A calculadora gráfica no ensino básico com o contributo da Mediação Semiótica

Este artigo visa analisar a resolução de uma tarefa de Geometria, de índole exploratória, com recurso ao artefacto mediador, calculadora gráfica. Procurou-se compreender como é que o aluno promoveu signos de artefacto através do desenvolvimento de esquemas de uso e esquemas de ação instrumentada. Posteriormente, na discussão coletiva, pretendemos analisar como é que a professora promoveu a transição desses signos de artefacto para signos matemáticos. Utilizando uma metodologia de investigação qualitativa de natureza interpretativa e descritiva, adotou-se a modalidade estudo de caso, focada no trabalho de dois pares de alunos. Os resultados evidenciam que a calculadora gráfica, funcionou como um instrumento de mediação semiótica e a orquestração da professora na discussão coletiva foi imprescindível para o desenvolvimento do potencial semiótico deste artefacto, resultando na construção do conhecimento matemático.Abstract This article aims to analyze the resolution of an exploratory Geometry task, with the mediator artifact, graphing calculator. We sought to understand how the student promoted artifact signs through the development of usage schemes and instrumented action schemes. Later, in the collective discussion, we sought to analyze how the teacher promoted the transition from artifact signs into mathematical signs. Using a qualitative research methodology of an interpretive and descriptive nature, a case study modality was used focusing on the work of two pairs of students. The results show that the graphing calculator worked as an instrument of semiotic mediation and the teacher’s orchestration in the collective discussion was essential to the development of the semiotic potential of this artifact, resulting in the construction of mathematical knowledge.Resumen Este artículo tiene como objetivo analizar la resolución de una tarea de Geometría, de naturaleza exploratoria, utilizando el artefacto mediador, la calculadora gráfica. Buscamos entender cómo el estudiante promovió signos de artefacto mediante el desarrollo de esquemas de uso y esquemas de acción instrumentada. Después, en el debate colectivo, buscamos analizar cómo el profesor promovió la transición de estos signos de artefacto a signos matemáticos. Utilizando una metodología de investigación cualitativa de carácter interpretativo y descriptivo, se adoptó la modalidad de estudio de caso, centrada en el trabajo de dos parejas de estudiantes. Los resultados muestran que la calculadora gráfica funcionó como un instrumento de mediación semiótica y la orquestación de la profesora en la discusión colectiva fue indispensable para el desarrollo del potencial semiótico de este artefacto, lo que resultó en la construcción del conocimiento matemático.Résumé Cet article vise à analyser la résolution d’une tâche Géométrique, de nature exploratoire, à l’aide du médiateur d’artefacts, calculatrice graphique. Nous avons essayé de comprendre comment l’élève a promu des signes d’artefacts grâce à l’élaboration de schémas d’utilisation et de schémas d’action instrumentés. Plus tard, dans la discussion collective, nous avons l’intention d’analyser comment l’enseignant a favorisé la transition de ces signes d’artefacts vers des signes mathématiques. En utilisant une méthodologie de recherche qualitative de nature interprétative et descriptive, la modalité de l’étude de cas a été adoptée, axée sur le travail de deux paires d’étudiants. Les résultats montrent que la calculatrice graphique fonctionnait comme un instrument de médiation sémiotique et que l’orchestration de l’enseignant dans la discussion collective était indispensable au développement du potentiel sémiotique de cet artefact, ce qui a entraîné la construction de connaissances mathématiques.info:eu-repo/semantics/publishedVersio

Intradermal DNA Electroporation Induces Cellular and Humoral Immune Response and Confers Protection against HER2/neu Tumor

Skin represents an attractive target for DNA vaccine delivery because of its natural richness in APCs, whose targeting may potentiate the effect of vaccination. Nevertheless, intramuscular electroporation is the most common delivery method for ECTM vaccination. In this study we assessed whether intradermal administration could deliver the vaccine into different cell types and we analyzed the evolution of tissue infiltrate elicited by the vaccination protocol. Intradermal electroporation (EP) vaccination resulted in transfection of different skin layers, as well as mononuclear cells. Additionally, we observed a marked recruitment of reactive infiltrates mainly 6–24 hours after treatment and inflammatory cells included CD11c+. Moreover, we tested the efficacy of intradermal vaccination against Her2/neu antigen in cellular and humoral response induction and consequent protection from a Her2/neu tumor challenge in Her2/neu nontolerant and tolerant mice. A significant delay in transplantable tumor onset was observed in both BALB/c ( ≤ 0,0003) and BALB-neuT mice ( = 0,003). Moreover, BALB-neuT mice displayed slow tumor growth as compared to control group ( < 0,0016). In addition, while in vivo cytotoxic response was observed only in BALB/c mice, a significant antibody response was achieved in both mouse models. Our results identify intradermal EP vaccination as a promising method for delivering Her2/neu DNA vaccine

Expressed Alu repeats as a novel, reliable tool for normalization of real-time quantitative RT-PCR data

Expressed Alu repeats are a reliable, accurate and universal reference for use in RT-qPCR normalization of human gene

Cell wall-associated alpha-glucan is instrumental for Mycobacterium tuberculosis to block CD1 molecule expression and disable the function of dendritic cell derived from infected monocyte.

