERVE HYPOPLASIA
No full textMitochondrial carriers (MCs) form a large family of nuclear-encoded transporters embedded in the inner mitochondrial membrane and in a few cases in other organelle membranes (Palmieri, 2013). The members of this superfamily are widespread in eukaryotes and involved in numerous metabolic pathways and cell functions. They can be easily recognized by their striking sequence features, i.e., a tripartite structure, six transmembrane α-helices and a 3-fold repeated signature motifs. Members of the family vary greatly in the nature and size of their transported substrates, modes of transport (i.e., uniport, symport or antiport) and driving forces, although the molecular mechanism of substrate translocation may be basically the same. In recent years mutations in the MC genes have been shown to be responsible for 11 diseases (Palmieri, 2013), highlighting the important role of MCs in metabolism. MC impairing mutations affect three main regions crucial for substrate translocation. A first group of mutations affects MC conformational changes and locates at PG levels or at the aromatic belts (Pierri et al., 2013). A second group of mutations affects substrate specificity and locates at the common substrate binding site (Robinson et al., 2008) and at the substrate binding area (Pierri et al., 2013). A further group of mutations locate at residues of the m-/c-gates (Palmieri et al., 2013; Robinson et al., 2008) and at residues of the m-gate area (Pierri et al. 2013). For this last group of mutations, it appears difficult to establish if the impaired function is due to the lack of substrate specificity (or substrate recognition) or to the wrong triggering of conformational changes. Two mutations, one at the PG level 1 and one at the common substrate binding site, impairing citrate translocation within SLC25A1_CTP protein are presented. The two mutations are found to be responsible of agenesis of corpus callosum and optic nerve hypoplasia (Edvardson et al., 2013).
References
1. Palmieri F. The mitochondrial transporter family SLC25: identification, properties and physiopathology. Mol Aspects Med. 2013;34:465.
2. Pierri CL, Palmieri F, De Grassi A. Single-nucleotide evolution quantifies the importance of each site along the structure of mitochondrial carriers. Cell Mol Life Sci. 2013.
3. Robinson AJ, Overy C, Kunji ER. The mechanism of transport by mitochondrial carriers based on analysis of symmetry. Proc Natl Acad Sci U S A. 2008;105:17766.
4. Edvardson S, Porcelli V, Jalas C, Soiferman D, Kellner Y, Shaag A, Korman SH, Pierri CL, Scarcia P, Fraenkel ND, Segel R, Schechter A, Frumkin A, Pines O, Saada A, Palmieri L, Elpeleg O. Agenesis of corpus callosum and optic nerve hypoplasia due to mutations in SLC25A1 encoding the mitochondrial citrate transporter. J Med Genet. 2013;50:240
From rote procedures to meaningful ones: a blended semiotic approach
No full textThis paper proposed a blended learning approach for supporting undergraduate students to overcome rote learning practices and for helping them to reflect on the rules and relations of the mathematics they are doing. To this aim a learning activity has been set up: it consists in time-restricted online tasks (to solve problems and write argumentation to justify what done), online individual feedbacks from teacher/tutor, weekly face-to-face meeting to discuss the online work. Among the added values of such blended setting we highlight the chance of achieving practices focusing on crucial topic such as argumentation, which are not allowed in traditional lectures based on one-to-hundred/s communication. With respect to written argumentation, here we have investigated students’ protocols, according to the frame of the functional linguistics
Digital storytelling in mathematics: a competence-based methodology
No full textThis paper concerns with the use of digital storytelling in mathematics education as a competence-based methodology. It seems to be well apt to improve students’ capabilities be active solvers of real world problems, according to PISA framework. We present a storytelling model, which takes into account both research results about storytelling from pedagogical area and from story problems in mathematics education. According to the model, we present a use case, consisting in the implementation of a prototype. This latter has been made available to the Regional School Office of Campania (South of Italy) in the context of a project to support schools activities regarding mathematical literacy. Finally, we report some early students’ perceptions and discuss the constraints and limits of the prototype
Storytelling as a Skeleton to Design a Learning Unit: A Model for Teaching and Learning Optics