Summary We previously described an escape mechanism exploited by Mycobacterium tuberculosis (Mtb) to prevent the generation of fully competent dendritic cells (DC). We have now tested the effect of isolated mycobacterial components on human monocyte dif- ferentiation into DC and demonstrated that cell wall (CW)-associated alpha-glucan induces monocytes to differentiate into DC (Glu-MoDC) with the same altered phenotype and functional behaviour of DC derived from Mtb-infected monocytes (Mt-MoDC). In fact, Glu- MoDC lack CD1 molecule expression, fail to upregu- late CD80 and produce IL-10 but not IL-12. We also showed that Glu-MoDC are not able to prime effector T cells or present lipid antigens to CD1-restricted T-cell clones. Thus, we propose a mechanism of Mtb- monocyte interaction mediated by CW-associated alpha-glucan, which allows the bacterium to evade both innate and acquired immune responses

The role of mutated SOD1 gene in synaptic stripping and MHC class I expression following nerve axotomy in ALS murine model

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motoneuron death. Several cellular pathways have been described to be involved in ALS pathogenesis; however, the involvement of presynaptic stripping and the related MHC class I molecules in mutant SOD1 motoneurons remains to be clarified. To this purpose, we here investigated, for the first time, the motoneurons behavior, di per seand after facial axonal injury, in terms of synaptic stripping and MHC class I expression in wild-type (Wt) mice and in a murine model of ALS, the SOD1(G93A) mice, at the presymptomatic and symptomatic stage of the disease. Concerning Wt animals, we found a reduction in synaptophysin immunoreactivity and an increase of MHC class I molecules in facial motoneurons after axotomy. In uninjured motoneurons of SOD1(G93A) mice, an altered presynaptic framework was evident, and this phenomenon increased during the disease course. The alteration in the presynaptic input is related to excitatory fibers. Moreover, after injury, a further decrease of excitatory input was not associated to an upregulation of MHC class I molecules in motoneuron soma. This study demonstrates, for the first time, that the presence of mutated SOD1 protein affects the MHC class I molecules expression, altering the presynaptic input in motoneurons. Nevertheless, a positive MHC class I immunolabeling was evident in glial cells around facial injured motoneurons, underlying an involvement of these cells in synaptic stripping. This study contributes to better understand the involvement of the mutated SOD1 protein in the vulnerability of motoneurons after damage

Mycobacterium tuberculosis may escape helper T cell recognition by infecting human fibroblasts

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Blood volume is improved by forced mild physical training in the motor and hippocampal cortex of old mice

The effect of mild forced physical training [1] (treadmill running 30 min a day, five days a week for 30 days at belt speed = 8 m/min, 0% incline) on the motor and hippocampal brain cortex was investigated in old (&gt;24mo) mice by means of magnetic resonance imaging. The possible additive effect of physical training and testosterone [2] administration was also examined. Cortical thickness, quantitative transverse relaxation time (T2) maps, and regional cerebral blood volume (rCBV) were evaluated at baseline and after training. Results show that physical training alone induced significant increase of rCBV in both motor and hippocampal cortex. Cortex thickness and T2 maps were similar before and after training. Similar results were obtained in testosterone treated mice suggesting that testosterone does not add to physical training effect. This work provides first quantitative evidence that exercise initiated at old age is able to improve the hemodynamic status of the brain cortex in key regions for movement and cognition without inducing edema

Synaptic stripping and MHC class I expression in the facial motor nucleus of ALS mice

Pathogenetic mechanisms involved in the fatal, still incurable neurodegenerative disease amyotrophic lateral sclerosis (ALS), characterized by progressive motoneuron death, await full clarification, important for the development of new therapeutic approaches. In the ALS murine model provided by mutant SOD1(G93A) mice, we here investigated the presynaptic wiring of facial motoneurons in basal conditions and after facial nerve transection (a classical paradigm to examine the retrograde motoneuron response to injury), and major histocompatibility (MHC) class I antigen expression after axotomy. The study was based on fluorescent retrograde labeling of motoneurons, synaptophysin and MHC class I antigen immunostaining, electron microscopy. A significant decrease of excitatory axosomatic boutons was found in presymptomatic ALS mice compared to the wild-type (Wt) counterpart, indicating the occurrence of excitatory synapse detachment (presynaptic stripping) in mutant motoneurons. Synaptic stripping, which seems to represent a protective mechanism preserving the inhibitory input, became more marked in facial motoneurons of symptomatic ALS mice. After axotomy, synaptic stripping was consistently enhanced in ALS mice. In the axotomized facial motoneurons of Wt mice synaptic stripping was accompanied by induction of MHC class I antigens, immune molecules implicated in activity-dependent changes in synaptic connectivity and regeneration after injury. MHC class I antigen induction was instead decreased in the axotomized facial nucleus of presymptomatic ALS mice, and was very low, occurring only in glial cells, in symptomatic ALS mice. The findings demonstrate enhanced loss of excitatory presynaptic terminals, as well as a dissociation between this process and MHC class I antigen expression after injury, in motoneurons which carry a mutation committing them to death. The findings also implicate MHC class I antigen induction in glial cells surrounding ALS motoneurons in this intercellular crosstalk