No full textInstructional design is an essential part of teaching practice: both researchers and teachers are engaged in finding strategies to deal with this complex work. We propose the use of storytelling as a skeleton to structure a long-lasting teaching unit, maintaining coherence and giving meaning to its various elements. We refer to an interpretation of storytelling for educational purposes as a role-playing game, drawing inspiration from the Digital Interactive Storytelling in Mathematics framework. Designing a learning unit based on storytelling means integrating every moment of the teaching–learning process within the narrative: the teacher and students are all part of the same story, which motivates every activity carried out in the unit and contextualizes the tasks performed. Moreover, the assessment is also integrated into the narrative flow. In this study, we designed an exemplary Storytelling Learning Unit (SLU) model for the study of light, promoting modelling and argumentation skills in mathematics and physics. This unit, intended for ninth-grade students in an Italian scientific high school, was co-designed by the teacher of the class in which it will be implemented. This work particularly focuses on the design process. From reflection on the specific unit developed, general design principles for creating a SLU were hypothesized
Adaptative peer grading and formative assessment
No full textPeer grading is a process whereby students are required to grade some of their peers’ assignments as part of their own assignment. Peer grading is capable of improving students’ learning outcomes, metacognition and critical thinking and, at the same time, it can support formative assessment, saving teacher’s time and providing fast feedback, especially for large classes. In this paper we report the results of an experiment where a technology supported peer grading exercise has been assigned to students within a University course on calculus and linear algebra. To improve the reliability of students’ grades, several approaches have been experimented and the obtained results have been compared to grades coming from the teacher. Moreover, we attempted to understand how the peer grading task has contributed to reinforce the development of student’s explanation and argumentation processes
A blended teaching and learning environment for developing attitude towards mathematics
No full textThis paper reports on the experimentation of a blended learning approach
to mathematics at the University level. A first result regards how the teacher’s design exploited the didactical potentialities offered by the facilities of a platform, allowing the conceiving specific task based alternatively, on quiz and assignments. Teacher’s interventions aim to make students reflect, but mainly to make students focus and interrelate the three fundamental aspects of mathematical thinking: the intuitive, the algorithmic and the formal
Peer Review Methodology in a Blended Course for Mathematics Teacher Education
No full textIn the last years, the interest of mathematics educators in digital tools has progressively increased, having as
consequence a great impact on how teachers plan their teaching activities. In this paper we investigate, by using the
Meta-Didactical Transposition, if the peer review methodology, carried out in a blended course, can facilitate
the teachers as instructional designers. The aim of the metadidactical praxeologies put in action by the trainers was
focused on the sharing and reflection with the teachers on a specific topic relative to the argumentative competence. A
qualitative analysis of the educational activities produced by the teachers has shown that the peer review methodology
enables the teachers to improve their role of the instructional designer
The different typologies of assessment for the VSE Method Macro-phase
No full textThe focus of this paper concerns the e-assessment strategy for the valuation and validation of a particular abstract entity: the Virtual Scientific Experiment (VSE) model. This model is included in a particular didactic method, the VSE method (ELeGI D18), which allows the realisation of an inductive-experiential didactic approach. The choice of a particular method with respect to another method depends both on the evaluation of the tutor
in the context and the information linked to the acquisition of knowledge, competences and skills. The term ‘inductive’ comes from the Latin word epagoge and means the process that moves from specific instances up to a generalisation (Rescher, 1980). The induction refers to the different aspects of e-learning: from a more superficial learning (know-how) to a learning contextualised in time and space (know when and know where), where the mental models are made. It happens when the students take part in a specific activity, make intuitions and conduct analyses. More researches in this line are being carried out to find out how cognitive capability can be supported using
the adaptive techniques of assessment to improve the learning process
A collaborative vision for generating available learning experiences
No full textThe first part of this work collects possible directions of current
trends that rule and orientate the dynamics of knowledge (formal, informal), constituting an explanatory premise to the more and more coherent connection between technologies and knowledge seen in its evolution and complexity. In particular, we present the ontology model which the didactic solution of Polo L&K is based on and its applications related to the collaborative vision of learning design, both at a level of macro design (collaborative ontology management) and of micro designing (collaborative based learning experience design
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