Prospettive e potenzialità della digitalizzazione del settore forestale in Italia

Information and Communication Technologies (ICT) play a key role for improving the implementation of sustainable forest management at local, regional, and global level. The ICT potential to easily exploit a wider and more up-to-date set of information on the economic, environmental, and so- cial value of forests is of relevant help for the daily work of technicians, land owners, and companies in boosting the efficiency and effectiveness of forest management. The concept of “Precision Forestry” (PF) was developed from the early 2000s, as a branch of precision farming or precision agriculture. PF includes the use of ICT, remote and proximal sensing technologies, and other devices to coordinate and control several processes on a spatial scale (“Precision”) for monitoring, planning, and managing forest resources (“Forestry”). The aim of this monography is to collect and describe some of the most important PF experiences applied or potential- ly useful for the Italian forestry sector. It may represent a reference guide for the stakeholders, such as forest owners, professional technicians, public administrators, and policy makers. The book includes eleven chapters reviewing the main tech- nological tools available in the Italian context and the most recent advances of ICT in forestry, also focusing on the strengths and weaknesses of their practical implementation. The opportunities and challenges of implementing PF meth- ods, practices and technologies are also discussed. In the first two chapters the precision forestry concept and its historical development are introduced. In the third chap- ter some basic elements of ICT, GIS, Global Navigation Satellite Systems (GNSS), remote/proximal sensing, and related technologies which are essential for a better compre- hension of PF applications are recalled. In chapter 4 recent advances in large scale forest inventories with a focus on mapping and on the spatial estimation of forest variables integrating field surveys and multisource re- motely sensed data are described. Current advancements in the acquisition of field information including Terrestrial La- ser Scanning (TLS), new digital dendrometers, tree-talkers, terrestrial cameras, and APP for portable devices such as smartphones or tablets for dendrometric tree measures and new citizen science applications to support quantitative and qualitative spatial estimation of forest variables over large areas (i.e., forest health, fuel types) are also presented. The chapter ends up with the description of some experiences in the implementation of Forest Information Systems in Italy to provide a simple open-access to such new generation of spatial forest information. In chapter 5 PF tools, instruments, and technologies to sup- port sustainable forest management are illustrated. APPs developed to acquire field plots data to simulate manage- ment operations, the application of photogrammetric tech- nologies from Unmanned Aerial Vehicles and TLS data for monitoring with high-spatial scale forest monitoring and for acquiring indicators at single tree level are presented. A de- tailed description of new user-friendly tools for forest roadplanning, design and construction, as well as forest opera- tion planning is also included. Precision forest tree farming (with particular reference to poplar cultivation), useful to promote and increase the prof- itability and sustainability of forest plantations within the Italian context is described in chapter 6. The innovation and enhancement within the supply chain of wood plantations (from planting to harvesting, including monitoring and identification of stress) by soil proximal sensing techniques, Early Warning Systems, and specific software are highlight- ed. Considering the even higher market demands, promoted by the large-scale planting programs for climate changes mit- igation and the demands for propagation material for en- vironmental recovery, innovative techniques and methods supported by ICT in the forest nursery sector are described in chapter 7. In chapter 8 available technologies related to precision har- vesting are analyzed and described taking into consideration the wood chain efficiency, by means of improved commu- nications between the owner/buyer and operators as well as among machineries used in forest operations, health and safety of forest operators, environmental impacts mitigation and recovery, and operators training. Advanced communi- cation systems and sensors for the exchange of data and information between machines, machine-equipments and/or machine-operators, teleoperations and automation are also described. Chapters 9 and 10 are related to wood products traceabil- ity, timber quality assessment as well as the technologies for the optimization of wood transformation processes. The concepts of wood product traceability and tracing, togeth- er with latest digital technologies for the identification and tracking of the logs (i.e., fingerprinting and RFID), are de- tailly reported. Chapter 11 is finally dedicated to the relationship between the EU policy framework and the digitalization process in both agricultural and forestry sectors. The book summarizes, under a proactive and homogeneous framework, PF methods, tools and technologies in relation with the digital transition of the Italian forestry sectors. The authors hope this book will be useful for improving the implementation of sustainable forest management practic- es at all levels in Italy, providing a comprehensive review useful for policy makers, technicians, forestry owners and students

MAGIC and H.E.S.S. detect VHE gamma rays from the blazar OT081 for the first time: a deep multiwavelength study

https://pos.sissa.it/395/815/pdfPublished versio